Ugandan ART programme claims to reduce sexual risk taking and the risk of HIV transmission

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A programme in rural Uganda, which provides integrated antiretroviral (ART) treatment and prevention services to people in their own homes, has reported reductions in both sexual risk-taking behaviour and the estimated risk of HIV transmission among programme participants, according to a study in January's AIDS.

Six months after initiating ART, participants in the programme experienced dramatic reductions in viral load and reported a 70% decrease in risky sexual behaviour. Researchers calculated that the risk of cohort members transmitting HIV to their sexual partners decreased by at least 98%.

The programme also noted a clear increase in the use of condoms (which were freely provided) — contrasting with the results of another recent study from Uganda. However, even though there can be little doubt that the programme has had an impact in risk-taking, its ability to fully assess its own effectiveness may be somewhat limited (see below).

Background

While many studies have shown that ART can effectively be used to lower viral loads and slow disease progression in Africa, its potential impact on sexual risk behaviour and HIV transmission in that setting remains unclear. Some researchers have even developed mathematical models which suggest that any reduction in HIV transmission, due to the reduced infectiousness of low viral loads, could actually be offset by increases in risky sexual behaviour that could be seen with improved health on treatment (and the sustained numbers of HIV-infected individuals who are living longer).

Glossary

VCT

Short for voluntary counselling and testing.

disclosure

In HIV, refers to the act of telling another person that you have HIV. Many people find this term stigmatising as it suggests information which is normally kept secret. The terms ‘telling’ or ‘sharing’ are more neutral.

risky behaviour

In HIV, refers to any behaviour or action that increases an individual’s probability of acquiring or transmitting HIV, such as having unprotected sex, having multiple partners or sharing drug injection equipment.

person years

In a study “100 person years of follow-up” could mean that information was collected on 100 people for one year, or on 50 people for two years each, or on ten people over ten years. In practice, each person’s duration of follow-up is likely to be different.

bias

When the estimate from a study differs systematically from the true state of affairs because of a feature of the design or conduct of the study.

Recognising this as a potential danger, a team led by researchers from the US Centers for Disease Control’s (CDC) Global AIDS Program in Uganda, designed a home-based care ART project with built-in HIV-disclosure, partner-testing and prevention counselling. Working with a local organisation, The AIDS Support Organisation (TASO), HIV-infected adults from the rural Torono area of Uganda were enrolled into the programme beginning in May 2003. Home-based HIV voluntary counselling and testing (VCT) was offered to all participants’ household members and free ART was provided for those clinically eligible.

Prevention counselling

The starting point for the prevention counselling services in the programme was the disclosure of a person’s HIV-positive status to their cohabiting sex partners, who were then offered VCT. According to a previous report, acceptance of VCT was quite high when offered in this context. As is frequently the case, some of the partners were HIV-negative.

Programme counsellors interviewed participants about their desire for sex, sexual activity, opportunities for sex and condom-use "in a non-judgemental manner" at enrolment and every three months thereafter. They also worked with participants to develop “personal sexual behaviour plans in which they assessed their motivation for avoiding transmission and their current risk situation and made risk reduction plans that included how they might cope with increased sexual desires.” Counsellors discussed options for reducing transmission such as abstinence, condom use, reduced frequency of sex, and alternative forms of sexual expression. Condoms were freely provided to participants who requested them.

The trial

A 'before and after' study was planned to see what sort of impact the programme, both ART treatment and prevention counselling, would have on HIV transmission and sexual activity among its participants. Aside from the lab work, the data was derived from the patient interviews.

The programme enrolled 926 individuals between May 2003 and December 2004. Follow-up data from the six-month time point (give or take a month) was available for 815 people. Most participants had advanced HIV disease, with a mean CD4 count of 124 cells and a viral load of 226,000 copies/ml.

With such an ill population, it is perhaps not surprising that most of the subjects (53% of men and 79% of women) reported having had no sex (abstinence) in the three months before study entry. Roughly a third of these had chosen to be abstinent — the remainder reported that they hadn’t had any interest or the opportunity to have sex, because of poor health or not having a partner. Many of the women in particular were widowed.

