Diagnosing and treating latent tuberculosis infection

A new study from Yale Schools of Medicine and Public Health reveals the challenges in identifying high-risk people in urban settings, especially foreign-born individuals, who may have latent tuberculosis infection (LTBI). The study appears in the Journal of Community Health.

According to the Centers for Disease Control, foreign-born individuals contributed to 62.5 per cent of all new active TB infections in the US in 2011, but screening policies and programs are inconsistent for refugees and naturalizing citizens and do not address high-risk undocumented populations.

The method of directly observed therapy (DOT) has been the standard for diagnosing and treating active tuberculosis infection. But employing the method to find LTBI in inner-city populations, particularly among the foreign-born, has been challenging and largely understudied.

The researchers analysed data gathered between 2003 and 2011 from a comprehensive mobile healthcare clinic in New Haven, Connecticut. They looked at more than 2500 tuberculin skin tests, and found 356 new LTBIs.

Furthermore, the mobile healthcare van reached many people in population groups not generally reached by traditional methods. For example, undocumented immigrants were among the highest numbers of those being screened and treated, as were those - documented and not - who were born in a country ranked among the highest in tuberculosis prevalence.

''While the Affordable Care Act is likely to increase access to health care and provide insurance to people who are here legally, foreign-born persons here illegally will fail to interact with traditional healthcare systems and will not be detected and treated unless innovative services specifically target this population,'' according to senior author Frederick L. Altice, M.D., professor of medicine, section of infectious diseases at Yale School of Medicine.

''Foreign-born individuals needing tuberculosis screening services were largely shown to be employed within the community with relatively lower drug use and incarceration rates; this is a great opportunity to show our local and national policymakers that our new immigrants are productive drivers of our economy and need more attention to ensure that they remain in good health,'' according to first author Jamie Morano, MD, of the infectious diseases section at Yale School of Medicine.

Other authors are Mary Walton, Alexei Zelenev and R. Douglas Bruce of Yale School of Medicine.