Reducing Transmission

A prospective cohort study between May 2003 and December 2004 a total of 926 HIV-positive adults in rural Uganda found that within six months of initiating ART, risky sexual behavior reduced by 70%. Risky sex was defined as inconsistent or no condom use with partners of HIV-negative or unknown serostatus in the previous 3 months. Study participants were followed in a home-based ART program that included prevention counseling, voluntary counseling and testing (VCT) for cohabitating partners and condom provision. At baseline and follow-up, participants' HIV plasma viral load and partner- specific sexual behaviors were assessed. Estimated risk of HIV transmission from cohort members declined by 98%, from 45.7 to 0.9 per 1000 person years. More than 85% of risky sexual acts occurred within married couples.

A prospective cohort in Uganda of HIV-negative household members of HIV- positive patients on ART receiving home-based care found that risky sex decreased among HIV-negative adult household members. The study of 182 men and 273 women found that inconsistent condom use decreased from 29% at baseline to 15% at 24 months.

A comparative study of people living with HIV or AIDS on HAART and those receiving preventative therapy (PT) in Kenya found participants receiving HAART were more likely to report condom use at last sex and consistent condom use with regular partners than those receiving PT. The study also found fewer multiple and casual partners among PLWHA receiving HAART compared with those receiving PT. However, more than 40 percent of all participants in the study did not know the HIV status of their regular partners.

A 2007 review of evidence for the impact of ART on sexual behavior in developing countries found three relevant studies conducted in Africa—one in Côte d’Ivoire and two in Uganda. In each study, condom use at last sexual intercourse was significantly higher among ART patients compared to non-ART patients. In the Côte d’Ivoire study of 711 patients, condom use at last sex was 80 percent for ART patients versus 59 percent for non-patients, regardless of partnership type . Bateganya et al. (2005) on reported that of 926 participants in Uganda, of whom 164 received ART. Condom use was higher among ART patients: 71 percent used condom use at last sex with a spouse for ART patients, versus 47 percent for non-ART patients. Among study participants receiving weekly home-based ART delivery and individual counseling in Uganda, Bunnell et al. (2006) found that of 723 patients, with 354 ART-naïve patients and 369 ART-experienced patients, condom use at last sex increased from 59 to 82 percent among ART-experienced patients with uninfected partners or with partners they did not previously know, and from 58 to 74 percent among ART-experienced patients with HIV-positive partners. In individual counseling sessions, participants developed personal sexual behavior plans. Free condoms were provided. The available evidence indicates a significant reduction in risk behavior associated with ART in developing countries. However, there are few existing studies and the rigor of these studies is weak (Kennedy et al., 2007).

A study of longitudinal data from 2,993 HIV-discordant couples in Rwanda and Zambia from 2002 to 2008 found that couples where the HIV-positive partner was on ART were less likely to have self-reported vaginal sex not protected by condoms, presence of sperm on a vaginal smear or pregnancy than where the HIV- positive partner was not on ART.

An analysis of survey data from a cross-sectional study with 85 HIV- positive women from Uganda; 50 HIV-positive women in South Africa; and 44 HIV- positive women in Brazil found that HAART users were significantly (3.64 times) more likely to use condoms. Of the 179 HIV-positive women, 83 women reporting recent sexual intercourse, with 63% using condoms and 76% using contraceptive methods. Of the 179 HIV-positive women, 65% reported currently using HAART.

A survey of 277 participants attending an HIV care clinic from their initiation to treatment starting in October 2004 until May 2006 in Mozambique found that following ART, more participants used condoms for sexual intercourse. Interviewer administered surveys were conducted at ART initiation and one year later. Of 277 participants, 48% reported sexual activity three months prior to ART initiation, whereas over 63% reported sexual activity one year later. After one year of ART, more participants reported sexual activity, however, 77% were more likely to report correct and consistent condom use compared to 33% prior to ART initiation. Following ART initiation, 77% had disclosed their HIV-positive serostatus to their sexual partners compared to 58% prior to ART initiation. Prior to ART initiation, only 22.6% used condoms with HIV-negative or unknown status partners as compared to over 33.9% following ART initiation.

A review of publications from 1996 to 2009 with 11 cohorts reporting on 5,021 heterosexual couples and 461 HIV transmission events found that studies of heterosexual discordant couples observed no transmission in patients treated with ART and with viral load below 400 copies/ml but data were compatible with one transmission per 79 person-years. In ten studies with HIV- positive people not receiving antiretroviral therapy with 9,998 person years of follow-up, the overall HIV transmission rate, irrespective of viral load category and sexually transmitted diseases, the transmission rate was 5.64 per 100 person years. The largest number of serodiscordant couples was reported in five studies from sub-Saharan Africa. “There was insufficient data to allow estimation of summary rates of transmission through sexual intercourse without condoms, or to separate female-male and male-female transmission” . “This systematic review did not identify any study from which the risk of HIV transmission per act of unprotected sexual intercourse among persons with suppressed viremia following ART could be quantified directly. The available studies found no episodes of HIV transmission in discordant heterosexual couples If the HIV-infected partner was treated with ART and had a viral load below 400 copies/ml…The comparison of overall rates in patients on ART and not on ART nevertheless indicated that heterosexual transmission was reduced by 92%” (Attia et al., 2009: 1401).

"The Commission of Experts of Clinical HIV/AIDS Therapy of the Federal Office of Public Health of Switzerland concluded that an HIV-positive person who does not have an STI and is on HAART, with undetectable viral load under 40 copies per ml cannot transmit HIV sexually, as long as the person is completely adherent; viral load is undetectable for at least six months; and has no other STIs. It is estimated that in the case of complete suppression of viral load, the risk to transmit HIV through sexual intercourse without using condoms is less than 1 in 100,000. The Commission cautioned that this should apply only to patients who are highly motivated to be adherent, are in a stable relationship, are regularly followed by a physician, have no STIs, are in a mutually monogamous relationship and the HIV-negative partner is counseled and agrees to not use condoms. The HIV-negative partner must be the one to decide, since if they do acquire HIV, the consequences are most significant for the HIV-negative partner. Both partners must be counseled jointly . However, ability to detect viral load below 40 copies ml, regular physician monitoring and partner counseling as described in Switzerland in Vernazza et al., 2008 has not been described in a developing country context. Others have argued that treatment alone is not reliable, as women receiving antiretroviral therapy shed HIV (Cohen et al, 2009).

Data from 3,408 heterosexual HIV serodiscordant couples from seven African countries (Botswana, Kenya, Rwanda, South Africa, Tanzania, Uganda, and Zambia) was analyzed and found that ART use was associated with substantially lower risk for HIV transmission. Of 103 couples, only one transmission occurred when the HIV-positive couple had initiated treatment. Couples were followed for up to 24 months, with HIV testing of uninfected partners every three months. None of the HIV-positive partners who initiated treatment met national eligibility criteria for ARV treatment initiation . (Abstract)