Cotrimoxazole prophylaxis by HIV-infected persons in Uganda reduces morbidity and mortality among HIV-uninfected family members.

Background: The effect of cotrimoxazole prophylaxis taken by persons with HIV on community health and antimicrobial resistance is unknown.

Objective: To assess the effect of cotrimoxazole prophylaxis taken by persons with HIV on morbidity, mortality, and antimicrobial resistance of diarrheal pathogens infecting their HIV-negative family members.

Design: Prospective cohort in rural Uganda.

Methods: A total of 879 persons with HIV and 2771 HIV-negative family members received weekly home-visits. After 5 months, persons with HIV received daily cotrimoxazole prophylaxis and households were followed for an average of 17 additional months.

Findings: During the study, 224 participants with HIV (25%) and 29 household members (1%) died. Mortality among HIV-negative family members < 10 years old was 63% less during the cotrimoxazole period than before [hazard ratio, 0.37; 95% confidence interval (CI), 0.14-0.95; P = 0.04]. Malaria among family members was less common during cotrimoxazole treatment [incidence rate ratio (IRR), 0.62; CI, 0.53-0.74; P < 0.0001], as were diarrhea (IRR, 0.59; CI, 0.45-0.76; P = 0.0001), and hospitalizations (IRR, 0.57; CI, 0.36-0.92; P = 0.02). Death of a parent with HIV was associated with a threefold increase in mortality among HIV-negative children < 10 years old (hazard ratio, 2.9; CI, 1.1-8.1; P = 0.04). Of 134 bacterial isolates from family members before cotrimoxazole treatment, 89 (66%) were resistant to cotrimoxazole; of 75 recovered during cotrimoxazole treatment, 54 (72%) were resistant (P = 0.41).

Interpretation: Cotrimoxazole prophylaxis taken by persons with HIV was associated with decreased morbidity and mortality among family members. Antimicrobial resistance among diarrheal pathogens infecting family members did not increase. Concerns regarding the spread of bacterial resistance should not impede implementation of cotrimoxazole programs.