RESUMO
Recent declines in adult HIV-1 incidence have followed the large-scale expansion of antiretroviral therapy and primary HIV prevention across high-burden communities of sub-Saharan Africa. Mathematical modeling suggests that HIV risk will decline disproportionately in younger adult age-groups as interventions scale, concentrating new HIV infections in those >age 25 over time. Yet, no empirical data exist to support these projections. We conducted a population-based cohort study over a 16-y period (2004 to 2019), spanning the early scale-up of antiretroviral therapy and voluntary medical male circumcision, to estimate changes in the age distribution of HIV incidence in a hyperepidemic region of KwaZulu-Natal, South Africa, where adult HIV incidence has recently declined. Median age of HIV seroconversion increased by 5.5 y in men and 3.0 y in women, and the age of peak HIV incidence increased by 5.0 y in men and 2.0 y in women. Incidence declined disproportionately among young men (64% in men 15 to 19, 68% in men 20 to 24, and 46% in men 25 to 29) and young women (44% in women 15 to 19, 24% in women 20 to 24) comparing periods pre- versus post-universal test and treat. Incidence was stable (<20% change) in women aged 30 to 39 and men aged 30 to 34. Age shifts in incidence occurred after 2012 and were observed earlier in men than in women. These results provide direct epidemiological evidence of the changing demographics of HIV risk in sub-Saharan Africa in the era of large-scale treatment and prevention. More attention is needed to address lagging incidence decline among older individuals.
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Infecções por HIV/epidemiologia , HIV-1/fisiologia , Adolescente , Adulto , Distribuição por Idade , Fatores Etários , Feminino , Infecções por HIV/imunologia , Soropositividade para HIV/epidemiologia , Soropositividade para HIV/imunologia , HIV-1/imunologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , África do Sul/epidemiologia , Adulto JovemRESUMO
Population mobility is associated with higher-risk sexual behaviors in sub-Saharan Africa and is a key driver of the HIV epidemic. We conducted a longitudinal cohort study to estimate associations between recent mobility (overnight travel away from home in past six months) or migration (changes of residence over defined geopolitical boundaries) and higher-risk sexual behavior among co-resident couples (240 couples aged ≥ 16) from 12 rural communities in Kenya and Uganda. Data on concurrent mobility and sexual risk behaviors were collected every 6-months between 2015 and 2020. We used sex-pooled and sex-stratified multilevel models to estimate associations between couple mobility configurations (neither partner mobile, male mobile/female not mobile, female mobile/male not mobile, both mobile) and the odds of higher-risk (casual, commercial sex worker/client, one night stand, inherited partner, stranger) and concurrent sexual partnerships based on who was mobile. On average across all time points and subjects, mobile women were more likely than non-mobile women to have a higher-risk partner; similarly, mobile men were more likely than non-mobile men to report a higher-risk partnership. Men with work-related mobility versus not had higher odds of higher-risk partnerships. Women with work-related mobility versus not had higher odds of higher-risk partnerships. Couples where both members were mobile versus neither had greater odds of higher-risk partnerships. In analyses using 6-month lagged versions of key predictors, migration events of men, but not women, preceded higher-risk partnerships. Findings demonstrate HIV risks for men and women associated with mobility and the need for prevention approaches attentive to the risk-enhancing contexts of mobility.
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Infecções por HIV , Masculino , Humanos , Feminino , Estudos Longitudinais , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , População Rural , Uganda/epidemiologia , Quênia/epidemiologia , Comportamento Sexual , Estudos de Coortes , Parceiros SexuaisRESUMO
BACKGROUND: Accurate human immunodeficiency virus (HIV) risk assessment can guide optimal HIV prevention. We evaluated the performance of risk prediction models incorporating geospatial measures. METHODS: We developed and validated HIV risk prediction models in a population-based cohort in South Africa. Individual-level covariates included demographic and sexual behavior measures, and geospatial covariates included community HIV prevalence and viral load estimates. We trained models on 2012-2015 data using LASSO Cox models and validated predictions in 2016-2019 data. We compared full models to simpler models restricted to only individual-level covariates or only age and geospatial covariates. We compared the spatial distribution of predicted risk to that of high incidence areas (≥ 3/100 person-years). RESULTS: Our analysis included 19 556 individuals contributing 44 871 person-years and 1308 seroconversions. Incidence among the highest predicted risk quintile using the full model was 6.6/100 person-years (women) and 2.8/100 person-years (men). Models using only age group and geospatial covariates had similar performance (women: AUROCâ =â 0.65, men: AUROCâ =â 0.71) to the full models (women: AUROCâ =â 0.68, men: AUROCâ =â 0.72). Geospatial models more accurately identified high incidence regions than individual-level models; 20% of the study area with the highest predicted risk accounted for 60% of the high incidence areas when using geospatial models but only 13% using models with only individual-level covariates. CONCLUSIONS: Geospatial models with no individual measures other than age group predicted HIV risk nearly as well as models that included detailed behavioral data. Geospatial models may help guide HIV prevention efforts to individuals and geographic areas at highest risk.
