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1.  “It Is Like That, We Didn't Understand Each Other”: Exploring the Influence of Patient-Provider Interactions on Prevention of Mother-To-Child Transmission of HIV Service Use in Rural Tanzania 
PLoS ONE  2014;9(9):e106325.
Interactions between patients and service providers frequently influence uptake of prevention of mother-to-child transmission (PMTCT) HIV services in sub-Saharan Africa, but this process has not been examined in depth. This study explores how patient-provider relations influence PMTCT service use in four government facilities in Kisesa, Tanzania. Qualitative data were collected in 2012 through participatory group activities with community members (3 male, 3 female groups), in-depth interviews with 21 women who delivered recently (16 HIV-positive), 9 health providers, and observations in antenatal clinics. Data were transcribed, translated into English and analysed with NVIVO9 using an adapted theoretical model of patient-centred care. Three themes emerged: decision-making processes, trust, and features of care. There were few examples of shared decision-making, with a power imbalance in favour of providers, although they offered substantial psycho-social support. Unclear communication by providers, and patients not asking questions, resulted in missed services. Omission of pre-HIV test counselling was often noted, influencing women's ability to opt-out of HIV testing. Trust in providers was limited by confidentiality concerns, and some HIV-positive women were anxious about referrals to other facilities after establishing trust in their original provider. Good care was recounted by some women, but many (HIV-positive and negative) described disrespectful staff including discrimination of HIV-positive patients and scolding, particularly during delivery; exacerbated by lack of materials (gloves, sheets) and associated costs, which frustrated staff. Experienced or anticipated negative staff behaviour influenced adherence to subsequent PMTCT components. Findings revealed a pivotal role for patient-provider relations in PMTCT service use. Disrespectful treatment and lack of informed consent for HIV testing require urgent attention by PMTCT programme managers. Strategies should address staff behaviour, emphasizing ethical standards and communication, and empower patients to seek information about available services. Optimising provider-patient relations can improve uptake of maternal health services more broadly, and ART adherence.
PMCID: PMC4152246  PMID: 25180575
2.  The impact of voluntary counselling and testing services on sexual behaviour change and HIV incidence: observations from a cohort study in rural Tanzania 
BMC Infectious Diseases  2014;14:159.
It is widely assumed that voluntary counselling and testing (VCT) services contribute to HIV prevention by motivating clients to reduce sexual risk-taking. However, findings from sub-Saharan Africa have been mixed, particularly among HIV-negative persons. We explored associations between VCT use and changes in sexual risk behaviours and HIV incidence using data from a community HIV cohort study in northwest Tanzania.
Data on VCT use, sexual behaviour and HIV status were available from three HIV serological surveillance rounds undertaken in 2003–4 (Sero4), 2006–7 (Sero5) and 2010 (Sero6). We used multinomial logistic regression to assess changes in sexual risk behaviours between rounds, and Poisson regression to estimate HIV incidence.
The analyses included 3,613 participants attending Sero4 and Sero5 (3,474 HIV-negative and 139 HIV-positive at earlier round) and 2,998 attending Sero5 and Sero6 (2,858 HIV-negative and 140 HIV-positive at earlier round). Among HIV-negative individuals VCT use was associated with reductions in the number of sexual partners in the last year (aRR Seros 4–5: 1.42, 95% CI 1.07-1.88; aRR Seros 5–6: 1.68, 95% CI 1.25-2.26) and in the likelihood of having a non-cohabiting partner in the last year (aRR Seros 4–5: 1.57, 95% CI 1.10-2.25; aRR Seros 5–6: 1.48, 95% CI 1.07-2.04) or a high-risk partner in the last year (aRR Seros 5–6 1.57, 95% CI 1.06-2.31). However, VCT was also associated with stopping using condoms with non-cohabiting partners between Seros 4–5 (aRR 4.88, 95% CI 1.39-17.16). There were no statistically significant associations between VCT use and changes in HIV incidence, nor changes in sexual behaviour among HIV-positive individuals, possibly due to small sample sizes.
We found moderate associations between VCT use and reductions in some sexual risk behaviours among HIV-negative participants, but no impacts among HIV-positive individuals in the context of low overall VCT uptake. Furthermore, there were no significant changes in HIV incidence associated with VCT use, although declining background incidence and small sample sizes may have prevented us from detecting this. The impact of VCT services will ultimately depend upon rates of uptake, with further research required to better understand processes of behaviour change following VCT use.
