722 research outputs found
Understanding the gender disparity in HIV infection across countries in sub-Saharan Africa: Evidence from the Demographic and Health Surveys
Women in sub-SaharanAfrica bear a disproportionate burden of human immunodeficiency virus (HIV) infections, which is exacerbated by their role in society and biological vulnerability. The specific objectives of this article are to (i) determine the extent of gender disparity in HIV infection; (ii) examine the role of HIV behaviour factors on the gender disparity and (iii) establish how the gender disparity varies between individuals of different characteristics and across countries. The analysis involves multilevel logistic regression analysis applied to pooledDemographic andHealth Surveys data from 20 countries in sub-Saharan Africa conducted during 2003–2008. The findings suggest that women in sub- Saharan Africa have on average a 60%higher risk of HIV infection than their male counterparts. The risk for women is 70%higher than their male counterparts of similar sexual behaviour, suggesting that the observed gender disparity cannot be attributed to sexual behaviour. The results suggest that the risk ofHIV infection among women (compared to men) across countries in sub-Saharan Africa is further aggravated among those who are younger, in female-headed households, not in stable unions or marital partnerships or had an earlier sexual debut.⁄ acquired immune deficiency syndrome (AIDS) awareness and sexua
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Male circumcision for HIV prevention in high HIV prevalence settings: what can mathematical modelling contribute to informed decision making?
Experts from UNAIDS, WHO, and the South African Centre for Epidemiological Modelling report their review of mathematical models estimating the impact of male circumcision on HIV incidence in high HIV prevalence settings
The road to eliminate mother‐to‐child HIV transmission
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Direct microscopy versus sputum cytology analysis and bleach sedimentation for diagnosis of tuberculosis: a prospective diagnostic study.
ABSTRACT: BACKGROUND: Diagnostic options for pulmonary tuberculosis in resource-poor settings are commonly limited to smear microscopy. We investigated whether bleach concentration by sedimentation and sputum cytology analysis (SCA) increased the positivity rate of smear microscopy for smear-positive tuberculosis. METHODS: We did a prospective diagnostic study in a Medecins Sans Frontieres-supported hospital in Mindouli, Republic of Congo. Three sputum samples were obtained from 280 consecutive pulmonary tuberculosis suspects, and were processed according to WHO guidelines for direct smear microscopy. The remainder of each sputum sample was homogenised with 2.6% bleach, sedimented overnight, smeared, and examined blinded to the direct smear result for acid-fast bacilli (AFB). All direct smears were assessed for quality by SCA. If a patient produced fewer than three good-quality sputum samples, further samples were requested. Sediment smear examination was performed independently of SCA result on the corresponding direct smear. Positivity rates were compared using McNemar's test. RESULTS: Excluding SCA, 43.2% of all patients were diagnosed as positive on direct microscopy of up to three samples. 47.9% were diagnosed on sediment microscopy, with 48.2% being diagnosed on direct microscopy, sediment microscopy, or both. The positivity rate increased from 43.2% to 47.9% with a case definition of one positive smear ([greater than or equal to]1 AFB/100 high power fields) of three, and from 42.1% to 43.9% with two positive smears. SCA resulted in 87.9% of patients producing at least two good-quality sputum samples, with 75.7% producing three or more. Using a case definition of one positive smear, the incremental yield of bleach sedimentation was 14/121, or 11.6% (95% CI 6.5-18.6, p=0.001) and in combination with SCA was 15/121, or 12.4% (95% CI 7.1-19.6, p=0.002). Incremental yields with two positive smears were 5/118, or 4.2% (95% CI 1.4-9.6, p=0.062) and 7/118, or 5.9% (95% CI 2.4-11.8, p=0.016), respectively. CONCLUSIONS: The combination of bleach sedimentation and SCA resulted in significantly increased microscopy positivity rates with a case definition of either one or two positive smears. Implementation of bleach sedimentation led to a significant increase in the diagnosis of smear-positive patients. Implementation of SCA did not result in significantly increased diagnosis of tuberculosis, but did result in improved sample quality. Requesting extra sputum samples based on SCA results, combined with bleach sedimentation, could significantly increase the detection of smear-positive patients if routinely implemented in resource-limited settings where gold standard techniques are not available. We recommend that a pilot phase is undertaken before routine implementation to determine the impact in a particular context
Global trends in molecular epidemiology of HIV-1 during 2000-2007
Objective
To estimate the global and regional distribution of HIV-1 subtypes and recombinants between 2000 and 2007.
