Routine tuberculosis contact investigation yield and preventive treatment cascade in central Ethiopia

There is a global gap between tuberculosis incident cases and the notified cases. Active household contact investigation is one of the strategies to narrow this gap. It has the advantage of giving early diagnosis and preventive treatment to vulnerable and eligible groups. This study assessed the practice of contact investigation and tuberculosis preventive treatment adherence in central Ethiopia.

A cross-sectional study covering all registered bacteriologically confirmed pulmonary tuberculosis patients and their close contacts was conducted in central Ethiopia from January 1, 2022, to December 30, 2022.

A total of 1372 household contacts were declared by the index cases. From these 79.44 % (1090) contacts received a one-time tuberculosis screening giving a total of four (0.36 %) active TB cases. Among 484 household contacts of drug-resistant tuberculosis index cases, 5.53 % (14) had presumptive tuberculosis and 0.79 % (2) had active tuberculosis. While among 837 household contacts of drug-susceptible tuberculosis index cases presumptive TB cases were 1.91 % (16) and active TB cases were 0.23 % (2). Of the 142 eligible under 15 children 81.69 % (116) had started tuberculosis preventive treatment and 84.48 % (98) completed the treatment. On multivariable logistic regression, the associated factor for tuberculosis preventive treatment non-adherence was age 2-5 years (aOR, 0.02, 95 % CI (0.002-0.20) and age 5-15 years (aOR, 0.04,95 % CI (0.002-0 0.95)) P=<0.05).

There was low contact screening practice in the DR-TB index cases as compared to national and global targets. The yield of routine contact investigation was low and it indicates the quality of screening. Tuberculosis preventive treatment initiation and completion rates were also low as compared to those of many other countries and global achievements which need further improvement, especially for completion. Alternative mechanisms should be planned to increase the yield of tuberculosis screening and tuberculosis preventive treatment adherence.