PMCID: PMC3994406  PMID: 24655360
Voluntary counselling and testing; HIV; Sexual behaviour; Tanzania; Cohort study
3.  Using HIV-attributable mortality to assess the impact of antiretroviral therapy on adult mortality in rural Tanzania 
Global Health Action  2014;7:10.3402/gha.v7.21865.
The Tanzanian national HIV care and treatment programme has provided free antiretroviral therapy (ART) to HIV-positive persons since 2004. ART has been available to participants of the Kisesa open cohort study since 2005, but data to 2007 showed a slow uptake of ART and a modest impact on mortality. Additional data from the 2010 HIV serological survey provide an opportunity to update the estimated impact of ART in this setting.
The Kisesa Health and Demographic Surveillance Site (HDSS) has collected HIV serological data and demographic data, including verbal autopsy (VA) interviews since 1994. Serological data to the end of 2010 were used to make two estimates of HIV-attributable mortality, the first among HIV positives using the difference in mortality between HIV positives and HIV negatives, and the second in the population using the difference between the observed mortality rate in the whole population and the mortality rate among the HIV negatives. Four time periods (1994–1999, 2000–2004, 2005–2007, and 2008–2010) were used and HIV-attributable mortality estimates were analysed in detail for trends over time. A computer algorithm, InterVA-4, was applied to VA data to estimate the HIV-attributable mortality for the population, and this was compared to the estimates from the serological survey data.
Among HIV-positive adults aged 45–59 years, high mortality rates were observed across all time periods in both males and females. In HIV-positive men, the HIV-attributable mortality was 91.6% (95% confidence interval (CI): 84.6%–95.3%) in 2000–2004 and 86.3% (95% CI: 71.1%–93.3%) in 2008–2010, while among women, the HIV-attributable mortality was 87.8% (95% CI: 71.1%–94.3%) in 2000–2004 and 85.8% (95% CI: 59.6%–94.4%) in 2008–2010. In the whole population, using the serological data, the HIV-attributable mortality among men aged 30–44 years decreased from 57.2% (95% CI: 46.9%–65.3%) in 2000–2004 to 36.5% (95% CI: 18.8%–50.1%) in 2008–2010, while among women the corresponding decrease was from 57.3% (95% CI: 49.7%–63.6%) to 38.7% (95% CI: 27.4%–48.2%). The HIV-attributable mortality in the population using estimates from the InterVA model was lower than that from HIV sero-status data in the period prior to ART, but slightly higher once ART became available.
In the Kisesa HDSS, ART availability corresponds with a decline in adult overall mortality, although not as large as expected. Using InterVA to estimate HIV-attributable mortality showed smaller changes in HIV-related mortality following ART availability than the serological results.
PMCID: PMC3962553  PMID: 24656167
HIV-attributable mortality; ART; HDSS; InterVA model; serological survey; verbal autopsy
4.  Does the Spectrum model accurately predict trends in adult mortality? Evaluation of model estimates using empirical data from a rural HIV community cohort study in north-western Tanzania 
Global Health Action  2014;7:10.3402/gha.v7.21783.
Spectrum epidemiological models are used by UNAIDS to provide global, regional and national HIV estimates and projections, which are then used for evidence-based health planning for HIV services. However, there are no validations of the Spectrum model against empirical serological and mortality data from populations in sub-Saharan Africa.
Serologic, demographic and verbal autopsy data have been regularly collected among over 30,000 residents in north-western Tanzania since 1994. Five-year age-specific mortality rates (ASMRs) per 1,000 person years and the probability of dying between 15 and 60 years of age (45Q15,) were calculated and compared with the Spectrum model outputs. Mortality trends by HIV status are shown for periods before the introduction of antiretroviral therapy (1994–1999, 2000–2005) and the first 5 years afterwards (2005–2009).
Among 30–34 year olds of both sexes, observed ASMRs per 1,000 person years were 13.33 (95% CI: 10.75–16.52) in the period 1994–1999, 11.03 (95% CI: 8.84–13.77) in 2000–2004, and 6.22 (95% CI; 4.75–8.15) in 2005–2009. Among the same age group, the ASMRs estimated by the Spectrum model were 10.55, 11.13 and 8.15 for the periods 1994–1999, 2000–2004 and 2005–2009, respectively. The cohort data, for both sexes combined, showed that the 45Q15 declined from 39% (95% CI: 27–55%) in 1994 to 22% (95% CI: 17–29%) in 2009, whereas the Spectrum model predicted a decline from 43% in 1994 to 37% in 2009.
