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1.  Tuberculosis infection among homeless persons and caregivers in a high-tuberculosis-prevalence area in Japan: a cross-sectional study 
Background
Tuberculosis (TB) is a major public health problem. The Airin district of Osaka City has a large population of homeless persons and caregivers and is estimated to be the largest TB-endemic area in the intermediate-prevalence country, Japan. However, there have been few studies of homeless persons and caregivers. The objective of this study is to detect active TB and to assess the prevalence and risk factors for latent TB infection among homeless persons and caregivers.
Methods
We conducted a cross-sectional study for screening TB infection (active and latent TB infections) using questionnaire, chest X-ray (CXR), newly available assay for latent TB infection (QuantiFERON-TB Gold In-Tube; QFT) and clinical evaluation by physicians at the Osaka Socio-Medical Center Hospital between July 2007 and March 2008. Homeless persons and caregivers, aged 30-74 years old, who had not received CXR examination within one year, were recruited. As for risk factors of latent TB infection, the odds ratios (OR) and 95% confidence intervals (95% CI) for QFT-positivity were calculated using logistic regression model.
Results
Complete responses were available from 436 individuals (263 homeless persons and 173 caregivers). Four active TB cases (1.5%) among homeless persons were found, while there were no cases among caregivers. Out of these four, three had positive QFT results. One hundred and thirty-three (50.6%) homeless persons and 42 (24.3%) caregivers had positive QFT results. In multivariate analysis, QFT-positivity was independently associated with a long time spent in the Airin district: ≥10 years versus <10 years for homeless (OR = 2.53; 95% CI, 1.39-4.61) and for caregivers (OR = 2.32; 95% CI, 1.05-5.13), and the past exposure to TB patients for caregivers (OR = 3.21; 95% CI, 1.30-7.91) but not for homeless persons (OR = 1.51; 95% CI, 0.71-3.21).
Conclusions
Although no active TB was found for caregivers, one-quarter of them had latent TB infection. In addition to homeless persons, caregivers need examinations for latent TB infection as well as active TB and careful follow-up, especially when they have spent a long time in a TB-endemic area and/or have been exposed to TB patients.
doi:10.1186/1471-2334-11-22
PMCID: PMC3037881  PMID: 21255421
2.  Prevalence of tuberculosis, hepatitis C virus, and HIV in homeless people: a systematic review and meta-analysis 
The Lancet Infectious Diseases  2012;12(11):859-870.
Summary
Background
100 million people worldwide are homeless; rates of mortality and morbidity are high in this population. The contribution of infectious diseases to these adverse outcomes is uncertain. Accurate estimates of prevalence data are important for public policy and planning and development of clinical services tailored to homeless people. We aimed to establish the prevalence of tuberculosis, hepatitis C virus, and HIV in homeless people.
Methods
We searched PubMed, Embase, and Cumulative Index to Nursing and Allied Health Literature for studies of the prevalence of tuberculosis, hepatitis C virus, and HIV in homeless populations. We also searched bibliographic indices, scanned reference lists, and corresponded with authors. We explored potential sources of heterogeneity in the estimates by metaregression analysis and calculated prevalence ratios to compare prevalence estimates for homeless people with those for the general population.
Findings
We identified 43 eligible surveys with a total population of 63 812 (59 736 homeless individuals when duplication due to overlapping samples was accounted for). Prevalences ranged from 0·2% to 7·7% for tuberculosis, 3·9% to 36·2% for hepatitis C virus infection, and 0·3% to 21·1% for HIV infection. We noted substantial heterogeneity in prevalence estimates for tuberculosis, hepatitis C virus infection, and HIV infection (all Cochran's χ2 significant at p<0·0001; I2=83%, 95% CI 76–89; 95%, 94–96; and 94%, 93–95; respectively). Prevalence ratios ranged from 34 to 452 for tuberculosis, 4 to 70 for hepatitis C virus infection, and 1 to 77 for HIV infection. Tuberculosis prevalence was higher in studies in which diagnosis was by chest radiography than in those which used other diagnostic methods and in countries with a higher general population prevalence than in those with a lower general prevalence. Prevalence of HIV infection was lower in newer studies than in older ones and was higher in the USA than in the rest of the world.
Interpretation
Heterogeneity in prevalence estimates for tuberculosis, hepatitis C virus, and HIV suggests the need for local surveys to inform development of health services for homeless people. The role of targeted and population-based measures in the reduction of risks of infectious diseases, premature mortality, and other adverse outcomes needs further examination. Guidelines for screening and treatment of infectious diseases in homeless people might need to be reviewed.
Funding
The Wellcome Trust.
doi:10.1016/S1473-3099(12)70177-9
PMCID: PMC3494003  PMID: 22914343
3.  The Prevalence of Mental Disorders among the Homeless in Western Countries: Systematic Review and Meta-Regression Analysis 
PLoS Medicine  2008;5(12):e225.
Background
There are well over a million homeless people in Western Europe and North America, but reliable estimates of the prevalence of major mental disorders among this population are lacking. We undertook a systematic review of surveys of such disorders in homeless people.
Methods and Findings
We searched for surveys of the prevalence of psychotic illness, major depression, alcohol and drug dependence, and personality disorder that were based on interviews of samples of unselected homeless people. We searched bibliographic indexes, scanned reference lists, and corresponded with authors. We explored potential sources of any observed heterogeneity in the estimates by meta-regression analysis, including geographical region, sample size, and diagnostic method. Twenty-nine eligible surveys provided estimates obtained from 5,684 homeless individuals from seven countries. Substantial heterogeneity was observed in prevalence estimates for mental disorders among the studies (all Cochran's χ2 significant at p < 0.001 and all I2 > 85%). The most common mental disorders were alcohol dependence, which ranged from 8.1% to 58.5%, and drug dependence, which ranged from 4.5% to 54.2%. For psychotic illness, the prevalence ranged from 2.8% to 42.3%, with similar findings for major depression. The prevalence of alcohol dependence was found to have increased over recent decades.
Conclusions
Homeless people in Western countries are substantially more likely to have alcohol and drug dependence than the age-matched general population in those countries, and the prevalences of psychotic illnesses and personality disorders are higher. Models of psychiatric and social care that can best meet these mental health needs requires further investigation.
Seena Fazel and colleagues show, through a systematic review and meta-regression analysis, that homeless people in Western countries have a higher prevalence of alcohol and drug dependence and mental disorders.
Editors' Summary
Background.
In 2007, it was estimated that there were more than 1 million homeless people worldwide. The true magnitude of the problem is difficult to estimate with no internationally agreed definition for homelessness and with the different approaches taken by countries and organizations in counting homeless people.
What we do know is that this is a diverse group of people who have poorer physical and mental health than the general population, leading to premature death. We also know that addressing barriers to health care and behavioral interventions for alcohol and drug dependence and mental health problems in this population can lead to lasting health gains.
Why Was This Study Done?
Health care for the homeless is a major public health challenge. Public policy and health service development depend on reliable estimates of the prevalence (how common a particular characteristic, e.g., a disease, is in a specific group of people or a specific population) of illnesses. By using statistical methods, the researchers aimed to provide a quantitative synthesis of the available evidence on mental health problems in this population and explore reasons for the differences in reported prevalence rates of serious mental disorders between studies, neither which have been done previously.
What Did the Researchers Do and Find?
The researchers systematically searched for surveys that estimated the prevalence of mental disorders in homeless people. Their final sample of 29 studies included a total of 5,684 homeless individuals based in the US, UK, mainland Europe, and Australia. Their main finding was that the prevalences of serious mental disorders were raised compared with expected rates in the general population, and many orders of magnitude higher than age-matched community estimates for psychosis, alcohol dependence, and drug dependence. In addition, the analysis found that alcohol and drug dependence is the most common mental disorder in the homeless (compared to psychosis, depression, and personality disorder). Also, the prevalence estimates of psychosis were found to be as high as those for depression. This latter finding contrasts with community estimates and other “at risk” populations such as prisoners and refugees, where depression is more common. The authors found substantial variation in the prevalence rates for these various disorders, and demonstrated that participation rates were associated with these variations for psychosis, depression, and personality disorder and that studies conducted more recently reported higher rates of alcohol dependence.
What Do These Findings Mean?
This review raises a number of implications for health services for the homeless and research for this population. First, traditional models of service delivery, which focus on those with severe mental illness, may not meet the mental health needs of most homeless people who suffer from alcohol and drug dependence and personality disorder. Second, an integrated approach to treatment may be beneficial and should take into account mental health, alcohol and drug abuse, welfare, and housing needs. Finally, future research should include studies that follow a group over time to help us better understand the risks and pathways into (and out of) homelessness, particularly in non-Western populations where there appears to be a paucity of information.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050225.
