Why the increase?
Dr Shafer presented some behavioural data from their rural cohort which suggest that there has been a corresponding change in risky behaviour since 2000.
"Every year, since about 2000, there's been an increase in the rural population in the percentage of men aged 40 and above who have claimed to have had two or more casual partners in the last month," she said.
Although "condom use doesn't appear to have changed very much, the percentage of 16 year-olds who have ever had sex has also increased since 2000."
Additionally, Dr Shafer pointed out that since antiretroviral therapy only became available in Uganda in 2004 and the epidemiological trends began in 2000, the increases they are seeing "are not due to increased survival due to antiretroviral therapy."
Warning signs that Uganda's HIV prevalence may be on the rise again were presented to the Sixteenth International AIDS Conference in Toronto at a late-breaker session on Thursday. Data on both HIV prevalence and incidence show rising trends since 2000, which the investigators attribute to increased sexual risk behaviour, the natural epidemiological cycle, and "other factors". These may include a chronic condom shortage and the hotly debated 'ABC' policy which appears to focus on abstinence and faithfulness rather than condom use.
In the late 1980s, almost one-third of Uganda's adult population was estimated to be infected with HIV. This fell to about 15% in the early 1990s, and current HIV prevalence is estimated to be around 6%.
Some experts have credited the vigorous 'ABC' prevention strategy with helping to reduce HIV prevalence in Uganda throughout the 1990s. Others, however, have seriously questioned the true effects of this controversial approach saying that the marked decrease in prevalence touted by Ugandan government officials was mathematically implausible.
A study presented in February 2005 at the Twelfth Annual Retrovirus Conference in Boston found that it was primarily mortality, and not behaviour change, that was responsible for 80% of the reduced prevalence in one Ugandan district, and that it was condom use, rather than abstinence, that was primarily responsible for the lack of increase in HIV incidence.
Dr Leigh Anne Shafer of the Medical Research Council Programme on AIDS/Uganda Virus Research Institute (MRC/UVRI) in Entebbe, Uganda, reported HIV prevalence, incidence and sexual behaviour data from a rural cohort established in 1989, as well as surveillance data of HIV prevalence among pregnant women at 24 antenatal clinics throughout Uganda. Shaffer confirmed that increased in mortality, as well as out-migration, were the reasons behind the decreased prevalence of the mid-1990s. Nevertheless, she also showed data from the rural Masaka cohort demonstrating decreased HIV incidence between 1993 and 2000.
HIV prevalence reached its nadir in 2000 in the rural cohort, where it was found be 5.6% among men and 6.9% among women. However, in 2004, prevalence increased to 6.5% in men and 8.8% in women. In 2005, the upward trend appears to have continued for both prevalence and incidence.
Prevalence data since 2002 from the 24 antenatal clinics documented more mixed results. At seven of the sites, prevalence declined; at ten sites, it increased; and at seven sites, HIV prevalence remained unchanged.
Rigorous analysis of the rural cohort revealed an increase in incidence since 2000 among men and women in the 40-49 year-old age group. In fact, there was a new incidence peak in men between 40-49 years of age of approximately 9 per 1000 patient years that was higher than the peak seen between 1990-1994. According to Dr Shaffer, "This has new and important epidemiologic significance for public health because in the past, incidence peaked in the 25-29 age group and then declined".
Even though these data are not statistically significant, Dr Shafer noted later in a press conference, "among some subgroups there is some statistical significance, but it's not strong. For that to become significant we would need another year or two of data, which we do not believe that we should wait for." She stressed that it was important to react now to these epidemiologic trends "without delay."
The study's co-author, Dr Alex Opio of the National AIDS Control Programme at the Ugandan Ministry of Health, told the press conference that in response to the data, "there has been a strong re-emphasis on prevention efforts by the Ministry of Health...with a goal to consolidate previous successes." He added, however, that since evidence had shown that 'ABC' had worked in the past, for example, “later sexual debut,” they will continue to use this approach. "This policy is still very relevant," he said.
Are condom shortages fuelling the increases?
Stephen Lewis, the UN Special Envoy for HIV/AIDS in Africa, told the New York Times last year that a major condom shortage due to governmental restrictions on condom imports implemented late in 2004 was a direct consequence of PEPFAR's 'ABC' policy: "There is no question that the condom crisis in Uganda is being driven and exacerbated by PEPFAR," he said, adding that this "undoubtedly will cause significant numbers of infections which should never have occurred".
Speaking at a satellite session on Sunday, Beatrice Were of ActionAid Uganda spoke about how the 'ABC' policy has now become a policy that emphasises abstinence and fidelity over condom use, as highlighted in a report by Human Rights Watch published last year. "The 'C' part is now mainly silent," she said, and as a consequence, "the success story is unravelling."
However, Ministry of Health's Dr Alex Opio said that condom use had doubled from 60 million to 120 million per year over the past two years, and that PEPFAR's influence did not mean that condoms were not being promoted in Uganda.
Although he admitted that "we find it tremendously difficult to persuade the religious community to promote condom use," he added that "58% of couples in Uganda have just one partner who is HIV-positive and that's why condom use must be promoted, even within marriage."
Shafer LA, et al. HIV prevalence and incidence are no longer falling in Uganda - a case for renewed prevention efforts: evidence from a rural population cohort 1989-2005, and from ANC surveillance. Sixteenth International AIDS Conference, Toronto, abstract ThLB0108, 2006.