The 2022 mpox outbreak predominantly impacted gay, bisexual, and other men who have sex with men (gbMSM). Two models were developed to support situational awareness and management decisions in ...Canada. A compartmental model characterized epidemic drivers at national/provincial levels, while an agent‐based model (ABM) assessed municipal‐level impacts of vaccination. The models were parameterized and calibrated using empirical case and vaccination data between 2022 and 2023. The compartmental model explored: (1) the epidemic trajectory through community transmission, (2) the potential for transmission among non‐gbMSM, and (3) impacts of vaccination and the proportion of gbMSM contributing to disease transmission. The ABM incorporated sexual‐contact data and modeled: (1) effects of vaccine uptake on disease dynamics, and (2) impacts of case importation on outbreak resurgence. The calibrated, compartmental model followed the trajectory of the epidemic, which peaked in July 2022, and died out in December 2022. Most cases occurred among gbMSM, and epidemic trajectories were not consistent with sustained transmission among non‐gbMSM. The ABM suggested that unprioritized vaccination strategies could increase the outbreak size by 47%, and that consistent importation (≥5 cases per 10 000) is necessary for outbreak resurgence. These models can inform time‐sensitive situational awareness and policy decisions for similar future outbreaks.
Introduction
Men who have sex with men (MSM) and people who inject drugs (PWID) are disproportionately impacted by the HIV epidemic in Canada. Having the second‐highest provincial diagnosis rate, an ...improved understanding of the epidemic among these populations in Québec could aid ongoing elimination efforts. We estimated HIV incidence and other epidemic indicators among MSM and PWID in Montréal and across Québec using a back‐calculation model synthesizing surveillance data.
Methods
We developed a deterministic, compartmental mathematical model stratified by age, HIV status and disease progression, and clinical care stages. Using AIDS and HIV diagnoses data, including self‐reported time since the last negative test and laboratory results of CD4 cell count at diagnosis, we estimated HIV incidence in each population over 1975–2020 by modelling a cubic M‐spline. The prevalence, undiagnosed fraction, fraction diagnosed that started antiretroviral treatment (ART) and median time to diagnosis were also estimated. Since the COVID‐19 pandemic disrupted testing, we excluded 2020 data and explored this in sensitivity analyses.
Results
HIV incidence in all populations peaked early in the epidemic. In 2020, an estimated 97 (95% CrI: 33–227) and 266 (95% CrI: 103–508) HIV acquisitions occurred among MSM in Montréal and Québec, respectively. Among PWID, we estimated 2 (95% CrI: 0–14) and 6 (95% CrI: 1–26) HIV acquisitions in those same regions. With 2020 data, unless testing rates were reduced by 50%, these estimates decreased, except among Québec PWID, whose increased. Among all, the median time to diagnosis shortened to <2 years before 2020 and the undiagnosed fraction decreased to <10%. This fraction was higher in younger MSM, with 22% of 15–24 year‐olds living with HIV in Montréal (95% CrI: 9–39%) and 31% in Québec (95% CrI: 17–48%) undiagnosed by 2020 year‐end. Finally, ART access neared 100% in all diagnosed populations.
Conclusions
HIV incidence has drastically decreased in MSM and PWID across Québec, alongside significant improvements in diagnosis and treatment coverage—and the 2013 introduction of pre‐exposure prophylaxis. Despite this, HIV transmission continued. Effective efforts to halt this transmission and rapidly diagnose people who acquired HIV, especially among younger MSM, are needed to achieve elimination. Further, as the impacts of the COVID‐19 pandemic on HIV transmission are understood, increased efforts may be needed to overcome these.
Key populations, including sex workers, are at high risk of HIV acquisition and transmission. Men who pay for sex can contribute to HIV transmission through sexual relationships with both sex workers ...and their other partners. To characterize the population of men who pay for sex in sub-Saharan Africa (SSA), we analyzed population size, HIV prevalence, and use of HIV prevention and treatment.
We performed random-effects meta-analyses of population-based surveys conducted in SSA from 2000 to 2020 with information on paid sex by men. We extracted population size, lifetime number of sexual partners, condom use, HIV prevalence, HIV testing, antiretroviral (ARV) use, and viral load suppression (VLS) among sexually active men. We pooled by regions and time periods, and assessed time trends using meta-regressions. We included 87 surveys, totaling over 368,000 male respondents (15-54 years old), from 35 countries representing 95% of men in SSA. Eight percent (95% CI 6%-10%; number of surveys Ns = 87) of sexually active men reported ever paying for sex. Condom use at last paid sex increased over time and was 68% (95% CI 64%-71%; Ns = 61) in surveys conducted from 2010 onwards. Men who paid for sex had higher HIV prevalence (prevalence ratio PR = 1.50; 95% CI 1.31-1.72; Ns = 52) and were more likely to have ever tested for HIV (PR = 1.14; 95% CI 1.06-1.24; Ns = 81) than men who had not paid for sex. Men living with HIV who paid for sex had similar levels of lifetime HIV testing (PR = 0.96; 95% CI 0.88-1.05; Ns = 18), ARV use (PR = 1.01; 95% CI 0.86-1.18; Ns = 8), and VLS (PR = 1.00; 95% CI 0.86-1.17; Ns = 9) as those living with HIV who did not pay for sex. Study limitations include a reliance on self-report of sensitive behaviors and the small number of surveys with information on ARV use and VLS.