This study is further discussed in a PLoS Medicine Perspective by Helen Herrman
“How can health care systems effectively deal with the major health care needs of homeless people?” is a WHO initiative aimed at tackling the health care needs of homeless people
FEANTSA, the European Federation of National Organizations Working with the Homeless, is an umbrella of not-for-profit organizations that participate in or contribute to the fight against homelessness in Europe
The National Alliance to End Homelessness is a nonpartisan, mission-driven organization committed to preventing and ending homelessness in the US
Information and good practice solutions for the homelessness service sector in Australia can be found on the National Homelessness Information Clearinghouse Web site
Homeless Link is the national membership organization for frontline homelessness agencies in England with a mission to catalyze an end to homelessness
Homeless Man Speaks provides an “on-the-street” perspective
doi:10.1371/journal.pmed.0050225
PMCID: PMC2592351  PMID: 19053169
4.  The public health management of tuberculosis among the single homeless: is mass miniature x ray screening effective? 
STUDY OBJECTIVE--The aim was to test the assumption that mass miniature x ray screening of the single homeless (hostel residents) is a cost-effective means of controlling pulmonary tuberculosis. DESIGN--The study was a prospective experimental screening exercise to identify new cases of active tuberculosis completing treatment. SETTING--The setting was eight hostels in south London. A mobile x ray screening facility was set up outside the hostels. SUBJECTS--Subjects were 547 single homeless residents in the hostels. They were encouraged to attend for chest x ray, and for active follow up of abnormal x rays. MAIN RESULTS--No new cases of active tuberculosis were found. CONCLUSIONS--Mass miniature x ray is ineffective in controlling tuberculosis because of its unacceptability and increasing inaccessibility to this population.
PMCID: PMC1059522  PMID: 1583428
5.  Screening and Rapid Molecular Diagnosis of Tuberculosis in Prisons in Russia and Eastern Europe: A Cost-Effectiveness Analysis 
PLoS Medicine  2012;9(11):e1001348.
Daniel Winetsky and colleagues investigate eight strategies for screening and diagnosis of tuberculosis within prisons of the former Soviet Union.
Background
Prisons of the former Soviet Union (FSU) have high rates of multidrug-resistant tuberculosis (MDR-TB) and are thought to drive general population tuberculosis (TB) epidemics. Effective prison case detection, though employing more expensive technologies, may reduce long-term treatment costs and slow MDR-TB transmission.
Methods and Findings
We developed a dynamic transmission model of TB and drug resistance matched to the epidemiology and costs in FSU prisons. We evaluated eight strategies for TB screening and diagnosis involving, alone or in combination, self-referral, symptom screening, mass miniature radiography (MMR), and sputum PCR with probes for rifampin resistance (Xpert MTB/RIF). Over a 10-y horizon, we projected costs, quality-adjusted life years (QALYs), and TB and MDR-TB prevalence. Using sputum PCR as an annual primary screening tool among the general prison population most effectively reduced overall TB prevalence (from 2.78% to 2.31%) and MDR-TB prevalence (from 0.74% to 0.63%), and cost US$543/QALY for additional QALYs gained compared to MMR screening with sputum PCR reserved for rapid detection of MDR-TB. Adding sputum PCR to the currently used strategy of annual MMR screening was cost-saving over 10 y compared to MMR screening alone, but produced only a modest reduction in MDR-TB prevalence (from 0.74% to 0.69%) and had minimal effect on overall TB prevalence (from 2.78% to 2.74%). Strategies based on symptom screening alone were less effective and more expensive than MMR-based strategies. Study limitations included scarce primary TB time-series data in FSU prisons and uncertainties regarding screening test characteristics.
Conclusions
In prisons of the FSU, annual screening of the general inmate population with sputum PCR most effectively reduces TB and MDR-TB prevalence, doing so cost-effectively. If this approach is not feasible, the current strategy of annual MMR is both more effective and less expensive than strategies using self-referral or symptom screening alone, and the addition of sputum PCR for rapid MDR-TB detection may be cost-saving over time.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Tuberculosis (TB)—a contagious bacterial disease—is a major public health problem, particularly in low- and middle-income countries. In 2010, about nine million people developed TB, and about 1.5 million people died from the disease. Mycobacterium tuberculosis, the bacterium that causes TB, is spread in airborne droplets when people with active disease cough or sneeze. The characteristic symptoms of TB include fever, a persistent cough, and night sweats. Diagnostic tests include sputum smear microscopy (examination of mucus from the lungs for M. tuberculosis bacilli), mycobacterial culture (growth of M. tuberculosis from sputum), and chest X-rays. TB can also be diagnosed by looking for fragments of the M. tuberculosis genetic blueprint in sputum samples (sputum PCR). Importantly, sputum PCR can detect the genetic changes that make M. tuberculosis resistant to rifampicin, a constituent of the cocktail of antibiotics that is used to cure TB. Rifampicin resistance is an indicator of multidrug-resistant TB (MDR-TB), the emergence of which is thwarting ongoing global efforts to control TB.
Why Was This Study Done?
Prisons present unique challenges for TB control. Overcrowding, poor ventilation, and inadequate medical care increase the spread of TB among prisoners, who often come from disadvantaged populations where the prevalence of TB (the proportion of the population with TB) is already high. Prisons also act as reservoirs for TB, recycling the disease back into the civilian population. The prisons of the former Soviet Union, for example, which have extremely high rates of MDR-TB, are thought to drive TB epidemics in the general population. Because effective identification of active TB among prison inmates has the potential to improve TB control outside prisons, the World Health Organization recommends active TB case finding among prisoners using self-referral, screening with symptom questionnaires, or screening with chest X-rays or mass miniature radiography (MMR). But which of these strategies will reduce the prevalence of TB in prisons most effectively, and which is most cost-effective? Here, the researchers evaluate the relative effectiveness and cost-effectiveness of alternative strategies for screening and diagnosis of TB in prisons by modeling TB and MDR-TB epidemics in prisons of the former Soviet Union.
What Did the Researchers Do and Find?
The researchers used a dynamic transmission model of TB that simulates the movement of individuals in prisons in the former Soviet Union through different stages of TB infection to estimate the costs, quality-adjusted life years (QALYs; a measure of disease burden that includes both the quantity and quality of life) saved, and TB and MDR-TB prevalence for eight TB screening/diagnostic strategies over a ten-year period. Compared to annual MMR alone (the current strategy), annual screening with sputum PCR produced the greatest reduction in the prevalence of TB and of MDR-TB among the prison population. Adding sputum PCR for detection of MDR-TB to annual MMR screening did not affect the overall TB prevalence but slightly reduced the MDR-TB prevalence and saved nearly US$2,000 over ten years per model prison of 1,000 inmates, compared to MMR screening alone. Annual sputum PCR was the most cost-effective strategy, costing US$543/QALY for additional QALYs gained compared to MMR screening plus sputum PCR for MDR-TB detection. Other strategies tested, including symptom screening alone or combined with sputum PCR, were either more expensive and less effective or less cost-effective than these two options.
What Do These Findings Mean?
These findings suggest that, in prisons in the former Soviet Union, annual screening with sputum PCR will most effectively reduce TB and MDR-TB prevalence and will be cost-effective. That is, the cost per QALY saved of this strategy is less than the per-capita gross domestic product of any of the former Soviet Union countries. The paucity of primary data on some facets of TB epidemiology in prisons in the former Soviet Union and the assumptions built into the mathematical model limit the accuracy of these findings. Moreover, because most of the benefits of sputum PCR screening come from treating the MDR-TB cases that are detected using this screening approach, these findings cannot be generalized to prison settings without a functioning MDR-TB treatment program or with a very low MDR-TB prevalence. Despite these and other limitations, these findings provide valuable information about the screening strategies that are most likely to interrupt the TB cycle in prisons, thereby saving resources and averting preventable deaths both inside and outside prisons.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001348.
The World Health Organization provides information (in several languages) on all aspects of tuberculosis, including general information on tuberculosis diagnostics and on tuberculosis in prisons; a report published in the Bulletin of the World Health Organization in 2006 describes tough measures taken in Russian prisons to slow the spread of TB
The Stop TB Partnership is working towards tuberculosis elimination; patient stories about tuberculosis are available (in English and Spanish)
The US Centers for Disease Control and Prevention has information about tuberculosis, about its diagnosis, and about tuberculosis in prisons (some information in English and Spanish)
A PLOS Medicine Research Article by Iacapo Baussano et al. describes a systematic review of tuberculosis incidence in prisons; a linked editorial entitled The Health Crisis of Tuberculosis in Prisons Extends beyond the Prison Walls is also available
The Tuberculosis Survival Project, which aims to raise awareness of tuberculosis and provide support for people with tuberculosis, provides personal stories about treatment for tuberculosis; the Tuberculosis Vaccine Initiative also provides personal stories about dealing with tuberculosis
MedlinePlus has links to further information about tuberculosis (in English and Spanish)
doi:10.1371/journal.pmed.1001348
PMCID: PMC3507963  PMID: 23209384
6.  The role of entry screening in case finding of tuberculosis among asylum seekers in Norway 
BMC Public Health  2010;10:670.
