XVII International AIDS Conference: From Evidence to Action - Epidemiology

As the epidemic matures, accurate information about where new infections are occurring, and in which populations, is becoming increasingly critical in designing effective, targeted interventions relevant to current epidemiological trends. Although the quality and accuracy of HIV surveillance data and methodology have improved, in many cases the second generation WHO/UNAIDS surveillance system has not been fully implemented at the national level. National surveillance systems in many low and middle-income countries often do not collect disaggregated data on some most at risk populations, which is critical to developing targeted prevention interventions

High acceptability of voluntary counselling and HIV-testing but unacceptable loss to follow up in a prevention of mother-to-child HIV transmission programme in rural Malawi: scaling-up requires a different way of acting.

SETTING: Thyolo District Hospital, rural Malawi. OBJECTIVES: In a prevention of mother-to-child HIV transmission (PMTCT) programme, to determine: the acceptability of offering 'opt-out' voluntary counselling and HIV-testing (VCT); the progressive loss to follow up of HIV-positive mothers during the antenatal period, at delivery and to the 6-month postnatal visit; and the proportion of missed deliveries in the district. DESIGN: Cohort study. METHODS: Review of routine antenatal, VCT and PMTCT registers. RESULTS: Of 3136 new antenatal mothers, 2996 [96%, 95% confidence interval (CI): 95-97] were pre-test counselled, 2965 (95%, CI: 94-96) underwent HIV-testing, all of whom were post-test counselled. Thirty-one (1%) mothers refused HIV-testing. A total of 646 (22%) individuals were HIV-positive, and were included in the PMTCT programme. Two hundred and eighty-eight (45%) mothers and 222 (34%) babies received nevirapine. The cumulative loss to follow up (n=646) was 358 (55%, CI: 51-59) by the 36-week antenatal visit, 440 (68%, CI: 64-71) by delivery, 450 (70%, CI: 66-73) by the first postnatal visit and 524 (81%, CI: 78-84) by the 6-month postnatal visit. This left just 122 (19%, CI: 16-22) of the initial cohort still in the programme. The great majority (87%) of deliveries occurred at peripheral sites where PMTCT was not available. CONCLUSIONS: In a rural district hospital setting, at least 9 out of every 10 mothers attending antenatal services accepted VCT, of whom approximately one-quarter were HIV-positive and included in the PMTCT programme. The progressive loss to follow up of more than three-quarters of this cohort by the 6-month postnatal visit demands a 'different way of acting' if PMTCT is to be scaled up in our setting

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

An assessment of quality of home-based HIV counseling and testing performed by lay counselors in a rural sub-district of KwaZulu-Natal, South Africa

HIV counseling and testing (HCT) has been prioritized as one of the prevention strategies for HIV/AIDS, and promoted as an essential tool in scaling up and improving access to treatment, care and support especially in community settings. Home-based HCT (HBHCT) is a model that has consistently been found to be highly acceptable and has improved HCT coverage and uptake in low- and middle-income countries since 2002. It involves trained lay counselors going door-todoor offering pre-test counseling and providing HCT services to consenting eligible household members. Currently, there are few studies reporting on the quality of HBHCT services offered by lay counselors especially in Sub-Saharan Africa, including South Africa. This is a quantitative descriptive sub-study of a community randomized trial (Good Start HBHCT trial) which describes the quality of HBHCT provided by lay counselors. Quality of HBHCT was measured as scores comparing observed practice to prescribed protocols using direct observation. Data were collected through periodic observations of HCT sessions and exit interviews with clients. Counselor quality scores for pre-test counseling and post-test counseling sessions were created to determine the level of quality. For the client exit interviews a continuous score was created to assess how satisfied the clients were with the counseling session. A total of 196 (3%) observational assessments and 406 (6%) client exit interviews were completed. Overall, median scores for quality of counseling and testing were high for both HIV-negative and HIV-positive clients. For exit interviews all 406 (100%) clients had overall satisfaction with the counseling and testing services they received, however 11% were concerned about the counselor keeping their discussion confidential. Of all 406 clients, 393 (96.8%) intended to recommend the service to other people. In ensuring good quality HCT services, ongoing quality assessments are important to monitor quality of HCT after training

Trends of Zambia’s tuberculosis burden over the past two decades

Objectives:  To study trends in Zambia’s TB notification rates between 1990 and 2010 and to ascertain progress made towards TB control. Methods:  Retrospective review of TB notification returns and TB programme reports for the period from 1990 to 2010. Results:  Two distinct TB trend periods were identified: a period of rising trends up to a peak between 1990 and 2004 and a period of moderately declining trends between 2004 and 2010. Treatment outcomes improved over the two decades. Data on trends in paediatric TB, TB in prisoners and TB in pregnant women remain scanty and unreliable owing to poor diagnostic capability. There were no data available on trends on drug-resistant TB because of the lack of laboratory services to perform drug sensitivity testing. Conclusions:  The period of increasing TB between 1990 and 2000 coincided with an increase in HIV/AIDS. The period of slightly decreasing TB between 2004 and 2010 can be attributed to improved TB care, sustained DOTS implementation and improvement in TB diagnostic services. Newer diagnostics technologies for the rapid diagnosis of active TB cases and for drug-resistant testing, recently endorsed by the WHO, need to be implemented into the national TB programmes to detect more cases and to provide epidemiological and surveillance data from which to obtain an evidence base for guided investments for TB control. Alignment of TB and HIV services is required to achieve improved management outcomes

