Relatively low HIV infection rates in rural Uganda, but with high potential for a rise: a cohort study in Kayunga District, Uganda.
BACKGROUND
Few studies have been conducted in Uganda to identify and quantify the determinants of HIV-1 infection. We report results from a community-based cohort study, whose primary objectives were to determine HIV-1 prevalence, incidence, and determinants of these infections, among other objectives.


METHODS
Consenting volunteers from the rural district of Kayunga in Uganda aged 15-49 years were enrolled between March and July 2006. Participants were evaluated every six months. A questionnaire that collected information on behavioral and other HIV-1 risk factors was administered, and a blood sample obtained for laboratory analysis at each study visit.


RESULTS
HIV-1 prevalence among the 2025 participants was 9.9% (95% CI = 8.6%-11.2%). By the end of 12 months of follow-up, 1689.7 person-years had been accumulated, with a median follow-up time of 11.97 months. Thirteen HIV-1 incident cases were detected giving an annual HIV-1 incidence of 0.77% (95% CI = 0.35-1.19). Prevalence of HSV-2 infection was 57% and was strongly associated with prevalent HIV-1 infection (adjusted Odds Ratio = 3.9, 95% CI = 2.50-6.17); as well as incident HIV-1 infection (adjusted Rate Ratio (RR) = 8.7, 95% CI = 1.11-67.2). The single most important behavioral characteristic associated with incident HIV infection was the number of times in the past 6 months, a participant had sex with person(s) they suspected/knew were having sex with others; attaining statistical significance at 10 times and higher (adjusted RR = 6.3, 95% CI = 1.73-23.1). By the end of 12 months of follow-up, 259 participants (13%) were lost to follow-up, 13 (0.6%) had died, and 2 (0.1%) had withdrawn consent.


CONCLUSIONS
Despite relatively low HIV-1 incidence observed in this community, prevalence remains relatively high. In the presence of high prevalence of HSV-2 infection and the behavioral characteristic of having sex with more than one partner, there is potential for increase in HIV-1 incidence.
Guwatudde
David
D
Makerere University-Walter Reed Project, Kampala, Uganda. dguwatudde@muwrp.org
Wabwire-Mangen
Fred
F
Eller
Leigh Anne
LA
Eller
Michael
M
McCutchan
Francine
F
Kibuuka
Hannah
H
Millard
Monica
M
Sewankambo
Nelson
N
Serwadda
David
D
Michael
Nelson
N
Robb
Merlin
M
D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D015995:Prevalence; D012307:Risk Factors; D014454:Uganda / Q000453:epidemiology