Background
Most new cases of active tuberculosis in Norway are presently caused by imported strains and not transmission within the country. Screening for tuberculosis with a Mantoux test of everybody and a chest X-ray of those above 15 years of age is compulsory on arrival for asylum seekers.
We aimed to assess the effectiveness of entry screening of a cohort of asylum seekers. Cases detected by screening were compared with cases detected later. Further we have characterized cases with active tuberculosis.
Methods
All asylum seekers who arrived at the National Reception Centre between January 2005 - June 2006 with an abnormal chest X-ray or a Mantoux test ≥ 6 mm were included in the study and followed through the health care system. They were matched with the National Tuberculosis Register by the end of May 2008.
Cases reported within two months after arrival were defined as being detected by screening.
Results
Of 4643 eligible asylum seekers, 2237 were included in the study. Altogether 2077 persons had a Mantoux ≥ 6 mm and 314 had an abnormal chest X-ray. Of 28 cases with tuberculosis, 15 were detected by screening, and 13 at 4-27 months after arrival. Abnormal X-rays on arrival were more prevalent among those detected by screening. Female gender and Somalian origin increased the risk for active TB.
Conclusion
In spite of an imperfect follow-up of screening results, a reasonable number of TB cases was identified by the programme, with a predominance of pulmonary TB.
doi:10.1186/1471-2458-10-670
PMCID: PMC2991295  PMID: 21050453
7.  Tuberculosis and homelessness in Montreal: a retrospective cohort study 
BMC Public Health  2011;11:833.
Background
Montreal is Canada's second-largest city, where mean annual tuberculosis (TB) incidence from 1996 to 2007 was 8.9/100,000. The objectives of this study were to describe the epidemiology of TB among homeless persons in Montreal and assess patterns of transmission and sharing of key locations.
Methods
We reviewed demographic, clinical, and microbiologic data for all active TB cases reported in Montreal from 1996 to 2007 and identified persons who were homeless in the year prior to TB diagnosis. We genotyped all available Mycobacterium tuberculosis isolates by IS6110 restriction fragment length polymorphism (IS6110-RFLP) and spoligotyping, and used a geographic information system to identify potential locations for transmission between persons with matching isolates.
Results
There were 20 cases of TB in homeless persons, out of 1823 total reported from 1996-2007. 17/20 were Canadian-born, including 5 Aboriginals. Homeless persons were more likely than non-homeless persons to have pulmonary TB (20/20), smear-positive disease (17/20, odds ratio (OR) = 5.7, 95% confidence interval (CI): 1.7-20), HIV co-infection (12/20, OR = 14, 95%CI: 4.8-40), and a history of substance use. The median duration from symptom onset to diagnosis was 61 days for homeless persons vs. 28 days for non-homeless persons (P = 0.022). Eleven homeless persons with TB belonged to genotype-defined clusters (OR = 5.4, 95%CI: 2.2-13), and ten potential locations for transmission were identified, including health care facilities, homeless shelters/drop-in centres, and an Aboriginal community centre.
Conclusions
TB cases among homeless persons in Montreal raise concerns about delayed diagnosis and ongoing local transmission.
doi:10.1186/1471-2458-11-833
PMCID: PMC3229542  PMID: 22034944
8.  Vulnerability of Homeless People in Tehran, Iran, to HIV, Tuberculosis and Viral Hepatitis 
PLoS ONE  2014;9(6):e98742.
Background
Homeless people are at risk of contracting communicable infectious diseases, as they indulge in risky behaviours and lifestyle. This study was conducted to determine the prevalence of the aforementioned infections and related risk behaviours among homeless people in Tehran.
Methods
In this study a convenience sample of 593 homeless individuals was studied. The ELISA method was used for the detection of HIV, HCV and HBV. Clinical symptoms, sputum cultures, acid fast bacilli smears, and chest X-rays were used to identify active pulmonary tuberculosis, and the Interferon Gamma Release Assay (IGRA) test was used to identify latent tuberculosis.
Results
The prevalence of HIV, HBV, HCV and latent tuberculosis was 3.4%, 2.6%, 23.3% and 46.7%, respectively. Active pulmonary tuberculosis was found in 7 persons (1.2%). Injection drug use was an independent risk factor for HIV, HCV and HBV infections. Older people had a higher proportion of Mycobacterium tuberculosis infection (OR: 2.6, 95%CI: 1.9, 3.7) and HCV positivity (OR: 1.7, 95% CI: 1.1, 2.5).
Conclusion
Our findings highlighted that much more attention needs to be paid to the health of homeless people.
doi:10.1371/journal.pone.0098742
PMCID: PMC4045893  PMID: 24896247
9.  Tuberculosis in London: a decade and a half of no decline 
Thorax  2006;62(2):162-167.
Background
London accounts for nearly half of the national burden of tuberculosis. The incidence of tuberculosis has more than doubled in London in the past 15 years.
Methods
Data from the enhanced tuberculosis surveillance 1999–2003, the national tuberculosis surveys of 1993 and 1998, and tuberculosis notifications were compared and analysed.
Results
In 2003, 3048 patients with tuberculosis were reported in London, 45% of the national total. This represents an incidence of 41.3/100 000, five times higher than the rest of England and Wales, and in parts of London the incidence of tuberculosis is nine times the national average. 75% of people with tuberculosis in London are born abroad; nearly half have lived in the UK for <5 years, but a third for >10 years. 86% are from an ethnic minority group, and the incidence is highest in black Africans at 283/100 000 compared with 141, 141 and 8/100 000 for Pakistanis, Indians and whites, respectively. In absolute terms, a third of patients with tuberculosis in London are from Africa and nearly a third from the Indian subcontinent. Specific groups affected also include the homeless, prisoners, and hard drug and alcohol users as well as the immunosuppressed.
Conclusions
London reflects the worldwide rise in tuberculosis, with increasing incidence in ethnic minorities. Work has been carried out to combat this rise, but more is needed. Tuberculosis control and prevention strategies should be mindful of the changing epidemiology of tuberculosis in London, and provide information, diagnosis and treatment tailored to the specific needs of the capital and its at‐risk groups.
doi:10.1136/thx.2006.058313
PMCID: PMC2111261  PMID: 17101738
10.  Tuberculosis in London: the importance of homelessness, problem drug use and prison 
Thorax  2007;62(8):667-671.
Background
The control of tuberculosis (TB) is founded on early case detection and complete treatment of disease. In the UK, TB is concentrated in subgroups of the population in large urban centres. The impact of homelessness, imprisonment and problem drug use on TB control in London is reviewed.
Methods
A cohort study was undertaken of all patients with TB in Greater London to determine the point prevalence of disease in different groups and to examine risk factors for smear positivity, drug resistance, treatment adherence, loss to follow‐up and use of directly observed therapy (DOT).
Results
Data were collected on 97% (1941/1995) of eligible patients. The overall prevalence of TB was 27 per 100 000. An extremely high prevalence of TB was seen in homeless people (788/100 000), problem drug users (354/100 000) and prisoners (208/100 000). Multivariate analysis showed that problem drug use was associated with smear positive disease (OR 2.2, p<0.001), being part of a known outbreak of drug resistant TB (OR 3.5, p = 0.001) and loss to follow‐up (OR 2.7, p<0.001). Imprisonment was associated with being part of the outbreak (OR 10.3, p<0.001) and poor adherence (OR 3.9, p<0.001). Homelessness was associated with infectious TB (OR 1.6, p = 0.05), multidrug resistance (OR 2.1, p = 0.03), poor adherence (OR 2.5, p<0.001) and loss to follow‐up (OR 3.8, p<0.001). In London, homeless people, prisoners and problem drug users collectively comprise 17% of TB cases, 44% of smear positive drug resistant cases, 38% of poorly compliant cases and 44% of cases lost to follow‐up. 15% of these patients start treatment on DOT but 46% end up on DOT.