From 1994 to 2009, the observed decrease in ASMRs was steeper in younger age groups than that predicted by the Spectrum model, perhaps because the Spectrum model under-estimated the ASMRs in 30–34 year olds in 1994–99. However, the Spectrum model predicted a greater decrease in 45Q15 mortality than observed in the cohort, although the reasons for this over-estimate are unclear.
PMCID: PMC3895202  PMID: 24438873
HIV; adult mortality; Spectrum model; cohort
5.  Do accurate HIV and antiretroviral therapy knowledge, and previous testing experiences increase the uptake of HIV voluntary counselling and testing? Results from a cohort study in rural Tanzania 
BMC Public Health  2013;13:802.
Despite the introduction of free antiretroviral therapy (ART), the use of voluntary counselling and testing (VCT) services remains persistently low in many African countries. This study investigates how prior experience of HIV and VCT, and knowledge about HIV and ART influence VCT use in rural Tanzania.
In 2006–7, VCT was offered to study participants during the fifth survey round of an HIV community cohort study that includes HIV testing for research purposes without results disclosure, and a questionnaire covering knowledge, attitudes and practices around HIV infection and HIV services. Categorical variables were created for HIV knowledge and ART knowledge, with “good” HIV and ART knowledge defined as correctly answering at least 4/6 and 5/7 questions about HIV and ART respectively. Experience of HIV was defined as knowing people living with HIV, or having died from AIDS. Logistic regression methods were used to assess how HIV and ART knowledge, and prior experiences of HIV and VCT were associated with VCT uptake, with adjustment for HIV status and socio-demographic confounders.
2,695/3,886 (69%) men and 2,708/5,575 women (49%) had “good” HIV knowledge, while 613/3,886 (16%) men and 585/5575 (10%) women had “good” ART knowledge. Misconceptions about HIV transmission were common, including through kissing (55% of women, 43% of men), or mosquito bites (42% of women, 34% of men).
19% of men and 16% of women used VCT during the survey. After controlling for HIV status and socio-demographic factors, the odds of VCT use were lower among those with poor HIV knowledge (aOR = 0.5; p = 0.01 for men and aOR = 0.6; p < 0.01 for women) and poor ART knowledge (aOR = 0.8; p = 0.06 for men, aOR = 0.8; p < 0.01 for women), and higher among those with HIV experience (aOR = 1.3 for men and aOR = 1.6 for women, p < 0.01) and positive prior VCT experience (aOR = 2.0 for all men and aOR = 2.0 for HIV-negative women only, p < 0.001).
Two years after the introduction of free ART in this setting, misconceptions regarding HIV transmission remain rife and knowledge regarding treatment is worryingly poor, especially among women and HIV-positive people. Further HIV-related information, education and communication activities are urgently needed to improve VCT uptake in rural Tanzania.
PMCID: PMC3844310  PMID: 24007326
HIV; VCT; HIV testing; Tanzania; Cohort study
6.  Barriers and facilitating factors to the uptake of antiretroviral drugs for prevention of mother-to-child transmission of HIV in sub-Saharan Africa: a systematic review 
To investigate and synthesize reasons for low access, initiation and adherence to antiretroviral drugs by mothers and exposed babies for prevention of mother-to-child transmission (PMTCT) of HIV in sub-Saharan Africa.
A systematic literature review was conducted. Four databases were searched (Medline, Embase, Global Health and Web of Science) for studies conducted in sub-Saharan Africa from January 2000 to September 2012. Quantitative and qualitative studies were included that met pre-defined criteria. Antiretroviral (ARV) prophylaxis (maternal/infant) and combination antiretroviral therapy (ART) usage/registration at HIV care and treatment during pregnancy were included as outcomes.
Of 574 references identified, 40 met the inclusion criteria. Four references were added after searching reference lists of included articles. Twenty studies were quantitative, 16 were qualitative and eight were mixed methods. Forty-one studies were conducted in Southern and East Africa, two in West Africa, none in Central Africa and one was multi-regional. The majority (n=25) were conducted before combination ART for PMTCT was emphasized in 2006. At the individual-level, poor knowledge of HIV/ART/vertical transmission, lower maternal educational level and psychological issues following HIV diagnosis were the key barriers identified. Stigma and fear of status disclosure to partners, family or community members (community-level factors) were the most frequently cited barriers overall and across time. The extent of partner/community support was another major factor impeding or facilitating the uptake of PMTCT ARVs, while cultural traditions including preferences for traditional healers and birth attendants were also common. Key health-systems issues included poor staff-client interactions, staff shortages, service accessibility and non-facility deliveries.
