Tuberculosis testing abroad and treatment of American immigrants reduces spread


According to a study published online February 16 in Emerging infectious diseases.

“In our study of US-bound immigrants in Vietnam during their mandatory overseas medical examination prior to migration to the US, we identified a high proportion of US-bound immigrants with latent tuberculosis infection (ITBL) and offered them preventive treatment for tuberculosis,” co-author Christina R. Phares, PhD, of the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, said. Medscape Medical News.

“Overall, 88% of those who started treatment completed their treatment,” she said in an email. “This is a higher rate of treatment completion than seen in many post-arrival strategies in the United States.”

“This study has demonstrated that it is feasible to provide testing and treatment of LTBI during medical examination abroad, that it yields high initiation and completion rates, and that it should be considered a viable strategy to address LTBI among migrants to the United States,” lead author Amera Khan, DrPH, of the Stop TB Partnership in Geneva, Switzerland, said in a statement. E-mail.

The research team began the one-year Tuberculosis Prevention Abroad (PTOPS) pilot study in Vietnam in 2018 among US immigrant visa applicants. Study participants were 12 years of age or older and underwent required medical examinations, which included blood testing for tuberculosis with the interferon gamma release test (IGRA).

Eligible IGRA-positive participants who planned to complete their LTBI treatment before traveling to the United States were offered 3HP (12 weekly doses of isoniazid and rifapentine) free of charge. Of 5311 people recruited into the study, 2438 (46%) enrolled; 2276 had an IGRA treated; and 484 (21%) tested positive. Of the 452 participants eligible for 3HP, 304 (67%) started and 268 (88%) completed their treatment.

Pre-immigration strategies needed

Globally, tuberculosis is now the second leading cause of infectious disease death, behind COVID-19, Khan said. The United States has seen a slow and steady decline in incidence with an increasing proportion of tuberculosis among those born outside the country.

“About 70% of TB cases in the United States occur in people born outside of the United States, with the vast majority due to reactivation of latent TB infection acquired prior to their trip to the United States,” she said. “To make progress toward eliminating TB in the United States, we need innovative strategies to address the heavy burden of LTBI among immigrants.”

Jonathan E. Golub, PhD, MPH, an infectious disease specialist and professor of medicine, epidemiology, and international health at Johns Hopkins University School of Medicine in Baltimore, Maryland, was not involved in the study but agreed. is congratulated on his results. “This study clearly shows that a pre-departure ITL screening and treatment strategy can be successfully implemented,” he said. Medscape Medical News by email. “While the study highlights areas of the LTBI care cascade that need improvement, the message is clear that pre-departure screening and treatment has the potential to have a significant impact on TB rates among non-Americans born in the United States.”

Golub went on to explain that new LTBI screening technologies have been underutilized. “New, shorter treatment regimens for ITL provide more feasible choices for both providers and individuals applying for immigration visas. Combining IGRA with 3HP creates an effective and efficient strategy. This strategy n had not been tested prior to the study and the results are exciting.”

Golub pointed to an important aspect of the study: that many participants started treatment in Vietnam and completed it in the United States. “It shows that such a protocol offers the necessary flexibility and can be followed by health systems and patients,” Golub said. “If TB is ever to be eliminated in the United States, reducing TB in people not born in the United States must be a priority.”

The rifapentine used in the study was donated by Sanofi, the manufacturer of the drug. Khan, Phares and Golub reported no relevant financial relationships. The study was supported by a CDC cooperative agreement.

Emergency Infect Dis. 2022;28:582-590. Full Text

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