Conclusions
High levels of infectious and drug resistant disease, poor adherence and loss to follow‐up care indicate that TB is not effectively controlled among homeless people, prisoners and problem drug users in London.
doi:10.1136/thx.2006.065409
PMCID: PMC2117290  PMID: 17289861
11.  Tuberculosis burden in an urban population: a cross sectional tuberculosis survey from Guinea Bissau 
Background
Little is known about the prevalence of pulmonary tuberculosis (TB) in low income countries. We conducted a cross sectional survey for pulmonary TB and TB symptoms in Bissau, Guinea-Bissau, in an urban cohort with known HIV prevalence. TB surveillance in the area is routinely based on passive case finding.
Methods
Two cohorts were selected based on a previous HIV survey, but only 52.5% of those enrolled in the adult cohort had participated in the HIV survey. One cohort included all adults living in 384 randomly selected houses; in this cohort 8% (135/1687) were HIV infected. The other included individuals 50 years or older from all other houses in the study area; of these 11% (62/571) were HIV infected. Symptom screening was done through household visits using a standardised questionnaire. TB suspects were investigated with sputum smear microscopy and X-ray.
Results
In the adult cohort, we found 4 cases among 2989 individuals screened, giving a total TB prevalence of 134/100,000 (95% CI 36-342/100,000). In the >50 years cohort, we found 4 cases among 571 individuals screened, giving a total prevalence of 701/100,000 (191-1784/100.000). Two of the eight detected TB cases were unknown by the TB program. Of the total TB cases five were HIV uninfected while three had unknown HIV status. The prevalence of TB symptoms was 2.1% (63/2989) and 10.3% (59/571) in the two cohorts respectively.
Conclusions
In conclusion we found a moderately high prevalence of pulmonary TB and TB symptoms in the general population, higher among elderly individuals. By active case finding unknown cases were detected. Better awareness of TB and its symptoms needs to be promoted in low income settings.
doi:10.1186/1471-2334-10-96
PMCID: PMC2860354  PMID: 20398388
12.  Screening for pulmonary tuberculosis in type 2 diabetes elderly: a cross-sectional study in a community hospital 
BMC Public Health  2015;15:3.
Background
Tuberculosis is one of the major infectious diseases in Taiwan. It has an especially high prevalence in diabetes patients, in whom it is usually asymptomatic and are more likely to result in drug-resistant tuberculosis. The aim of the study was to aggressively screen high risk diabetic elderly, identify the prevalence of tuberculosis and its determinants.
Methods
Type 2 diabetes patients aged over 65 years were enrolled. They received chest X-rays, blood tests and the questionnaires to assess their medical history and symptoms. Suspicious cases were referred to the pulmonary or infectious disease outpatient clinics. Pulmonary tuberculosis was confirmed by sputum culture. Variables between groups were analyzed by Student t test, Chi-square test or Fisher’s exact test. Risk factors were assessed using univariate logistic regression and multiple logistic regression.
Results
A total of 3,087 patients participated this screening program and 7 patients screened positive for pulmonary tuberculosis. Another 5 patients were being under treatment when participating screening program. The prevalence rate was 3.89 per thousand people. The patients with male gender, smoking, liver cirrhosis or subjective body weight loss were associated with an increased risk of tuberculosis significantly. Subjective body weight loss (OR: 6.635 [95% CI: 2.096-21.007]), liver cirrhosis (OR: 10.307 [95% CI: 2.108-50.395]) and history of smoking (OR: 3.981 [95% CI: 1.246-12.718]) are independent risk factors. Among all 73 patients with active tuberculosis or tuberculosis history, they tended to be male, lower body mass index (BMI), more smoking history, more alcohol consumption, more family history of tuberculosis, higher low density lipoprotein (LDL), and less hypertension. However, there was no significant difference in the glycated hemoglobin (HbA1c) levels between the tuberculosis group and non-tuberculosis group.
Conclusions
Active screening program is helpful in detecting pulmonary tuberculosis in elderly diabetes patients. Subjective body weight loss, smoking and liver cirrhosis are independent risk factors.
doi:10.1186/1471-2458-15-3
PMCID: PMC4324855  PMID: 25572102
Pulmonary tuberculosis; Diabetes mellitus; Risk factors
13.  Development of a Standardized Screening Rule for Tuberculosis in People Living with HIV in Resource-Constrained Settings: Individual Participant Data Meta-analysis of Observational Studies 
PLoS Medicine  2011;8(1):e1000391.
Haileyesus Getahun and colleagues report the development of a simple, standardized tuberculosis (TB) screening rule for resource-constrained settings, to identify people living with HIV who need further investigation for TB disease.
Background
The World Health Organization recommends the screening of all people living with HIV for tuberculosis (TB) disease, followed by TB treatment, or isoniazid preventive therapy (IPT) when TB is excluded. However, the difficulty of reliably excluding TB disease has severely limited TB screening and IPT uptake in resource-limited settings. We conducted an individual participant data meta-analysis of primary studies, aiming to identify a sensitive TB screening rule.
Methods and Findings
We identified 12 studies that had systematically collected sputum specimens regardless of signs or symptoms, at least one mycobacterial culture, clinical symptoms, and HIV and TB disease status. Bivariate random-effects meta-analysis and the hierarchical summary relative operating characteristic curves were used to evaluate the screening performance of all combinations of variables of interest. TB disease was diagnosed in 557 (5.8%) of 9,626 people living with HIV. The primary analysis included 8,148 people living with HIV who could be evaluated on five symptoms from nine of the 12 studies. The median age was 34 years. The best performing rule was the presence of any one of: current cough (any duration), fever, night sweats, or weight loss. The overall sensitivity of this rule was 78.9% (95% confidence interval [CI] 58.3%–90.9%) and specificity was 49.6% (95% CI 29.2%–70.1%). Its sensitivity increased to 90.1% (95% CI 76.3%–96.2%) among participants selected from clinical settings and to 88.0% (95% CI 76.1%–94.4%) among those who were not previously screened for TB. Negative predictive value was 97.7% (95% CI 97.4%–98.0%) and 90.0% (95% CI 88.6%–91.3%) at 5% and 20% prevalence of TB among people living with HIV, respectively. Abnormal chest radiographic findings increased the sensitivity of the rule by 11.7% (90.6% versus 78.9%) with a reduction of specificity by 10.7% (49.6% versus 38.9%).
Conclusions
Absence of all of current cough, fever, night sweats, and weight loss can identify a subset of people living with HIV who have a very low probability of having TB disease. A simplified screening rule using any one of these symptoms can be used in resource-constrained settings to identify people living with HIV in need of further diagnostic assessment for TB. Use of this algorithm should result in earlier TB diagnosis and treatment, and should allow for substantial scale-up of IPT.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
In 2009, 1.7 million people died from tuberculosis (TB)—equating to 4,700 deaths a day—including 380,000 people living with HIV. TB remains the most common cause of death in people living with HIV and compared to people without HIV, people living with HIV are more than 20 times more likely to develop TB. Furthermore, TB infection may occur at any stage of HIV disease and is often the initial presentation of underlying HIV infection. Without antiretroviral treatment, up to 50% of people living with HIV who are diagnosed with TB die during the 6–8 months of TB treatment.
Although antiretroviral treatment can reduce the incidence of TB both at the individual and population level, people living with HIV on antiretroviral treatment still have higher TB incidence rates and a higher risk of dying from TB. Therefore, the World Health Organization recommends regular screening for active TB disease in all people living with HIV, so those identified as having active TB disease can be provided with appropriate treatment, and isoniazid preventive therapy (to help mitigate TB morbidity, mortality, and transmission) can be given to vulnerable individuals who do not yet have active TB.
Why Was This Study Done?
There is currently no internationally accepted evidence-based tool to screen for TB in people living with HIV—a serious gap given that the presenting signs and symptoms of TB in people living with HIV are different from those in people without HIV. Therefore, the researchers aimed to develop a simple, standardized TB screening rule for resource-constrained settings, on the basis of the best available evidence that would adequately distinguish between people living with HIV who are very unlikely to have TB from those who require further investigation for TB disease.
What Did the Researchers Do and Find?
The researchers selected 12 studies that met their strict criteria, then asked the authors of these studies for primary data so that they could map individual-level data to identify five symptoms common to most studies. Using a statistical model, the researchers devised 23 screening rules derived from these five symptoms and used meta-analysis methods (bivariate random-effects meta-analysis) and the association of study-level and individual-level correlates (hierarchical summary relative operating characteristic curves) to evaluate the sensitivity and specificity of each tool used in each individual study.
