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1.  Molecular Diagnostics for Gonorrhoea: Implications for Antimicrobial Resistance and the Threat of Untreatable Gonorrhoea 
PLoS Medicine  2014;11(2):e1001598.
This Essay from Nicola Low and colleagues discusses the importance of the nucleic acid amplification tests for rapid detection of N. gonorrhoeae and its resistance determinants, as well as the importance of ensuring their rational use, as priorities for controlling both gonorrhoea and antimicrobial resistance.
Please see later in the article for the Editors' Summary
doi:10.1371/journal.pmed.1001598
PMCID: PMC3913554  PMID: 24503544
2.  Transmission of Chlamydia trachomatis through sexual partnerships: a comparison between three individual-based models and empirical data 
Chlamydia trachomatis is the most common bacterial sexually transmitted infection (STI) in many developed countries. The highest prevalence rates are found among young adults who have frequent partner change rates. Three published individual-based models have incorporated a detailed description of age-specific sexual behaviour in order to quantify the transmission of C. trachomatis in the population and to assess the impact of screening interventions. Owing to varying assumptions about sexual partnership formation and dissolution and the great uncertainty about critical parameters, such models show conflicting results about the impact of preventive interventions. Here, we perform a detailed evaluation of these models by comparing the partnership formation and dissolution dynamics with data from Natsal 2000, a population-based probability sample survey of sexual attitudes and lifestyles in Britain. The data also allow us to describe the dispersion of C. trachomatis infections as a function of sexual behaviour, using the Gini coefficient. We suggest that the Gini coefficient is a useful measure for calibrating infectious disease models that include risk structure and highlight the need to estimate this measure for other STIs.
doi:10.1098/rsif.2011.0131
PMCID: PMC3223622  PMID: 21653569
Chlamydia trachomatis; sexual partnerships; individual-based model; Natsal 2000; Gini coefficient
3.  National, Regional, and Global Trends in Infertility Prevalence Since 1990: A Systematic Analysis of 277 Health Surveys 
PLoS Medicine  2012;9(12):e1001356.
Gretchen Stevens and colleagues use information from demographic reproductive health surveys to estimate the global, regional, and country levels, patterns, and trends in infertility between 1990 and 2010.
Background
Global, regional, and national estimates of prevalence of and tends in infertility are needed to target prevention and treatment efforts. By applying a consistent algorithm to demographic and reproductive surveys available from developed and developing countries, we estimate infertility prevalence and trends, 1990 to 2010, by country and region.
Methods and Findings
We accessed and analyzed household survey data from 277 demographic and reproductive health surveys using a consistent algorithm to calculate infertility. We used a demographic infertility measure with live birth as the outcome and a 5-y exposure period based on union status, contraceptive use, and desire for a child. We corrected for biases arising from the use of incomplete information on past union status and contraceptive use. We used a Bayesian hierarchical model to estimate prevalence of and trends in infertility in 190 countries and territories. In 2010, among women 20–44 y of age who were exposed to the risk of pregnancy, 1.9% (95% uncertainty interval 1.7%, 2.2%) were unable to attain a live birth (primary infertility). Out of women who had had at least one live birth and were exposed to the risk of pregnancy, 10.5% (9.5%, 11.7%) were unable to have another child (secondary infertility). Infertility prevalence was highest in South Asia, Sub-Saharan Africa, North Africa/Middle East, and Central/Eastern Europe and Central Asia. Levels of infertility in 2010 were similar to those in 1990 in most world regions, apart from declines in primary and secondary infertility in Sub-Saharan Africa and primary infertility in South Asia (posterior probability [pp] ≥0.99). Although there were no statistically significant changes in the prevalence of infertility in most regions amongst women who were exposed to the risk of pregnancy, reduced child-seeking behavior resulted in a reduction of primary infertility among all women from 1.6% to 1.5% (pp = 0.90) and a reduction of secondary infertility among all women from 3.9% to 3.0% (pp>0.99) from 1990 to 2010. Due to population growth, however, the absolute number of couples affected by infertility increased from 42.0 million (39.6 million, 44.8 million) in 1990 to 48.5 million (45.0 million, 52.6 million) in 2010. Limitations of the study include gaps in survey data for some countries and the use of proxies to determine exposure to pregnancy.
