Zim Records Surprising Success in HIV Prevention
By Staff Writer
HIV prevalence rates have declined in Zimbabwe despite the political turmoil that has engulfed the country in the last few years. This is according to a study published in PLoSMedicine, an open access peer reviewed medical journal published by the American Public Library of Sciences.
There is growing recognition that primary prevention, including behaviour change, must be central in the fight against HIV/AIDS. The earlier successes in Thailand and Uganda may not be fully relevant to the severely affected countries of southern Africa. The researchers conducted an extensive multi-disciplinary synthesis of the available data on the causes of the remarkable HIV decline that has occurred in Zimbabwe (29 per cent estimated adult prevalence in 1997 to 16 per cent in 2007), in the context of severe social, political, and economic disruption.
The behavioral changes associated with HIV reduction—mainly reductions in extramarital, commercial, and casual sexual relations, and associated reductions in partner concurrency—appear to have been stimulated primarily by increased awareness of AIDS deaths and secondarily by the country's economic deterioration. These changes were probably aided by prevention programmes utilizing both mass media and church-based, workplace-based, and other inter-personal communication activities.
While the often cited prevention success stories of Thailand and Uganda are inspiring and informative, some of the specific socio-cultural, historical, and other factors in the southern African region—now the global epicentre of the HIV pandemic—are distinctive. In these “hyper-endemic” settings, where adult HIV prevalence ranges from 12 to 26 per cent , HIV transmission is highly generalized. The unprecedented HIV decline and associated behaviour change in Uganda, mainly involving large reductions in multiple sexual partnerships occurred some 20 years ago and under rather different contextual and programmatic circumstances.
More recent examples of HIV prevalence reduction are emerging, including from Kenya, Haiti, the Dominican Republic, Malawi, and Ethiopia. Given the severe HIV epidemics that continue to plague parts of sub-Saharan Africa, there is an urgent need for studies identifying the proximate as well as underlying causes for these encouraging trends. In this study, the researchers review and summarize the principal findings of their comprehensive interdisciplinary analysis (commissioned by two United Nations agencies, the United Nations Populations Fund [UNFPA] and United Nations HIV-AIDS Programme [UNAIDS]) of the causes behind the considerable HIV decline in Zimbabwe, including evidence for changes in patterns of sexual behaviour and the contextual and possible programmatic reasons for these changes.
HIV prevalence data from national antenatal clinic surveillance and the household-based 2005/6 Demographic and Health Survey (DHS) were used to fit a mathematical model to estimate trends in HIV incidence and AIDS deaths in Zimbabwe. Data from the DHS and other longitudinal surveys were used to examine the possible contributions of changes in sexual behaviour to reductions in HIV infection. Published data from focus group discussions with 90 adult men and 110 women in diverse urban and rural sites and several dozen in-depth key informant interviews as well as an extensive historical mapping of prevention programmes were examined in assessing the contributions of different contextual and programmatic factors to observed changes in behaviour. Finally, DHS data on various potential proximal and contextual determinants of behaviour change for Zimbabwe were compared with similar data for seven other southern African countries to identify distinctive patterns that might help to explain the earlier and faster HIV decline observed in Zimbabwe.
According to the findings, HIV incidence peaked around 1991 and declined as part of the natural course of epidemic maturation; incidence decline wass accelerated between about 1999 and 2003 due to reductions in sexual risk behaviour. Notably, incidence declined a little earlier in urban areas. The model suggests behaviour change could have continued partly into 2004 in rural areas, but the majority of changes were concentrated within the 1999–2003 period.
Interpretation of data on the causes of HIV declines in other countries (e.g., Uganda) has proved to be contentious and problematic when drawing conclusions for policy. Therefore, to establish a consensus among key stakeholders on the roles of different potential causes of HIV decline in Zimbabwe, a national stakeholders meeting was held in Harare in May 2008 to examine the evidence assembled during this study. Stakeholders from a broad range of backgrounds attended the meeting, including high-level representatives of civil society and international organizations as well as senior non-political appointees within the Ministry of Health and Child Welfare and the National AIDS Council. At the meeting, the proximate and underlying contextual and programmatic factors that could have contributed to Zimbabwe's declining HIV epidemic were ranked systematically according to whether they were considered likely, plausible, or unlikely to be major contributors to the HIV decline, based upon triangulation of the data described above and from other relevant studies.
It was found that the prevalence of other Sexually Transmitted Infections (STIs) was greatly reduced during the early 1990s, mainly due to widespread syndromic management services. It has been hypothesized that STI treatment during the early phases of an HIV epidemic may help to reduce transmission (although this is unconfirmed by observational evidence; e.g., given the absence of HIV declines in several other African countries that had also implemented early and aggressive STI control programmes). Reported condom use increased steadily during the 1990s (reaching 59 per cent among men for last non-marital sexual encounter in the 1994 DHS), but did not increase further between 1999 and 2005/6. However, there is some evidence for modest improvement in the consistency of condom use among women in casual partnerships, a more important measure for reducing infection risk than reported use at last sex.
In assessing the underlying factors for the national prevalence decline , high AIDS mortality appears to have been the dominant factor for stimulating behaviour change. Both empirical and modeling-derived estimates indicate that AIDS deaths increased dramatically during the mid-to-late 1990s, before stabilizing after 2000. Moreover, men and women in focus groups and interviews repeatedly and consistently reported personal exposure to AIDS mortality and the resulting fear of contracting the virus to be the primary motivation for changes in sexual behavior, particularly reductions in casual sex and other multiple sexual partnerships
The severe economic decline, taking hold in the late 1990s/early 2000s, appears to have played a considerable secondary role in amplifying patterns of behaviour change, particularly partner reduction. Gross domestic product in Zimbabwe began to slump in the late 1990s, declining by about 40 per cent between 1999 and 2005, with average real earnings plummeting by 90 per cent during the same period. And many men in focus groups and interviews reported that having less disposable income has increasingly led to reduced ability to purchase sex or maintain multiple sexual relationships.