Paying for sex is prevalent, and men who ever paid for sex were 50% more likely to be living with HIV compared to other men in these 35 countries. Further prevention efforts are needed for this vulnerable population, including improved access to HIV testing and condom use initiatives. Men who pay for sex should be recognized as a priority population for HIV prevention.
ObjectivesUse of illicit substances during sex (chemsex) may increase transmission of HIV and other STIs. Pre-exposure prophylaxis (PrEP) is highly effective at preventing HIV transmission, providing ...an important prevention tool for those who practise chemsex. However, it does not prevent acquisition of other STIs. We aim to examine the impact of chemsex on STI incidence among gay, bisexual and other men who have sex with men (gbMSM), and transgender women using PrEP in Montréal, Canada.MethodsWe linked baseline sociodemographic and behavioural data with follow-up STI testing from 2013 to 2020 among PrEP users in the l’Actuel PrEP Cohort (Canada). Focusing on the 24 months following PrEP initiation, we estimated the effect of chemsex reported at baseline on cumulative incidence of gonorrhoea and chlamydia using Kaplan-Meier curves and survival analyses. We investigated the role of polysubstance use and effect modification by sociodemographic factors.ResultsThere were 2086 clients (2079 cisgender gbMSM, 3 transgender gbMSM, 4 transgender women) who initiated PrEP, contributing 1477 years of follow-up. There were no incident HIV infections among clients on PrEP. Controlling for sociodemographic confounders, clients reporting chemsex at baseline had a 32% higher hazard of gonorrhoea/chlamydia diagnosis (adjusted HR=1.32; 95% CI: 1.10 to 1.57), equivalent to a risk increase of 8.9 percentage points (95% CI: 8.5 to 9.4) at 12 months. The effect was greater for clients who reported polysubstance use (adjusted HR=1.51; 95% CI: 1.21 to 1.89). The strength of the effect of chemsex on STI incidence varied by age, education and income.ConclusionAmong PrEP users, chemsex at baseline was linked to increased incidence of gonorrhoea and chlamydia. This effect was stronger for people reporting multiple chemsex substances. The high STI incidence among gbMSM who report chemsex highlights the importance of PrEP for this population and the need for integrated services that address the complexities of sexualised substance use.
Sub-Saharan Africa (SSA) has the highest cervical cancer (CC) burden globally-worsened by its HIV epidemics. In 2020, the World Health Organization (WHO) introduced a CC elimination strategy with ...goals for vaccination, screening, and treatment. To benchmark progress, we examined temporal trends in screening coverage, percent screened at least twice by the age of 45, screening coverage among women living with HIV (WLHIV), and pre-cancer treatment coverage in SSA.
We conducted a systematic analysis of cross-sectional population-based surveys. It included 52 surveys from 28 countries (2000 to 2020) with information on CC screening among women aged 25 to 49 years (N = 151,338 women). We estimated lifetime and past 3-year screening coverage by age, year, country, and HIV serostatus using a Bayesian multilevel model. Post-stratification and imputations were done to obtain aggregate national, regional, and SSA-level estimates. To measure re-screening by age 45, a life table model was developed. Finally, self-reported pre-cancer treatment coverage was pooled across surveys using a Bayesian meta-analysis. Overall, an estimated 14% (95% credible intervals 95% CrI: 11% to 21%) of women aged 30 to 49 years had ever been screened for CC in 2020, with important regional and country-level differences. In Eastern and Western/Central Africa, regional screening coverages remained constant from 2000 to 2020 and WLHIV had greater odds of being screened compared to women without HIV. In Southern Africa, however, screening coverages increased and WLHIV had equal odds of screening. Notably this region was found to have higher screening coverage in comparison to other African regions. Rescreening rates were high among women who have already been screened; however, it was estimated that only 12% (95% CrI: 10% to 18%) of women had been screened twice or more by age 45 in 2020. Finally, treatment coverage among 4 countries with data was 84% (95% CrI: 70% to 95%). Limitations of our analyses include the paucity of data on screening modality and the few countries that had multiple surveys.
Overall, CC screening coverage remains sub-optimal and did not improve much over the last 2 decades, outside of Southern Africa. Action is needed to increase screening coverage if CC elimination is to be achieved.
In sub-Saharan Africa (SSA), integrating HIV testing into antenatal care (ANC) has been crucial toward reducing mother-to-child transmission of HIV. With the introduction of new testing modalities, ...we explored temporal trends in HIV testing within and outside of ANC and identified sociodemographic determinants of testing during ANC.
We analyzed data from 139 nationally representative household surveys conducted between 2005 and 2021, including more than 2.2 million women aged 15-49 years in 41 SSA countries. We extracted data on women's recent HIV testing history (<24 months), by modality (ie, at ANC versus outside of ANC) and sociodemographic variables (ie, age, socioeconomic status, education level, number of births, urban/rural). We used Bayesian generalized linear mixed models to estimate HIV testing coverage and the proportion of those that tested as part of ANC.
