scholarly journals PopART-IBM, a highly efficient stochastic individual-based simulation model of generalised HIV epidemics developed in the context of the HPTN 071 (PopART) trial

2021 ◽  
Vol 17 (9) ◽  
pp. e1009301
Author(s):  
Michael Pickles ◽  
Anne Cori ◽  
William J. M. Probert ◽  
Rafael Sauter ◽  
Robert Hinch ◽  
...  
Keyword(s):  
Hiv Transmission ◽  
Hiv Prevalence ◽  
Computationally Efficient ◽  
Multiple Sources ◽  
Individual Based Model ◽  
Hiv Epidemiology ◽  
High Prevalence ◽  
Bayesian Inference Framework ◽  
Individual Based Simulation ◽  
Key Indicators

Mathematical models are powerful tools in HIV epidemiology, producing quantitative projections of key indicators such as HIV incidence and prevalence. In order to improve the accuracy of predictions, such models need to incorporate a number of behavioural and biological heterogeneities, especially those related to the sexual network within which HIV transmission occurs. An individual-based model, which explicitly models sexual partnerships, is thus often the most natural type of model to choose. In this paper we present PopART-IBM, a computationally efficient individual-based model capable of simulating 50 years of an HIV epidemic in a large, high-prevalence community in under a minute. We show how the model calibrates within a Bayesian inference framework to detailed age- and sex-stratified data from multiple sources on HIV prevalence, awareness of HIV status, ART status, and viral suppression for an HPTN 071 (PopART) study community in Zambia, and present future projections of HIV prevalence and incidence for this community in the absence of trial intervention.

scholarly journals PopART-IBM, a highly efficient stochastic individual-based simulation model of generalised HIV epidemics developed in the context of the HPTN 071 (PopART) trial

2020 ◽  
Author(s):  
Michael Pickles ◽  
Anne Cori ◽  
William Probert ◽  
Rafael Sauter ◽  
Sarah Fidler ◽  
...  
Keyword(s):  
Hiv Transmission ◽  
Hiv Prevalence ◽  
Computationally Efficient ◽  
Multiple Sources ◽  
Individual Based Model ◽  
Hiv Epidemiology ◽  
High Prevalence ◽  
Bayesian Inference Framework ◽  
Individual Based Simulation ◽  
Key Indicators

Mathematical models are powerful tools in HIV epidemiology, producing quantitative projections of key indicators such as HIV incidence and prevalence. In order to improve the accuracy of predictions, such models need to incorporate a number of behavioural and biological heterogeneities, especially those related to the sexual network within which HIV transmission occurs. An individual-based model, which explicitly models sexual partnerships, is thus often the most natural type of model to choose. In this paper we present PopART-IBM, a computationally efficient individual-based model capable of simulating 50 years of an HIV epidemic in a large, high-prevalence community in under a minute. We show how the model calibrates within a Bayesian inference framework to detailed age- and sex-stratified data from multiple sources on HIV prevalence, awareness of HIV status, ART status, and viral suppression for an HPTN 071 (PopART) study community in Zambia, and present future projections of HIV prevalence and incidence for this community in the absence of trial intervention.

scholarly journals Association of HIV prevalence and concurrency of sexual partnerships in South Africa’s language groups: An ecological analysis

2013 ◽  
Vol 14 (1) ◽  
pp. 25-28 ◽  
Author(s):  
Chris Kenyon
Keyword(s):  
Sexual Partner ◽  
Hiv Transmission ◽  
Hiv Prevalence ◽  
Hiv Incidence ◽  
Ecological Analysis ◽  
Sexual Partnerships ◽  
Multiple Sexual Partners ◽  
Language Groups ◽  
High Prevalence ◽  
Partner Concurrency

