HIV and human papillomavirus (HPV) are two heavy hitting sexually transmitted infections (STIs). Meta-analyses of the association between HPV prevalence and HIV acquisition and the association between HIV prevalence and new HPV detection have estimated a two-fold increased risk in both directions, after adjusting for individual-level (sexual behavioural) factors. The studies argue that biological mechanisms may be responsible for these increased risks, but they also concur that residual confounding due to behaviour at the sexual network level cannot be ruled out. We used an individual based model to shed some light on the matter.
Cari van Schalkwyk
With the current situation in South Africa, showing only a modest decline in new TB cases since 2012, new avenues and strategies to identify TB cases need to be explored, tested and implemented. Systematic symptom screening in high risk populations, when this translates to screening everyone in the community, is not very sensitive or cost-effective. The TB programme might therefore consider screening all individuals at primary healthcare facility level, irrespective of their reason for attending. The use of a screening tool with improved sensitivity in comparison to symptom screening alone would be preferable, followed by the current diagnostic algorithm.
The biennial International AIDS Society (IAS) Conference on HIV Science was held in Paris, France in July 2017. This article presents some of the highlights of the conference, including the roll of PrEP and the promise of long-acting injectable ARVs, as well as contributions of SACEMA staff in the areas of HIV and Hepatitis C, and HIV and cervical cancer. Basic, clinical, epidemiological and operational research on HIV and the HIV response must continue to be prioritised even while we strengthen our health systems and improve the implementation of existing interventions.
Household contacts of active TB cases are at increased risk of TB infection and several studies have measured TB prevalence in this key population. The study described here not only measured TB prevalence, but also measured TB and HIV incidence in the household contacts of 729 TB index cases in the Matlosana sub-district in North West Province. We concluded that the efficacy of contact tracing for TB control purposes might be improved by a second intensified case finding visit and by providing preventive treatment against TB for both HIV-infected and HIV-seronegative household contacts of TB cases.
In 2011, the Ministry of Health in Swaziland joined forces with the WHO, the Global Fund and SACEMA to do the first in depth health programmes progress evaluation using triangulation from key empirical data sources. The focus was on key questions like: Given increasing coverage of ART, has ART reduced adult and/or infant mortality?; Can TB trends be related to trends in HIV prevalence, ART coverage and combined TB/HIV interventions?; Can trends in infant mortality be related to uptake of PMTCT?
SACEMA presented modelling work on e.g. incidence and prevalence of HIV at the two recent HIV and AIDS conference.
Robust affordable means for estimating HIV incidence at the population level continue to be elusive and much desired. As resources are invested in developing more appropriate tests for recent infection, the methods for evaluating and optimising the performance of candidate tests need to be further refined. We have recently explored a range of statistical methods for estimating the mean duration of recent infection (MDRI) by investigating a data set from Harare, Zimbabwe. We investigated whether there is an optimum way of estimating the mean recency duration for this dataset. We also ask how estimates of the mean recency duration and incidence are affected by our choice of cut-off and whether these effects differ with our choice of estimation method.