The authors of the selected studies were able to provide data for 29,523 participants, of whom 10,057 were people living with HIV. The dataset included 9,626 people living with HIV who had TB screening and sputum culture performed, of which 8,148 individuals could be evaluated on the five symptoms of interest from nine of 12 studies. TB disease was diagnosed in 5.8% of people living with HIV and the best performing rule was the presence of any one of the following: current cough (any duration), fever, night sweats, or weight loss. The overall sensitivity of the rule was 78.9% and the specificity was 49.6%. However, the sensitivity of the rule increased to 90.1% among participants selected from clinical settings and to 88.0% among those who were not previously screened for TB.
What Do These Findings Mean?
The results of this study suggest that in resource-constrained settings, the absence of current cough, fever, night sweats, and weight loss (all inclusive) can identify those people living with HIV who have a low probability of having TB disease. Furthermore, any one of these symptoms can be used in resource-constrained settings to identify people living with HIV who are in need of further diagnostic assessment for TB.
Despite the limitations of the methodology used in this study, until there are evidence-based and internationally recommended guidelines for the diagnosis and treatment of TB in people living with HIV, use of the algorithm developed and presented in this study could result in earlier TB diagnosis and treatment for people living with HIV and could help to substantially scale-up isoniazid preventive therapy.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000391.
The World Health Organization has information about TB in people living with HIV
The US Centers for Disease Control and Prevention also provide information about TB and HIV coinfection
The World Health Organization also has information about isoniazid preventative therapy
The Stop TB Partnership's TB/HIV Working Group provide information about TB and HIV co-infection
doi:10.1371/journal.pmed.1000391
PMCID: PMC3022524  PMID: 21267059
14.  Evaluation of a directly observed six months fully intermittent treatment regimen for tuberculosis in patients suspected of poor compliance. 
Thorax  1996;51(11):1130-1133.
BACKGROUND: Although a priority for tuberculosis control is to achieve the maximum cure rate, compliance with chemotherapy in specific high risk groups (homeless, intravenous drug abusers, chronic alcoholics) is usually poor. METHODS: From January 1990 to December 1994 102 patients with tuberculosis (96 pulmonary, six extrapulmonary) who were poorly compliant with treatment were treated with a six month fully intermittent (twice weekly) directly observed regimen. They comprised 71 homeless subjects, 50 chronic alcoholics, 23 intravenous drug abusers, nine infected with HIV, and 11 who had previously abandoned a daily antituberculosis regimen; 53 had more than one of these risk factors. Treatment included isoniazid and rifampicin for six months and pyrazinamide during the first two months. Patients who failed to take their medication on two consecutive occasions were actively sought by telephone or by personal search. RESULTS: After two months of treatment 95 of the 102 patients had taken their medication regularly and 90 of them had negative cultures. Four of the remaining patients had negative cultures after three months. At the end of the six months 87 patients had completed treatment and were considered cured. Only 15 patients abandoned the treatment (13 of whom had more than one risk factor). Only three relapses occurred in the 102 patients at one year follow up and in the 88 patients followed for two years. Two patients required a change of treatment due to major side effects. Although intravenous drug abuse was the only predictor of non-compliance in the multivariate analysis, if the available variables in the second month of treatment were analysed, current poor compliance and abandonment of treatment in the past were found to be significantly associated with non-compliance. CONCLUSIONS: This study shows the efficacy of this intermittent regimen and the effectiveness of a directly observed treatment programme.
PMCID: PMC1090526  PMID: 8958898
15.  The Infectiousness of Tuberculosis Patients Coinfected with HIV 
PLoS Medicine  2008;5(9):e188.
Background
The current understanding of airborne tuberculosis (TB) transmission is based on classic 1950s studies in which guinea pigs were exposed to air from a tuberculosis ward. Recently we recreated this model in Lima, Perú, and in this paper we report the use of molecular fingerprinting to investigate patient infectiousness in the current era of HIV infection and multidrug-resistant (MDR) TB.
Methods and Findings
All air from a mechanically ventilated negative-pressure HIV-TB ward was exhausted over guinea pigs housed in an airborne transmission study facility on the roof. Animals had monthly tuberculin skin tests, and positive reactors were removed for autopsy and organ culture for M. tuberculosis. Temporal exposure patterns, drug susceptibility testing, and DNA fingerprinting of patient and animal TB strains defined infectious TB patients. Relative patient infectiousness was calculated using the Wells-Riley model of airborne infection. Over 505 study days there were 118 ward admissions of 97 HIV-positive pulmonary TB patients. Of 292 exposed guinea pigs, 144 had evidence of TB disease; a further 30 were tuberculin skin test positive only. There was marked variability in patient infectiousness; only 8.5% of 118 ward admissions by TB patients were shown by DNA fingerprinting to have caused 98% of the 125 characterised cases of secondary animal TB. 90% of TB transmission occurred from inadequately treated MDR TB patients. Three highly infectious MDR TB patients produced 226, 52, and 40 airborne infectious units (quanta) per hour.
Conclusions
A small number of inadequately treated MDR TB patients coinfected with HIV were responsible for almost all TB transmission, and some patients were highly infectious. This result highlights the importance of rapid TB drug-susceptibility testing to allow prompt initiation of effective treatment, and environmental control measures to reduce ongoing TB transmission in crowded health care settings. TB infection control must be prioritized in order to prevent health care facilities from disseminating the drug-resistant TB that they are attempting to treat.
Using a guinea pig detection system above an HIV-tuberculosis ward, Rod Escombe and colleagues found that most transmitted tuberculosis originated from patients with inadequately treated multidrug-resistant tuberculosis.
Editors' Summary
Background.
Every year, more than nine million people develop tuberculosis—a contagious infection usually of the lungs—and nearly two million people die from the disease. Tuberculosis is caused by Mycobacterium tuberculosis. These bacteria are spread in airborne droplets when people with the disease cough or sneeze. Most people infected with M. tuberculosis never become ill—their immune system contains the infection. However, the bacteria remain dormant within the body and can cause tuberculosis years later if host immunity declines. The symptoms of tuberculosis include a persistent cough, weight loss, and night sweats. Diagnostic tests for the disease include chest X-rays, the tuberculin skin test, and sputum cultures (in which bacteriologists try to grow M. tuberculosis from mucus brought up from the lungs by coughing). Tuberculosis can usually be cured by taking several powerful antibiotics daily for several months.
Why Was This Study Done?
Scientists performed definitive experiments on airborne tuberculosis transmission in the 1950s by exposing guinea pigs to the air from a tuberculosis ward. They found that a minority of patients actually transmit tuberculosis, that the infectiousness of transmitters varies greatly, and that effective antibiotic treatment decreases infectiousness. Since the 1950s, however, multidrug-resistant (MDR) and more recently extensively drug-resistant (XDR) strains of M. tuberculosis have become widespread. Treatment of drug-resistant tuberculosis is much more difficult than normal tuberculosis, requiring even more antibiotics, and for long periods, up to 2 years and beyond. In addition, HIV (the virus that causes AIDS) has emerged. HIV weakens the immune system so HIV-positive people are much more likely to develop active tuberculosis (and to die from the disease, which also speeds the development of HIV/AIDS) than people with a healthy immune system. Have these changes altered tuberculosis transmission between people? The answer to this question might help to optimize the control of tuberculosis infection, particularly in hospitals. In this study, the researchers investigate current patterns of tuberculosis infectiousness among HIV-positive patients by recreating the 1950s guinea pig model for tuberculosis transmission in a hospital in Lima, Perú.
What Did the Researchers Do and Find?
The researchers passed all the air from an HIV–tuberculosis ward over guinea pigs housed in an animal facility on the hospital's roof. The guinea pigs were tested monthly with tuberculin skin tests, and tissues from positive animals were examined for infection with M. tuberculosis. Sputum was also collected daily from the patients on the ward. The researchers then used the timing of patient admissions and guinea pig infections, together with the drug susceptibility patterns and DNA fingerprints of the M. tuberculosis strains isolated from the animals and the patients, to identify which patients had infected which guinea pigs. Finally, they used a mathematical equation to calculate the relative infectiousness of each patient in airborne infectious units (“quanta”) per hour. During the 505 study days, although 97 HIV-positive patients with tuberculosis were admitted to the ward, just ten patients were responsible for virtually all the characterized cases of tuberculosis among the guinea pigs. Six of these patients had MDR tuberculosis that had been suboptimally treated. The average patient infectiousness over the entire study period was 8.2 quanta per hour—six times greater than the average infectiousness recorded in the 1950s. Finally, the three most infectious patients (all of whom had suboptimally treated MDR tuberculosis) produced 226, 52, and 40 quanta per hour.
What Do These Findings Mean?
