HIV This Week

White RG, Orroth KK, Glynn JR, Freeman EE, Bakker R, Habbema JD, Terris-Prestholt F, Kumaranayake  L, Buve´A, and Hayes RJ. Treating Curable Sexually Transmitted Infections to Prevent HIV in Africa. Still an Effective Control Strategy? J Acquir Immune Defic Syndr 2007 Dec 20; [Epub ahead of print].

Evidence regarding the effectiveness of sexually transmitted infection (STI) treatment for HIV prevention in Africa is equivocal, leading some policy makers to question whether it should continue to be promoted for HIV control. White and colleagues explore whether treating curable STIs remains a cost-effective HIV control strategy in Africa. The model STDSIM was fitted to the characteristics of 4 populations in East and West Africa. Over the simulated HIV epidemics, the population-attributable fractions (PAFs) of incident HIV attributable to STIs, the impact of syndromic STI management on HIV incidence, and the cost per HIV infection averted were evaluated and compared with an estimate of lifetime HIV treatment costs (US $3500).Throughout the HIV epidemics in all cities, the total population-attributable fractions for all STIs remained high, with 50% of HIV transmission attributed to STIs. The PAF for herpes simplex virus type 2 increased during the epidemics, whereas the PAF for curable STIs and the relative impact of syndromic management decreased. The models showed that the absolute impact of syndromic management remains high in generalized epidemics, and it remained cost-saving in 3 of the 4 populations in which the cost per HIV infection averted ranged between US $321 and $1665. Curable STI interventions may remain cost-saving in populations with generalized HIV epidemics, particularly in populations with high-risk behaviours or low male circumcision rates.

Editors’ note: In the end, after the results of randomised controlled trials have been discussed and debated, and all is said and done, treatment and control of curable sexually transmitted infections should be a priority for its own sake – and it can reduce HIV transmission, particularly early on in HIV epidemics. Modelling impact and costs can inform optimal resource allocation.