Determinants and Incidence of Tuberculosis among adults living with HIV, who completed Isoniazid Preventive Therapy from 2019 to 2023, Mainland Tanzania

The study analyzed 38,407 adults living with HIV on antiretroviral therapy who completed isoniazid preventive therapy in Tanzania between 2019 and 2023. The mean age of participants was 36.7 years, with 63 percent female. During a median follow-up of 17.9 months, 901 new tuberculosis cases were identified, representing an incidence rate of 1.40 per 1,000 person-months. The median time to tuberculosis development was 10.12 months. Higher tuberculosis risk was found in women, unmarried individuals, and breastfeeding mothers, while persons aged 25 to 34 years and 45 years or older had lower risk. Geographically, persons in Eastern, Western, and Lake zones had lower risk compared to the Northern zone. The study confirmed the protective effect of isoniazid preventive therapy, but indicated that its protection lasts only approximately 10 months rather than 18 months as stated in Tanzanian guidelines.