Is sexual risk taking behaviour changing in rural south-west Uganda? Behaviour trends in a rural population cohort 1993-2006.

OBJECTIVE: To describe sexual behaviour trends in a rural Ugandan cohort in the context of an evolving HIV epidemic, 1993-2006. METHODS: Sexual behaviour data were collected annually from a population cohort in which HIV serological surveys were also conducted. Behaviour trends were determined using survival analysis and logistic regression. Trends are reported based on the years in which the respective indicators were collected. RESULTS: Between 1993 and 2006, median age at first sex increased from 16.7 years to 18.2 years among 17-20-year-old girls and from 18.5 years to 19.9 years among boys. Both sexes reported a dip in age at sexual debut between 1998 and 2001. One or more casual partners in the past 12 months among men rose from 11.6% in 1997 to 12.7% in 2004 and then declined to 10.2% in 2006. Among women it increased from 1.4% in 1997 to 3.7% in 2004 and then reduced to 1.4% in 2006. The rise in casual partners between 1997 and 2004 was driven mainly by older age groups. Trends in condom use with casual partners varied by age, increasing among those aged 35+ years, declining in the middle age groups and presenting a dip and then a rise in the youngest aged group (13-19 years). CONCLUSION: Among youth, risky behaviour declined but increased in the late 1990s/early 2000s. Among those aged 35+ years, condom use rose but casual partners also rose. Several indicators portrayed a temporary increase in risk taking behaviour from 1998 to 2002.

Declines in HIV prevalence can be associated with changing sexual behaviour in Uganda, urban Kenya, Zimbabwe, and urban Haiti.

OBJECTIVE: To determine whether observed changes in HIV prevalence in countries with generalised HIV epidemics are associated with changes in sexual risk behaviour. METHODS: A mathematical model was developed to explore the relation between prevalence recorded at antenatal clinics (ANCs) and the pattern of incidence of infection throughout the population. To create a null model a range of assumptions about sexual behaviour, natural history of infection, and sampling biases in ANC populations were explored to determine which factors maximised declines in prevalence in the absence of behaviour change. Modelled prevalence, where possible based on locally collected behavioural data, was compared with the observed prevalence data in urban Haiti, urban Kenya, urban Cote d'Ivoire, Malawi, Zimbabwe, Rwanda, Uganda, and urban Ethiopia. RESULTS: Recent downturns in prevalence observed in urban Kenya, Zimbabwe, and urban Haiti, like Uganda before them, could only be replicated in the model through reductions in risk associated with changes in behaviour. In contrast, prevalence trends in urban Cote d'Ivoire, Malawi, urban Ethiopia, and Rwanda show no signs of changed sexual behaviour. CONCLUSIONS: Changes in patterns of HIV prevalence in urban Kenya, Zimbabwe, and urban Haiti are quite recent and caution is required because of doubts over the accuracy and representativeness of these estimates. Nonetheless, the observed changes are consistent with behaviour change and not the natural course of the HIV epidemic.

Trends in antenatal HIV prevalence in urban Uganda associated with uptake of preventive sexual behaviour.

BACKGROUND: Epidemiological surveillance in Uganda has consistently shown declining HIV prevalence particularly among young antenatal women since the early 1990s, correlated with increased uptake of protective sexual behaviour. OBJECTIVE: To describe trends in sexual behaviour nationwide and antenatal HIV prevalence from urban sentinel sites in Uganda (1989-2002). METHODS: Review of antenatal HIV seroprevalence data from the sentinel surveillance system (1989-2002) and data on sexual behavioural indicators from the AIDS module of the National Demographic and Health Surveys (1989, 1995 and 2000/01). Trends in biological and behavioural indicators assessed. RESULTS: Antenatal HIV seroprevalence in seven urban clinics peaked around 1992 (15-30%) followed by a steady decline by 2002 (5-12%), most markedly among women aged 15-19 and 20-24 years. This coincided with increased primary and secondary abstinence among young people nationwide. Median age at sexual debut increased from 16.5 in 1989 to 17.3 in 2000 for women and from 17.6 in 1995 to 18.3 in 2000 for men. Premarital sex among women and multiple partnerships decreased between 1995 and 2000. There were no significant changes in reporting of extramarital sex among men. Ever use of condoms increased from 1% among women in 1989 and 16% among men in 1995 to 16% and 40% in 2000, respectively. Between 1995 and 2000, condom use at last sex with a non-regular partner increased from 35% to 59% and 20% to 39% among men and women, respectively. CONCLUSION: The ecological correlation between the trends in HIV prevalence and incidence and the increase in protective sexual behaviour during the 1990s makes a compelling case for continuing prevention efforts in Uganda.