Long-standing health-systems issues (such as staffing and service accessibility) and community-level factors (particularly stigma, fear of disclosure and lack of partner support) have not changed over time and continue to plague PMTCT programmes more than 10 years after their introduction. The potential of PMTCT programmes to virtually eliminate vertical transmission of HIV will remain elusive unless these barriers are tackled. The prominence of community-level factors in this review points to the importance of community-driven approaches to improve uptake of PMTCT interventions, although packages of solutions addressing barriers at different levels will be important.
PMCID: PMC3717402  PMID: 23870277
HIV; vertical transmission; prevention; barriers; review; Africa
7.  Low Rates of Repeat HIV Testing Despite Increased Availability of Antiretroviral Therapy in Rural Tanzania: Findings from 2003–2010 
PLoS ONE  2013;8(4):e62212.
HIV counselling and testing (HCT) services can play an important role in HIV prevention by encouraging safe sexual behaviours and linking HIV-infected clients to antiretroviral therapy (ART). However, regular repeat testing by high-risk HIV-negative individuals is important for timely initiation of ART as part of the ‘treatment as prevention’ approach.
To investigate HCT use during a round of HIV serological surveillance in northwest Tanzania in 2010, and to explore rates of repeat testing between 2003 and 2010.
HCT services were provided during the fourth, fifth and sixth rounds of serological surveillance in 2003–2004 (Sero-4), 2006–2007 (Sero-5) and 2010 (Sero-6). HCT services have also been available at a government-run health centre and at other clinics in the study area since 2005. Questionnaires administered during sero-surveys collected information on socio-demographic characteristics, sexual behaviour and reported previous use of HCT services.
The proportion of participants using HCT increased from 9.4% at Sero-4 to 16.6% at Sero-5 and 25.5% at Sero-6. Among participants attending all three sero-survey rounds (n = 2,010), the proportions using HCT twice or more were low, with 11.1% using the HCT service offered at sero-surveys twice or more, and 25.3% having tested twice or more if reported use of HCT outside of sero-surveys was taken into account. In multivariable analyses, individuals testing HIV-positive were less likely to repeat test than individuals testing HIV-negative (aOR 0.17, 95% CI 0.006–0.52).
Although HCT service use increased over time, it was disappointing that the proportions ever testing and ever repeat-testing were not even larger, considering the increasing availability of HCT and ART in the study area. There was some evidence that HIV-negative people with higher risk sexual behaviours were most likely to repeat test, which was encouraging in terms of the potential to pick-up those at greatest risk of HIV-infection.
PMCID: PMC3633850  PMID: 23626791
8.  Are integrated HIV services less stigmatizing than stand-alone models of care? A comparative case study from Swaziland 
Integrating HIV with primary health services has the potential to reduce HIV-related stigma through delivering care in settings disassociated with HIV. This study investigated the relationship between integrated care and felt stigma. The study design was a comparative case study of four models of HIV care in Swaziland, ranging from fully integrated to fully stand-alone HIV care.
An exit survey (N=602) measured differences in felt stigma across model of care; the primary outcome “perception of HIV status exposure through clinic attendance” was analyzed using multivariable logistic regression. In-depth interviews (N=22) explored whether and how measured differences in stigma experiences were related to service integration.
There were significant differences in perceived status exposure across models of care. After adjustment for potential confounding between sites, those at a partially integrated site and a partially stand-alone site had greater odds of perceived status exposure than those at the fully stand-alone site (aOR 3.33, 95% CI 1.98–5.60; and aOR 11.84, 95% CI 6.89–20.36, respectively). There was no difference between the fully stand-alone and the fully integrated clinic. Qualitative data suggested that many clients at HIV-only sites felt greater confidentiality knowing that those around them were positive, and support was gained from other HIV care clients. Confidentiality was maintained in various ways, even in stand-alone sites, through separate waiting areas for HIV testing and HIV treatment, and careful clinic and room labelling.
The relationship between model of care and stigma was complex, and the hypothesis that stigma is higher at stand-alone sites did not hold true in this high prevalence setting. Policy-makers should ensure that service integration does not increase stigma, in particular within partially integrated models of care.
PMCID: PMC3545202  PMID: 23336726
systems integration; health services research; stigma; HIV; primary care; reproductive health services
9.  Evaluation of knowledge levels amongst village AIDS committees after undergoing HIV educational sessions: results from a pilot study in rural Tanzania 
Village AIDS committees (VAC) were formed by the Tanzanian government in 2003 to provide HIV education to their communities. However, their potential has not been realised due to their limited knowledge and misconceptions surrounding HIV, which could be addressed through training of VAC members. In an attempt to increase HIV knowledge levels and address common misconceptions amongst the VACs, an HIV curriculum was delivered to members in rural north western Tanzania.
