Rapid elimination of cervical cancer while maintaining the harms and benefits ratio of cervical cancer screening: a modelling study.

BACKGROUND: Human papillomavirus (HPV) vaccination and intensifying screening expedite cervical cancer (CC) elimination, yet also deteriorate the balance between harms and benefits of screening. We aimed to find screening strategies that eliminate CC rapidly but maintain an acceptable harms-benefits ratio of screening. METHODS: Two microsimulation models (STDSIM and MISCAN) were applied to simulate HPV transmission and CC screening for the Dutch female population between 2022 and 2100. We estimated the CC elimination year and harms-benefits ratios of screening for 228 unique scenarios varying in vaccination (coverage and vaccine type) and screening (coverage and number of lifetime invitations in vaccinated cohorts). The acceptable harms-benefits ratio was defined as the number of women needed to refer (NNR) to prevent one CC death under the current programme for unvaccinated cohorts (82.17). RESULTS: Under current vaccination conditions (bivalent vaccine, 55% coverage in girls, 27.5% coverage in boys), maintaining current screening conditions is projected to eliminate CC by 2042, but increases the present NNR with 41%. Reducing the number of lifetime screens from presently five to three and increasing screening coverage (61% to 70%) would prevent an increase in harms and only delay elimination by 1 year. Scaling vaccination coverage to 90% in boys and girls with the nonavalent vaccine is estimated to eliminate CC by 2040 under current screening conditions, but exceeds the acceptable NNR with 23%. Here, changing from five to two lifetime screens would keep the NNR acceptable without delaying CC elimination. CONCLUSIONS: De-intensifying CC screening in vaccinated cohorts leads to little or no delay in CC elimination while it substantially reduces the harms of screening. Therefore, de-intensifying CC screening in vaccinated cohorts should be considered to ensure acceptable harms-benefits ratios on the road to CC elimination.

No increased HIV risk in general population near sex work sites: A nationally representative cross-sectional study in Zimbabwe.

OBJECTIVES: Sex work sites have been hypothesised to be at the root of the observed heterogeneity in HIV prevalence in sub-Saharan Africa. We determined if proximity to sex work sites is associated with HIV prevalence among the general population in Zimbabwe, a country with one of the highest HIV prevalence in the world. METHODS: In this cross-sectional study we use a unique combination of nationally representative geolocated individual-level data from 16,121 adults (age 15-49 years) from 400 sample locations and the locations of 55 sex work sites throughout Zimbabwe; covering an estimated 95% of all female sex workers (FSWs). We calculated the shortest distance by road from each survey sample location to the nearest sex work site, for all sites and by type of sex work site, and conducted univariate and multivariate multilevel logistic regressions to determine the association between distance to sex work sites and HIV seropositivity, controlling for age, sex, male circumcision status, number of lifetime sex partners, being a FSW client or being a stable partner of an FSW client. RESULTS: We found no significant association between HIV seroprevalence and proximity to the nearest sex work site among the general population in Zimbabwe, regardless of which type of site is closest (city site adjusted odds ratio [aOR] 1.010 [95% confidence interval {CI} 0.992-1.028]; economic growth point site aOR 0.982 [95% CI 0.962-1.002]; international site aOR 0.995 [95% CI 0.979-1.012]; seasonal site aOR 0.987 [95% CI 0.968-1.006] and transport site aOR 1.007 [95% CI 0.987-1.028]). Individual-level indicators of sex work were significantly associated with HIV seropositivity: being an FSW client (aOR 1.445 [95% CI 1.188-1.745]); nine or more partners versus having one to three lifetime partners (aOR 2.072 [95% CI 1.654-2.596]). CONCLUSIONS: Sex work sites do not seem to directly affect HIV prevalence among the general population in surrounding areas. Prevention and control interventions for HIV at these locations should primarily focus on sex workers and their clients, with special emphasis on including and retaining mobile sex workers and clients into services.

Evidence-based policymaking when evidence is incomplete: The case of HIV programme integration.

Jan Hontelez and co-authors discuss the use of different types of evidence to inform HIV program integration.

Integrating HIV services and other health services: A systematic review and meta-analysis.