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Síndrome da Imunodeficiência Adquirida , Infecções por HIV , HIV-1 , Síndrome da Imunodeficiência Adquirida/epidemiologia , Feminino , Infecções por HIV/epidemiologia , Humanos , Incidência , Masculino , Fatores de Risco , População Rural , África do Sul/epidemiologiaRESUMO
PURPOSE: This study describes patterns of community-level stigmatizing attitudes towards mental illness (MI) in central Mozambique. METHODS: Data for this study come from a representative community household survey of 2933 respondents ≥ 18 years old in Manica and Sofala Provinces, Mozambique. Six MI stigma questions represented primary research outcomes. Bivariate and multivariable analyses examined the relationship between key explanatory factors and each stigma question. Spatial analyses analyzed the smoothed geographic distribution of responses to each question and explored the association between geographic location and MI stigma controlling for individual-level socio-demographic factors. RESULTS: Stigmatizing attitudes towards MI are prevalent in central Mozambique. Analyses showed that males, people who live in urban places, divorced and widowed individuals, people aged 18-24, people with lower education, people endorsing no religion, and people in lower wealth quintiles tended to have significantly higher levels of stigmatizing attitudes towards MI. Individuals reporting depressive symptoms scored significantly higher on stigmatizing questions, potentially indicating internalized stigma. Geographic location is significantly associated with people's response to five of the stigma questions even after adjusting for individual-level factors. CONCLUSION: Stigmatizing attitudes towards MI are common in central Mozambique and concentrated amongst specific socio-demographic groups. However, geographic analyses suggest that structural factors within communities and across regions may bear a greater influence on MI stigma than individual-level factors alone. Further implementation science should consider focusing on identifying the most significant modifiable structural factors associated with MI stigma in LMICs to inform the development, testing, and optimization of multi-level stigma prevention interventions.
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Atitude Frente a Saúde , Geografia/estatística & dados numéricos , Transtornos Mentais/psicologia , Estigma Social , Estereotipagem , Adolescente , Adulto , Características da Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Moçambique/epidemiologia , Prevalência , Inquéritos e Questionários , Adulto JovemRESUMO
BACKGROUND: Large geographical variations in the intensity of the HIV epidemic in sub-Saharan Africa call for geographically targeted resource allocation where burdens are greatest. However, data available for mapping the geographic variability of HIV prevalence and detecting HIV 'hotspots' is scarce, and population-based surveillance data are not always available. Here, we evaluated the viability of using clinic-based HIV prevalence data to measure the spatial variability of HIV in South Africa and Tanzania. METHODS: Population-based and clinic-based HIV data from a small HIV hyper-endemic rural community in South Africa as well as for the country of Tanzania were used to map smoothed HIV prevalence using kernel interpolation techniques. Spatial variables were included in clinic-based models using co-kriging methods to assess whether cofactors improve clinic-based spatial HIV prevalence predictions. Clinic- and population-based smoothed prevalence maps were compared using partial rank correlation coefficients and residual local indicators of spatial autocorrelation. RESULTS: Routinely-collected clinic-based data captured most of the geographical heterogeneity described by population-based data but failed to detect some pockets of high prevalence. Analyses indicated that clinic-based data could accurately predict the spatial location of so-called HIV 'hotspots' in > 50% of the high HIV burden areas. CONCLUSION: Clinic-based data can be used to accurately map the broad spatial structure of HIV prevalence and to identify most of the areas where the burden of the infection is concentrated (HIV 'hotspots'). Where population-based data are not available, HIV data collected from health facilities may provide a second-best option to generate valid spatial prevalence estimates for geographical targeting and resource allocation.
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Análise de Dados , Epidemias , Infecções por HIV/epidemiologia , Instalações de Saúde , Análise Espacial , Epidemias/prevenção & controle , Epidemias/estatística & dados numéricos , Infecções por HIV/diagnóstico , Instalações de Saúde/estatística & dados numéricos , Inquéritos Epidemiológicos/métodos , Inquéritos Epidemiológicos/estatística & dados numéricos , Humanos , África do Sul/epidemiologia , Tanzânia/epidemiologiaRESUMO
BACKGROUND: Lack of accurate data on the distribution of sub-national populations in low- and middle-income countries impairs planning, monitoring, and evaluation of interventions. Novel, low-cost methods to develop unbiased survey sampling frames at sub-national, sub-provincial, and even sub-district levels are urgently needed. This article details our experience using remote satellite imagery to develop a provincial-level representative community survey sampling frame to evaluate the effects of a 7-year health system intervention in Sofala Province, Mozambique. METHODS: Mozambique's most recent census was conducted in 2007, and no data are readily available to generate enumeration areas for representative health survey sampling frames. To remedy this, we partnered with the Humanitarian OpenStreetMap Team to digitize every building in Sofala and Manica provinces (685,189 Sofala; 925,713 Manica) using up-to-date remote satellite imagery, with final results deposited in the open-source OpenStreetMap database. We then created a probability proportional to size sampling frame by overlaying a grid of 2.106 km resolution (0.02 decimal degrees) across each province, and calculating the number of buildings within each grid square. Squares containing buildings were used as our primary sampling unit with replacement. Study teams navigated to the geographic center of each selected square using geographic positioning system coordinates, and then conducted a standard "random walk" procedure to select 20 households for each time a given square was selected. Based on sample size calculations, we targeted a minimum of 1500 households in each province. We selected 88 grids within each province to reach 1760 households, anticipating ongoing conflict and transport issues could preclude the inclusion of some clusters. RESULTS: Civil conflict issues forced the exclusion of 8 of 31 subdistricts in Sofala and 15 of 39 subdistricts in Manica. Using Android tablets, Open Data Kit software, and a remote RedCap data capture system, our final sample included 1549 households in Sofala (4669 adults; 4766 children; 33 missing age) and 1538 households in Manica (4422 adults; 4898 children; 33 missing age). CONCLUSIONS: Other implementation or evaluation teams may consider employing similar methods to track population distributions for health systems planning or the development of representative sampling frames using remote satellite imagery.
