Wolfgang Hladik

Declines in HIV prevalence can be associated with changing sexual behaviour in Uganda, urban Kenya, Zimbabwe, and urban Haiti

Objective: To determine whether observed changes in HIV prevalence in countries with generalised HIV epidemics are associated with changes in sexual risk behaviour. Methods: A mathematical model was developed to explore the relation between prevalence recorded at antenatal clinics (ANCs) and the pattern of incidence of infection throughout the population. To create a null model a range of assumptions about sexual behaviour, natural history of infection, and sampling biases in ANC populations were explored to determine which factors maximised declines in prevalence in the absence of behaviour change. Modelled prevalence, where possible based on locally collected behavioural data, was compared with the observed prevalence data in urban Haiti, urban Kenya, urban Cote d’Ivoire, Malawi, Zimbabwe, Rwanda, Uganda, and urban Ethiopia. Results: Recent downturns in prevalence observed in urban Kenya, Zimbabwe, and urban Haiti, like Uganda before them, could only be replicated in the model through reductions in risk associated with changes in behaviour. In contrast, prevalence trends in urban Cote d’Ivoire, Malawi, urban Ethiopia, and Rwanda show no signs of changed sexual behaviour. Conclusions: Changes in patterns of HIV prevalence in urban Kenya, Zimbabwe, and urban Haiti are quite recent and caution is required because of doubts over the accuracy and representativeness of these estimates. Nonetheless, the observed changes are consistent with behaviour change and not the natural course of the HIV epidemic.

Risk Factors for Recent HIV Infection in Uganda

CONTEXT Studies of factors associated with acquiring human immunodeficiency virus (HIV) are often based on prevalence data that might not reflect recent infections. OBJECTIVE To determine demographic, biological, and behavioral factors for recent HIV infection in Uganda. DESIGN AND SETTING Nationally representative household survey of cross-sectional design conducted in Uganda from August 2004 through January 2005; data were analyzed until November 2007. PARTICIPANTS There were 11,454 women and 9905 men aged 15 to 59 years who were eligible. Questionnaires were completed for 10,826 women (95%) and 8830 men (89%); of those interviewed, blood specimens were collected for 10,227 women (94%) and 8298 men (94%). MAIN OUTCOME MEASURE Specimens seropositive for HIV were tested with the BED IgG capture-based enzyme immunosorbent assay to identify recent seroconversions (median, 155 days) using normalized optical density of 0.8 and adjustments. RESULTS Of the 1023 HIV infections with BED results, 172 (17%) tested as recent. In multivariate analysis, risk factors associated with recent HIV infection included female sex (adjusted odds ratio [aOR], 2.4; 95% confidence interval [CI], 1.1-5.2); current marital status (widowed vs never married, aOR, 6.1; 95% CI, 2.8-13.3; divorced vs never married, aOR, 3.0; 95% CI, 1.5-6.1); geographic region (north central Uganda vs central Uganda/Kampala, aOR, 2.6; 95% CI, 1.7-4.1); number of sex partners in past year (> or = 2 compared with none; aOR, 2.9; 95% CI, 1.6-5.5); herpes simplex virus type 2 infection (aOR, 3.9; 95% CI, 2.6-5.8); report of a sexually transmitted disease in the past year (aOR, 1.7; 95% CI, 1.2-2.4); and being an uncircumcised man (aOR, 2.5; 95% CI, 1.1-5.3). Among married participants, recent HIV infection was associated with never using condoms with partners outside of marriage (aOR, 3.2; 95% CI, 1.7-6.1) compared with individuals having no outside partners. The risk of incident HIV infection for married individuals who used condoms with at least 1 outside partner was similar to that of those who did not have any partners outside of marriage (aOR, 1.0; 95% CI, 0.3-2.7). CONCLUSION A survey of individuals in Uganda who were tested with an HIV assay used to establish recent infection identified risk factors, which offers opportunities for prevention initiatives.