BACKGROUND: Integration of HIV services with other health services has been proposed as an important strategy to boost the sustainability of the global HIV response. We conducted a systematic and comprehensive synthesis of the existing scientific evidence on the impact of service integration on the HIV care cascade, health outcomes, and cost-effectiveness. METHODS AND FINDINGS: We reviewed the global quantitative empirical evidence on integration published between 1 January 2010 and 10 September 2021. We included experimental and observational studies that featured both an integration intervention and a comparator in our review. Of the 7,118 unique peer-reviewed English-language studies that our search algorithm identified, 114 met all of our selection criteria for data extraction. Most of the studies (90) were conducted in sub-Saharan Africa, primarily in East Africa (55) and Southern Africa (24). The most common forms of integration were (i) HIV testing and counselling added to non-HIV services and (ii) non-HIV services added to antiretroviral therapy (ART). The most commonly integrated non-HIV services were maternal and child healthcare, tuberculosis testing and treatment, primary healthcare, family planning, and sexual and reproductive health services. Values for HIV care cascade outcomes tended to be better in integrated services: uptake of HIV testing and counselling (pooled risk ratio [RR] across 37 studies: 1.67 [95% CI 1.41-1.99], p < 0.001), ART initiation coverage (pooled RR across 19 studies: 1.42 [95% CI 1.16-1.75], p = 0.002), time until ART initiation (pooled RR across 5 studies: 0.45 [95% CI 0.20-1.00], p = 0.050), retention in HIV care (pooled RR across 19 studies: 1.68 [95% CI 1.05-2.69], p = 0.031), and viral suppression (pooled RR across 9 studies: 1.19 [95% CI 1.03-1.37], p = 0.025). Also, treatment success for non-HIV-related diseases and conditions and the uptake of non-HIV services were commonly higher in integrated services. We did not find any significant differences for the following outcomes in our meta-analyses: HIV testing yield, ART adherence, HIV-free survival among infants, and HIV and non-HIV mortality. We could not conduct meta-analyses for several outcomes (HIV infections averted, costs, and cost-effectiveness), because our systematic review did not identify sufficient poolable studies. Study limitations included possible publication bias of studies with significant or favourable findings and comparatively weak evidence from some world regions and on integration of services for key populations in the HIV response. CONCLUSIONS: Integration of HIV services and other health services tends to improve health and health systems outcomes. Despite some scientific limitations, the global evidence shows that service integration can be a valuable strategy to boost the sustainability of the HIV response and contribute to the goal of 'ending AIDS by 2030', while simultaneously supporting progress towards universal health coverage.

Mapping and characterising areas with high levels of HIV transmission in sub-Saharan Africa: A geospatial analysis of national survey data.

BACKGROUND: In the generalised epidemics of sub-Saharan Africa (SSA), human immunodeficiency virus (HIV) prevalence shows patterns of clustered micro-epidemics. We mapped and characterised these high-prevalence areas for young adults (15-29 years of age), as a proxy for areas with high levels of transmission, for 7 countries in Eastern and Southern Africa: Kenya, Malawi, Mozambique, Tanzania, Uganda, Zambia, and Zimbabwe. METHODS AND FINDINGS: We used geolocated survey data from the most recent United States Agency for International Development (USAID) demographic and health surveys (DHSs) and AIDS indicator surveys (AISs) (collected between 2008-2009 and 2015-2016), which included about 113,000 adults-of which there were about 53,000 young adults (27,000 women, 28,000 men)-from over 3,500 sample locations. First, ordinary kriging was applied to predict HIV prevalence at unmeasured locations. Second, we explored to what extent behavioural, socioeconomic, and environmental factors explain HIV prevalence at the individual- and sample-location level, by developing a series of multilevel multivariable logistic regression models and geospatially visualising unexplained model heterogeneity. National-level HIV prevalence for young adults ranged from 2.2% in Tanzania to 7.7% in Mozambique. However, at the subnational level, we found areas with prevalence among young adults as high as 11% or 15% alternating with areas with prevalence between 0% and 2%, suggesting the existence of areas with high levels of transmission Overall, 15.6% of heterogeneity could be explained by an interplay of known behavioural, socioeconomic, and environmental factors. Maps of the interpolated random effect estimates show that environmental variables, representing indicators of economic activity, were most powerful in explaining high-prevalence areas. Main study limitations were the inability to infer causality due to the cross-sectional nature of the surveys and the likely under-sampling of key populations in the surveys. CONCLUSIONS: We found that, among young adults, micro-epidemics of relatively high HIV prevalence alternate with areas of very low prevalence, clearly illustrating the existence of areas with high levels of transmission. These areas are partially characterised by high economic activity, relatively high socioeconomic status, and risky sexual behaviour. Localised HIV prevention interventions specifically tailored to the populations at risk will be essential to curb transmission. More fine-scale geospatial mapping of key populations,-such as sex workers and migrant populations-could help us further understand the drivers of these areas with high levels of transmission and help us determine how they fuel the generalised epidemics in SSA.