Conclusions
We analyzed demographic and reproductive household survey data to reveal global patterns and trends in infertility. Independent from population growth and worldwide declines in the preferred number of children, we found little evidence of changes in infertility over two decades, apart from in the regions of Sub-Saharan Africa and South Asia. Further research is needed to identify the etiological causes of these patterns and trends.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Reproductive health is a priority global health area: the target for Millennium Development Goal 5B is to provide universal access to reproductive health by 2015. The indicators for monitoring progress in reaching this target are contraceptive prevalence rate, adolescent birth rate, antenatal care coverage, and the unmet need for family planning. Infertility, the inability to conceive after a prolonged period (the length of time varies in different definitions) of unprotected intercourse, is a critical but much neglected aspect of reproductive health. The inability to have children affects couples worldwide and causes emotional and psychological distress in both men and women. Many factors—including physiological, genetic, environmental, and social— contribute to infertility. According to the World Health Organization, infertility resulting from sexually transmitted diseases or reproductive tract infections is particularly problematic in Africa and Latin America.
Why Was This Study Done?
The researchers used a uniform measure of infertility that incorporated live birth as the outcome of interest (as this information is more commonly reported than pregnancies), a five-year “exposure period,” that is, a five-year period of being in an intimate relationship, not using contraceptives, and wanting a child (as the researchers calculated that this period was necessary to accommodate the time it takes to become pregnant and have a child, and to allow for incomplete information on frequency of unprotected intercourse). The researchers used a statistical model (Bayesian hierarchical model) to generate estimates for levels and trends of infertility in 190 countries over the time period 1990 to 2010 using information collected from national demographic and reproductive health surveys. The most data was available for South Asia and Sub-Saharan Africa.
What Did the Researchers Do and Find?
The researchers found that in 2010, 1.9% of women aged 20–44 years who wanted to have children were unable to have their first live birth (primary infertility), and 10.5% of women with a previous live birth were unable to have an additional live birth (secondary infertility). The researchers found that the levels of infertility were similar in 1990 and 2010, with only a slight overall decrease in primary infertility (0.1%, but with a more pronounced drop in Sub-Saharan Africa and South Asia) and a modest overall increase in secondary infertility (0.4%). Age affected infertility rates: the prevalence of primary infertility was higher among women aged 20–24 years than among older women. The age pattern was reversed and even more pronounced for secondary infertility. And primary infertility rates among women wanting children also varied by region, from 1.5% in Latin America and the Caribbean in 2010, to 2.6% in North Africa and the Middle East. With a few exceptions, global and country patterns of secondary infertility were similar to those of primary infertility.
What Do These Findings Mean?
These findings suggest that in 2010, an estimated 48.5 million couples worldwide were unable to have a child after five years. However, these findings also suggest that global levels of primary and secondary infertility hardly changed between 1990 and 2010. It is important to note that an infertility measure based on ability to become pregnant (rather than having a live birth—the outcome used in this study) may show different levels of infertility, and using an exposure period shorter than the five years used in this study would produce higher rates of infertility. However, because of the lack of widespread data collection on time to pregnancy, the methods used and results shown in this study provide useful insights into global, regional, and country patterns and trends in infertility.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001356.
The World Health Organization has information on reproductive health
Wikipedia defines infertility and gives some useful information (note that Wikipedia is a free online encyclopedia that anyone can edit)
Patient friendly information on infertility can be found at PubMed Health and NHS Choices
doi:10.1371/journal.pmed.1001356
PMCID: PMC3525527  PMID: 23271957
4.  Individual and Population Level Effects of Partner Notification for Chlamydia trachomatis 
PLoS ONE  2012;7(12):e51438.
Partner notification (PN or contact tracing) is an important aspect of treating bacterial sexually transmitted infections (STIs), such as Chlamydia trachomatis. It facilitates the identification of new infected cases that can be treated through individual case management. PN also acts indirectly by limiting onward transmission in the general population. However, the impact of PN, both at the level of individuals and the population, remains unclear. Since it is difficult to study the effects of PN empirically, mathematical and computational models are useful tools for investigating its potential as a public health intervention. To this end, we developed an individual-based modeling framework called Rstisim. It allows the implementation of different models of STI transmission with various levels of complexity and the reconstruction of the complete dynamic sexual partnership network over any time period. A key feature of this framework is that we can trace an individual’s partnership history in detail and investigate the outcome of different PN strategies for C. trachomatis. For individual case management, the results suggest that notifying three or more partners from the preceding 18 months yields substantial numbers of new cases. In contrast, the successful treatment of current partners is most important for preventing re-infection of index cases and reducing further transmission of C. trachomatis at the population level. The findings of this study demonstrate the difference between individual and population level outcomes of public health interventions for STIs.
doi:10.1371/journal.pone.0051438
PMCID: PMC3520891  PMID: 23251534
5.  Resurgence of HIV Infection among Men Who Have Sex with Men in Switzerland: Mathematical Modelling Study 
PLoS ONE  2012;7(9):e44819.