An evaluation of HIV knowledge was conducted prior to and post-delivery of HIV training sessions, within members of three VACs in Kisesa ward. Quantitative surveys were used with several open-ended questions to identify local misconceptions and evaluate HIV knowledge levels. Short educational training sessions covering HIV transmission, prevention and treatment were conducted, with each VAC using quizzes, role-plays and participatory learning and action tools. Post-training surveys occurred up to seven days after the final training session.
Before the training, "good" HIV knowledge was higher amongst men than women (p = 0.041), and among those with previous HIV education (p = 0.002). The trade-centre had a faster turn-over of VAC members, and proximity to the trade-centre was associated with a shorter time on the committee.
Training improved HIV knowledge levels with more members achieving a "good" score in the post-training survey compared with the baseline survey (p = < 0.001). The training programme was popular, with 100% of participants requesting further HIV training in the future and 51.7% requesting training at three-monthly intervals.
In this setting, a series of HIV training sessions for VACs demonstrated encouraging results, with increased HIV knowledge levels following short educational sessions. Further work is required to assess the success of VAC members in disseminating this HIV education to their communities, as well as up-scaling this pilot study to other regions in Tanzania with different misconceptions.
PMCID: PMC3262745  PMID: 22165999
10.  Barriers to Sustaining Antiretroviral Treatment in Kisesa, Tanzania 
AIDS patient care and STDs  2009;23(3):203-210.
Two years after the introduction of free antiretroviral therapy (ART) in Tanzania and in spite of the logistical support provided to facilitate clinic attendance, a considerable level of attrition from the program was identified among clients from a semi-rural ward. Qualitative research on ART patients’ health-seeking behavior identified factors affecting sustained attendance at treatment clinics. A mix of methods was used for data collection including semi-structured interviews with 42 clients and 11 service providers and 4 participatory group activities conducted with members of a post-test group between October and December 2006. A socio-ecological framework guided data analysis to categorize facilitators and barriers into individual, social, programmatic, and structural level influences, and subsequently explored their interaction and relative significance in shaping ART clients’ behavior. Our findings suggest that personal motivation and self-efficacy contribute to program retention, and are affected by other individual-level experiences such as perceived health benefits or disease severity. However, these determinants are influenced by others’ opinions and beliefs in the community, and constrained by programmatic and structural barriers. Individuals can develop the requisite willingness to sustain strict treatment requirements in a challenging context, but are more likely to do so within supportive family and community environments. Effectiveness and sustainability of ART roll-out could be strengthened by strategic intervention at different levels, with particular attention to community-level factors such as social networks’ influence and support.
PMCID: PMC2776987  PMID: 19866538
11.  From HIV diagnosis to treatment: evaluation of a referral system to promote and monitor access to antiretroviral therapy in rural Tanzania 
Individuals diagnosed with HIV in developing countries are not always successfully linked to onward treatment services, resulting in missed opportunities for timely initiation of antiretroviral therapy, or prophylaxis for opportunistic infections. In collaboration with local stakeholders, we designed and assessed a referral system to link persons diagnosed at a voluntary counselling and testing (VCT) clinic in a rural district in northern Tanzania with a government-run HIV treatment clinic in a nearby city.
Two-part referral forms, with unique matching numbers on each side were implemented to facilitate access to the HIV clinic, and were subsequently reconciled to monitor the proportion of diagnosed clients who registered for these services, stratified by sex and referral period. Delays between referral and registration at the HIV clinic were calculated, and lists of non-attendees were generated to facilitate tracing among those who had given prior consent for follow up.
Transportation allowances and a "community escort" from a local home-based care organization were introduced for patients attending the HIV clinic, with supportive counselling services provided by the VCT counsellors and home-based care volunteers. Focus group discussions and in-depth interviews were conducted with health care workers and patients to assess the acceptability of the referral procedures.
Referral uptake at the HIV clinic averaged 72% among men and 66% among women during the first three years of the national antiretroviral therapy (ART) programme, and gradually increased following the introduction of the transportation allowances and community escorts, but declined following a national VCT campaign. Most patients reported that the referral system facilitated their arrival at the HIV clinic, but expressed a desire for HIV treatment services to be in closer proximity to their homes. The referral forms proved to be an efficient and accepted method for assessing the effectiveness of the VCT clinic as an entry point for ART.
The referral system reduced delays in seeking care, and enabled the monitoring of access to HIV treatment among diagnosed persons. Similar systems to monitor referral uptake and linkages between HIV services could be readily implemented in other settings.