These findings show that a few inadequately treated HIV-positive patients with MDR tuberculosis caused nearly all the tuberculosis transmission to guinea pigs during this study. They also show for the first time that tuberculosis infectiousness among HIV-positive patients is very variable. The increase in the average patient infectiousness in this study compared to that seen in the 1950s hints at the possibility that HIV infection might increase tuberculosis infectiousness. However, studies that directly compare the tuberculosis infectiousness of HIV-positive and HIV-negative patients are needed to test this possibility. More importantly, this study demonstrates the potentially high infectiousness of inadequately treated MDR TB patients and their importance in ongoing TB transmission. These findings suggest that rapid, routine testing of antibiotic susceptibility should improve tuberculosis control by ensuring that patients with MDR TB are identified and treated effectively and quickly. Finally, they re-emphasize the importance of implementing environmental control measures (for example, adequate natural or mechanical ventilation of tuberculosis wards, or crowded waiting rooms or emergency departments where tuberculosis patients may be found) to prevent airborne tuberculosis transmission in health-care facilities, particularly in areas where many patients are HIV positive and/or where MDR tuberculosis is common.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050188.
The US National Institute of Allergy and Infectious Diseases provides information on all aspects of tuberculosis, including multidrug-resistance tuberculosis, and on tuberculosis and HIV
The US Centers for Disease Control and Prevention provide several fact sheets and other information resources about all aspects of tuberculosis (in English and Spanish)
The World Health Organization's 2008 report on global tuberculosis control—surveillance, planning, financing provides a snapshot of the current state of the global tuberculosis epidemic and links to information about all aspects of tuberculosis and its control (in several languages)
HIVInsite provides detailed information about coinfection with HIV and tuberculosis
• Avert, an international AIDS charity, also provides information about the interaction between HIV and tuberculosis
Tuberculosis Infection-Control in the Era of Expanding HIV Care and Treatment is a report from the World Health Organization
doi:10.1371/journal.pmed.0050188
PMCID: PMC2535657  PMID: 18798687
16.  Conventional and Molecular Epidemiology of Tuberculosis in Homeless Patients in Budapest, Hungary 
Journal of Clinical Microbiology  2004;42(12):5931-5934.
In Hungary the incidence of tuberculosis among the homeless population was 676 per 100,000 in 2002. Sixty-nine percent (140 patients) of all homeless tuberculosis patients were notified in Budapest (the capital). Therefore, a retrospective study that included 66 homeless tuberculosis patients notified in Budapest in 2002 was conducted to determine the rate of recent transmission of the disease and medical risk factors and to identify transmission pathways by means of conventional and molecular epidemiologic methods. IS6110 DNA fingerprinting revealed that 71.2% of the isolates could be clustered. Thirty-four (51.5%) patients belonged to five major clusters (size, from 4 to 11 individuals), and 13 (19.7%) belonged to six smaller clusters. Additional analysis of patient records found that 2 (18%) of the 11 patients in cluster A, 3 (37.5%) of the 8 patients in cluster B, and 2 (33%) of the 6 patients in cluster C were residents of the same three homeless shelters during the diagnosis of tuberculosis. Review of the database of the National Tuberculosis Surveillance Center (NTSC) revealed that 21.2% of the cases have not been reported to the NTSC. These findings indicate that the screening and treatment of tuberculosis among the homeless need to be strengthened and also warrant the review of environmental control steps in public shelters. Improvement of adherence of clinicians to surveillance reporting regulations is also necessary.
doi:10.1128/JCM.42.12.5931-5934.2004
PMCID: PMC535239  PMID: 15583345
17.  The Clinical Characteristics and Predictors of Treatment Success of Pulmonary Tuberculosis in Homeless Persons at a Public Hospital in Busan 
Korean Journal of Family Medicine  2012;33(6):372-380.
Background
Homelessness is associated with an increased risk of exposure to Mycobacterium tuberculosis. Several factors, including alcoholism, malnutrition, lack of stable housing, combine to make tuberculosis more prevalent in the homeless. The aims of this study were to determine the factors associated with increasing success rate of tuberculosis treatment in the homeless.
Methods
A cross-sectional analysis of the clinical features in 142 pulmonary tuberculosis-positive homeless patients admitted to the Busan Medical Center from January 2001 to December 2010 was carried out. These results were compared with a successful treatment group and incomplete treatment group. We also evaluated the risk factors of treatment non-completion. Statistical analysis for the comparisons was performed using a χ2 test, independent samples t-test, and multiple logistic regression.
Results
Comparison of clinical characteristics showed significant differences between the two groups in the type of residence (P < 0.001), diseases with risk factors (P = 0.003), and history of tuberculosis treatment (P = 0.009). Multiple regression analysis revealed the residence (odds ratio [OR], 4.77; 95% confidence interval [CI], 2.05 to 11.10; P < 0.001) and comorbidity with risk factor (OR, 2.72; 95% CI, 1.13 to 6.53; P = 0.025) to be independently associated with treatment success.
Conclusion
To improve the success rate of tuberculosis treatment in the homeless person, anti tuberculosis medication should be taken until the end of treatment and a management system for the homeless person is required. Further social and medical concerns for stable housing and management of comorbidity may lead to an improvement in the successful tuberculosis treatment of homeless person.
doi:10.4082/kjfm.2012.33.6.372
PMCID: PMC3526720  PMID: 23267423
Homeless Persons; Tuberculosis, Pulmonary; Treatment
18.  Burden of mental disorders and unmet needs among street homeless people in Addis Ababa, Ethiopia 
BMC Medicine  2014;12(1):138.
Background
The impact of mental disorders among homeless people is likely to be substantial in low income countries because of underdeveloped social welfare and health systems. As a first step towards advocacy and provision of care, we conducted a study to determine the burden of psychotic disorders and associated unmet needs, as well as the prevalence of mental distress, suicidality, and alcohol use disorder among homeless people in Addis Ababa, the capital of Ethiopia.
Methods
A cross-sectional survey was conducted among street homeless adults. Trained community nurses screened for potential psychosis and administered standardized measures of mental distress, alcohol use disorder and suicidality. Psychiatric nurses then carried out confirmatory diagnostic interviews of psychosis and administered a locally adapted version of the Camberwell Assessment of Needs Short Appraisal Schedule.
Results
We assessed 217 street homeless adults, about 90% of whom had experienced some form of mental or alcohol use disorder: 41.0% had psychosis, 60.0% had hazardous or dependent alcohol use, and 14.8% reported attempting suicide in the previous month. Homeless people with psychosis had extensive unmet needs with 80% to 100% reporting unmet needs across 26 domains. Nearly 30% had physical disability (visual and sensory impairment and impaired mobility). Only 10.0% of those with psychosis had ever received treatment for their illness. Most had lived on the streets for over 2 years, and alcohol use disorder was positively associated with chronicity of homelessness.
Conclusion
Psychoses and other mental and behavioural disorders affect most people who are street homeless in Addis Ababa. Any programme to improve the condition of homeless people should include treatment for mental and alcohol use disorders. The findings have significant implications for advocacy and intervention programmes, particularly in similar low income settings.
Electronic supplementary material
The online version of this article (doi:10.1186/s12916-014-0138-x) contains supplementary material, which is available to authorized users.
doi:10.1186/s12916-014-0138-x
PMCID: PMC4147171  PMID: 25139042
Homelessness; Rooflessness; Mental illness; Severe mental disorder; Prevalence; Unmet needs; Low- and middle-income country; Ethiopia
19.  Pulmonary tuberculosis among political asylum seekers screened at Heathrow Airport, London, 1995–9 
Thorax  2002;57(2):152-156.
Background: Over 50% of cases of tuberculosis (TB) in the UK occur in people born overseas, and new entrants to the country are screened for TB. A study was undertaken to determine the prevalence and disease characteristics of pulmonary TB in new entrants to the UK seeking political asylum.
Methods: A retrospective analysis of the results of screening 53 911 political asylum seekers arriving at Heathrow Airport between 1995 and 1999 was performed by studying Airport Health Control Unit records and hospital medical records. Outcome measures were chest radiograph abnormalities, sputum smear, culture, and drug resistance data for Mycobacterium tuberculosis.
Results: The overall prevalence of active TB in political asylum seekers was 241 per 100 000. There were large variations in prevalences of TB between asylum seekers from different regions, with low rates from the Middle East and high rates from the Indian subcontinent and sub-Saharan Africa. The frequency of drug resistance was high; 22.6% of culture positive cases were isoniazid resistant, 7.5% were multidrug resistant (resistant to both isoniazid and rifampicin), and 4% of cases diagnosed with active disease had multidrug resistant TB.