Evidence for scaling up HIV treatment in sub-Saharan Africa: A call for incorporating health system constraints.

Jan Hontelez and colleagues argue that the cost-effectiveness studies of HIV treatment scale-up need to include health system constraints to be more informative.

Behavioural disinhibition in the general population during the antiretroviral therapy roll-out in Sub-Saharan Africa: systematic review and meta-analysis.

OBJECTIVES: Improved life expectancy and reduced transmission probabilities due to ART may result in behavioural disinhibition - that is an increase in sexual risk behaviour in response to a perceived lower risk of HIV. We examined trends in sexual risk behaviour in the general population of sub-Saharan African countries 1999-2015. METHODS: We systematically reviewed scientific literature of sexual behaviour and reviewed trends in Demographic and Health Surveys. A meta-analysis on four indicators of sexual risk behaviour was performed: unprotected sex, multiple sexual partners, commercial sex and prevalence of sexually transmitted infections. RESULTS: Only two peer-reviewed studies met our inclusion criteria, while our review of DHS data spanned 18 countries and 16 years (1999-2015). We found conflicting trends in sexual risk behaviour. Reported unprotected sex decreased consistently across the 18 countries, for both sexes. In contrast, reporting multiple partners was decreasing over the period 1999 to the mid-2000s, yet has been consistently increasing thereafter. Similar trends were found for reported sexually transmitted infections and commercial sex (men only). CONCLUSIONS: In conclusion, we found no clear evidence of behavioural disinhibition due to expanded access to ART in sub-Saharan Africa. Substantial increases in condom use coincided with increases in reported multiple partners, commercial sex and sexually transmitted infections, especially during the period of ART scale-up. Further research is needed into how these changes might affect HIV transmission.

Public Health Benefits of Routine Human Papillomavirus Vaccination for Adults in the Netherlands: A Mathematical Modeling Study.

BACKGROUND: Expanding routine human papillomavirus (HPV) vaccination to adults could be an effective strategy to improve prevention of HPV infection and cervical cancer. METHODS: We evaluated the following adult vaccination strategies for women only and for both women and men in addition to the current girls-only vaccination program in the Netherlands, using the established STDSIM microsimulation model: one-time mass campaign, vaccination at the first cervical cancer screening visit, vaccination at sexual health clinics, and combinations of these strategies. RESULTS: The estimated impact of expanding routine vaccination to adult women is modest, with the largest incremental reductions in the incidence of HPV infection occurring when offering vaccination both at the cervical cancer screening visit and during sexually transmitted infection (STI) consultations (about 20% lower after 50 years for both HPV-16 and HPV-18). Adding male vaccination during STI consultations leads to more-substantial incidence reductions: 63% for HPV-16 and 84% for HPV-18. The incremental number needed to vaccinate among women is 5.48, compared with 0.90 for the current vaccination program. CONCLUSIONS: Offering vaccination to adults, especially at cervical cancer screening visits (for women) and during STI consultations (for both sexes), would substantially reduce HPV incidence and would be an efficient policy option to improve HPV prevention and subsequently avert cervical and possibly male HPV-related cancers.

Elimination of HIV in South Africa through expanded access to antiretroviral therapy: a model comparison study.