Design
Country-specific HIV-1 molecular epidemiology data were combined with estimates of the number of HIV-infected people in each country.
Method
Cross-sectional HIV-1 subtyping data were collected from 65913 samples in 109 countries between 2000 and 2007. The distribution of HIV-1 subtypes in individual countries was weighted according to the number of HIV-infected people in each country to generate estimates of regional and global HIV-1 subtype distribution for the periods 2000–2003 and 2004–2007.
Results
Analysis of the global distribution of HIV-1 subtypes and recombinants in the two time periods indicated a broadly stable distribution of HIV-1 subtypes worldwide with a notable increase in the proportion of circulating recombinant forms (CRFs), a decrease in unique recombinant forms (URFs), and an overall increase in recombinants. In 2004–2007, subtype C accounted for nearly half (48%) of all global infections, followed by subtypes A (12%) and B (11%), CRF02_AG (8%), CRF01_AE (5%), subtype G (5%) and D(2%). Subtypes F, H, J and K together cause fewer than 1% of infections worldwide. Other CRFs and URFs are each responsible for 4% of global infections, bringing the combined total of worldwide CRFs to 16% and all recombinants (CRFs plus URFs) to 20%.
Conclusions
The global and regional distributions of individual subtypes and recombinants are broadly stable, although CRFs may play an increasing role in the HIV pandemic. The global diversity of HIV-1 poses a formidable challenge to HIV vaccine development.Fil: Hemelaar, Joris. University of Oxford; Reino UnidoFil: Gouwsb, Eleanor. UNAIDS; SuizaFil: Ghysb, Peter D.. UNAIDS; SuizaFil: Osmanov, Saladin. WHO-UNAIDS HIV Vaccine Initiative; SuizaFil: WHO-UNAIDS Network for HIV Isolation and Characterisation.Fil: Salomon, Horacio Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin
Feasibility and acceptability of rapid HIV screening in a labour ward in Togo
Background: HIV screening in a labour ward is the last opportunity to initiate an antiretroviral prophylaxis among pregnant women living with HIV to prevent mother-to-child HIV transmission. Little is known about the feasibility and acceptability of HIV screening during labour in West Africa. Findings: A cross-sectional survey was conducted in the labour ward at the Tokoin Teaching Hospital in Lomé (Togo) between May and August 2010. Pregnant women admitted for labour were randomly selected to enter the study and were interviewed on the knowledge of their HIV status. Clinical and biological data were collected from the individual maternal health chart. HIV testing or re-testing was systematically proposed to all pregnant women. Among 1530 pregnant women admitted for labour, 508 (32.2%) were included in the study. Information on HIV screening was available in the charts of 359 women (71%). Overall, 467 women accepted HIV testing in the labour ward (92%). The HIV prevalence was 8.8% (95% confidence interval: 6.4 to 11.7%). Among the 41 women diagnosed as living with HIV during labour, 34% had not been tested for HIV during pregnancy and were missed opportunities. Antiretroviral prophylaxis had been initiated antenatally for 24 women living with HIV and 17 in the labour room. Conclusions: This study is the first to show in West Africa that HIV testing in a labour room is feasible and well accepted by pregnant women. HIV screening in labour rooms needs to be routinely implemented to reduce missed opportunities for intervention aimed at HIV care and prevention, especially PMTCT
Guidelines for using HIV testing technologies in surveillance: selection, evaluation, and implementation
[UNAIDS/WHO Working Group on Global HIV/AIDS and STI Surveillance]."WHO/CDS/CSR/EDC/2001.16.""UNAIDS/01.22E.""Global surveillance of HIV/AIDS and sexually transmitted infections (STIs) is a joint effort of the World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS (UNAIDS). The UNAIDS/WHO Working Group on Global HIV/AIDS and STI Surveillance, initiated in November 1996, is the main coordination and implementation mechanism for UNAIDS and WHO to compile the best information available and to improve the quality of data needed for informed decision-making and planning at national, regional and global levels. ... The Centers for Disease Control and Prevention (CDC), Atlanta, USA, deserves special credit for having prepared these Guidelines. The key professional staff, Dr. Christopher Murrill and Dr. Rebecca Martin, should be congratulated for their efforts in producing this document, with editorial assistance from Ms. Sadhna Patel and Ms. Beatrice Divine." - p. iiAlso available via the World Wide Web.Includes bibliographical references (p. 37-38)
Understanding low sensitivity of community-based HIV rapid testing: experiences from the HPTN 071 (PopART) trial in Zambia and South Africa.