HIV Infection among Men Who Have Sex with Men in Kampala, Uganda–A Respondent Driven Sampling Survey

Background Ugandas generalized HIV epidemic is well described, including an estimated adult male HIV prevalence in Kampala of 4.5%, but no data are available on the prevalence of and risk factors for HIV infection among men who have sex with men (MSM). Methodology/Principal Findings From May 2008 to February 2009, we used respondent-driven sampling to recruit MSM ≥18 years old in Kampala who reported anal sex with another man in the previous three months. We collected demographic and HIV-related behavioral data through audio computer-assisted self-administered interviews. Laboratory testing included biomarkers for HIV and other sexually transmitted infections. We obtained population estimates adjusted for the non-random sampling frame using RDSAT and STATA. 300 MSM were surveyed over 11 waves; median age was 25 years (interquartile range, 21–29 years). Overall HIV prevalence was 13.7% (95% confidence interval [CI] 7.9%–20.1%), and was higher among MSM ≥25 years (22.4%) than among MSM aged 18–24 years (3.9%, odds ratio [OR] 5.69, 95% CI 2.02–16.02). In multivariate analysis, MSM ≥25 years (adjusted OR [aOR] 4.32, 95% CI 1.33–13.98) and those reporting ever having been exposed to homophobic abuse (verbal, moral, sexual, or physical abuse; aOR 5.38, 95% CI 1.95–14.79) were significantly more likely to be HIV infected. Conclusions/Significance MSM in Kampala are at substantially higher risk for HIV than the general adult male population. MSM reporting a lifetime history of homophobic abuse are at increased risk of being HIV infected. Legal challenges and stigma must be overcome to provide access to tailored HIV prevention and care services.

The contribution of family planning towards the prevention of vertical HIV transmission in Uganda.

Background Uganda has one of the highest total fertility rates (TFR) worldwide. We compared the effects of antiretroviral (ARV) prophylaxis for the prevention of mother-to-child HIV transmission (PMTCT) to that of existing family planning (FP) use and estimated the burden of pediatric HIV disease due to unwanted fertility. Methodology/Principal Findings Using the demographic software Spectrum, a baseline mathematical projection to estimate the current pediatric HIV burden in Uganda was compared to three hypothetical projections: 1) without ARV-PMTCT (to estimate the effect of ARV-PMTCT), 2) without contraception (effect of existing FP use), 3) without unwanted fertility (effect of unmet FP needs). Key input parameters included HIV prevalence, ARV-PMTCT uptake, MTCT probabilities, and TFR. We estimate that in 2007, an estimated 25,000 vertical infections and 17,000 pediatric AIDS deaths occurred (baseline projection). Existing ARV-PMTCT likely averted 8.1% of infections and 8.5% of deaths. FP use likely averted 19.7% of infections and 13.1% of deaths. Unwanted fertility accounted for 21.3% of infections and 13.4% of deaths. During 2008–2012, an estimated 131,000 vertical infections and 71,000 pediatric AIDS deaths will occur. The projected scale up of ARV-PMTCT (from 39%–57%) may avert 18.1% of infections and 24.5% of deaths. Projected FP use may avert 21.6% of infections and 18.5% of deaths. Unwanted fertility will account for 24.5% of infections and 19.8% of deaths. Conclusions Existing FP use contributes as much or more than ARV-PMTCT in mitigating pediatric HIV in Uganda. Expanding FP services can substantially contribute towards PMTCT.

