Abstract:
BACKGROUND: Monitoring dynamics in HIV-1 infection and risk behaviours is
important in evaluating, adjusting and scaling up prevention programmes. The
objective of this study was to estimate trends in the prevalence of HIV-1
infection and risk behaviours over 15 years in a rural village population in
Kilimanjaro region of Tanzania using repeated population-based cross-sectional
surveys.
METHODS: Four rounds of HIV-1 sero-epidemiological and behavioural surveys were
completed during 1991 to 2005 in the study village. House-to-house registrations
of people aged 15-44 years with an address in the village were conducted before
each survey. All consenting individuals were then interviewed for pertinent risk
behaviours and tested for HIV-1 seropositivity.
RESULTS: Participation proportions ranged from 73.0% to 79.1%. Overall, age and
sex-adjusted HIV-1 prevalence increased from 3.2% in 1991 to 5.6 % in 2005
(relative increase 75.0%; ptrend < 0.001). The increase was significant for both
men and women (ptrends < 0.001) and more evident among women aged 35-44 years
(2.0% to 13.0%, ptrend < 0.001). Among participants aged 15-24 years a decrease
in number of sexual partners was observed with a corresponding stable HIV-1
prevalence. Participants aged 25-44 years continued to report multiple sexual
partners, and this was corroborated with increased HIV-1 prevalence trend (4.0%
to 9.0%, ptrends < 0.001). Among men aged 25-44 years and women aged 15-24 years
significant increases in condom use were observed (ptrend < 0.01).
CONCLUSION: The HIV-1 prevalence seems to have increased among older participants
but remained stable among younger participants. Encouraging trends toward safer
sex practices were observed among young participants, while only modest
behavioural changes were seen among the older participants. Prevention efforts in
rural areas need to be intensified and to address people of all ages.