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

Adult male circumcision as an intervention against HIV: An operational study of uptake in a South African community (ANRS 12126)

<p>Abstract</p> <p>Background</p> <p>To evaluate the knowledge, attitudes and beliefs about adult male circumcision (AMC), assess the association of AMC with HIV incidence and prevalence, and estimate AMC uptake in a Southern African community.</p> <p>Methods</p> <p>A cross-sectional biomedical survey (ANRS-12126) conducted in 2007-2008 among a random sample of 1198 men aged 15 to 49 from Orange Farm (South Africa). Face-to-face interviews were conducted by structured questionnaire. Recent HIV infections were evaluated using the BED incidence assay. Circumcision status was self-reported and clinically assessed. Adjusted HIV incidence rate ratios (aIRR) and prevalence ratios (aPR) were calculated using Poisson regression.</p> <p>Results</p> <p>The response rate was 73.9%. Most respondents agreed that circumcised men could become HIV infected and needed to use condoms, although 19.3% (95%CI: 17.1% to 21.6%) asserted that AMC protected fully against HIV. Among self-reported circumcised men, 44.9% (95%CI: 39.6% to 50.3%) had intact foreskins. Men without foreskins had lower HIV incidence and prevalence than men with foreskins (aIRR = 0.35; 95%CI: 0.14 to 0.88; aPR = 0.45, 95%CI: 0.26 to 0.79). No significant difference was found between self-reported circumcised men with foreskins and other uncircumcised men. Intention to undergo AMC was associated with ethnic group and partner and family support of AMC. Uptake of AMC was 58.8% (95%CI: 55.4% to 62.0%).</p> <p>Conclusions</p> <p>AMC uptake in this community is high but communication and counseling should emphasize what clinical AMC is and its effect on HIV acquisition. These findings suggest that AMC roll-out is promising but requires careful implementation strategies to be successful against the African HIV epidemic.</p

Implementing services for Early Infant Diagnosis (EID) of HIV: a comparative descriptive analysis of national programs in four countries

<p>Abstract</p> <p>Background</p> <p>There is a significant increase in survival for HIV-infected children who have early access to diagnosis and treatment. The goal of this multi-country review was to examine when and where HIV-exposed infants and children are being diagnosed, and whether the EID service is being maximally utilized to improve health outcomes for HIV-exposed children.</p> <p>Methods</p> <p>In four countries across Africa and Asia existing documents and data were reviewed and key informant interviews were conducted. EID testing data was gathered from the central testing laboratories and was then complemented by health facility level data extraction which took place using a standardized and validated questionnaire</p> <p>Results</p> <p>In the four countries reviewed from 2006 to 2009 EID sample volumes rose dramatically to an average of >100 samples per quarter in Cambodia and Senegal, >7,000 samples per quarter in Uganda, and >2,000 samples per quarter in Namibia. Geographic coverage of sites also rapidly expanded to 525 sites in Uganda, 205 in Namibia, 48 in Senegal, and 26 in Cambodia in 2009. However, only a small proportion of testing was done at lower-level health facilities: in Uganda Health Center IIs and IIIs comprised 47% of the EID collection sites, but only 11% of the total tests, and in Namibia 15% of EID sites collected >93% of all samples. In all countries except for Namibia, more than 50% of the EID testing was done after 2 months of age. Few sites had robust referral mechanisms between EID and ART. In a sub-sample of children, we noted significant attrition of infants along the continuum of care post testing. Only 22% (Senegal), 37% (Uganda), and 38% (Cambodia) of infants testing positive by PCR were subsequently initiated onto treatment. In Namibia, which had almost universal EID coverage, more than 70% of PCR-positive infants initiated ART in 2008.</p> <p>Conclusions</p> <p>While EID testing has expanded dramatically, a large proportion of PCR- positive infants are initiated on treatment. As EID services continue to scale-up, more programmatic attention and support is needed to retain HIV-exposed infants in care and ensure that those testing positive initiate treatment in a timely manner. Namibia's experience demonstrates that it is feasible for a rural, low-income country to achieve high national coverage of infant testing and treatment.</p

How fast could HIV change gene frequencies in the human population?

Infectious diseases have the potential to act as strong forces for genetic selection on the populations they affect. Human immunodeficiency virus (HIV) is a prime candidate to impose such genetic selection owing to the vast number of people it infects and the varying susceptibility of different human leucocyte antigen (HLA) types to HIV disease progression. We have constructed a model of HIV infection that differentiates between these HLA types, and have used reported estimates of the number of people infected with HIV and the different rates of progression to acquired immunodeficiency syndrome (AIDS) to provide a lower bound estimate on the length of time it would take for HIV to impose major genetic change in humans. We find that an HIV infection similar to that currently affecting sub-Saharan Africa could not yet have caused more than a 3 per cent decrease in the proportion of individuals who progress quickly to disease. Such an infection is unlikely to cause major genetic change (defined as a decrease in the proportion of quickly progressing individuals to under 50 per cent of their starting proportion) until 400 years have passed since HIV emergence. However, in very severely affected populations, there is a chance of observing such major genetic changes after another 50 years