Kaposi Sarcoma-Associated Herpesvirus (KSHV) Seroprevalence in Population-Based Samples of African Children: Evidence for At Least 2 Patterns of KSHV Transmission

BACKGROUND Kaposi sarcoma-associated herpesvirus (KSHV) infection is endemic among adult populations in Africa. A prevailing view is that childhood transmission is primarily responsible for the high seroprevalence of KSHV among adults that is observed throughout the continent. However, few studies have directly examined children, particularly in locations where KS is not commonly endemic. METHODS Participants were children aged 1.5-8.9 years, including 427 children from a population-based sample in South Africa, 422 from a population-based sample in Uganda, and 567 from a clinic-based sample in Uganda. All serum specimens were tested by the same laboratory for KSHV antibodies with use of 2 enzyme immunoassays (against K8.1 and ORF65) and 1 immunofluorescence assay. RESULTS KSHV seroprevalence was 7.5%-9.0% among South African children and was not associated with age. In contrast, in the Ugandan population-based sample, KSHV seroprevalence increased from 10% among 2-year-old children to 30.6% among 8-year-old children (P(trend) < .001). In the Ugandan clinic-based sample, seroprevalence increased from 9.3% among 2-year-old children to 36.4% among 8-year-old children (P(trend) < .001). CONCLUSION Two distinct relationships between age and KSHV infection among children imply that KSHV transmission among children is not uniform throughout Africa and is therefore not always responsible for the high seroprevalence observed in adults. There are at least 2 patterns of KSHV transmission in Africa.

Strengthening the Reporting of Observational Studies in Epidemiology for respondent-driven sampling studies: "STROBE-RDS" statement.

Objectives Respondent-driven sampling (RDS) is a new data collection methodology used to estimate characteristics of hard-to-reach groups, such as the HIV prevalence in drug users. Many national public health systems and international organizations rely on RDS data. However, RDS reporting quality and available reporting guidelines are inadequate. We carried out a systematic review of RDS studies and present Strengthening the Reporting of Observational Studies in Epidemiology for RDS Studies (STROBE-RDS), a checklist of essential items to present in RDS publications, justified by an explanation and elaboration document. Study Design and Setting We searched the MEDLINE (1970–2013), EMBASE (1974–2013), and Global Health (1910–2013) databases to assess the number and geographical distribution of published RDS studies. STROBE-RDS was developed based on STROBE guidelines, following Guidance for Developers of Health Research Reporting Guidelines. Results RDS has been used in over 460 studies from 69 countries, including the USA (151 studies), China (70), and India (32). STROBE-RDS includes modifications to 12 of the 22 items on the STROBE checklist. The two key areas that required modification concerned the selection of participants and statistical analysis of the sample. Conclusion STROBE-RDS seeks to enhance the transparency and utility of research using RDS. If widely adopted, STROBE-RDS should improve global infectious diseases public health decision making.

Respondent driven sampling--where we are and where should we be going?

Respondent Driven Sampling (RDS) is a novel variant of link tracing sampling that has primarily been used to estimate the characteristics of hard-to-reach groups, such as the HIV prevalence of drug users.1 ‘Seeds’ are selected by convenience from a population of interest (target population) and given coupons. Seeds then use these coupons to recruit other people, who themselves become recruiters. Recruits are given compensation, usually money, for taking part in the survey and also an incentive for recruiting others. This process continues in recruitment ‘waves’ until the survey is stopped. Estimation methods are then applied to account for the biased recruitment, for example, the presumed over-recruitment of people with more acquaintances, in an attempt to generate estimates for the underlying population. RDS has quickly become popular and relied on by major public health organisations, including the US Centers for Disease Control and Prevention and Family Health International, chiefly because it is often found to be an efficient method of recruitment in hard-to-reach groups, but also because of the availability of custom written software incorporating inference methods that are designed to generate estimates that are representative of the wider population of interest, despite the biased sampling. As demonstrated by RDSs popularity,1 there was a clear need for new methods of data collection on hard-to-reach groups. However, RDS has not been without its critics. Its reliance on the target population for recruitment introduced ethicalw1 and sampling concerns.w2 If RDS estimates are overly biased or the variance is unacceptably high, then RDS will be little more than another method of convenience sampling. If these errors can be minimised however, then RDS has the potential to become a very useful survey methodology. In this editorial we highlight that ‘RDS’ includes both data collection and statistical inference methods, discuss the limitations …

