The use of laboratory assays to identify recent infections among samples collected in cross-sectional surveys provides a potentially powerful way to measure HIV incidence. Ongoing evaluations of candidate laboratory assays have highlighted improvements and shortcomings of individual assays in correctly identifying and classifying people as recently infected. We tested two candidate assays, Sedia Limiting Antigen (LAg) and BioRad avidity assays (BioRad) against samples from a prospective cohort study in which incidence was measured directly. BioRad and LAg avidity assays have false recent rates that are up to 8 times lower than those for the BED assay, providing the potential for improved estimates of HIV incidence.
A new formal ‘R Package’ to support incidence estimation is available on the Comprehensive R Archive Network (CRAN). This is the canonical way that the R community distributes stable packages to share functionality, and it is the heart and soul of the R coding environment. The new release through CRAN will make a substantial range of functionalities around incidence survey design and survey data analysis seamlessly and flexibly available to any skilled R programmer/analyst.
UNAIDS has reported that the prevalence of people infected with HIV but who are not on ART, the incidence of HIV, and AIDS related mortality are falling. The Health Metrics Institute recently made their own, semi-independent, assessment of the trends in each of these indicators and reached similar conclusions with small differences arising from the use of somewhat different assumptions. Both analyses suggest that the world is on track to end AIDS by 2030, but this will depend on continued expansion of treatment at about the present rate together with supportive prevention efforts in Sub-Saharan Africa. Unfortunately, the data on which these analyses are based is weak in almost all places and better data on patient monitoring, follow-up and support, including drug procurement, supply and delivery, and better routing surveillance are needed.
The recent HSRC household survey reports that the HIV prevalence among adolescents and young people is declining. Although the decline is important, the focus needs to be on the fact that the reported HIV prevalence levels are still very high, together with alarmingly high levels of HIV incidence. Prevention methods have demonstrated effectiveness in reducing the risk of HIV acquisition among many of the most-at-risk populations. More research is needed, however, into how HIV is spread among the adolescent population and how to decrease this spread.
Individuals across Africa may have changed their sexual behaviour following the visibility of AIDS in the public sphere in the mid to late 1990s. Though each change in behaviour may have been small, the changes affected simultaneously different aspects of individual sexuality, and added up cumulatively into a moderate reduction in sexual behaviour at the individual level. In turn, this change in individual behaviour was translated into massive disruption of sexual networks at the population level. This made it difficult for HIV to propagate in the population leading to large declines in HIV incidence and prevalence.
Community assault (CA) is widespread in the township of Khayelitsha, Cape Town, South Africa. Anecdotal evidence suggests that victims of CA are worse off than other assault cases, but scientific data on the rate and severity of CA cases are lacking for SA. We therefore conducted a case count study to estimate the rate of CA among adults in Khayelitsha and comparing the injury severity and survival probability between cases of CA and other assault (non-CA) cases.