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Características da Família , Inquéritos Epidemiológicos/métodos , Imagens de Satélites/métodos , Inquéritos e Questionários , Adolescente , Adulto , Censos , Criança , Feminino , Inquéritos Epidemiológicos/estatística & dados numéricos , Humanos , Masculino , Moçambique/epidemiologia , Imagens de Satélites/estatística & dados numéricos , Inquéritos e Questionários/estatística & dados numéricos , Adulto JovemRESUMO
BACKGROUND: Community-based oral pre-exposure prophylaxis (PrEP) provision has the potential to expand PrEP coverage. HIV self-testing can facilitate PrEP community-based delivery but might have lower sensitivity than facility-based HIV testing, potentially leading to inappropriate PrEP use among people with HIV and subsequent development of drug resistance. We aimed to evaluate the impact of HIV self-testing use for PrEP scale-up. METHODS: We parameterised an agent-based network model, EMOD-HIV, to simulate generic tenofovir disoproxil fumarate and emtricitabine PrEP scale-up in western Kenya using four testing scenarios: provider-administered nucleic acid testing, provider-administered rapid diagnostic tests detecting antibodies, blood-based HIV self-testing, or oral fluid HIV self-testing. Scenarios were compared with a no PrEP counterfactual. Individuals aged 18-49 years with one or more heterosexual partners who screened HIV-negative were eligible for PrEP. We assessed the cost and health impact of rapid PrEP scale-up with high coverage over 20 years, and the budget impact over 5 years, using various HIV testing modalities. FINDINGS: PrEP coverage of 29% was projected to avert approximately 54% of HIV infections and 17% of HIV-related deaths among adults aged 18-49 years over 20 years; health impacts were similar across HIV testing modalities used to deliver PrEP. The percentage of HIV infections with PrEP-associated nucleoside reverse transcriptase inhibitor (NRTI) drug resistance was 0·6% (95% uncertainty intervals 0·4-0·9) in the blood HIV self-testing scenario and 0·8% (0·6-1·0) in the oral HIV self-testing scenario, compared with 0·3% (0·2-0·3) in the antibody rapid diagnostic testing scenario and 0·2% (0·1-0·2) in the nucleic acid testing scenario. Accounting for background NRTI resistance, we found similarly low proportions of drug resistance across scenarios. The budget impact of implementing PrEP using HIV self-testing and provider-administered rapid diagnostic tests were similar, while nucleic acid testing was approximately 50% more costly. INTERPRETATION: Scaling up PrEP using HIV self-testing has similar health impacts, costs, and low risk of drug resistance as provider-administered rapid diagnostic tests. Policy makers should consider leveraging HIV self-testing to expand PrEP access among those at HIV risk. FUNDING: The Bill and Melinda Gates Foundation.
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Fármacos Anti-HIV , Infecções por HIV , Ácidos Nucleicos , Profilaxia Pré-Exposição , Adulto , Humanos , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Fármacos Anti-HIV/uso terapêutico , Quênia/epidemiologia , Autoteste , Emtricitabina/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Teste de HIV , Ácidos Nucleicos/uso terapêuticoRESUMO
HIV incidence in eastern and southern Africa has historically been concentrated among girls and women aged 15-24 years. As new cases decline with HIV interventions, population-level infection dynamics may shift by age and gender. Here, we integrated population-based surveillance of 38,749 participants in the Rakai Community Cohort Study and longitudinal deep-sequence viral phylogenetics to assess how HIV incidence and population groups driving transmission have changed from 2003 to 2018 in Uganda. We observed 1,117 individuals in the incidence cohort and 1,978 individuals in the transmission cohort. HIV viral suppression increased more rapidly in women than men, however incidence declined more slowly in women than men. We found that age-specific transmission flows shifted: whereas HIV transmission to girls and women (aged 15-24 years) from older men declined by about one-third, transmission to women (aged 25-34 years) from men that were 0-6 years older increased by half in 2003 to 2018. Based on changes in transmission flows, we estimated that closing the gender gap in viral suppression could have reduced HIV incidence in women by half in 2018. This study suggests that HIV programmes to increase HIV suppression in men are critical to reduce incidence in women, close gender gaps in infection burden and improve men's health in Africa.