Kaposi's sarcoma in Uganda: Risk factors for human herpesvirus 8 infection among blood donors

Human herpesvirus 8 (HHV-8) is etiologically linked to Kaposis sarcoma, a common cancer in Uganda. The authors assessed HHV-8 seroprevalence, risk factors for infection, and HHV-8 assays in a cross-sectional study of Ugandan blood donors. Of 3,736 specimens, the authors selected 203 reactive for HIV, hepatitis B surface antigen (HBsAg), or syphilis, and, randomly, 203 nonreactive specimens. For HHV-8 testing, the authors used two peptide-based enzyme-linked immunosorbent assays (EIAs), ORFK8.1 and ORF65, and an immunofluorescence assay (IFA). Specimens reactive in at least two assays or on IFA alone were considered HHV-8-seropositive. Prevalence estimates were weighted to account for the sampling scheme. Overall HHV-8 seroprevalence was 40%. HHV-8 seroprevalence was higher among HBsAg-positive donors (53%) than HBsAg-negative donors (39%; p =.02) and higher among HIV-positive donors (63%) than HIV-negative donors (39%; p <.001). HHV-8 seroreactivity showed no trend with age. Kappa values for assay concordances were 0.68 (ORFK8.1 EIA and IFA), 0.37 (ORF65 EIA and K8.1 EIA), and 0.29 (ORF65 EIA and IFA). The association between HHV-8 and HBsAg positivity and the lack of association between HHV-8 and age point to primarily nonsexual HHV-8 transmission during childhood. The association with HIV indicates sexual transmission may also occur. The role of ORF65 EIA in testing specimens from Africa warrants further evaluation.

HIV/AIDS in Ethiopia: where is the epidemic heading?

Objectives: A possible decline in prevalence of HIV in some sub-Saharan African countries has been reported recently. The present study aimed to evaluate the prevalence and incidence of HIV and behavioural data to investigate trends in HIV/AIDS in Ethiopia. Methods: A review was conducted of published reports and literature, raw and modelled (using Epidemic Projection Package and Spectrum software) surveillance data and estimates from antenatal clinics (ANCs) and data from voluntary counselling and testing centres. Observations were restricted to the adult population. Results: Between 2001 and 2003, more ANC sites showed a decline than a rise in HIV prevalence, but most lacked statistical significance. Modelled data suggested a rise in prevalence of HIV in rural areas (2003: 2.6%) and in all Ethiopia (2003: 4.4%), but a stable or declining prevalence in Addis Ababa (2003: 14.6%) and other urban areas (2003: 11.8%). Modelled HIV incidence, inferred from prevalence changes, showed a slowly rising trend in Addis Ababa (2003: 2.0%), other urban areas (2003: 1.7%), and rural Ethiopia (2003: 0.46%). The total burden of HIV/AIDS is expected also to rise substantially due to population growth. In Addis Ababa, crude data on HIV prevalence from ANCs too suggested a falling trend. Voluntary counselling and testing data from 2002 to 2004 supported this trend but indicated a mixed trend pattern for high risk behaviour. No other serial behavioural trend data were available. Conclusions: Lack of quality data on behavioural trends impedes the interpretation of prevalence and incidence data in Ethiopia. Modelled data suggest an expanding HIV epidemic in rural and all Ethiopia, but a possible decline in some urban areas. Crude site prevalence values may be more sensitive to acute changes, possibly indicating a slowing/reversal of the epidemic’s expansion.

Prevalence and screening costs of hepatitis C virus among Ugandan blood donors.

Background  Screening donated blood for hepatitis C virus (HCV) is important for HCV prevention and is routinely practiced in North America and Europe. However, in many African countries little is known about HCV prevalence or cost‐effectiveness of HCV antibody (anti‐HCV) screening.