PMCID: PMC2788344  PMID: 19906291
12.  "Just like fever": a qualitative study on the impact of antiretroviral provision on the normalisation of HIV in rural Tanzania and its implications for prevention 
Once effective therapy for a previously untreatable condition is made available, a normalisation of the disease often occurs. As part of a broader initiative to monitor the implementation of the national antiretroviral therapy (ART) programme, this qualitative study investigated the impact of ART availability on perceptions of HIV in a rural ward of North Tanzania and its implications for prevention.
A mix of qualitative methods was used including semi-structured interviews with 53 ART clinic clients and service providers. Four group activities were conducted with persons living with HIV. Data were analyzed using the qualitative software package NVIVO-7.
People on ART often reported feeling increasingly comfortable with their status reflecting a certain "normalization" of the disease. This was attributed to seeing other people affected by HIV, regaining physical health, returning to productive activities and receiving emotional support from health service providers. Overcoming internalized feelings of shame facilitated disclosure of HIV status, helped to sustain treatment, and stimulated VCT uptake. However "blaming" stigma - where people living with HIV were considered responsible for acquiring a "moral disease" - persisted in the community and anticipating it was a key barrier to disclosure and VCT uptake. Attributing HIV symptoms to witchcraft seemed an effective mechanism to transfer "blame" from the family unit to an external force but could lead to treatment interruption.
As long as an HIV diagnosis continues to have moral connotations, a de-stigmatisation of HIV paralleling that occurring with diseases like cancer is unlikely to occur. Maximizing synergies between HIV treatment and prevention requires an enabling environment for HIV status disclosure, treatment continuation, and safer sexual behaviours. Local leaders should be informed and sensitised and communities mobilised to address the blame-dimension of HIV stigma.
PMCID: PMC2759900  PMID: 19740437
13.  Estimating the Extent of Vaccine-Derived Poliovirus Infection 
PLoS ONE  2008;3(10):e3433.
Eight outbreaks of paralytic polio attributable to circulating vaccine-derived poliovirus (cVDPV) have highlighted the risks associated with oral poliovirus vaccine (OPV) use in areas of low vaccination coverage and poor hygiene. As the Polio Eradication Initiative enters its final stages, it is important to consider the extent to which these viruses spread under different conditions, so that appropriate strategies can be devised to prevent or respond to future cVDPV outbreaks.
Methods and Findings
This paper examines epidemiological (temporal, geographic, age, vaccine history, social group, ascertainment), and virological (type, genetic diversity, virulence) parameters in order to infer the numbers of individuals likely to have been infected in each of these cVDPV outbreaks, and in association with single acute flaccid paralysis (AFP) cases attributable to VDPVs. Although only 114 virologically-confirmed paralytic cases were identified in the eight cVDPV outbreaks, it is likely that a minimum of hundreds of thousands, and more likely several million individuals were infected during these events, and that many thousands more have been infected by VDPV lineages within outbreaks which have escaped detection.
Our estimates of the extent of cVDPV circulation suggest widespread transmission in some countries, as might be expected from endemic wild poliovirus transmission in these same settings. These methods for inferring extent of infection will be useful in the context of identifying future surveillance needs, planning for OPV cessation and preparing outbreak response plans.
PMCID: PMC2570794  PMID: 18958288
14.  Using age-specific mortality of HIV infected persons to predict Anti-Retroviral Treatment need: a comparative analysis of data from five African population-based cohort studies 
To present a simple method for estimating population-level anti-retroviral therapy (ART) need that does not rely on knowledge of past HIV incidence.
A new approach to estimating ART need is developed based on calculating age-specific proportions of HIV-infected adults expected to die within a fixed number of years in the absence of treatment. Mortality data for HIV-infected adults in the pre-treatment era from five African HIV cohort studies were combined to construct a life table, starting at age 15, smoothed with a Weibull model. Assuming that ART should be made available to anyone expected to die within 3 years, conditional 3-year survival probabilities were computed to represent proportions needing ART. The build-up of ART need in a successful programme continuously recruiting infected adults into treatment as they age to within 3 years of expected death was represented by annually extending the conditional survival range.
The Weibull model: survival probability in the infected state from age 15 = exp(−0.0073 × (age − 15)1.69) fitted the pooled age-specific mortality data very closely. Initial treatment need for infected persons increased rapidly with age, from 15% at age 20–24 to 32% at age 40–44 and 42% at age 60–64. Overall need in the treatment of naïve population was 24%, doubling within 5 years in a programme continually recruiting patients entering the high-risk period for dying.