Background
New HIV infections in men who have sex with men (MSM) have increased in Switzerland since 2000 despite combination antiretroviral therapy (cART). The objectives of this mathematical modelling study were: to describe the dynamics of the HIV epidemic in MSM in Switzerland using national data; to explore the effects of hypothetical prevention scenarios; and to conduct a multivariate sensitivity analysis.
Methodology/Principal Findings
The model describes HIV transmission, progression and the effects of cART using differential equations. The model was fitted to Swiss HIV and AIDS surveillance data and twelve unknown parameters were estimated. Predicted numbers of diagnosed HIV infections and AIDS cases fitted the observed data well. By the end of 2010, an estimated 13.5% (95% CI 12.5, 14.6%) of all HIV-infected MSM were undiagnosed and accounted for 81.8% (95% CI 81.1, 82.4%) of new HIV infections. The transmission rate was at its lowest from 1995–1999, with a nadir of 46 incident HIV infections in 1999, but increased from 2000. The estimated number of new infections continued to increase to more than 250 in 2010, although the reproduction number was still below the epidemic threshold. Prevention scenarios included temporary reductions in risk behaviour, annual test and treat, and reduction in risk behaviour to levels observed earlier in the epidemic. These led to predicted reductions in new infections from 2 to 26% by 2020. Parameters related to disease progression and relative infectiousness at different HIV stages had the greatest influence on estimates of the net transmission rate.
Conclusions/Significance
The model outputs suggest that the increase in HIV transmission amongst MSM in Switzerland is the result of continuing risky sexual behaviour, particularly by those unaware of their infection status. Long term reductions in the incidence of HIV infection in MSM in Switzerland will require increased and sustained uptake of effective interventions.
doi:10.1371/journal.pone.0044819
PMCID: PMC3443082  PMID: 23024766
6.  Timing of progression from Chlamydia trachomatis infection to pelvic inflammatory disease: a mathematical modelling study 
BMC Infectious Diseases  2012;12:187.
Background
Pelvic inflammatory disease (PID) results from the ascending spread of microorganisms from the vagina and endocervix to the upper genital tract. PID can lead to infertility, ectopic pregnancy and chronic pelvic pain. The timing of development of PID after the sexually transmitted bacterial infection Chlamydia trachomatis (chlamydia) might affect the impact of screening interventions, but is currently unknown. This study investigates three hypothetical processes for the timing of progression: at the start, at the end, or throughout the duration of chlamydia infection.
Methods
We develop a compartmental model that describes the trial structure of a published randomised controlled trial (RCT) and allows each of the three processes to be examined using the same model structure. The RCT estimated the effect of a single chlamydia screening test on the cumulative incidence of PID up to one year later. The fraction of chlamydia infected women who progress to PID is obtained for each hypothetical process by the maximum likelihood method using the results of the RCT.
Results
The predicted cumulative incidence of PID cases from all causes after one year depends on the fraction of chlamydia infected women that progresses to PID and on the type of progression. Progression at a constant rate from a chlamydia infection to PID or at the end of the infection was compatible with the findings of the RCT. The corresponding estimated fraction of chlamydia infected women that develops PID is 10% (95% confidence interval 7-13%) in both processes.
Conclusions
The findings of this study suggest that clinical PID can occur throughout the course of a chlamydia infection, which will leave a window of opportunity for screening to prevent PID.
doi:10.1186/1471-2334-12-187
PMCID: PMC3505463  PMID: 22883325
Chlamydia infection; Pelvic inflammatory disease; Mathematical model; Compartmental model; Randomised controlled trials
7.  The Role of Reinfection and Partner Notification in the Efficacy of Chlamydia Screening Programs 
The Journal of Infectious Diseases  2011;203(3):372-377.
Repeated Chlamydia trachomatis infections after treatment are common. One reason is reinfection from untreated partners in ongoing sexual partnerships. Mathematical models that are used to predict the impact of screening on reducing chlamydia prevalence often do not incorporate reinfection and might overestimate the expected impact. We describe a pair compartmental model that explicitly incorporates sexual partnership duration and reinfection. The pair model predicts a weaker impact of screening when compared directly with a model that does not accommodate partnerships. Effective management of sex partners to prevent reinfection might need to be strengthened in chlamydia control programs.
doi:10.1093/infdis/jiq050
PMCID: PMC3071108  PMID: 21186257
8.  Intravaginal Practices, Bacterial Vaginosis, and HIV Infection in Women: Individual Participant Data Meta-analysis 
PLoS Medicine  2011;8(2):e1000416.