INTRODUCTION: Population-wide HIV testing services (HTS) must be delivered in order to achieve universal antiretroviral treatment (ART) coverage. To accurately deliver HTS at such scale, non-facility-based HIV point-of-care testing (HIV-POCT) is necessary but requires rigorous quality assurance (QA). This study assessed the performance of community-wide HTS in Zambia and South Africa (SA) as part of the HPTN 071 (PopART) study and explores the impact of quality improvement interventions on HTS performance. METHODS: Between 2014 and 2016, HIV-POCT was undertaken within households both as part of the randomly selected HPTN 071 research cohort (Population Cohort [PC]) and as part of the intervention provided by community HIV-care providers. HIV-POCT followed national algorithms in both countries. Consenting PC participants provided a venous blood sample in addition to being offered HIV-POCT. We compared results obtained in the PC using a laboratory-based gold standard (GS) testing algorithm and HIV-POCT. Comprehensive QA mechanisms were put in place to support the community-wide testing. Participants who were identified as having a false negative or false positive HIV rapid test were revisited and offered retesting. RESULTS: We initially observed poor sensitivity (45-54%, 95% confidence interval [CI] 31-69) of HIV-POCT in the PC in SA compared to sensitivity in Zambia for the same time period of 95.8% (95% CI 93-98). In both countries, specificity of HIV-POCT was >98%. With enhanced QA interventions and adoption of the same HIV-POCT algorithm, sensitivity in SA improved to a similar level as in Zambia. CONCLUSIONS: This is one of the first reports of HIV-POCT performance during wide-scale delivery of HTS compared to a GS laboratory algorithm. HIV-POCT in a real-world setting had a lower sensitivity than anticipated. Appropriate choice of HIV-POCT algorithms, intensive training and supervision, and robust QA mechanisms are necessary to optimize HIV-POCT test performance when testing is delivered at a community level. HIV-POCT in clients who did not disclose that they were on ART may have contributed to false negative HIV-POCT results and should be the topic of future research
PrEP as a feature in the optimal landscape of combination HIV prevention in sub-Saharan Africa
INTRODUCTION: The new WHO guidelines recommend offering pre-exposure prophylaxis (PrEP) to people who are at substantial risk of HIV infection. However, where PrEP should be prioritised, and for which population groups, remains an open question. The HIV landscape in sub-Saharan Africa features limited prevention resources, multiple options for achieving cost saving, and epidemic heterogeneity. This paper examines what role PrEP should play in optimal prevention in this complex and dynamic landscape. METHODS: We use a model that was previously developed to capture subnational HIV transmission in sub-Saharan Africa. With this model, we can consider how prevention funds could be distributed across and within countries throughout sub-Saharan Africa to enable optimal HIV prevention (that is, avert the greatest number of infections for the lowest cost). Here, we focus on PrEP to elucidate where, and to whom, it would optimally be offered in portfolios of interventions (alongside voluntary medical male circumcision, treatment as prevention, and behaviour change communication). Over a range of continental expenditure levels, we use our model to explore prevention patterns that incorporate PrEP, exclude PrEP, or implement PrEP according to a fixed incidence threshold. RESULTS: At low-to-moderate levels of total prevention expenditure, we find that the optimal intervention portfolios would include PrEP in only a few regions and primarily for female sex workers (FSW). Prioritisation of PrEP would expand with increasing total expenditure, such that the optimal prevention portfolios would offer PrEP in more subnational regions and increasingly for men who have sex with men (MSM) and the lower incidence general population. The marginal benefit of including PrEP among the available interventions increases with overall expenditure by up to 14% (relative to excluding PrEP). The minimum baseline incidence for the optimal offer of PrEP declines for all population groups as expenditure increases. We find that using a fixed incidence benchmark to guide PrEP decisions would incur considerable losses in impact (up to 7%) compared with an approach that uses PrEP more flexibly in light of prevailing budget conditions. CONCLUSIONS: Our findings suggest that, for an optimal distribution of prevention resources, choices of whether to implement PrEP in subnational regions should depend on the scope for impact of other possible interventions, local incidence in population groups, and total resources available. If prevention funding were to become restricted in the future, it may be suboptimal to use PrEP according to a fixed incidence benchmark, and other prevention modalities may be more cost-effective. In contrast, expansions in funding could permit PrEP to be used to its full potential in epidemiologically driven prevention portfolios and thereby enable a more cost-effective HIV response across Africa
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