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Infecções por HIV , Masculino , Humanos , Feminino , Idoso , Infecções por HIV/epidemiologia , Uganda/epidemiologia , Estudos de Coortes , Genômica , IncidênciaRESUMO
For many pathogens with environmental stages, or those carried by vectors or intermediate hosts, disease transmission is strongly influenced by pathogen, host, and vector movements across complex landscapes, and thus quantitative measures of movement rate and direction can reveal new opportunities for disease management and intervention. Genetic assignment methods are a set of powerful statistical approaches useful for establishing population membership of individuals. Recent theoretical improvements allow these techniques to be used to cost-effectively estimate the magnitude and direction of key movements in infectious disease systems, revealing important ecological and environmental features that facilitate or limit transmission. Here, we review the theory, statistical framework, and molecular markers that underlie assignment methods, and we critically examine recent applications of assignment tests in infectious disease epidemiology. Research directions that capitalize on use of the techniques are discussed, focusing on key parameters needing study for improved understanding of patterns of disease.
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Doenças Transmissíveis/transmissão , Vetores de Doenças , Interações Hospedeiro-Parasita/genética , Administração Oral , Migração Animal , Animais , Doença de Chagas/prevenção & controle , Coccidioidomicose/genética , Coccidioidomicose/prevenção & controle , Genética Populacional , Geografia , Humanos , Inseticidas , Vacina Antirrábica/administração & dosagem , Guaxinins/parasitologia , Sciuridae/parasitologia , Sifonápteros/parasitologia , Triatoma , Yersinia pestis/genéticaRESUMO
OBJECTIVES: Mobility (international/internal migration, and localized mobility) is a key driver of the HIV epidemic. While mobility is associated with higher-risk sexual behavior in women, a possible association with condom, modern contraceptive, and dual method use among women living with HIV (WLHIV), is unknown. In addition, HIV status and sexual behaviors such as relationship concurrency may also affect condom, modern contraceptive, and dual method use. STUDY DESIGN: We surveyed sexually active women (N = 1067) aged 15 to 49 in 12 communities in Kenya and Uganda participating in a test-and-treat trial in 2015 to 2016. Generalized (unordered) multinomial logistic regression models accounting for community clustering examined associations between mobility (overnight travel away from home in past 6 months and any migration within past 2 years) and condom, modern contraceptive (i.e., oral contraceptive pills, injectables, intrauterine devices, implants, vasectomy, tubal ligation; excluding male/female condoms), and dual method use within past 6 months, adjusting for key covariates such as HIV status and relationship concurrency. RESULTS: WLHIV relative to HIV-negative women (ratios of relative risk [RRR] = 3.76, 95% confidence interval [CI]: 2.40-5.89), and women in concurrent relative to monogamous relationships (RRR = 4.03, 95% CI 1.9-8.50) had higher odds of condom use alone. In contraceptive use models, WLHIV relative to HIV-negative women were less likely to use modern contraceptive methods alone (RRR = 0.51, 95% CI 0.36-0.73). Relationship concurrency (RRR = 4.51, 95% CI 2.10-9.67) and HIV status (RRR = 3.97, 95% CI 2.43-6.50) were associated with higher odds of dual method use while mobility was marginally associated with higher odds of dual method use (RRR = 1.65, 95% CI 0.99-2.77, p = 0.057). CONCLUSIONS: Mobility had a potential impact on dual method use in Kenya and Uganda. In addition, our findings highlight that WLHIV were using condoms and dual methods more, but modern contraceptives less, than HIV-negative women. Those in concurrent relationships were also more likely to use condoms or dual methods. These findings suggest that in a context of high mobility, women may be appropriately assessing risks and taking measures to protect themselves and their partners from unintended pregnancies and acquisition and transmission of HIV. IMPLICATIONS: Our findings point to a need to strengthen accessibility of sexual and reproductive health services for both mobile and residentially stable women in settings of high mobility and high HIV prevalence.
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Preservativos , Infecções por HIV , Gravidez , Feminino , Humanos , Masculino , Estudos Transversais , Uganda/epidemiologia , Quênia/epidemiologia , Infecções por HIV/epidemiologia , Comportamento Contraceptivo , Anticoncepcionais OraisRESUMO
HIV incidence in eastern and southern Africa has historically been concentrated among girls and women aged 15-24 years. As new cases decline with HIV interventions, population-level infection dynamics may shift by age and gender. Here, we integrated population-based surveillance of 38,749 participants in the Rakai Community Cohort Study and longitudinal deep sequence viral phylogenetics to assess how HIV incidence and population groups driving transmission have changed from 2003 to 2018 in Uganda. We observed 1,117 individuals in the incidence cohort and 1,978 individuals in the transmission cohort. HIV viral suppression increased more rapidly in women than men, however incidence declined more slowly in women than men. We found that age-specific transmission flows shifted, while HIV transmission to girls and women (aged 15-24 years) from older men declined by about one third, transmission to women (aged 25-34 years) from men that were 0-6 years older increased by half in 2003 to 2018. Based on changes in transmission flows, we estimated that closing the gender gap in viral suppression could have reduced HIV incidence in women by half in 2018. This study suggests that HIV programs to increase HIV suppression in men are critical to reduce incidence in women, close gender gaps in infection burden and improve men's health in Africa.
