Presence of BV-related bacterial species in the vaginal microbiota may contribute to the vulnerability of African women to HIV

The association between disruptions of vaginal microbiota and vulnerability to STIs has been widely discussed. Tamarelle & Astagneau (STI) report a study based in a French STI clinic showing some evidence of greater vulnerability to Chlamydia in the case of microbiota not dominated by Lactobacillus crispatus. The more important question of an association of BV-related bacteria with vulnerability to HIV has been in the air for a long time (Schmid & Koumans (STI)).  Gosmann & Kwon, in a recent study of South African women showed a four-fold decreased vulnerability among women with L. crispatus-dominated microbiota compared with women with microbiota dominated by non-Lactobacillus communities other than Gardnerella. Read More

How Can We Wipe out HIV?

In the 1980s, being HIV positive was a death sentence: it was a question of when, not if, the infected person would develop AIDS. Now under control in most Western countries, AIDS remains an incurable and often fatal disease in other parts of the world. How to defeat it? Xenius takes stock of the situation in South Africa, where the HIV infection rate is the highest in the world. Read More

The risk network approach to HIV detection: something like contact tracing?

There has been considerable debate on the most effective and cost-effective means of accessing untested HIV- or STI-infected individuals. One frequently canvassed strategy is that of respondent driven sampling (RDS). This involves issuing suitable ‘seeds’ (e.g. recently diagnosed MSM) with coupons to distribute to others in their sexual or social networks.  Wei & Raymond (STI) in a recent study of black MSM in San Francisco compare RDS very favourably with time location sampling (TLS) as a method of recruitment of those most likely to be at risk. Similary, Rosenberg & Miller (STI) in a small study in Malawi observe the superior effectiveness of infected, over non-infected seeds in discovering untested individuals (31% vs. 11%). Much, of course, depends on the target group; so, for example, Weir & Chen (STI) find in favour of ‘venue-based’ sampling over RDS in the case of Chinese FSW. Read More

How should HIV-specific charitable interventions like PEPFAR be evaluated?

There has been considerable debate on the most effective and cost-effective means of accessing untested HIV- or STI-infected individuals. One frequently canvassed strategy is that of respondent driven sampling (RDS). This involves issuing suitable ‘seeds’ (e.g. recently diagnosed MSM) with coupons to distribute to others in their sexual or social networks.  Wei & Raymond (STI) in a recent study of black MSM in San Francisco compare RDS very favourably with time location sampling (TLS) as a method of recruitment of those most likely to be at risk. Similary, Rosenberg & Miller (STI) in a small study in Malawi observe the superior effectiveness of infected, over non-infected seeds in discovering untested individuals (31% vs. 11%). Much, of course, depends on the target group; so, for example, Weir & Chen (STI) find in favour of ‘venue-based’ sampling over RDS in the case of Chinese FSW. Read More