Pooling of data from 14,874 women in an individual participant data meta-analysis by Nicola Low and colleagues reveals that some intravaginal practices increase the risk of HIV acquisition.
Background
Identifying modifiable factors that increase women's vulnerability to HIV is a critical step in developing effective female-initiated prevention interventions. The primary objective of this study was to pool individual participant data from prospective longitudinal studies to investigate the association between intravaginal practices and acquisition of HIV infection among women in sub-Saharan Africa. Secondary objectives were to investigate associations between intravaginal practices and disrupted vaginal flora; and between disrupted vaginal flora and HIV acquisition.
Methods and Findings
We conducted a meta-analysis of individual participant data from 13 prospective cohort studies involving 14,874 women, of whom 791 acquired HIV infection during 21,218 woman years of follow-up. Data were pooled using random-effects meta-analysis. The level of between-study heterogeneity was low in all analyses (I2 values 0.0%–16.1%). Intravaginal use of cloth or paper (pooled adjusted hazard ratio [aHR] 1.47, 95% confidence interval [CI] 1.18–1.83), insertion of products to dry or tighten the vagina (aHR 1.31, 95% CI 1.00–1.71), and intravaginal cleaning with soap (aHR 1.24, 95% CI 1.01–1.53) remained associated with HIV acquisition after controlling for age, marital status, and number of sex partners in the past 3 months. Intravaginal cleaning with soap was also associated with the development of intermediate vaginal flora and bacterial vaginosis in women with normal vaginal flora at baseline (pooled adjusted odds ratio [OR] 1.24, 95% CI 1.04–1.47). Use of cloth or paper was not associated with the development of disrupted vaginal flora. Intermediate vaginal flora and bacterial vaginosis were each associated with HIV acquisition in multivariable models when measured at baseline (aHR 1.54 and 1.69, p<0.001) or at the visit before the estimated date of HIV infection (aHR 1.41 and 1.53, p<0.001), respectively.
Conclusions
This study provides evidence to suggest that some intravaginal practices increase the risk of HIV acquisition but a direct causal pathway linking intravaginal cleaning with soap, disruption of vaginal flora, and HIV acquisition has not yet been demonstrated. More consistency in the definition and measurement of specific intravaginal practices is warranted so that the effects of specific intravaginal practices and products can be further elucidated.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Since the first reported case of acquired immunodeficiency syndrome (AIDS) in 1981, the number of people infected with the human immunodeficiency virus (HIV), which causes AIDS, has risen steadily. By the end of 2009, an estimated 33.3 million people were living with HIV/AIDS. At the beginning of the epidemic, more men than women were infected with HIV but now, globally, more than half of all adults living with HIV/AIDS are women, and HIV/AIDS is the leading cause of death among women of child-bearing age. In sub-Saharan Africa, where more than two-thirds of HIV-positive people live, the situation for women is particularly bad. About 12 million women live with HIV/AIDS in this region compared with about 8 million men; among 15–24 year-olds, women are eight times more likely than men to be HIV-positive. This pattern of infection has developed because in sub-Saharan Africa most people contract HIV through heterosexual sex.
Why Was This Study Done?
If modifiable factors that increase women's vulnerability to HIV infection could be identified, it might be possible to develop effective female-initiated prevention interventions. Some experts think that intravaginal practices such as cleaning the vagina with soap or a cloth increase the risk of HIV infection by damaging the vagina's lining or by increasing bacterial vaginosis (a condition in which harmful bacteria disrupt the healthy vaginal flora) but the evidence for such an association is inconclusive. In this meta-analysis, the researchers pool individual participant data from several prospective longitudinal cohort studies to assess the association between intravaginal practices and HIV acquisition among women in sub-Saharan Africa. Meta-analysis is a statistical method that combines data from several studies to get a clearer view of the factors associated with of a disease than is possible from individual studies. In a prospective longitudinal cohort study, groups of participants with different baseline characteristics (here, women who did or did not use intravaginal practices), who do not have the outcome of interest at the start of the study (here, HIV infection) are followed to see whether these characteristics affect disease development.
What Did the Researchers Do and Find?
