The value of different tuberculosis (tb) case detection strategies in childhood tb control in a high-tb burden population dense area, western kenya, 2012-2015: a cluster randomized trial

Contact investigation is recommended for close contacts of TB patients to identify undiagnosed cases of active and latent TB to initiate them on curative and preventive therapy respectively. Because contact invitation is conducted in Kenya, the value of TB contact investigation in childhood TB control is unknown. To compare the yield of contact investigation (intervention arm) to contact invitation (control arm) in contributing to childhood TB control, a cluster randomized trial was conducted in Kisumu County between 2014 and 2015 a period prior to the implementation of standardized contact investigation. This was done to compare TB cases diagnosed and children receiving IPT in the pre- intervention (2012-2013) and intervention (2014-2015) years, and in the intervention years using a minimum sample size of 15 per arm. Of 77 facilities identified for the study, 65 facilities were randomized to a contact screening strategy; a TB contact investigation strategy in isolation (n=4), in combination with health facility screening (n=19), or in combination with both enhanced facility screening and mobile units (n=31) with the remainder, (n=11) randomized to the standard approach i.e. TB contact invitation. Facilities distribution did not differ by category of services or patient type. In the pre-intervention and post-intervention years, TB number of TB cases diagnosed in children increased by 20 (75% from intervention arm). During the intervention years TB cases decreased by 17 (29% from intervention arm); the intervention arm contributed to 100% and 75% of the children put on IPT whose implementation had just begun. Contact investigation enhanced childhood TB control in comparison to routine approaches. Critical support ought to be availed to the TB screening cascade to facilitate contact investigation and IPT implementation as well as ingrain contact investigation within existing community health systems.