Novel TB infection diagnostic test among key populations in Mexicali

Published in August 20205 in the PLOS Global Public Health

The state of Baja California in Mexico has one of the highest rates of TB in the country. Before this study began, the city of Mexicali committed to using a comprehensive approach for TB elimination, which signaled their intent to innovate and collaborate to understand the local burden of disease and implement better strategies for identifying, treating, and preventing TB. There was therefore a substantial amount of political will and local interest in implementing a study of this kind. Although these results are grounded in the Mexicali context, they’re certainly applicable to other settings. Our findings around the acceptability and usability of the tuberculin skin test and novel, near-point-of-care IGRA tests will be informative for designing more effective diagnostic tests and TB programs, particularly among key TB populations like people who use drugs, household contacts, and people in prisons. Similarly,

For SEATRAC member Amanda Brumwell, this was an excellent opportunity to learn how design acceptable surveys that are effective in non-US, non-English speaking settings.

"I’m grateful to have had the opportunity to learn how to design a pragmatic study that could be implemented in a non-US setting. In the process, I also learned quite a lot about data management and choosing the right statistical tests... I expect that our test concordance findings will be informative for future studies and TB burden estimations, especially in high TB burden groups and in Latin American settings".

As a PhD candidate in global health metrics and implementation science, Amanda thinks a lot about how evidence-based practices could be delivered more effectively in real-world settings. Two of the most notable conclusions from these studies was that (1) a newer TB infection test (a near-point-of-care IGRA) was acceptable and performed well compared to the standard of care, and (2) that differentiated TB care  strategies are needed for different populations. Therefore, the next logical step would be to test different, tailored implementation strategies for delivering this new TB test across a larger population, so that they can assess how well it performs in terms of TB detection at a broader scale, how that performance can be enhanced for different groups, and how it can be effectively embedded within a TB elimination program.

Read more about this cross-sectional study evaluating the prevalence of TB infection (TBI) and concordance of TST and IGRA in three high-risk populations in Mexicali, Baja California, Mexico in BMJ Open.