Investigating the Acceptability and Feasibility of Home-based TB Testing of Household Contacts Using a New, Mobile Point-of-care Technology

In 2013, WHO estimated that 3.3 million cases of TB had been missed (undiagnosed or with a significant delay in diagnosis or treatment). "Missed" TB cases are a key driver of TB transmission, with approximately 9 million individuals developing TB globally each year, equivalent to 126 cases per 100,000 population. The overall goal of this proposal is to evaluate the utility of home-based point-of-care TB testing for early diagnosis and linkage to care of household contacts of TB patients, addressing the need for intensive case finding and early detection of infectious TB. Although well-accepted as an effective strategy for boosting HIV diagnosis and treatment rates, until recently home-based testing for TB has been impossible, as there has never existed an effective, mobile PoC technology for rapid diagnosis of TB. With the development of the new GeneXpert® Omni diagnostic platform from Cepheid, home-based TB testing is now possible. Now is the time to study whether home-based testing for TB is feasible, and will contribute to early case detection or improve time-to-treatment rates.

This project has two Specific Aims:

1. To determine the acceptability and feasibility of using point-of-care technology to perform home-based TB testing of household contacts of TB patients, with subaim 1(a): To assess the intent-to-seek care of household contacts symptomatic for TB, and subaim 1(b): To determine the proportion of household contacts symptomatic for TB consenting to be tested (acceptability) and uptake of treatment referrals by those individuals infected with TB within 30 days of testing (feasibility);
2. To describe the outcomes of household contacts screened and tested for TB in their home compared to those screened and referred for testing in a health facility, with subaim 2(a): To describe the barriers and facilitators to clinic follow-up by household contacts symptomatic for TB and provided with referral for TB testing or treatment initiation, and subaim 2(b): To determine whether point-of-care home-based TB testing reduces time-to-treatment initiation.

An exploratory study will be conducted in a high TB prevalence area of Eastern Cape Province, South Africa. Specifically, households of TB patients initiating treatment at one of 6 collaborating clinics will be offered a point-of-care home-based TB test, with referral for immediate treatment when testing positive. In accordance with the South African National TB Management Guidelines (SA-NTMG), all smear positive pulmonary TB (PTB) patients recruited and consented will be asked to provide a list of all household contacts for a household contact investigation. The household contact investigation team will then, in keeping with South African National Department of Health guidelines, seek verbal consent from all household contacts to conduct TB symptom screening. During symptom screening, intent-to-seek care will be assessed for all reported symptoms. If one household member screens positive, then the whole household will be randomized to either the Intervention; home-based GeneXpert point-of-care (PoC) test or Control arm; standard home-based TB symptom screening with referral for testing.