The researchers pooled individual participant data from 13 prospective cohort studies in sub-Saharan Africa involving nearly 15,000 women, 791 of whom acquired HIV, and asked whether HIV infection within 2 years of study enrollment was associated with self-reported intravaginal practices. That is, were women who used specific intravaginal practices more likely to become infected with HIV than women who did not use these practices? After controlling for age, marital status, and the number of recent sex partners, women who used cloth or paper to clean their vagina were nearly one and half times more likely to have acquired HIV infection as women who did not use this practice (a pooled adjusted hazard ratio [aHR] of 1.47). The insertion of products to dry or tighten the vagina and intravaginal cleaning with soap also increased women's chances of acquiring HIV (aHRs of 1.31 and 1.24, respectively). Moreover, intravaginal cleaning with soap was associated with the development of bacterial vaginosis, and disrupted vaginal flora and bacterial vaginosis were both associated with an increased risk of HIV acquisition.
What Do These Findings Mean?
These findings suggest that some intravaginal practices increase the risk of HIV acquisition but they do not prove that there is a causal link between any intravaginal practice, disruption of vaginal flora, and HIV acquisition. It could be that the women who use intravaginal practices share other unknown characteristics that affect their vulnerability to HIV infection. The accuracy of these findings is also likely to be affected by the use of self-reported data and inconsistent definitions of intravaginal practices. Nevertheless, given the widespread use of intravaginal practices in some sub-Saharan countries (95% of female sex workers in Kenya use such practices, for example), these findings suggest that encouraging women to use less harmful intravaginal practices (for example, washing with water alone) should be included in female-initiated HIV prevention research strategies in sub-Saharan Africa and other regions where intravaginal practices are common.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000416
The US National Institute of Allergy and Infectious Diseases provides information on HIV infection and AIDS and on bacterial vaginosis
The US Centers for Disease Control and Prevention has information on all aspects of HIV/AIDS, including specific information about HIV/AIDS and women; it also has information on bacterial vaginosis (in English and Spanish)
HIV InSite has information on all aspects of HIV/AIDS
Information is available from Avert, an international AIDS nonprofit on all aspects of HIV/AIDS, including HIV/AIDS and women and HIV/AIDS in Africa (in English and Spanish)
A full description of the researchers' study protocol is available
Several Web sites provide information on microbicides Global Campaign for Microbicides, Microbicides Development Programme, Microbicides Trials Network, and International Partnership for Microbicides
doi:10.1371/journal.pmed.1000416
PMCID: PMC3039685  PMID: 21358808
10.  Travelling far but staying close to home 
Sexually Transmitted Infections  2007;83(7):501-502.
doi:10.1136/sti.2007.028928
PMCID: PMC2598662  PMID: 18024707
11.  Testing for sexually transmitted infections in general practice: cross-sectional study 
BMC Public Health  2010;10:667.
Background
Primary care is an important provider of sexual health care in England. We sought to explore the extent of testing for chlamydia and HIV in general practice and its relation to associated measures of sexual health in two contrasting geographical settings.
Methods
We analysed chlamydia and HIV testing data from 64 general practices and one genitourinary medicine (GUM) clinic in Brent (from mid-2003 to mid-2006) and 143 general practices and two GUM clinics in Avon (2004). We examined associations between practice testing status, practice characteristics and hypothesised markers of population need (area level teenage conception rates and Index of Multiple Deprivation, IMD scores).
Results
No HIV or chlamydia testing was done in 19% (12/64) of general practices in Brent, compared to 2.1% (3/143) in Avon. In Brent, the mean age of general practitioners (GPs) in Brent practices that tested for chlamydia or HIV was lower than in those that had not conducted testing. Practices where no HIV testing was done had slightly higher local teenage conception rates (median 23.5 vs. 17.4/1000 women aged 15-44, p = 0.07) and served more deprived areas (median IMD score 27.1 vs. 21.8, p = 0.05). Mean yearly chlamydia and HIV testing rates, in practices that did test were 33.2 and 0.6 (per 1000 patients aged 15-44 years) in Brent, and 34.1 and 10.3 in Avon, respectively. In Brent practices only 20% of chlamydia tests were conducted in patients aged under 25 years, compared with 39% in Avon.
Conclusions
There are substantial geographical differences in the intensity of chlamydia and HIV testing in general practice. Interventions to facilitate sexually transmitted infection and HIV testing in general practice are needed to improve access to effective sexual health care. The use of routinely-collected laboratory, practice-level and demographic data for monitoring sexual health service provision and informing service planning should be more widely evaluated.
doi:10.1186/1471-2458-10-667
PMCID: PMC2988740  PMID: 21047396
12.  Mapping HIV/STI behavioural surveillance in Europe 
BMC Infectious Diseases  2010;10:290.