Sexual intercourse was most common among those in stable relationships. Out of only around 318 people in stable relationships, 100 men (65%) and 96 women (59%) reported intercourse in the past 3 months, while only 13% of the men and 9% of the women (out of 605 participants) not living with a regular partner reported having sexual intercourse in the previous 3 months.

Overall, 255 (28) of the study participants reported being sexually active (with a total 280 partners). 44% of women and 45% of men reported having unprotected sex with at least one partner in the three months before the study began.

At programme entry, around 126 participants reported having sexual partners who were HIV-negative or whose status was unknown. Some had more than one, with a grand total of 137 ‘partnerships of risk.’ Six month follow-up data were available for 96 participants with 102 partnerships of risk. Of these, 49 partners had been confirmed to be HIV-negative after the start of the programme by VCT. The remaining partnerships of risk lived outside of the home.

Results at six months

As in many studies, ART was highly effective. Focusing on the 96 individuals having sex with HIV-negative partners or partners of unknown status, 94 (85%) achieved a viral load below 1700 copies/ml by month six.

Clients reported similar amounts of sexual activity between baseline and follow-up but reported more consistent condom use. They had less unprotected sex with partners of negative or unknown status — from 56 (6%) down to 20 individuals (2%) reporting any unprotected sex with a partner of risk (p = 0.0001). This was despite a dramatic increase in the number reporting an increase in sexual desires (from 13 to 131) and opportunities for sex (from 36 to 215) as their health improved.

The researchers then calculated the risk of HIV transmission to the HIV-negative partners based upon the participants viral loads and sexual activity. They concluded that the estimated risk of HIV transmission to partners of negative and unknown status fell from 45.7 per 1000 person years at the start of the programme to 0.9 per 1000 person years at follow-up, representing a 98% decrease.

There was only one new HIV seroconversion reported among sex-partners living in the same household who had been HIV-negative at the start of the programme. However, it was not clear whether all 49 VCT patients had tested again yet (tests are offered once a year). Also the number of patients involved in this assessment at this point is rather small and follow-up too brief to reach any conclusions about a reduction in actual transmissions.

Study limitations

This CDC-Uganda team deserves a lot of credit for pioneering this integrated HIV treatment and prevention programme and taking it into one of the most challenging situations: homes in rural Africa. It is especially impressive that counselling was “non-judgemental,” focusing on risk reduction and that condoms were offered freely — particularly since the programme is PEPFAR-funded. Some factions in the US have strongly discouraged condom distribution in the developing world, arguing that US money should only go to prevention programmes stressing abstinence. It is likely that the researchers fought hard to incorporate all of these services into its prevention programme

That being said, the researchers themselves note a weakness in the study: the same study counsellors who provided on-going risk reduction counselling also interviewed participants (at baseline and every three months afterward). “This may have led to under-reporting of risky sex by participants,” they write.

The authors maintain that the counsellors were trained "to minimise bias", but the potential for bias nonetheless remains. Counsellors have a vested interest in seeing that their efforts are successful. Conversely, if they try to act without bias, there is a possibility that they may overcompensate and influence the results. Finally, no matter how much training to be non-judgemental counsellors receive, participants in the programme are not likely to forget what the counsellor has been saying the previous six months.

This is not to say that the programme is not a success, only that it is difficult to assess the effectiveness of the interventions based solely upon these follow-up interviews.

The authors also note that "without a randomised efficacy trial, it is not possible to disaggregate the effects of our prevention activities from the effects of providing ART alone." If the reduction in risky sexual behaviour is as great as the participants reported, it would be useful to know whether each component of the prevention services was beneficial. For example, it is possible that HIV disclosure in the home combined with partner testing had the greatest impact on sexual behaviour (among regular couples at least).

It must also be noted that six months is a pretty short period — it will be interesting to see whether reductions in risky behaviour continue as participants feel and look better and the novelty of the programme has worn off.

Reference:

Bunnell R et al. Changes in sexual behavior and risk of HIV transmission after antiretroviral therapy and prevention interventions in rural Uganda. AIDS 20: 85–92, 2006.