Conclusions: The prevalence rate of TB in political asylum seekers entering the UK through Heathrow Airport is high and more M tuberculosis isolates from asylum seekers are drug resistant than in the UK population. Extrapolating these figures, it is estimated that 101 political asylum seekers with active pulmonary TB enter the UK every year, of whom about 25 would have smear positive disease.
doi:10.1136/thorax.57.2.152
PMCID: PMC1746236  PMID: 11828046
20.  Active pulmonary tuberculosis and latent tuberculosis infection among homeless people in Seoul, South Korea: a cross-sectional study 
BMC Public Health  2013;13:720.
Background
The aim of this study was to determine the prevalence rate of latent TB infection (LTBI) and active TB among homeless in Seoul metropolitan city, South Korea, and to compare the TB burden among homeless people with that of a control group.
Methods
The homeless participants were recruited from five sites between October 30, 2009 and April 12, 2010. LTBI was diagnosed through the QuantiFERON(R) TB Gold In-Tube(QFT-GIT) assay and a tuberculin skin test(TST) and, and active PTB was diagnosed based on chest radiography.
Results
Among 313 participants, the prevalence of LTBI was 75.9% (95% CI, 71.1-80.8%) and 79.8% (95% CI, 74.9-84.7%) based on a QFT-GIT assay and the TST, respectively, and that of active PTB was 5.8% (95% CI, 3.2-8.3%). The prevalence of LTBI among homeless participants was about five times higher than controls. Also, the age-specific prevalence rate ratio of active PTB was as high as 24.86.
Conclusions
The prevalence rate of LTBI as well as active PTB among homeless people was much higher than that of the general population in South Korea. Thus, adequate strategies to reduce the TB burden among homeless people are needed.
doi:10.1186/1471-2458-13-720
PMCID: PMC3750398  PMID: 23914947
Tuberculosis; X-rays; Latent-TB infection (LTBI); Prevalence; Active pulmonary TB (PTB); Homeless
21.  Screening for HIV-Associated Tuberculosis and Rifampicin Resistance before Antiretroviral Therapy Using the Xpert MTB/RIF Assay: A Prospective Study 
PLoS Medicine  2011;8(7):e1001067.
In a prospective study, Stephen Lawn and colleagues find that pre-ART screening with Xpert MTB/RIF increased tuberculosis case detection by 45% compared to smear microscopy in HIV-positive patients at high risk of TB risk. AE competing interests must also pull through to the proof. “The Academic Editor, Madhukar Pai, declares that he consults for the Bill & Melinda Gates Foundation (BMGF). The BMGF supported FIND which was involved in the development of the Xpert MTB/RIF assay. He also co-chairs the Stop TB Partnership's New Diagnostics Working Group that was involved in the WHO endorsement of the Xpert assay.” Linked: Scott pmed.1001061; Evans pmed.1001064; Dowdy pmed.1001063
Background
The World Health Organization has endorsed the Xpert MTB/RIF assay for investigation of patients suspected of having tuberculosis (TB). However, its utility for routine TB screening and detection of rifampicin resistance among HIV-infected patients with advanced immunodeficiency enrolling in antiretroviral therapy (ART) services is unknown.
Methods and Findings
Consecutive adult HIV-infected patients with no current TB diagnosis enrolling in an ART clinic in a South African township were recruited regardless of symptoms. They were clinically characterised and invited to provide two sputum samples at a single visit. The accuracy of the Xpert MTB/RIF assay for diagnosing TB and drug resistance was assessed in comparison with other tests, including fluorescence smear microscopy and automated liquid culture (gold standard) and drug susceptibility testing. Of 515 patients enrolled, 468 patients (median CD4 cell count, 171 cells/µl; interquartile range, 102–236) produced at least one sputum sample, yielding complete sets of results from 839 samples. Mycobacterium tuberculosis was cultured from 81 patients (TB prevalence, 17.3%). The overall sensitivity of the Xpert MTB/RIF assay for culture-positive TB was 73.3% (specificity, 99.2%) compared to 28.0% (specificity, 100%) using smear microscopy. All smear-positive, culture-positive disease was detected by Xpert MTB/RIF from a single sample (sensitivity, 100%), whereas the sensitivity for smear-negative, culture-positive TB was 43.4% from one sputum sample and 62.3% from two samples. Xpert correctly identified rifampicin resistance in all four cases of multidrug-resistant TB but incorrectly identified resistance in three other patients whose disease was confirmed to be drug sensitive by gene sequencing (specificity, 94.1%; positive predictive value, 57%).
Conclusions
In this population of individuals at high risk of TB, intensive screening using the Xpert MTB/RIF assay increased case detection by 45% compared with smear microscopy, strongly supporting replacement of microscopy for this indication. However, despite the ability of the assay to rapidly detect rifampicin-resistant disease, the specificity for drug-resistant TB was sub-optimal.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Tuberculosis (TB)—a contagious bacterial infection that mainly affects the lungs—is a leading cause of illness and death among people who are infected with HIV, the virus that causes AIDS by destroying the immune system, which leaves infected individuals susceptible to other infections. TB is caused by Mycobacterium tuberculosis, which is spread in airborne droplets when people with the disease cough or sneeze. Its symptoms include a persistent cough, weight loss, and night sweats. Diagnostic tests for TB include chest X-rays, sputum smear analysis (microscopic examination of mucus coughed up from the lungs for M. tuberculosis bacilli), and mycobacterial liquid culture (the growth of M. tuberculosis from sputum and determination of its drug sensitivity). TB can be cured by taking several drugs daily for six months, although the recent emergence of multidrug-resistant TB (MDR-TB) is making the disease increasingly hard to treat.
Why Was This Study Done?
TB is a major problem in clinics that provide antiretroviral therapy (ART) for HIV-positive people in resource-limited settings. Not only is it a major cause of sickness and mortality in those affected by it, but TB (especially MDR-TB) can also spread to other patients attending the same clinic for health services. Rapid diagnosis and appropriate treatment are very important to reduce these risks. Unfortunately, sputum smear analysis—the mainstay of TB diagnosis in resource-limited settings—only detects about a fifth of TB cases when used as a screening tool before initiating ART. Chest X-rays are costly and don't always detect TB, and liquid culture—the gold standard method for TB diagnosis—is costly, technically difficult, and slow. Consequently, the World Health Organization (WHO) recently endorsed a new test for the investigation of patients suspected of having TB, especially in regions where HIV infection and MDR-TB are common. Xpert MTB/RIF is an automated DNA test that detects M. tuberculosis and DNA differences that make the bacteria resistant to the drug rifampicin (an indicator of MDR-TB) within 2 hours. In this study, the researchers investigate whether Xpert MTB/RIF could be used as a routine screening test to increase TB detection among HIV-positive people initiating ART.
What Did the Researchers Do and Find?
The researchers collected sputum from HIV-infected adults with no current TB diagnosis enrolling at an ART clinic in a South African township where HIV infection and TB are both common. They then compared the diagnostic accuracy of Xpert MTB/RIF (performed at a centralized laboratory) with that of several other tests, including liquid culture (the reference test). Nearly a fifth of the patients had culture-positive TB. Xpert MTB/RIF identified three-quarters of these patients (a sensitivity of 73.3%). By contrast, the sensitivity of smear microscopy was 28%. The new test's specificity (the proportion of patients with a negative Xpert MTB/RIF result among patients without TB) was 99.2%. That is, Xpert MTB/RIF had a low false-positive rate. Notably, Xpert MTB/RIF detected all cases of smear-positive, culture-positive TB but only 43.4% of smear-negative, culture-positive cases from a single sputum sample; it detected 62.3% of such cases when two sputum samples were analyzed. Finally, Xpert MTB/RIF correctly identified rifampicin resistance in all four patients who had MDR-TB but incorrectly identified resistance in three patients with drug-sensitive TB.
What Do These Findings Mean?
In this population of HIV-positive patients with a high TB risk, pre-ART screening with Xpert MTB/RIF increased case detection by 45% compared to smear microscopy, a finding that needs confirming in other settings. Importantly, Xpert MTB/RIF reduced the delay in diagnosis of TB from more than 20 days to two days. This delay would be reduced further by doing the assay at ART clinics rather than at a centralized testing facility, but the diagnostic accuracy of point-of-care testing needs evaluating. Overall, these findings (and those of an accompanying article by Scott et al. that examines the performance of Xpert MTB/RIF in an area where HIV infection is common) support the replacement of smear microscopy with Xpert MTB/RIF for pre-ART TB screening (provided misdiagnosis of rifampicin resistance can be reduced). These findings also suggest that routine screening with Xpert MTB/RIF could reduce the risk of MDR-TB outbreaks in HIV care and treatment settings and improve outcomes for HIV-positive patients with MDR-TB who currently often die before a diagnosis of TB can be made.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001056.