Background
Used in conjunction with biological surveillance, behavioural surveillance provides data allowing for a more precise definition of HIV/STI prevention strategies. In 2008, mapping of behavioural surveillance in EU/EFTA countries was performed on behalf of the European Centre for Disease prevention and Control.
Method
Nine questionnaires were sent to all 31 member States and EEE/EFTA countries requesting data on the overall behavioural and second generation surveillance system and on surveillance in the general population, youth, men having sex with men (MSM), injecting drug users (IDU), sex workers (SW), migrants, people living with HIV/AIDS (PLWHA), and sexually transmitted infection (STI) clinics patients. Requested data included information on system organisation (e.g. sustainability, funding, institutionalisation), topics covered in surveys and main indicators.
Results
Twenty-eight of the 31 countries contacted supplied data. Sixteen countries reported an established behavioural surveillance system, and 13 a second generation surveillance system (combination of biological surveillance of HIV/AIDS and STI with behavioural surveillance). There were wide differences as regards the year of survey initiation, number of populations surveyed, data collection methods used, organisation of surveillance and coordination with biological surveillance. The populations most regularly surveyed are the general population, youth, MSM and IDU. SW, patients of STI clinics and PLWHA are surveyed less regularly and in only a small number of countries, and few countries have undertaken behavioural surveys among migrant or ethnic minorities populations. In many cases, the identification of populations with risk behaviour and the selection of populations to be included in a BS system have not been formally conducted, or are incomplete. Topics most frequently covered are similar across countries, although many different indicators are used. In most countries, sustainability of surveillance systems is not assured.
Conclusion
Although many European countries have established behavioural surveillance systems, there is little harmonisation as regards the methods and indicators adopted. The main challenge now faced is to build and maintain organised and functional behavioural and second generation surveillance systems across Europe, to increase collaboration, to promote robust, sustainable and cost-effective data collection methods, and to harmonise indicators.
doi:10.1186/1471-2334-10-290
PMCID: PMC2959062  PMID: 20920339
13.  Direct transmission: introducing a new feature in STI 
Peter Piot talks about STI, HIV and UNAIDS
doi:10.1136/sti.2007.028118
PMCID: PMC2598719  PMID: 17911141
16.  What can be gained from comprehensive disaggregate surveillance? The Avon Surveillance System for Sexually Transmitted Infections 
Sexually Transmitted Infections  2007;83(5):411-415.
Objective
To describe a new disaggregate surveillance system covering key diagnosed sexually transmitted infections in a UK locality.
Methods
The Avon System for Surveillance of Sexually Transmitted Infections (ASSIST) collects computerised person‐ and episode‐based information about laboratory‐diagnosed sexually transmitted infections from genitourinary medicine (GUM) clinics, the Avon Brook Clinic, and the Health Protection Agency and trust laboratories in primary care trusts in Avon. The features of the system are illustrated here, by describing chlamydia‐testing patterns according to the source of test, age and sex, and by mapping the distribution of chlamydia across Bristol, UK.
Results
Between 2000 and 2004, there were 821 685 records of tests for sexually transmitted infections, with 23 542 positive results. The proportion of tests and positive results for chlamydia and gonorrhoea sent from general practice increased over time. Most chlamydia tests in both GUM and non‐specialist settings were performed on women aged >25 years, but positivity rates were highest in women aged <25 years. The positivity rate remained stable between 2000 and 2004. Including data from all diagnostic settings, chlamydia rates were about twice as high as those estimated only from genitourinary clinic cases.
Conclusions
The ASSIST model could be a promising new tool for planning and measuring sexual health services in England if it can become sustainable and provide more timely data using fewer resources. Collecting denominator data and including infections diagnosed in primary care are essential for meaningful surveillance.
doi:10.1136/sti.2006.023440
PMCID: PMC2659036  PMID: 17344247
17.  Sexual health of ethnic minority MSM in Britain (MESH project): design and methods 
BMC Public Health  2010;10:419.
Background
Men who have sex with men (MSM) remain the group most at risk of acquiring HIV infection in Britain. HIV prevalence appears to vary widely between MSM from different ethnic minority groups in this country for reasons that are not fully understood. The aim of the MESH project was to examine in detail the sexual health of ethnic minority MSM living in Britain.
Methods/Design
The main objectives of the MESH project were to explore among ethnic minority MSM living in Britain: (i) sexual risk behaviour and HIV prevalence; (ii) their experience of stigma and discrimination; (iii) disclosure of sexuality; (iv) use of, and satisfaction with sexual health services; (v) the extent to which sexual health services (for treatment and prevention) are aware of the needs of ethnic minority MSM.