Background. There is considerable variation in HIV prevalence between different language groups in South Africa (SA). Sexual partner concurrency has been linked to the spread of HIV, but its effect on differential HIV transmission within SA’s language groups has not been investigated quantitatively. Objective. This ecological analysis was intended to explore the degree to which the variation in HIV prevalence according to language group can be explained by differential concurrency rates. Method. Linear regression was used to assess the association between each language group’s HIV prevalence and four risk factors: the prevalence of concurrency, multiple sexual partners in the preceding year, circumcision, and condom utilisation. Results. In multivariate analysis, only the point prevalence of concurrency remained associated with HIV prevalence. Conclusion. There is evidence of a high prevalence of point concurrency in sexual partnerships in SA’s most HIV-affected language groups. Together with evidence that relatively small decreases in concurrency can lead to large declines in HIV incidence, this provides impetus for interventions to promote having only one sexual partner at a time. S Afr J HIV Med 2013;14(1):25-28. DOI:10.7196/SAJHIVMED.884

Comparing the Impact of Religious Discourse on HIV/AIDS in Islam and Christianity in Africa

2012 ◽  
Vol 8 ◽  
Author(s):  
Sloane Speakman
Keyword(s):  
Social Factors ◽  
Negative Relationship ◽  
Hiv Prevalence ◽  
Religious Discourse ◽  
Prevalence Rates ◽  
The Social ◽  
High Prevalence ◽  
Islam And Christianity ◽  
Sub Saharan ◽  
The Impact

In examining the strikingly high prevalence rates of HIV in many parts of Africa, reaching as high as 5% in some areas, how does the discourse promoted by the predominant religions across the continent, Islam and Christianity, affect the outlook of their followers on the epidemic? This question becomes even more intriguing after discovering the dramatic difference in rate of HIV prevalence between Muslims and Christians in Africa, confirmed by studies that have found a negative relationship to exist between HIV prevalence and being Muslim in Africa, even in Sub-Saharan African nations. Why does this gap in prevalence rates exist? Does Islam advocate participating in less risky behavior more so than Christianity? By comparing the social construction, epidemiological understanding and public responses among Muslim populations in Africa with Christian ones, it becomes apparent that many similarities exist between the two regarding discourse and that, rather than religious discourse itself, other social factors, such as circumcision practices, contribute more to the disparity in HIV prevalence than originally thought.

scholarly journals High HIV prevalence and associated factors in a remote community in the Rwenzori region of Western Uganda

2010 ◽  
Vol 2 (2) ◽  
pp. 13 ◽  
Author(s):  
John Rubaihayo ◽  
Akib Surat ◽  
Mughusu Ezekiel ◽  
Abaasa Andrew
Keyword(s):  
Hiv Transmission ◽  
Risk Behaviour ◽  
Population Based ◽  
Cross Sectional Study ◽  
Sexual Partners ◽  
Hiv Prevalence ◽  
Community Perceptions ◽  
Cross Sectional ◽  
Multiple Sexual Partners ◽  
Western Uganda

In Uganda, previous studies have shown a tremendous decline in HIV prevalence over the past two decades due to changes in sexual behavior with a greater awareness of the risks involved. However, studies in Fort-Portal municipality, a rural town in Western Uganda, continued to show a persistent high HIV prevalence despite the various interventions in place. We conducted a study to establish the current magnitude of HIV prevalence and the factors associated with HIV prevalence in this community. This cross-sectional study was conducted between July and November 2008. Participants were residents of Fort-Portal municipality aged 15-49 years. A population-based HIV sero-survey and a clinical review of prevention of mother to child HIV transmission (PMTCT) and voluntary counseling and HIV Testing (VCT) records were used to collect quantitative data. An inteviewer administered structured questionnaire was used to collect qualitative data on social deographics, risk behaviour and community perceptions. Focus group discussions (FGDs) and in-depth interviews provided supplementary data on community perceptions. Logistic regression was used in the analysis. The overall HIV prevalence in the general population was 16.1% [95% CI; 12.5-20.6]. Prevalence was lower among women (14.5%; 95% CI; 10.0-19.7) but not significantly different from that among men (18.7%; 95% CI; 12.5-26.3) (c2=0.76, P=0.38). Having more than 2 sexual partners increased the odds of HIV by almost 2.5 times. None or low education and age over 35 years were independently associated with HIV prevalence (P<0.05). Most participants attributed the high HIV prevalence to promiscuity/multiple sexual partners (32.5%), followed by prostitution (13.6%), alcoholism (10.1%), carelessness (10.1%), poverty (9.7%), ignorance (9.5%)), rape (4.7%), drug abuse (3.6%) and others (malice/malevolence, laziness, etc.) (6.2%). Although there was a slight decline compared to previous reports, the results from this study confirm that HIV prevalence is still high in this community. In order to prevent new infections, the factors mentioned above need to be addressed, and we recommend that education aimed at changing individual behavior should be intensified in this community.