RESUMO
Developmental models, such as degree-day models, are commonly used to predict the impact of future climate change on the intensity, distribution, and timing of the transmission of infectious diseases, particularly those caused by pathogens carried by vectors or intermediate hosts. Resulting projections can be useful in policy discussions concerning regional or national responses to future distributions of important infectious diseases. Although the simplicity of degree-day models is appealing, little work has been done to analyze their ability to make reliable projections of the distribution of important pathogens, vectors, or intermediate hosts in the presence of the often considerable parametric uncertainty common to such models. Here, a population model of Oncomelania hupensis, the intermediate host of Schistosoma japonicum, was used to investigate the sensitivity of host range predictions in Sichuan Province, China, to uncertainty in two key degree-day model parameters: delta(min) (minimum temperature threshold for development) and K (total degree-days required for completion of snail development). The intent was to examine the consequences of parametric uncertainty in a plausible biological model, rather than to generate the definitive model. Results indicate that model output, the seasonality of population dynamics, and range predictions, particularly along the edge of the range, are highly sensitive to changes in model parameters, even at levels of parametric uncertainty common to such applications. Caution should be used when interpreting the results of degree-day models used to generate predictions of disease distribution and risk under scenarios of future climate change, and predictions should be considered most reliable when the temperature ranges used in projections resemble those used to estimate model parameters. Given the potential for substantial changes in degree-day model output with modest changes in parameter values, caution is warranted when results will be used to inform policy and management decisions.
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Mudança Climática/estatística & dados numéricos , Modelos Teóricos , Caramujos/fisiologia , Animais , China , Demografia , Reservatórios de Doenças , Schistosoma japonicum/fisiologia , Estações do Ano , Caramujos/parasitologia , Temperatura , Fatores de TempoRESUMO
INTRODUCTION: Models that project the impact and cost-effectiveness of HIV pre-exposure prophylaxis (PrEP) must specify how PrEP use aligns with HIV exposure. We hypothesized that varying PrEP use according to individual-level partnership dynamics rather than prioritization to population subgroups based on average risk will result in larger incidence reductions and greater efficiency. METHODS: We used an individual-based network transmission model calibrated to HIV dynamics in Eswatini to simulate PrEP use among individuals ages 15-34 between 2022 and 2031 under two paradigms of PrEP delivery: "Risk Group" and "Partnership." In the "Risk Group" paradigm, we varied PrEP coverage by risk groups (low, medium and high) defined by average partnership frequency and concurrency. In the "Partnership" paradigm, all individuals are potentially eligible for PrEP, but we assumed use occurs only during partnerships and varied prioritization by partner HIV status (no prioritization to high prioritization with HIV-positive partners). We calculated person-time on PrEP and incidence relative to a no PrEP scenario and estimated efficiency as the person-years of PrEP needed to avert one additional infection (NNT). RESULTS: In the Risk Group paradigm, restricting PrEP to the high-risk group was the most efficient (NNT = 17), but the number of infections averted was limited by the small size of the high-risk group. Expanding PrEP use to all risk groups averted up to three times more infections but with lower efficiency (NNT = 202). PrEP use under the Partnership paradigm was 2-6 times more efficient (NNT = 33-102) than the Risk Group paradigm with all groups eligible for PrEP. A 33% reduction in incidence among 15- to 34-year-olds was achieved at 46% (95% CI: 39-52%) PrEP coverage in the Risk Group paradigm and 6% (95% CI: 5-7%) to 17% (95% CI: 14-20%) in the Partnership paradigm. CONCLUSIONS: Modelling PrEP use based on risk groups resulted in a sharp trade-off between PrEP efficiency and impact, whereas PrEP use predicated on partnerships resulted in much higher efficiency for widespread PrEP availability. Model estimates of PrEP impact and cost-effectiveness in generalized epidemics are strongly influenced by assumptions about how PrEP use aligns with individual-level HIV exposure heterogeneity.