HIV testing coverage (<24 months) increased substantially between 2005 and 2021 from 8% to 38%, with significant variations between countries and subregions. Two percent of women received an HIV test in the 24 months preceding the survey interview as part of ANC in 2005 and 11% in 2021. Among women who received an HIV test in the 24 months preceding the survey, the probability of testing at ANC was significantly greater for multiparous, adolescent girls, rural women, women in the poorest wealth quintile, and women in West and Central Africa.
ANC testing remains an important component to achieving high levels of HIV testing coverage and benefits otherwise underserved women, which could prove instrumental to progress toward universal knowledge of HIV status in SSA.
Summary Background Vaginal fistula is a serious medical disorder characterised by an abnormal opening between the vagina and the bladder or rectum, which results in continuous leakage of urine or ...stool. The burden of this disorder in sub-Saharan Africa is uncertain. We estimated the lifetime and point prevalence of symptoms of vaginal fistula in this region using national household surveys based on self-report of symptoms. Methods We considered all Demographic and Health Surveys (DHS) and Multiple Indicators Cluster Surveys (MICS) from sub-Saharan Africa and included data for women of reproductive age (15–49 years). We estimated lifetime prevalence and point prevalence of vaginal fistula with use of Bayesian hierarchical meta-analysis. Findings We included 19 surveys in our analysis, including 262 100 respondents. Lifetime prevalence was 3·0 cases (95% credible interval 1·3–5·5) per 1000 women of reproductive age. After imputation of missing data, point prevalence was 1·0 case (0·3–2·4) per 1000 women of reproductive age. Ethiopia had the largest number of women who presently have symptoms of vaginal fistula. Interpretation This study is the first to estimate the burden of vaginal fistula in 19 sub-Saharan Africa countries using nationally representative survey data. Point prevalence was slightly lower than previously estimated but these earlier estimates are within the prevalence's credible intervals. Although vaginal fistula is relatively rare, it is still too common in sub-Saharan Africa. Funding None.
The use of larval source management is not prioritized by contemporary malaria control programs in sub-Saharan Africa despite historical success. Larviciding, in particular, could be effective in ...urban areas where transmission is focal and accessibility to Anopheles breeding habitats is generally easier than in rural settings. The objective of this study is to assess the effectiveness of a community-based microbial larviciding intervention to reduce the prevalence of malaria infection in Dar es Salaam, United Republic of Tanzania.
Larviciding was implemented in 3 out of 15 targeted wards of Dar es Salaam in 2006 after two years of baseline data collection. This intervention was subsequently scaled up to 9 wards a year later, and to all 15 targeted wards in 2008. Continuous randomized cluster sampling of malaria prevalence and socio-demographic characteristics was carried out during 6 survey rounds (2004-2008), which included both cross-sectional and longitudinal data (N = 64,537). Bayesian random effects logistic regression models were used to quantify the effect of the intervention on malaria prevalence at the individual level. Effect size estimates suggest a significant protective effect of the larviciding intervention. After adjustment for confounders, the odds of individuals living in areas treated with larviciding being infected with malaria were 21% lower (Odds Ratio = 0.79; 95% Credible Intervals: 0.66-0.93) than those who lived in areas not treated. The larviciding intervention was most effective during dry seasons and had synergistic effects with other protective measures such as use of insecticide-treated bed nets and house proofing (i.e., complete ceiling or window screens).
A large-scale community-based larviciding intervention significantly reduced the prevalence of malaria infection in urban Dar es Salaam.
Previous studies have highlighted a range of individual determinants associated with HIV testing but few have assessed the role of contextual factors. The objective of this paper is to examine the ...influence of both individual and community-level determinants of HIV testing uptake in Burkina Faso.
Using nationally representative cross-sectional data from the 2010 Demographic and Health Survey, the determinants of lifetime HIV testing were examined for sexually active women (n = 14,656) and men (n = 5680) using modified Poisson regression models.
One third of women (36%; 95% Confidence Interval (CI): 33-37%) reported having ever been tested for HIV compared to a quarter of men (26%; 95% CI: 24-27%). For both genders, age, education, religious affiliation, household wealth, employment, media exposure, sexual behaviors, and HIV knowledge were associated with HIV testing. After adjustment, women living in communities where the following characteristics were higher than the median were more likely to report uptake of HIV testing: knowledge of where to access testing (Prevalence Ratio PR = 1.41; 95% CI: 1.34-1.48), willing to buy food from an infected vendor (PR = 2.06; 95% CI: 1.31-3.24), highest wealth quintiles (PR = 1.18; 95% CI: 1.10-1.27), not working year-round (PR = 0.90; 95% CI: 0.84-0.96), and high media exposure (PR = 1.11; 95% CI: 1.03-1.19). Men living in communities where the proportion of respondents were more educated (PR = 1.23; 95% CI: 1.07-1.41) than the median were more likely to be tested.
This study shed light on potential mechanisms through which HIV testing could be increased in Burkina Faso. Both individual and contextual factors should be considered to design effective strategies for scaling-up HIV testing.
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