scholarly journals Comparison of two individual-based model simulators for HIV epidemiology in a population with HSV-2 using as case study Yaoundé-Cameroon, 1980-2005

2019 ◽  
Author(s):  
Diana M Hendrickx ◽  
João Dinis Sousa ◽  
Pieter J.K. Libin ◽  
Wim Delva ◽  
Jori Liesenborgs ◽  
...  
Keyword(s):  
Model Complexity ◽  
Individual Based Model ◽  
Policy Makers ◽  
Basic Model ◽  
Hiv Epidemiology ◽  
Hiv Epidemic ◽  
Simplex Virus ◽  
Evidence For Policy ◽  
The Impact

ABSTRACTModel comparisons have been widely used to guide intervention strategies to control infectious diseases. Agreement between different models is crucial for providing robust evidence for policy-makers because differences in model properties can influence their predictions. In this study, we compared models implemented by two individual-based model simulators for HIV epidemiology in a population with Herpes simplex virus type 2 (HSV-2). For each model simulator, we constructed four models, starting from a simplified basic model and stepwise including more model complexity. For the resulting eight models, the predictions of the impact of behavioural interventions on the HIV epidemic in Yaoundé (Cameroon) were compared. The results show that differences in model assumptions and model complexity can influence the size of the predicted impact of the intervention, as well as the predicted qualitative behaviour of the HIV epidemic after the intervention. Moreover, two models that agree in their predictions of the HIV epidemic in the absence of intervention can have different outputs when predicting the impact of interventions. Without additional data, it is impossible to determine which of these two models is the most reliable. These findings highlight the importance of making more data available for the calibration and validation of epidemiological models.

HIV Prevalence Trends and Disparities by Gender and Urban-rural Residence Among Adolescents in Sub-saharan Africa

2020 ◽  
Author(s):  
Reka Maulide Cane ◽  
Dessalegn Melesse ◽  
Nkomba Kayeyi ◽  
Abubakar Manu ◽  
Yohannes Dibaba Wado ◽  
...  
Keyword(s):  
Hiv Testing ◽  
Hiv Transmission ◽  
Hiv Prevalence ◽  
Sub Saharan Africa ◽  
Annual Rate ◽  
Lower Prevalence ◽  
Average Annual Rate ◽  
African Countries ◽  
Urban Rural ◽  
Sub Saharan

Abstract Background In sub-Saharan Africa HIV transmission is a major challenge in adolescents, especially among girls and those living in urban settings. Major international efforts have aimed at reducing sexual transmission. This analysis aims to assess the trends in HIV prevalence by gender in adolescents, as well as urban-rural disparities. Methods HIV prevalence data were obtained for 30 countries with a national survey since 2010 and for 23 countries with one survey circa 2005 and a recent survey circa 2015. Countries were grouped into 2% or higher and lower than 2% HIV prevalence among girls 15–19 years in the first survey. Country medians and average annual rates of changes were used to summarize the trends. Data on HIV incidence at ages 15–24 and prevalence at 5–9 and 10–14 years were reviewed from 11 recent national surveys. Trends in urban-rural disparities in HIV prevalence and selected indicators of sexual and HIV testing behaviours were assessed for females and males 15–24 years, using the same surveys. Results HIV prevalence among girls 15–19 years declined in the higher HIV prevalence group from 5.7–2.6% during 2005–2015, corresponding with an average annual rate of reduction of 6.5% per year. Among boys, the median HIV prevalence declined from 2.1–1.2% in the higher prevalence group. Smaller changes were observed in the lower prevalence country group where median HIV prevalence among girls decreased from 0.7–0.4% (average annual rate of reduction 5.9%). Girl – boy differences at 10–14 years were small with a country median HIV of 1.0% and 1.3%, respectively. Urban females and males 15–24 had at least 1.5 times higher HIV prevalence than their rural counterparts, and all experienced similar declines during 2005–2015. Condom use and HIV testing increased among adolescents in both higher and lower prevalence countries, but indicators of sexual activity showed little change over time. Conclusions HIV prevalence declined in almost all countries during the last decade, in both urban and rural settings, for both sexes. The urban-rural gap persisted and HIV transmission to girls, but not boys, is still a major challenge in eastern and southern African countries.

