Prevalence and incidence of HIV-1 infection among employees of a large textile business and their wives in Kinshasa, 1991-1996

BACKGROUND: The Democratic Republic of Congo has been experiencing a critical economic situation for several years, resulting in a favorable context for the spread of HIV-infection. A study was performed in a large textile factory in Kinshasa, to determine prevalence and incidence of HIV-infection among employees and their wives. METHODS: From February to November 1996, a cross-sectional study was conducted among 2010 employees (1859 males, 151 females) of the factory and their 1198 female partners. Participants responded to a structured questionnaire and HIV testing was performed after an informed consent was obtained in a pre-test counselling session. Using a reconstituted population of 1580 employees (1502 males, 78 females) and their 806 female partners (all HIV-seronegative in 1990), we determined the HIV incidence between 1990 and 1996. Employees included manual workers, middle managers and senior managers. RESULTS: Overall prevalence and incidence rates were 2.1% (95% CI=1.6%-2.6%) and 0.16/100 persons-years (95% CI=0.09-0.22) respectively. Reported condom use was associated with HIV infection in men (OR=2.5; 95% CI=1.2-5.3) and their spouces (OR=1; 95% CI=0.02-10.7) and with a history of urethral discharge in men (OR=4.1; 95% CI=1-30.1). The HIV incidence between 1990 and 1996 was 0,2/100 person-years (95% CI=0.1-0.2). The seroconversion risk increased from manual workers to senior managers (chi-square for linear trend=12.9; p<0.001). CONCLUSIONS: Despite the deterioration of health services and the economical instability in Kinshasa, HIV prevalence and incidence rates in this factory were much lower than rates observed in factories in same East and Southern African countries. Comparative prospective studies using a similar methodology are needed to better understand the reasons for these differences.