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Epidemias , Infecções por HIV , Profilaxia Pré-Exposição , Humanos , Adolescente , Adulto Jovem , Adulto , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Profilaxia Pré-Exposição/métodos , Sexo Seguro , Modelos Teóricos , Epidemias/prevenção & controleRESUMO
OBJECTIVE: We examined whether human mobility was associated with antiretroviral treatment adherence, measured via antiretroviral hair concentrations. DESIGN: This is a cross-sectional analysis of adults on antiretroviral treatment in East Africa at baseline in an observational cohort study. METHODS: Participants reported recent mobility (overnight travel) and histories of migration (changes of residence), including reasons, frequency/duration, and locations. Hair antiretroviral concentrations were analyzed using validated methods. We estimated associations between mobility and antiretroviral concentrations via linear regression adjusted for age, sex, region, years on treatment. RESULTS: Among 383 participants, half were women and the median age was 40. Among men, 25% reported recent work-related mobility, 30% nonwork mobility, and 11% migrated in the past year (mostly across district boundaries); among women, 6 and 57% reported work-related and nonwork mobility, respectively, and 8% recently migrated (mostly within district). Those reporting work-related trips 2 nights or less had 72% higher hair antiretroviral levels (Pâ=â0.02) than those who did not travel for work; in contrast, nonwork mobility (any duration, vs. none) was associated with 24% lower levels (Pâ=â0.06). Intra-district migrations were associated with 59% lower antiretroviral levels than nonmigrants (Pâ=â0.003) while inter-district migrations were not (27% higher, Pâ=â0.40). CONCLUSION: We found that localized/intra-district migration and nonwork travel-more common among women-were associated with lower adherence, potentially reflecting care interruptions or staying with family/friends unaware of the participants' status. In contrast, short work-related trips-more common among men-were associated with higher adherence, perhaps reflecting higher income. Adherence interventions may require tailoring by sex and forms of mobility.
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Infecções por HIV , Adulto , África Oriental , Antirretrovirais , Estudos Transversais , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Cooperação e Adesão ao TratamentoRESUMO
Background: Co-circulating respiratory pathogens can interfere with or promote each other, leading to important effects on disease epidemiology. Estimating the magnitude of pathogen-pathogen interactions from clinical specimens is challenging because sampling from symptomatic individuals can create biased estimates. Methods: We conducted an observational, cross-sectional study using samples collected by the Seattle Flu Study between 11 November 2018 and 20 August 2021. Samples that tested positive via RT-qPCR for at least one of 17 potential respiratory pathogens were included in this study. Semi-quantitative cycle threshold (Ct) values were used to measure pathogen load. Differences in pathogen load between monoinfected and coinfected samples were assessed using linear regression adjusting for age, season, and recruitment channel. Results: 21,686 samples were positive for at least one potential pathogen. Most prevalent were rhinovirus (33·5%), Streptococcus pneumoniae (SPn, 29·0%), SARS-CoV-2 (13.8%) and influenza A/H1N1 (9·6%). 140 potential pathogen pairs were included for analysis, and 56 (40%) pairs yielded significant Ct differences (p < 0.01) between monoinfected and co-infected samples. We observed no virus-virus pairs showing evidence of significant facilitating interactions, and found significant viral load decrease among 37 of 108 (34%) assessed pairs. Samples positive with SPn and a virus were consistently associated with increased SPn load. Conclusions: Viral load data can be used to overcome sampling bias in studies of pathogen-pathogen interactions. When applied to respiratory pathogens, we found evidence of viral-SPn facilitation and several examples of viral-viral interference. Multipathogen surveillance is a cost-efficient data collection approach, with added clinical and epidemiological informational value over single-pathogen testing, but requires careful analysis to mitigate selection bias.
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BACKGROUND: Growing travel connectivity and economic development have dramatically increased the magnitude of human mobility in Africa. In public health, vulnerable population groups such as mobile individuals are at an elevated risk of sexually transmitted diseases, including HIV. METHODS: The population-based Demographic Health Survey data of five Southern African countries with different HIV epidemic intensities (Angola, Malawi, South Africa, Zambia, and Zimbabwe) were used to investigate the association between HIV serostatus and population mobility adjusting for socio-demographic, sexual behavior and spatial covariates. RESULTS: Mobility was associated with HIV seropositive status only in Zimbabwe (adjusted odds ratio [AOR] = 1.37 [95% confidence interval [CI]: 1.01-1.67]). These associations were not significant in Angola, Malawi, South Africa, and Zambia. Females had higher odds of mobility than males in Zimbabwe (AOR = 1.37, CI: 1.10-1.69). The odds of mobility decreased with age in all five countries. CONCLUSIONS: Our findings highlight the heterogeneity of the social and health determinants of mobile populations in several countries with different HIV epidemic intensities. Effective interventions using precise geographic focus combined with detailed attribute characterization of mobile populations can enhance their impact especially in areas with high density of mobile individuals and high HIV prevalence.