scholarly journals Prevention of Perinatal HIV Transmission in an Area of High HIV Prevalence in the United States

2021 ◽  
Vol 228 ◽  
pp. 101-109
Author(s):  
Wei Li A. Koay ◽  
Jiaqi Zhang ◽  
Krishna V. Manepalli ◽  
Caleb J. Griffith ◽  
Amanda D. Castel ◽  
...  
Keyword(s):  
United States ◽  
Hiv Transmission ◽  
The United States ◽  
Hiv Prevalence ◽  
Perinatal Hiv

Homelessness and HIV Transmission

2017 ◽  
Author(s):  
Kimberly Livingstone ◽  
Daniel B. Herman ◽  
Naomi Adler ◽  
Ezra S. Susser
Keyword(s):  
United States ◽  
Antiretroviral Therapy ◽  
Cause Of Death ◽  
Hiv Transmission ◽  
The United States ◽  
Homeless Persons ◽  
Hiv Prevalence ◽  
Morbidity And Mortality ◽  
Treatment And Prevention ◽  
Hiv Aids

Homelessness is associated with both poorer health and higher risk of morbidity and mortality. Recent research suggests that with growing availability of antiretroviral therapy and the expansion of housing alternatives for chronically homeless persons, HIV is no longer a leading cause of death among the homeless. Nonetheless, HIV prevalence is significantly higher among homeless persons than among their housed counterparts. This chapter examines the association between HIV/AIDS and homelessness in the United States. After providing a brief overview of homelessness and the characteristics of specific homeless subpopulations, we discuss HIV prevalence, transmission, treatment and prevention among people who are homeless in the United States.

Syphilis and HIV Infection among Displaced Pregnant Women in Rural Mozambique

1994 ◽  
Vol 5 (2) ◽  
pp. 117-123 ◽  
Author(s):  
H A Cossa ◽  
S Gloyd ◽  
R G Vaz ◽  
E Folgosa ◽  
E Simbine ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Pregnant Women ◽  
Hiv Transmission ◽  
Perinatal Transmission ◽  
Anal Intercourse ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Hiv Seroprevalence ◽  
High Prevalence ◽  
History Of

A cross-sectional study was conducted among displaced pregnant women in Mozambique to determine the prevalence and correlates of HIV infection and syphilis. Between September 1992 and February 1993, 1728 consecutive antenatal attendees of 14 rural clinics in Zambézia were interviewed, examined, and tested for HIV and syphilis antibodies. The seroprevalence of syphilis and HIV were 12.2% and 2.9%, respectively. Reported sexual abuse was frequent (8.4%) but sex for money was uncommon. A positive MHA-TP result was significantly associated with unmarried status, history of past STD, HIV infection, and current genital ulcers, vaginal discharge, or genital warts. Significant correlates of HIV seropositivity included anal intercourse, history of past STD, and syphilis. In summary, displaced pregnant women had a high prevalence of syphilis but a relatively low HIV seroprevalence suggesting recent introduction of HIV infection in this area or slow spread of the epidemic. A syphilils screening and treatment programme is warranted to prevent perinatal transmission and to reduce the incidence of chancres as a cofactor for HIV transmission.

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