A reasonable projection of treatment need in an ART naive population can be made based on the age and gender profile of HIV-infected people.
PMCID: PMC3443363  PMID: 22943377
antiretroviral therapy; lifetable models; AIDS; HIV; cohort studies; mortality; Africa
15.  Trends in the uptake of voluntary counselling and testing for HIV in rural Tanzania in the context of the scale up of antiretroviral therapy 
To describe trends in voluntary counselling and testing (VCT) use and to assess whether high-risk and infected individuals are receiving counselling and learning their HIV status in rural Tanzania.
During two rounds of linked serological surveys (2003–2004 and 2006–2007) with anonymous HIV testing among adults, VCT was offered to all participants. The crude and adjusted odds ratios for completing VCT in each survey were calculated to compare uptake by demographic, behavioural and clinical characteristics, stratified by sex. Repeat testing patterns were also investigated.
The proportion of participants completing VCT increased from 10% in 2003–2004 to 17% in 2006–2007, and among HIV-infected persons from 14% to 25%. A higher proportion of men than women completed VCT in both rounds, but the difference declined over time. Socio-demographic and behavioural factors associated with VCT completion were similar across rounds, including higher adjusted odds of VCT with increasing numbers of sexual partners in the past 12 months. The proportion having ever-completed VCT reached 26% among 2006–2007 attendees, with repeat testing rates highest among those aged 35–44 years. Among 3923 participants attending both rounds, VCT completion in 2006–2007 was 17% among 3702 who were HIV negative in both rounds, 19% among 124 who were HIV infected in both rounds and 22% among 96 who seroconverted between rounds.
VCT services are attracting HIV-infected and high-risk individuals. However, 2 years after the introduction of antiretroviral therapy, the overall uptake remains low. Intensive mobilisation efforts are needed to achieve regular and universal VCT use.
PMCID: PMC3443372  PMID: 22943375
voluntary counselling and testing; HIV; Tanzania; cohort study
16.  The impact of antiretroviral therapy on adult mortality in rural Tanzania 
To describe the impact of antiretroviral therapy (ART) on mortality rates among adults participating in an HIV community cohort study in north-west Tanzania.
Serological and demographic surveillance rounds have been undertaken in a population of approximately 30 000 people since 1994. Free HIV care including ART has been available since 2005. Event history analysis was used to compare mortality rates among HIV-negative and HIV-positive adults in the 5-year period before and after the introduction of ART. Crude and adjusted hazard ratios were calculated using exponential regression models. Interaction between time period and HIV status was assessed to investigate whether there was a non-linear relationship between these two variables.
Male and female mortality patterns varied over the pre- and post-ART period. In women, the crude death rate fell for both HIV negatives and HIV positives hazard rate ratio (HRR = 0.71; 95%CI 0.51–0.99 and HRR = 0.68; 95%CI: 0.46–0.99, respectively). For men, the mortality among the HIV negatives increased (HRR = 1.47; 95%CI: 1.06–2.03) while the decline in mortality among the HIV positives (HRR = 0.77; 95%CI 0.52–1.13) was not statistically significant. The largest decrease in HIV-positive mortality over the two periods was among the 30- to 44-year-old age group for women and among the 45- to 59-year-old age group for men.
There has been a modest effect on mortality in the study population following the introduction of free ART 5 years ago. Improving access to treatment and placing greater focus on retaining individuals on treatment are essential if the full potential of treatment for reducing HIV-related mortality is to be realised.
PMCID: PMC3443374  PMID: 22943380
antiretroviral therapy; HIV; mortality; cohort; Tanzania
17.  Antiretroviral therapy uptake and coverage in four HIV community cohort studies in sub-Saharan Africa 
To compare socio-demographic patterns in access to antiretroviral therapy (ART) across four community HIV cohort studies in Africa.
Data on voluntary counselling and testing and ART use among HIV-infected persons were analysed from Karonga (Malawi), Kisesa (Tanzania), Masaka (Uganda) and Manicaland (Zimbabwe), where free ART provision started between 2004 and 2007. ART coverage was compared across sites by calculating the proportion on ART among those estimated to need treatment, by age, sex and educational attainment. Logistic regression was used to identify socio-demographic characteristics associated with undergoing eligibility screening at an ART clinic within 2 years of being diagnosed with HIV, for three sites with information on diagnosis and screening dates.
