HIV This Week

Lingappa JR, Lambdin B, Bukusi EA, Ngure K, Kavuma L, Inambao M, Kanweka W, Allen S, Kiarie JN, Makhema J, Were E, Manongi R, Coetzee D, de Bruyn G,Delany-Moretlwe S, Magaret A, Mugo N, Mujugira A, Ndase P, Celum C; for the Partners in Prevention HSV-2/HIV Transmission Study Group. Regional Differences in Prevalence of HIV-1 Discordance in Africa and Enrollment of HIV-1 Discordant Couples into an HIV-1 Prevention Trial. PLoS ONE. 2008; 3(1):e1411.

Most HIV-1 transmission in Africa occurs among HIV-1-discordant couples (one partner HIV-1 infected and one uninfected) who are unaware of their discordant HIV-1 serostatus. Given the high HIV-1 incidence among HIV-1 discordant couples and to assess efficacy of interventions for reducing HIV-1 transmission, HIV-1 discordant couples represent a critical target population for HIV-1 prevention interventions and prevention trials. Substantial regional differences exist in HIV-1 prevalence in Africa, but regional differences in HIV-1 discordance among African couples, has not previously been reported. The Partners in Prevention herpes simplex virus type 2 (HSV-2)/HIV-1 Transmission Trial ("Partners HSV-2 Study"), the first large HIV-1 prevention trial in Africa involving HIV-1 discordant couples, completed enrolment in May 2007. Partners HSV-2 Study recruitment data from 12 sites from East and Southern Africa were used to assess HIV-1 discordance among couples accessing couples HIV-1 counselling and testing, and to correlate with enrolment of HIV-1 discordant couples. HIV-1 discordance at Partners HSV-2 Study sites ranged from 8-31% of couples tested from the community. Across all study sites and, among all couples with one HIV-1 infected partner, almost half (49%) of couples were HIV-1 discordant. Site-specific monthly enrolment of HIV-1 discordant couples into the clinical trial was not directly associated with prevalence of HIV-1 discordance, but was modestly correlated with national HIV-1 counselling and testing rates and access to palliative care/basic health care (r = 0.74, p = 0.09). In conclusion, HIV-1 discordant couples are a critical target for HIV-1 prevention in Africa. In addition to community prevalence of HIV-1 discordance, national infrastructure for HIV-1 testing and healthcare delivery and effective community outreach strategies impact recruitment of HIV-1 discordant couples into HIV-1 prevention trials.

Editors’ note: In the screening phase for a large trial assessing the impact of herpes simplex-2 (HSV-2) suppression with acyclovir in co-infected (HIV-1, HSV-2) partners of HIV-negative, HSV-2 negative people, 51,900 couples were tested. Among all the couples tested in which HIV infection was found, 36 to 85% of them, depending on the study site, were discordant with an overall rate of 49%. Because discordant couples are such an important population for HIV prevention (in reality, HIV prevalence is 50% in the couple’s bed), community mobilisation to encourage couples to be tested as couples, rather than as individuals, and to provide social support to couples who learn their discordant or positive concordant status is an urgent public health priority.