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BACKGROUND: The number of people on antiretroviral therapy (ART) requiring treatment monitoring in low-resource settings is rapidly increasing. Point-of-care (POC) testing for ART monitoring might alleviate burden on centralised laboratories and improve clinical outcomes, but its cost-effectiveness is unknown. METHODS: We used cost and effectiveness data from the STREAM trial in South Africa (February, 2017-October, 2018), which evaluated POC testing for viral load, CD4 count, and creatinine, with task shifting from professional to lower-cadre registered nurses compared with laboratory-based testing without task shifting (standard of care). We parameterised an agent-based network model, EMOD-HIV, to project the impact of implementing this intervention in South Africa over 20 years, simulating approximately 175â000 individuals per run. We assumed POC monitoring increased viral suppression by 9 percentage points, enrolment into community-based ART delivery by 25 percentage points, and switching to second-line ART by 1 percentage point compared with standard of care, as reported in the STREAM trial. We evaluated POC implementation in varying clinic sizes (10-50 patient initiating ART per month). We calculated incremental cost-effectiveness ratios (ICERs) and report the mean and 90% model variability of 250 runs, using a cost-effectiveness threshold of US$500 per disability-adjusted life-year (DALY) averted for our main analysis. FINDINGS: POC testing at 70% coverage of patients on ART was projected to reduce HIV infections by 4·5% (90% model variability 1·6 to 7·6) and HIV-related deaths by 3·9% (2·0 to 6·0). In clinics with 30 ART initiations per month, the intervention had an ICER of $197 (90% model variability -27 to 863) per DALY averted; results remained cost-effective when varying background viral suppression, ART dropout, intervention effectiveness, and reduction in HIV transmissibility. At higher clinic volumes (≥40 ART initiations per month), POC testing was cost-saving and at lower clinic volumes (20 ART initiations per month) the ICER was $734 (93 to 2569). A scenario that assumed POC testing did not increase enrolment into community ART delivery produced ICERs that exceeded the cost-effectiveness threshold for all clinic volumes. INTERPRETATION: POC testing is a promising strategy to cost-effectively improve patient outcomes in moderately sized clinics in South Africa. Results are most sensitive to changes in intervention impact on enrolment into community-based ART delivery. FUNDING: National Institutes of Health.
Assuntos
Monitoramento de Medicamentos/economia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/economia , Testes Imediatos/economia , Fármacos Anti-HIV/economia , Fármacos Anti-HIV/uso terapêutico , Contagem de Linfócito CD4 , Análise Custo-Benefício , Creatinina/sangue , Monitoramento de Medicamentos/enfermagem , Monitoramento de Medicamentos/normas , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , Humanos , Modelos Teóricos , África do Sul/epidemiologia , Resposta Viral Sustentada , Carga Viral/efeitos dos fármacosRESUMO
INTRODUCTION: Heterogeneity of sociodemographics and risk behaviours across the HIV treatment cascade could influence the public health impact of universal ART in sub-Saharan Africa if those not virologically suppressed are more likely to be part of a risk group contributing to onward infections. Sociodemographic and risk heterogeneity across the treatment cascade has not yet been comprehensively described or quantified and we seek to systematically review and synthesize research on this topic among adults in Africa. METHODS: We conducted a systematic review of peer-reviewed literature in Embase and MEDLINE databases as well as grey literature sources published in English between 2014 and 2018. We included studies that included people living with HIV (PLHIV) aged ≥15 years, and reported a 90-90-90 outcome: awareness of HIV-positive status, ART use among those diagnosed or viral suppression among those on ART. We summarized measures of association between sociodemographics, within each outcome, and as a composite measure of population-wide viral suppression. RESULTS AND DISCUSSION: From 3533 screened titles, we extracted data from 92 studies (50 peer-reviewed, 42 grey sources). Of included studies, 32 reported on awareness, 53 on ART use, 32 on viral suppression and 23 on population-wide viral suppression. The majority of studies were conducted in South Africa, Uganda, and Malawi and reported data for age and gender. When stratified, PLHIV ages 15 to 24 years had lower median achievement of the treatment cascade (60-49-81), as compared to PLHIV ≥25 years (70-63-91). Men also had lower median achievement of the treatment cascade (66-72-85), compared to women (79-76-89). For population-wide viral suppression, women aged ≥45 years had achieved the 73% target, while the lowest medians were among 15- to 24-year-old men (37%) and women (49%). CONCLUSIONS: Considerable heterogeneity exists by age and gender for achieving the HIV 90-90-90 treatment goals. These results may inform delivery of HIV testing and treatment in sub-Saharan Africa, as targeting youth and men could be a strategic way to maximize the population-level impact of ART.