BACKGROUND: Expanded access to antiretroviral therapy (ART) using universal test and treat (UTT) has been suggested as a strategy to eliminate HIV in South Africa within 7 y based on an influential mathematical modeling study. However, the underlying deterministic model was criticized widely, and other modeling studies did not always confirm the study's finding. The objective of our study is to better understand the implications of different model structures and assumptions, so as to arrive at the best possible predictions of the long-term impact of UTT and the possibility of elimination of HIV. METHODS AND FINDINGS: We developed nine structurally different mathematical models of the South African HIV epidemic in a stepwise approach of increasing complexity and realism. The simplest model resembles the initial deterministic model, while the most comprehensive model is the stochastic microsimulation model STDSIM, which includes sexual networks and HIV stages with different degrees of infectiousness. We defined UTT as annual screening and immediate ART for all HIV-infected adults, starting at 13% in January 2012 and scaled up to 90% coverage by January 2019. All models predict elimination, yet those that capture more processes underlying the HIV transmission dynamics predict elimination at a later point in time, after 20 to 25 y. Importantly, the most comprehensive model predicts that the current strategy of ART at CD4 count ≤350 cells/µl will also lead to elimination, albeit 10 y later compared to UTT. Still, UTT remains cost-effective, as many additional life-years would be saved. The study's major limitations are that elimination was defined as incidence below 1/1,000 person-years rather than 0% prevalence, and drug resistance was not modeled. CONCLUSIONS: Our results confirm previous predictions that the HIV epidemic in South Africa can be eliminated through universal testing and immediate treatment at 90% coverage. However, more realistic models show that elimination is likely to occur at a much later point in time than the initial model suggested. Also, UTT is a cost-effective intervention, but less cost-effective than previously predicted because the current South African ART treatment policy alone could already drive HIV into elimination. Please see later in the article for the Editors' Summary.

HIV prevalence, risk behaviour, and treatment and prevention cascade outcomes among cisgender men, transgender women, and transgender men who sell sex in Zimbabwe: a cross-sectional analysis of programme data.

BACKGROUND: There is a paucity of evidence on HIV vulnerabilities and service engagements among people who sell sex in sub-Saharan Africa and identify as cisgender men, transgender women, or transgender men. We aimed to describe sexual risk behaviours, HIV prevalence, and access to HIV services among cisgender men, transgender women, and transgender men who sell sex in Zimbabwe. METHODS: We did a cross-sectional analysis of routine programme data that were collected between July 1, 2018, and June 30, 2020, from cisgender men who sell sex, transgender women who sell sex, and transgender men who sell sex, as part of accessing sexual and reproductive health and HIV services provided through the Sisters with a Voice programme, at 31 sites across Zimbabwe. All people who sell sex reached by the programme had routine data collected, including routine HIV testing, and were referred using a network of peer educators. Sexual risk behaviours, HIV prevalence, and HIV services uptake during the period from July, 2018, to June, 2020, were analysed through descriptive statistics by gender group. FINDINGS: A total of 1003 people who sell sex were included in our analysis: 423 (42·2%) cisgender men, 343 (34·2%) transgender women, and 237 (23·6%) transgender men. Age-standardised HIV prevalence estimates were 26·2% (95% CI 22·0-30·7) among cisgender men, 39·4% (34·1-44·9) among transgender women, and 38·4% (32·1-45·0) among transgender men. Among people living with HIV, 66·0% (95% CI 55·7-75·3) of cisgender men, 74·8% (65·8-82·4) of transgender women, and 70·2% (59·3-79·7) of transgender men knew their HIV status, and 15·5% (8·9-24·2), 15·7% (9·5-23·6), and 11·9% (5·9-20·8) were on antiretroviral therapy, respectively. Self-reported condom use was consistently low across gender groups, ranging from 26% (95% CI 22-32) for anal sex among transgender women to 32% (27-37) for vaginal sex among cisgender men. INTERPRETATION: These unique data show that people who sell sex and identify as cisgender men, transgender women, or transgender men in sub-Saharan Africa have high HIV prevalences and risk of infection, with alarmingly low access to HIV prevention, testing, and treatment services. There is an urgent need for people-centred HIV interventions for these high-risk groups and for more inclusive HIV policies and research to ensure we truly attain universal access for all. FUNDING: Aidsfonds Netherlands.

