Changes in HIV prevalence among men and women between the 2005-06 and 2010-11 Zimbabwe Demographic and Health Surveys

Monitoring trends in determinants of HIV can be important to explain changes in HIV prevalence. In Zimbabwe, men and women were tested for HIV in two consecutive rounds of the Zimbabwe Demographic and Health Survey (ZDHS), 2005-06 and 2010-11. This paper analyzes the changes in HIV prevalence among men and women between the two surveys by selected background characteristics and associated risk factors. Methods: We analyzed the 2005-06 and 2010-11 ZDHS data sets and reported the proportional changes in HIV prevalence at the 95% confidence level. Using linear combinations of estimators (LINCOM) in linear and logistic regression, we explored the associations of change in HIV prevalence with 1) socio-demographic characteristics, 2) sexual risk-behaviour characteristics, and 3) biological characteristics, using STATA 12.1. Results: Overall, women experienced a greater decline in HIV prevalence between 200506 and 2010-11 than men—16% (p = 0.001) compared with 15% (p = 0.008). In rural areas, the decline among women was even larger—19% (p = 0.002) compared with 13% (p = 0.073) among men, and the decline was statistically significant for women. In urban areas, the decline in HIV prevalence was greater among men than women—17% (p = 0.089) compared with 9% (p = 0.144), however the decline was not statistically significant for men. The decline in HIV prevalence by marital status was greater among those in marital union—men 23% (p < 0.001) and women 20% (p < 0.001)—than among those who were single—men 7% (p = 0.628) and women 10% (p = 0.406). There were notable declines in HIV prevalence among both men and women who reported age at first sex at 16 years and older—men 23% (p < 0.001) and women 21% (p<0.001). Among the largest declines in HIV prevalence were those seen among men and women who used a condom at last sexual intercourse in the past 12 months—men 33% (p = 0.001) and women 32% (p < 0.001). The decline in HIV prevalence was slightly greater among men who were circumcised than among those who were not—15% (p = 0.313) compared with 14% (p = 0.017). Multivariate analysis confirmed the decline in HIV prevalence in both sexes between the two surveys, particularly in rural areas, among those with secondary or higher education, and those in the two wealthiest quintiles. Of the sexual risk behaviours, being currently in union, having their first sexual intercourse at age 16 or older, and having used a condom at last sexual intercourse were all associated with a decline in HIV prevalence. Discussion and Conclusion: The larger declines in HIV prevalence among women than men in Zimbabwe suggest that gender-focused programming can lead to substantial reductions in HIV prevalence among target groups. Additionally, it is recognized that residence (urban-rural and province) is an important factor associated with the observed changes in HIV prevalence in Zimbabwe and needs to be taken into consideration when designing programme interventions. Finally, health programmes should continue to target individual sexual-risk behaviours and promote those that are associated with decline in HIV prevalence; these include increasing age at first sexual intercourse to at least 16 years and older, condom use during risky sexual intercourse, and voluntary medical circumcision for men.