The research was conducted between 2006 and 2008 in four national samples: (i) ethnic minority MSM living in Britain; (ii) a comparison group of white British MSM living in Britain; (iii) NHS sexual health clinic staff in 15 British towns and cities with significant ethnic minority communities and; (iv) sexual health promotion/HIV prevention service providers. We also recruited men from two "key migrant" groups living in Britain: MSM born in Central or Eastern Europe and MSM born in Central or South America.
Internet-based quantitative and qualitative research methods were used. Ethnic minority MSM were recruited through advertisements on websites, in community venues, via informal networks and in sexual health clinics. White and "key migrant" MSM were recruited mostly through Gaydar, one of the most popular dating sites used by gay men in Britain. MSM who agreed to take part completed a questionnaire online. Ethnic minority MSM who completed the online questionnaire were asked if they would be willing to take part in an online qualitative interview using email.
Service providers were identified through the British Association of Sexual Health and HIV (BASHH) and the Terrence Higgins Trust (THT) CHAPS partnerships. Staff who agreed to take part were asked to complete a questionnaire online.
The online survey was completed by 1241 ethnic minority MSM, 416 men born in South and Central America or Central and Eastern Europe, and 13,717 white British MSM; 67 ethnic minority MSM took part in the online qualitative interview. In addition 364 people working in sexual health clinics and 124 health promotion workers from around Britain completed an online questionnaire.
Discussion
The findings from this study will improve our understanding of the sexual health and needs of ethnic minority MSM in Britain.
doi:10.1186/1471-2458-10-419
PMCID: PMC2916902  PMID: 20630087
19.  Focus on chlamydia 
Sexually Transmitted Infections  2007;83(4):251-252.
doi:10.1136/sti.2007.026898
PMCID: PMC2598690  PMID: 17664356
20.  Healthcare and patient costs of a proactive chlamydia screening programme: the Chlamydia Screening Studies project 
Sexually Transmitted Infections  2007;83(4):276-281.
Background and objective
Most economic evaluations of chlamydia screening do not include costs incurred by patients. The objective of this study was to estimate both the health service and private costs of patients who participated in proactive chlamydia screening, using mailed home‐collected specimens as part of the Chlamydia Screening Studies project.
Methods
Data were collected on the administrative costs of the screening study, laboratory time and motion studies and patient‐cost questionnaire surveys were conducted. The cost for each screening invitation and for each accepted offer was estimated. One‐way sensitivity analysis was conducted to explore the effects of variations in patient costs and the number of patients accepting the screening offer.
Results
The time and costs of processing urine specimens and vulvo‐vaginal swabs from women using two nucleic acid amplification tests were similar. The total cost per screening invitation was £20.37 (95% CI £18.94 to 24.83). This included the National Health Service cost per individual screening invitation £13.55 (95% CI £13.15 to 14.33) and average patient costs of £6.82 (95% CI £5.48 to 10.22). Administrative costs accounted for 50% of the overall cost.
Conclusions
The cost of proactive chlamydia screening is comparable to those of opportunistic screening. Results from this study, which is the first to collect private patient costs associated with a chlamydia screening programme, could be used to inform future policy recommendations and provide unique primary cost data for economic evaluations.
doi:10.1136/sti.2006.023374
PMCID: PMC2598691  PMID: 17229792
21.  Screening programmes for chlamydial infection: when will we ever learn? 
BMJ : British Medical Journal  2007;334(7596):725-728.
With more countries recommending screening programmes for chlamydial infection, Nicola Low argues that such programmes are not underpinned by sound evidence
doi:10.1136/bmj.39154.378079.BE
PMCID: PMC1847869  PMID: 17413173
22.  Intravaginal Practices, Vaginal Infections and HIV Acquisition: Systematic Review and Meta-Analysis 
PLoS ONE  2010;5(2):e9119.
Background
Intravaginal practices are commonly used by women to manage their vaginal health and sexual life. These practices could, however, affect intravaginal mucosal integrity. The objectives of this study were to examine evidence for associations between: intravaginal practices and acquisition of HIV infection; intravaginal practices and vaginal infections; and vaginal infections and HIV acquisition.