HIV treatment as prevention: systematic comparison of mathematical models of the potential impact of antiretroviral therapy on HIV incidence in South Africa.

BACKGROUND: Many mathematical models have investigated the impact of expanding access to antiretroviral therapy (ART) on new HIV infections. Comparing results and conclusions across models is challenging because models have addressed slightly different questions and have reported different outcome metrics. This study compares the predictions of several mathematical models simulating the same ART intervention programmes to determine the extent to which models agree about the epidemiological impact of expanded ART. METHODS AND FINDINGS: Twelve independent mathematical models evaluated a set of standardised ART intervention scenarios in South Africa and reported a common set of outputs. Intervention scenarios systematically varied the CD4 count threshold for treatment eligibility, access to treatment, and programme retention. For a scenario in which 80% of HIV-infected individuals start treatment on average 1 y after their CD4 count drops below 350 cells/µl and 85% remain on treatment after 3 y, the models projected that HIV incidence would be 35% to 54% lower 8 y after the introduction of ART, compared to a counterfactual scenario in which there is no ART. More variation existed in the estimated long-term (38 y) reductions in incidence. The impact of optimistic interventions including immediate ART initiation varied widely across models, maintaining substantial uncertainty about the theoretical prospect for elimination of HIV from the population using ART alone over the next four decades. The number of person-years of ART per infection averted over 8 y ranged between 5.8 and 18.7. Considering the actual scale-up of ART in South Africa, seven models estimated that current HIV incidence is 17% to 32% lower than it would have been in the absence of ART. Differences between model assumptions about CD4 decline and HIV transmissibility over the course of infection explained only a modest amount of the variation in model results. CONCLUSIONS: Mathematical models evaluating the impact of ART vary substantially in structure, complexity, and parameter choices, but all suggest that ART, at high levels of access and with high adherence, has the potential to substantially reduce new HIV infections. There was broad agreement regarding the short-term epidemiologic impact of ambitious treatment scale-up, but more variation in longer term projections and in the efficiency with which treatment can reduce new infections. Differences between model predictions could not be explained by differences in model structure or parameterization that were hypothesized to affect intervention impact.

Costs, effects and cost-effectiveness of breast cancer control in Ghana.

OBJECTIVE: Breast cancer control in Ghana is characterised by low awareness, late-stage treatment and poor survival. In settings with severely constrained health resources, there is a need to spend money wisely. To achieve this and to guide policy makers in their selection of interventions, this study systematically compares costs and effects of breast cancer control interventions in Ghana. METHODS: We used a mathematical model to estimate costs and health effects of breast cancer interventions in Ghana from the healthcare perspective. Analyses were based on the WHO-CHOICE method, with health effects expressed in disability-adjusted life years (DALYs), costs in 2009 US dollars (US$) and cost-effectiveness ratios (CERs) in US$ per DALY averted. Analyses were based on local demographic, epidemiological and economic data, to the extent these data were available. RESULTS: Biennial screening by clinical breast examination (CBE) of women aged 40-69 years, in combination with treatment of all stages, seems the most cost-effective intervention (costing $1299 per DALY averted). The intervention is also economically attractive according to international standards on cost-effectiveness. Mass media awareness raising (MAR) is the second best option (costing $1364 per DALY averted). Mammography screening of women of aged 40-69 years (costing $12,908 per DALY averted) cannot be considered cost-effective. CONCLUSIONS: Both CBE screening and MAR seem economically attractive interventions. Given the uncertainty about the effectiveness of these interventions, only their phased introduction, carefully monitored and evaluated, is warranted. Moreover, their implementation is only meaningful if the capacity of basic cancer diagnostic, referral and treatment and possibly palliative services is simultaneously improved.

HIV prevalence among men who have sex with men, transgender women and cisgender male sex workers in sub-Saharan Africa: a systematic review and meta-analysis.