Among adults known to be HIV-infected from serological surveys, the proportion who knew their HIV status was 93% in Karonga, 37% in Kisesa, 46% in Masaka and 25% in Manicaland. Estimated ART coverage was highest in Masaka (68%) and lowest in Kisesa (2%). The proportion of HIV-diagnosed persons who were screened for ART eligibility within 2 years of diagnosis ranged from 14% in Kisesa to 84% in Masaka, with the probability of screening uptake increasing with age at diagnosis in all sites.
Higher HIV testing rates among HIV-infected persons in the community do not necessarily correspond with higher uptake of ART, nor more equitable treatment coverage among those in need of treatment. In all sites, young adults tend to be disadvantaged in terms of accessing and initiating ART, even after accounting for their less urgent need.
PMCID: PMC3443383  PMID: 22943378
antiretroviral therapy; access; coverage; sub-Saharan Africa
18.  The effect of antiretroviral therapy provision on all-cause, AIDS and non-AIDS mortality at the population level – a comparative analysis of data from four settings in Southern and East Africa 
To provide a broad and up-to-date picture of the effect of antiretroviral therapy (ART) provision on population-level mortality in Southern and East Africa.
Data on all-cause, AIDS and non-AIDS mortality among 15–59 year olds were analysed from demographic surveillance sites (DSS) in Karonga (Malawi), Kisesa (Tanzania), Masaka (Uganda) and the Africa Centre (South Africa), using Poisson regression. Trends over time from up to 5 years prior to ART roll-out, to 4–6 years afterwards, are presented, overall and by age and sex. For Masaka and Kisesa, trends are analysed separately for HIV-negative and HIV-positive individuals. For Karonga and the Africa Centre, trends in AIDS and non-AIDS mortality are analysed using verbal autopsy data.
For all-cause mortality, overall rate ratios (RRs) comparing the period 2–6 years following ART roll-out with the pre-ART period were 0.58 (5.9 vs. 10.2 deaths per 1000 person-years) in Karonga, 0.79 (7.2 vs. 9.1 deaths per 1000 person-years) in Kisesa, 0.61 (6.7 compared with 11.0 deaths per 1000 person-years) in Masaka and 0.79 (14.8 compared with 18.6 deaths per 1000 person-years) in the Africa Centre DSS. The mortality decline was seen only in HIV-positive individuals/AIDS mortality, with no decline in HIV-negative individuals/non-AIDS mortality. Less difference was seen in Kisesa where ART uptake was lower.
Falls in all-cause mortality are consistent with ART uptake. The largest falls occurred where ART provision has been decentralised or available locally, suggesting that this is important.
PMCID: PMC3443384  PMID: 22943383
antiretroviral therapy; mortality; sub-Saharan Africa
19.  Reliance on condoms for contraceptive protection among HIV care and treatment clients: a mixed methods study on contraceptive choice and motivation within a generalised epidemic 
Sexually Transmitted Infections  2014;90(5):394-400.
To (i) describe the contraceptive practices of HIV care and treatment (HCTx) clients in Manzini, Swaziland, including their unmet needs for family planning (FP), and compare these with population-level estimates; and (ii) qualitatively explore the causal factors influencing contraceptive choice and use.
Mixed quantitative and qualitative methods were used. A cross-sectional survey conducted among HCTx clients (N=611) investigated FP and condom use patterns. Using descriptive statistics, findings were compared with population-level estimates derived from Swaziland Demographic and Health Survey data, weighted for clustering. In-depth interviews were conducted with HCTx providers (n=16) and clients (n=22) and analysed thematically.
64% of HCTx clients reported current contraceptive use; most relied on condoms alone, few practiced dual method use. Rates of condom use for FP among female HCTx clients (77%, 95% CI 71% to 82%) were higher than population-level estimates in the study region (50% HIV-positive, 95% CI 43% to 57%; 37% HIV-negative, 95% CI 31% to 43%); rates of unmet FP needs were similar when condom use consistency was accounted for (32% HCTx, 95% CI 26% to 37%; vs 35% HIV-positive, 95% CI 28% to 43%; 29% HIV-negative, 95% CI 24% to 35%). Qualitative analysis identified motivational factors influencing FP choice: fears of reinfection; a programmatic focus on condoms for people living with HIV; changing sexual behaviours before and after antiretroviral therapy (ART) initiation; failure to disclose to partners; and contraceptive side effect fears.
Fears of reinfection prevailed over consideration of pregnancy risk. Given current evidence on reinfection, HCTx services must move beyond a narrow focus on condom promotion, particularly for those in seroconcordant relationships, and consider diverse strategies to meet reproductive needs.
PMCID: PMC4112496  PMID: 24695990

Results 1-19 (19)