This study is further discussed in a PLoS Medicine Perspective by Carlton Evans; a related PLoS Medicine Research Article by Scott et al. is also available
WHO provides information (in several languages) on all aspects of tuberculosis, including general information on tuberculosis diagnostics and specific information on the Xpert MTB/RIF test; further information about WHO's endorsement of Xpert MTB/RIF is included in a recent Strategic and Technical Advisory Group for Tuberculosis report
WHO also provides information about tuberculosis and HIV
The US National Institute of Allergy and Infectious Diseases has detailed information on tuberculosis and HIV/AIDS
The US Centers for Disease Control and Prevention also has information about tuberculosis, including information on the diagnosis of and on tuberculosis and HIV co-infection
Information is available from Avert, an international AIDS charity, on many aspects of HIV/AIDS, including information on HIV-related tuberculosis (in English and Spanish)
doi:10.1371/journal.pmed.1001067
PMCID: PMC3144215  PMID: 21818180
22.  Sputum smear negative pulmonary tuberculosis: sensitivity and specificity of diagnostic algorithm 
BMC Research Notes  2011;4:475.
Background
The diagnosis of pulmonary tuberculosis in patients with Human Immunodeficiency Virus (HIV) is complicated by the increased presence of sputum smear negative tuberculosis. Diagnosis of smear negative pulmonary tuberculosis is made by an algorithm recommended by the National Tuberculosis and Leprosy Programme that uses symptoms, signs and laboratory results.
The objective of this study is to determine the sensitivity and specificity of the tuberculosis treatment algorithm used for the diagnosis of sputum smear negative pulmonary tuberculosis.
Methods
A cross-section study with prospective enrollment of patients was conducted in Dar-es-Salaam Tanzania. For patients with sputum smear negative, sputum was sent for culture. All consenting recruited patients were counseled and tested for HIV. Patients were evaluated using the National Tuberculosis and Leprosy Programme guidelines and those fulfilling the criteria of having active pulmonary tuberculosis were started on anti tuberculosis therapy. Remaining patients were provided appropriate therapy. A chest X-ray, mantoux test, and Full Blood Picture were done for each patient. The sensitivity and specificity of the recommended algorithm was calculated. Predictors of sputum culture positive were determined using multivariate analysis.
Results
During the study, 467 subjects were enrolled. Of those, 318 (68.1%) were HIV positive, 127 (27.2%) had sputum culture positive for Mycobacteria Tuberculosis, of whom 66 (51.9%) were correctly treated with anti-Tuberculosis drugs and 61 (48.1%) were missed and did not get anti-Tuberculosis drugs. Of the 286 subjects with sputum culture negative, 107 (37.4%) were incorrectly treated with anti-Tuberculosis drugs. The diagnostic algorithm for smear negative pulmonary tuberculosis had a sensitivity and specificity of 38.1% and 74.5% respectively. The presence of a dry cough, a high respiratory rate, a low eosinophil count, a mixed type of anaemia and presence of a cavity were found to be predictive of smear negative but culture positive pulmonary tuberculosis.
Conclusion
The current practices of establishing pulmonary tuberculosis diagnosis are not sensitive and specific enough to establish the diagnosis of Acid Fast Bacilli smear negative pulmonary tuberculosis and over treat people with no pulmonary tuberculosis.
doi:10.1186/1756-0500-4-475
PMCID: PMC3216301  PMID: 22044882
Sputum smear negative; Human Immunodeficiency Virus; Symptoms
23.  Unique health care utilization patterns in a homeless population in Ghent 
Background
Existing studies concerning the health care use of homeless people describe higher utilisation rates for hospital-based care and emergency care, and lower rates for primary care by homeless people compared to the general population. Homeless people are importantly hindered and/or steered in their health care use by barriers directly related to the organisation of care. Our goal is to describe the accessibility of primary health care services, secondary care and emergency care for homeless people living in an area with a universal primary health care system and active guidance towards this unique system.
Methods
Observational, cross-sectional study design. Data from the Belgian National health survey were merged with comparable data collected by means of a face-to-face interview from homeless people in Ghent. 122 homeless people who made use of homeless centres and shelters in Ghent were interviewed using a reduced version of the Belgian National Health survey over a period of 5 months. 2-dimensional crosstabs were built in order to study the bivariate relationship between health care use (primary health care, secondary and emergency care) and being homeless. To determine the independent association, a logistic model was constructed adjusting for age and sex.
Results and Discussion
Homeless people have a higher likelihood to consult a GP than the non-homeless people in Ghent, even after adjusting for age and sex. The same trend is demonstrated for secondary and emergency care.
Conclusions
Homeless people in Ghent do find the way to primary health care and make use of it. It seems that the universal primary health care system in Ghent with an active guidance by social workers contributes to easier GP access.
doi:10.1186/1472-6963-10-242
PMCID: PMC2933678  PMID: 20723222
24.  Influenza vaccination, inverse care and homelessness: cross-sectional survey of eligibility and uptake during the 2011/12 season in London 
BMC Public Health  2014;14:44.
Background
Influenza vaccination eligibility and uptake among homeless adults has not been previously assessed in the UK. This cross-sectional survey aimed to measure the proportion of homeless people visited by an NHS outreach service (Find and Treat) who were eligible for and had received vaccination during 2011/12.
Methods
A cross-sectional survey was carried out in 27 separate homeless hostels, day centres and drug services in London between July and August in 2012. Eligibility for the survey was by virtue of being in attendance at one of 27 venues visited by Find and Treat. No specific exclusion criteria were used.
Results
455 clients took part in the survey out of 592 approached (76.9%). A total of 190 homeless people (41.8%; 95% CI: 34.5,50.5) were eligible for influenza vaccination. In those aged 16–64, eligibility due to clinical risk factors was 38.9% (95% CI: 31.5,48.2). Uptake of vaccination in homeless 16–64 year olds with a clinical risk factor during the 2011/12 influenza season was 23.7% (95% CI: 19.8,28.3) compared to national levels of 53.2% (excluding pregnant women). In those aged over 65, uptake was 42.9% (95% CI: 16.7,100.0) compared with 74.0% nationally.
Conclusions
This study demonstrates that the homeless population have high levels of chronic health problems predisposing them to severe complications of influenza, but vaccine uptake levels that are less than half those seen among eligible GP patient groups in England. It provides a clear example of the health inequalities and inverse care law that impact this population. The results of this study provide strong justification for intensifying efforts to ensure homeless people have access to influenza vaccination.
doi:10.1186/1471-2458-14-44
PMCID: PMC3906096  PMID: 24433371
25.  Tuberculosis screening and follow-up of asylum seekers in Norway: a cohort study 
BMC Public Health  2009;9:141.
Background
About 80% of new tuberculosis cases in Norway occur among immigrants from high incidence countries. On arrival to the country all asylum seekers are screened with Mantoux test and chest x-ray aimed to identify cases of active tuberculosis and, in the case of latent tuberculosis, to offer follow-up or prophylactic treatment.
We assessed a national programme for screening, treatment and follow-up of tuberculosis infection and disease in a cohort of asylum seekers.
Methods
Asylum seekers ≥ 18 years who arrived at the National Reception Centre from January 2005 to June 2006, were included as the total cohort. Those with a Mantoux test ≥ 6 mm or positive x-ray findings were included in a study group for follow-up.
Data were collected from public health authorities in the municipality to where the asylum seekers had moved, and from hospital based internists in case they had been referred to specialist care.
Individual subjects included in the study group were matched with the Norwegian National Tuberculosis Register which receive reports of everybody diagnosed with active tuberculosis, or who had started treatment for latent tuberculosis.
Results
The total cohort included 4643 adult asylum seekers and 97.5% had a valid Mantoux test. At least one inclusion criterion was fulfilled by 2237 persons. By end 2007 municipal public health authorities had assessed 758 (34%) of them. Altogether 328 persons had been seen by an internist. Of 314 individuals with positive x-rays, 194 (62%) had seen an internist, while 86 of 568 with Mantoux ≥ 15, but negative x-rays (16%) were also seen by an internist. By December 31st 2006, 23 patients were diagnosed with tuberculosis (prevalence 1028/100 000) and another 11 were treated for latent infection.
Conclusion
The coverage of screening was satisfactory, but fewer subjects than could have been expected from the national guidelines were followed up in the community and referred to an internist. To improve follow-up of screening results, a simplification of organisation and guidelines, introduction of quality assurance systems, and better coordination between authorities and between different levels of health care are all required.
doi:10.1186/1471-2458-9-141
PMCID: PMC2689201  PMID: 19442260

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