INTRODUCTION: Developing effective targets, policies and services for key populations requires estimations of population sizes and HIV prevalence across countries and regions. We estimated the relative and absolute HIV prevalence among men who have sex with men (MSM), transgender women and men, and male and transgender sex workers (MSW and TGSW) in sub-Saharan African countries using peer-reviewed literature. METHODS: We performed a systematic review of peer-reviewed studies assessing HIV prevalence in MSM, transgender women and men, MSW and TGSW in sub-Saharan Africa between 2010 and 2021, following PRISMA guidelines. We searched Embase, Medline Epub, Africa Index Medicus, Africa Journal Online, Web of Science and Google Scholar. We calculated HIV prevalence ratios (PRs) between the study prevalence, and the geospatial-, sex, time and age-matched general population prevalence. We extrapolated results for MSM and transgender women to estimate HIV prevalence and the number living with HIV for each country in sub-Saharan Africa using pooled review results, and regression approximations for countries with no peer-reviewed data. RESULTS AND DISCUSSION: We found 44 articles assessing HIV prevalence in MSM, 10 in transgender women, five in MSW and zero in transgender men and TGSW. Prevalence among MSM and transgender women was significantly higher compared to the general population: PRs of 11.3 [CI: 9.9-12.9] for MSM and 8.1 [CI: 6.9-9.6] for transgender women in Western and Central Africa, and, respectively, 1.9 [CI: 1.7-2.0] and 2.1 [CI: 1.9-2.4] in Eastern and Southern Africa. Prevalence among MSW was significantly higher in both Nigeria (PR: 12.4 [CI: 7.3-21.0]) and Kenya (PR: 8.6 [CI: 4.6-15.6]). Extrapolating our findings for MSM and transgender women resulted in an estimated HIV prevalence of 15% or higher for about 60% of all sub-Saharan African countries for MSM, and for all but two countries for transgender women. CONCLUSIONS: HIV prevalence among MSM and transgender women throughout sub-Saharan Africa is alarmingly high. This high prevalence, coupled with the specific risks and vulnerabilities faced by these populations, highlights the urgent need for risk-group-tailored prevention and treatment interventions across the sub-continent. There is a clear gap in knowledge on HIV prevalence among transgender men, MSW and TGSW in sub-Saharan Africa.

The Differential Risk of Cervical Cancer in HPV-Vaccinated and -Unvaccinated Women: A Mathematical Modeling Study.

BACKGROUND: With increased uptake of vaccination against human papillomavirus (HPV), protection against cervical cancer will also increase for unvaccinated women, due to herd immunity. Still, the differential risk between vaccinated and unvaccinated women might warrant a vaccination-status-screening approach. To understand the potential value of stratified screening protocols, we estimated the risk differentials in HPV and cervical cancer between vaccinated and unvaccinated women. METHODS: We used STDSIM, an individual-based model of HPV transmission and control, to estimate the HPV prevalence reduction over time, after introduction of HPV vaccination. We simulated scenarios of bivalent or nonavalent vaccination in females-only or females and males, at 20% coverage increments. We estimated relative HPV-type-specific prevalence reduction compared with a no-vaccination counterfactual and then estimated the age-specific cervical cancer risk by vaccination status. RESULTS: The relative cervical cancer risk for unvaccinated compared with vaccinated women ranged from 1.7 (bivalent vaccine for females and males; 80% coverage) to 10.8 (nonavalent vaccine for females-only; 20% coverage). Under 60% vaccination coverage, which is a representative coverage for several western countries, including the United States, the relative risk (RR) varies between 2.2 (bivalent vaccine for females and males) and 9.2 (nonavalent vaccine for females). CONCLUSIONS: We found large cervical cancer risk differences between vaccinated and unvaccinated women. In general, our model shows that the RR is higher in lower vaccine coverages, using the nonavalent vaccine, and when vaccinating females only. IMPACT: To avoid a disbalance in harms and benefits between vaccinated and unvaccinated women, vaccination-based screening needs serious consideration.

Declining trend of serological syphilis among genitourinary medicine patients in the Gambia, West Africa.