Assuntos
Infecções por HIV/tratamento farmacológico , Adolescente , Demografia , Feminino , Infecções por HIV/diagnóstico , Humanos , Malaui , Masculino , Avaliação de Resultados em Cuidados de Saúde , Fatores de Risco , Fatores Socioeconômicos , África do Sul , Uganda , Adulto JovemRESUMO
INTRODUCTION: Over one hundred implementation studies of HIV pre-exposure prophylaxis (PrEP) are completed, underway or planned. We synthesized evidence from these studies to inform mathematical modelling of the prevention cascade for oral and long-acting PrEP in the setting of western Kenya, one of the world's most heavily HIV-affected regions. METHODS: We incorporated steps of the PrEP prevention cascade - uptake, adherence, retention and re-engagement after discontinuation - into EMOD-HIV, an open-source transmission model calibrated to the demography and HIV epidemic patterns of western Kenya. Early PrEP implementation research from East Africa was used to parameterize prevention cascades for oral PrEP as currently implemented, delivery innovations for oral PrEP, and future long-acting PrEP. We compared infections averted by PrEP at the population level for different cascade assumptions and sub-populations on PrEP. Analyses were conducted over the 2020 to 2040 time horizon, with additional sensitivity analyses for the time horizon of analysis and the time when long-acting PrEP becomes available. RESULTS: The maximum impact of oral PrEP diminished by over 98% across all prevention cascades, with the exception of long-acting PrEP under optimistic assumptions about uptake and re-engagement after discontinuation. Long-acting PrEP had the highest population-level impact, even after accounting for possible delays in product availability, primarily because its effectiveness does not depend on drug adherence. Retention was the most significant cascade step reducing the potential impact of long-acting PrEP. These results were robust to assumptions about the sub-populations receiving PrEP, but were highly influenced by assumptions about re-initiation of PrEP after discontinuation, about which evidence was sparse. CONCLUSIONS: Implementation challenges along the prevention cascade compound to diminish the population-level impact of oral PrEP. Long-acting PrEP is expected to be less impacted by user uptake and adherence, but it is instead dependent on product availability in the short term and retention in the long term. To maximize the impact of long-acting PrEP, ensuring timely product approval and rollout is critical. Research is needed on strategies to improve retention and patterns of PrEP re-initiation.
Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/prevenção & controle , Profilaxia Pré-Exposição , Adolescente , Adulto , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Quênia , Masculino , Adesão à Medicação , Profilaxia Pré-Exposição/métodos , Serviços Preventivos de Saúde , Adulto JovemRESUMO
BACKGROUND: The rapid scale-up of antiretroviral therapy (ART) towards the UNAIDS 90-90-90 goals over the last decade has sparked considerable debate as to whether universal test and treat can end the HIV-1 epidemic in sub-Saharan Africa. We aimed to develop a network transmission model, calibrated to capture age-specific and sex-specific gaps in the scale-up of ART, to estimate the historical and future effect of attaining and surpassing the UNAIDS 90-90-90 treatment targets on HIV-1 incidence and mortality, and to assess whether these interventions will be enough to achieve epidemic control (incidence of 1 infection per 1000 person-years) by 2030. METHODS: We used eSwatini (formerly Swaziland) as a case study to develop our model. We used data on HIV prevalence by 5-year age bins, sex, and year from the 2007 Swaziland Demographic Health Survey (SDHS), the 2011 Swaziland HIV Incidence Measurement Survey, and the 2016 Swaziland Population Health Impact Assessment (PHIA) survey. We estimated the point prevalence of ART coverage among all HIV-infected individuals by age, sex, and year. Age-specific data on the prevalence of male circumcision from the SDHS and PHIA surveys were used as model inputs for traditional male circumcision and scale-up of voluntary medical male circumcision (VMMC). We calibrated our model using publicly available data on demographics; HIV prevalence by 5-year age bins, sex, and year; and ART coverage by age, sex, and year. We modelled the effects of five scenarios (historical scale-up of ART and VMMC [status quo], no ART or VMMC, no ART, age-targeted 90-90-90, and 100% ART initiation) to quantify the contribution of ART scale-up to declines in HIV incidence and mortality in individuals aged 15-49 by 2016, 2030, and 2050. FINDINGS: Between 2010 and 2016, status-quo ART scale-up among adults (aged 15-49 years) in eSwatini (from 34·0% in 2010 to 74·1% in 2016) reduced HIV incidence by 43·57% (95% credible interval 39·71 to 46·36) and HIV mortality by 56·17% (54·06 to 58·92) among individuals aged 15-49 years, with larger reductions in incidence among men and mortality among women. Holding 2016 ART coverage levels by age and sex into the future, by 2030 adult HIV incidence would fall to 1·09 (0·87 to 1·29) per 100 person-years, 1·42 (1·13 to 1·71) per 100 person-years among women and 0·79 (0·63 to 0·94) per 100 person-years among men. Achieving the 90-90-90 targets evenly by age and sex would further reduce incidence beyond status-quo ART, primarily among individuals aged 15-24 years (an additional 17·37% [7·33 to 26·12] reduction between 2016 and 2030), with only modest additional incidence reductions in adults aged 35-49 years (1·99% [-5·09 to 7·74]). Achieving 100% ART initiation among all people living with HIV within an average of 6 months from infection-an upper bound of plausible treatment effect-would reduce adult HIV incidence to 0·73 infections (0·55 to 0·92) per 100 person-years by 2030 and 0·46 (0·33 to 0·59) per 100 person-years by 2050. INTERPRETATION: Scale-up of ART over the last decade has already contributed to substantial reductions in HIV-1 incidence and mortality in eSwatini. Focused ART targeting would further reduce incidence, especially in younger individuals, but even the most aggressive treatment campaigns would be insufficient to end the epidemic in high-burden settings without a renewed focus on expanding preventive measures. FUNDING: Global Good Fund and the Bill & Melinda Gates Foundation.