Introduction: persons in close proximity with Tuberculosis (TB) patients are at risk of TB infection. Contact investigation (CI) has not been scaled up to full implementation by the National Tuberculosis Program in Kenya. As part of a TB household CI study, we documented key concerns that the TB program in Kenya need to consider when transitioning from routine contact invitation to standardized contact investigation.

Methods: a mixed methods evaluation, using participant documents, databases and meeting notes, was conducted between 2014 and 2015 in Kisumu County, Kenya. Qualitative data were manually coded as per emerging themes. Quantitative data was summarized into proportions of participants that received specific services.

Results: of 554 TB index cases recruited, 95% listed at least one household contact and a total of 1974 contacts; 2,068 contacts were however identified during a home visit (median no. of contacts per index 5 IQR 3-7). Of 98% (1,907/1945) of contacts scheduled for eligibility assessment, 1,855 (99%) were "household contacts" and 1519 (82%) assented enrolment. Of 346 (23%) child contacts (aged <5years), 82% had tuberculin skin test done; only 71% of symptomatic child contacts had Chest x-ray examination. Isoniazid Preventive Therapy initiation and completion rates were 15% and 20% respectively. Study procedures required the use of relational databases and a huge resource investment.

Conclusion: TB programs should take into account the size of the proposed target population and infrastructure to support screening and treatment of contacts prior to transitioning to standardized contact investigation.