BACKGROUND: Syphilis is a common disease in Africa and may be an important contributor to the HIV epidemic. Trends in syphilis prevalence are important in their own right and because syphilis is a cofactor for HIV infection. In this study we analyzed trends in serological syphilis prevalence at a sexually transmitted infections (STI) clinic in The Gambia. METHODS: At the Genitourinary Medicine clinic of the Medical Research Council in The Gambia patients were routinely screened for syphilis using a 2-test algorithm, measuring rapid plasma reagin followed by the Treponema pallidum haemagglutination assay. Serological syphilis was defined as both tests being positive. We determined year to year trends in serological syphilis. Logistic regression was used to identify risk factors. RESULTS: Over the period 1994-2007, 23,674 people were tested for syphilis. The prevalence of serological syphilis dropped from 11.2% in 1994 to 1.5% in 2007 (P <0.0001; chi test for trend). Significant risk factors for serological syphilis in women were found to be ethnicity, commercial sex work, and HIV infection. No associations between serological syphilis and possible risk factors in men were found. CONCLUSIONS: This study identified a strong and significant downward trend in the prevalence of serological syphilis among patients attending the Genitourinary Medicine clinic in The Gambia in the period 1994-2007. These results suggest that syphilis prevalence may be declining in the general population, in the absence of a targeted control program. Research is needed to identify the reasons for this decline.

Economy, migrant labour and sex work: interplay of HIV epidemic drivers in Zimbabwe over three decades.

BACKGROUND: HIV took off rapidly in Zimbabwe during the 1980s. Yet, between 1998 and 2003, as the economy faltered, HIV prevalence declined abruptly and without clear explanation. METHODS: We reviewed epidemiological, behavioural, and economic data over three decades to understand changes in economic conditions, migrant labour and sex work that may account for observed fluctuations in Zimbabwe's HIV epidemic. Potential biases related to changing epidemic paradigms and data sources were examined. RESULTS: Early studies describe rural poverty, male migrant labour and sex work as conditions facilitating HIV/sexually transmitted infection (STI) transmission. By the mid-1990s, as Zimbabwe's epidemic became more generalized, research focus shifted to general population household surveys. Yet, less than half as many men than women were found at home during surveys in the 1990s, increasing to 80% during the years of economic decline. Other studies suggest that male demand for sex work fell abruptly as migrant workers were laid off, picking up again when the economy rebounded after 2009. Numbers of clients reported by sex workers, and their STI rates, followed similar patterns reaching a nadir in the early 2000s. Studies from 2009 describe a return to more active sex work, linked to increasing client demand, as well as a revitalized programme reaching sex workers. CONCLUSION: The importance of the downturn in migrant labour and resultant changes in sex work may be underestimated as drivers of Zimbabwe's rapid HIV incidence and prevalence declines. Household surveys underrepresent populations at the highest risk of HIV/STI acquisition and transmission, and these biases vary with changing economic conditions.

Epidemiological And Health Systems Implications Of Evolving HIV And Hypertension In South Africa And Kenya.

Health systems in sub-Saharan Africa are facing an ongoing HIV epidemic and increasing burden of noncommunicable disease. With the focus shifting to the development of comprehensive primary health care and chronic disease treatment, multidisease modeling is integral to estimating future health care needs. We extended an established agent-based model of HIV transmission to include hypertension in two rural settings: KwaZulu-Natal, South Africa, and western Kenya. We estimated that from 2018 to 2028 hypertension prevalence would increase from 40 percent to 46 percent in KwaZulu-Natal and from 29 percent to 35 percent in western Kenya, while HIV prevalence is stabilizing and predicted to decrease. As the health system burden in sub-Saharan Africa is changing, innovative chronic disease treatment and the broadening of successful programs, such as integrated HIV and noncommunicable disease care, are necessary to reach universal health care coverage.

HIV Treatment Substantially Decreases Hospitalization Rates: Evidence From Rural South Africa.

The effect of HIV treatment on hospitalization rates for HIV-infected people has never been established. We quantified this effect in a rural South African community for the period 2009-13. We linked clinical data on HIV treatment start dates for more than 2,000 patients receiving care in the public-sector treatment program with five years of longitudinal data on self-reported hospitalizations from a community-based population cohort of more than 100,000 adults. Hospitalization rates peaked during the first year of treatment and were about five times higher, compared to hospitalization rates after four years on treatment. Earlier treatment initiation could save more than US$300,000 per 1,000 patients over the first four years of HIV treatment, freeing up scarce resources. Future studies on the cost-effectiveness of HIV treatment should include these effects.