Methodology/Principal Findings
We conducted a systematic review of prospective longitudinal studies, searching 15 electronic databases of journals and abstracts from two international conferences to 31st January 2008. Relevant articles were selected and data extracted in duplicate. Results were examined visually in forest plots and combined using random effects meta-analysis where appropriate. Of 2120 unique references we included 22 publications from 15 different studies in sub-Saharan Africa and the USA. Seven publications from five studies examined a range of intravaginal practices and HIV infection. No specific vaginal practices showed a protective effect against HIV or vaginal infections. Insertion of products for sex was associated with HIV in unadjusted analyses; only one study gave an adjusted estimate, which showed no association (hazard ratio 1.09, 95% confidence interval, CI 0.71, 1.67). HIV incidence was higher in women reporting intravaginal cleansing but confidence intervals were wide and heterogeneity high (adjusted hazard ratio 1.88, 95%CI 0.53, 6.69, I2 83.2%). HIV incidence was higher in women with bacterial vaginosis (adjusted effect 1.57, 95%CI 1.26, 1.94, I2 19.0%) and Trichomonas vaginalis (adjusted effect 1.64, 95%CI 1.28, 2.09, I2 0.0%).
Conclusions/Significance
A pathway linking intravaginal cleaning practices with vaginal infections that increase susceptibility to HIV infection is plausible but conclusive evidence is lacking. Intravaginal practices do not appear to protect women from vaginal infections or HIV and some might be harmful.
doi:10.1371/journal.pone.0009119
PMCID: PMC2817741  PMID: 20161749
23.  Imported Malaria in Children in Industrialized Countries, 1992–2002 
Emerging Infectious Diseases  2009;15(2):185-191.
Children account for a considerable proportion of cases imported to the United States and Europe.
Children account for an appreciable proportion of total imported malaria cases, yet few studies have quantified these cases, identified trends, or suggested evidence-based prevention strategies for this group of travelers. We therefore sought to identify numbers of cases and deaths, Plasmodium species, place of malaria acquisition, preventive measures used, and national origin of malaria in children. We analyzed retrospective data from Australia, Denmark, France, Germany, Italy, Japan, the Netherlands, Sweden, Switzerland, the United Kingdom, and the United States and data provided by the United Nations World Tourism Organization. During 1992–2002, >17,000 cases of imported malaria in children were reported in 11 countries where malaria is not endemic; most (>70%) had been acquired in Africa. Returning to country of origin to visit friends and relatives was a risk factor. Malaria prevention for children should be a responsibility of healthcare providers and should be subsidized for low-income travelers to high-risk areas.
doi:10.3201/eid1502.080712
PMCID: PMC2657617  PMID: 19193261
pediatric; malaria; children; travel; research
24.  Emergence and Spread of Chlamydia trachomatis Variant, Sweden 
Emerging Infectious Diseases  2008;14(9):1462-1465.
A variant of Chlamydia trachomatis that had escaped detection by commonly used systems was discovered in Sweden in 2006. In a nationwide study, we found that it is now prevalent across Sweden, irrespective of the detection system used. Genetic analysis by multilocus sequence typing identified a predominant variant, suggesting recent emergence.
doi:10.3201/eid1409.080153
PMCID: PMC2603114  PMID: 18760021
Chlamydia trachomatis; Sweden; genetic variant; diagnostics; PCR; infectious diseases; epidemiology; surveillance; dispatch
25.  Cost effectiveness of home based population screening for Chlamydia trachomatis in the UK: economic evaluation of chlamydia screening studies (ClaSS) project 
BMJ : British Medical Journal  2007;335(7614):291.
Objective To investigate the cost effectiveness of screening for Chlamydia trachomatis compared with a policy of no organised screening in the United Kingdom.
Design Economic evaluation using a transmission dynamic mathematical model.
Setting Central and southwest England.
Participants Hypothetical population of 50 000 men and women, in which all those aged 16-24 years were invited to be screened each year.
Main outcome measures Cost effectiveness based on major outcomes averted, defined as pelvic inflammatory disease, ectopic pregnancy, infertility, or neonatal complications.
Results The incremental cost per major outcome averted for a programme of screening women only (assuming eight years of screening) was £22 300 (€33 000; $45 000) compared with no organised screening. For a programme screening both men and women, the incremental cost effectiveness ratio was approximately £28 900. Pelvic inflammatory disease leading to hospital admission was the most frequently averted major outcome. The model was highly sensitive to the incidence of major outcomes and to uptake of screening. When both were increased the cost effectiveness ratio fell to £6200 per major outcome averted for screening women only.
Conclusions Proactive register based screening for chlamydia is not cost effective if the uptake of screening and incidence of complications are based on contemporary empirical studies, which show lower rates than commonly assumed. These data are relevant to discussions about the cost effectiveness of the opportunistic model of chlamydia screening being introduced in England.
doi:10.1136/bmj.39262.683345.AE
PMCID: PMC1941857  PMID: 17656504

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