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IAS 2013: Combination Prevention Trial Shows Drop in HIV Incidence, Increase in Testing


Results from Project ACCEPT, a pioneering HIV prevention trial comparing the effects of mobile HIV testing, community mobilization, and enhanced support for people with HIV, versus standard voluntary counseling and testing, were announced at the recent 7th International AIDS Society Conference on HIV Pathogenesis, Treatment, and Prevention in Kuala Lumpur.

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Project ACCEPT is the first controlled trial comparing the efficacy of a prevention intervention versus standard of care between 2 separate, matched communities, rather than between randomized individuals. It was designed to examine how widespread community mobilization and mobile testing changed group behavior and community norms, as well as whether it produced a drop in HIV infections.

In fact, Project ACCEPT only produced a modest 14% drop in the rate of new HIV infections (incidence) -- though HIV incidence in mature epidemics is very hard to change with behavioral interventions. But it produced a greater fall in incidence among older women, and a considerable increase in HIV testing among men, who in Africa have tended to be less engaged with care and more likely to remain undiagnosed. It also reported drops in the number of sex partners reported by people with HIV and the proportion who had multiple partners.

Background and Methods

The basic question Project ACCEPT was designed to answer was: How does an enhanced HIV prevention program perform in terms of its effect on HIV incidence, behavior, and testing in an entire community, compared with a community where standard, clinic-based HIV counseling and testing is offered?

By some measures, the study is by far the largest HIV intervention trial ever mounted. Altogether, nearly half a million people live in the communities included in the trial and could have made use of the programs it offered. Nearly 57,000 people took part in a final post-intervention assessment gauging behavior at the end of the trial, of whom over 54,000 agreed to be tested for HIV. These tests included an HIV incidence assay that could establish the approximate time of infection and therefore the incidence rate. Over 14,500 people took part in a baseline survey to establish sexual behavior and HIV testing rates at the start of the survey.

ACCEPT's intervention was provided to 24 communities and its effects were compared to standardized voluntary counseling and testing (VCT) in 24 matched communities. The average population in the communities was 9800, or 470,400 people in all. These communities were in 5 geographical areas in 4 countries: urban Soweto and rural KwaZulu-Natal in South Africa, and rural areas in Tanzania, Zimbabwe, and Thailand.

It took 4 years to prepare the ground for the study and the actual randomized study took 3 years, between 2006 and 2009, with post-intervention surveys and qualitative interviews extending to 2011. Communities were matched in socioeconomic profile and chosen to be geographically separate from each other. In urban Soweto, community pairs were picked from opposite ends of the area, with researchers even studying aerial images to see if travel between matched areas was common.

Importantly, people were not tested for HIV at the start of the trial. This is due to the trial's radical methodology. As principal investigator Glenda Gray said, "If people had tested positive, we would have offered them the intervention." In other words, this was not a study of individuals: researchers wanted a way of assessing HIV incidence in entire communities and comparing the efficacy of different interventions -- which they got.

Testing in both arms was in fact restricted to 18- to 32-year olds, because they are at highest risk of HIV but, as the principal investigator for the Tanzanian sites, David Celentano, pointed out, the effect of the intervention was not restricted to people coming forward for testing. The community-randomization aspect means that those who got tested might not have been influenced directly by the other interventions, but may have been influenced by peers or family members who had. In addition, those who took part in the baseline and post-intervention surveys were not necessarily the same people who took tests or took part in educational and support activities.

Project ACCEPT was also a long trial from gestation to final result. Gray noted that it was conceived in 2000 to 2001, at a time when there were much lower rates of HIV testing in Africa than there are today. Most people were unaware of their HIV status and there was a low motivation to test, given that antiretroviral therapy was only starting to be rolled out in some countries. The prevalent VCT model did not work well; it required people to self-identify as being at-risk and be motivated enough to go to an HIV center that, in rural areas, could be a long distance away.

Project ACCEPT was devised as a remedy to this. First, and most obviously, HIV testing was taken into communities, either by using mobile vans or by testing teams periodically visiting villages. Perhaps as importantly, the testing program was preceded and accompanied by 'community mobilization.' What this meant in one context was illustrated by Suwat Chariyalertsak, principal investigator for the Thai sites, who ran through a whole series of awareness-raising events ranging from community education days through appearances at music festivals to persuading village elders to take public tests to kick off the testing program.

The ACCEPT program was also designed to be adaptable as ongoing data on uptake came through. In Thailand, for instance, during the first year of the study, the number of people tested per day fell, from 23 to 14. Consultation meetings showed that community members had difficulty in accessing the mobile test sites during the day, so testing was extended to evenings, and was accompanied by a series of 'edutainment' events. Testing rates had increased by the end of the study to 53 a day.

Results in Detail

At baseline, HIV prevalence and annual incidence in the local communities ranged from 31% and 3.9%, respectively, in KwaZulu-Natal to 1% and less than 0.1% in Thailand (there were so few HIV infections in Thailand during the trial -- 3 individuals -- that Thailand was excluded from the incidence analysis).

There was 14% lower HIV incidence in intervention communities than there was in standard VCT communities. Among women aged 25 to 32, incidence was 30% lower. In men, incidence was reduced by 19% overall, and in men over 25, by 22%. Disappointingly, however, HIV incidence was only lower by 5% in men under 25, and it was no lower than in the control group in younger women. Young women remain the group most vulnerable to HIV yet hardest to influence, as a number of African studies of other prevention methods have found.

The number of people tested was 25% higher in intervention communities than in control communities, and among men it was 45% higher. This represents a considerable achievement as -- due to prenatal testing -- women testing for HIV outnumber men 2:1 in Africa generally. In Project ACCEPT, as many men as women were tested. The proportion of the population tested increased from 14% to 32% during the trial (a 128% increase) in intervention communities, versus from 16% to 26% in control communities (a 62% increase). In absolute numbers, about 50,000 people got tested 80,000 times during the study, meaning that a majority tested more than once.

In terms of sexual health risk, the significant falls in risk were among HIV positive people: the number of sex partners HIV positive people had fell by 8% overall, and 18% among men, in intervention communities compared to control communities. The proportion reporting multiple partners was 30% lower in intervention communities.

Acceptance of HIV testing as a social norm, as measured on a 5-point scale, increased slightly (up 6%) in intervention communities. Disappointingly, stigma against HIV did not fall in intervention communities, but Celentano commented that this was probably a fault of the stigma questionnaire, which assumed people would be willing to admit to stigmatizing attitudes towards people with HIV; in fact very few admitted to having them, so stigma measures could not fall much further.

When asked what she would include in the intervention if Project ACCEPT was designed today, Gray commented that one of the big challenges was linkage to care for people who were diagnosed with HIV. This was when some of the 'local community' aspect of care had to stop, and people were instead sent to the nearest HIV center for their tests and antiretroviral drugs, though they received counseling and safer-sex advice locally. In some cases, both the ACCEPT team and the local HIV clinic were funded by PEPFAR, and in this case patients could be traced, but in others ACCEPT relied on informal feedback.

"There was attrition but it's hard to say what it was," said Gray, adding that in some rural areas the nearest HIV clinic could be a day's journey away. Project ACCEPT had done a good job of bringing testing to communities; as Gray noted, there might need to be further task-shifting to bring treatment to communities too.

See also:



D Rausch, G Gray, D Celentano, and S Chariyalertsak.Mobile Versus Clinic-Based HIV Testing: Results of the Project Accept RCT. 7th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention. Kuala Lumpur, June 30-July 3, 2013. Special Session TUSS01.