U.S. Centers for Disease Control and Prevention report finds newly discovered tuberculosis higher among foreign-born with more than 10 years in United States than among more recent arrivals
With a drop in the numbers of new tuberculosis patients between 2015 and 2016, TB incidence in the U.S. is once again going in the right direction, but not fast enough to see the last of the disease in this country by the end of the 21st century, according to data released this week.
Last year, 9,287 new cases of the disease were reported to the National Tuberculosis Surveillance System, information the U.S. Centers for Disease Control and Prevention indicates is preliminary in today’s Morbidity and Mortality Weekly Report. While that represents an improvement over the 9,546* new cases of TB illness in 2015 — the first increase in new cases in more than two decades — the findings, the authors of the report write, indicate the need to both strengthen and sustain current public health programs and to expand efforts to test for and treat TB infection among populations at highest risks for developing the disease.
The data is accompanied by an analysis of findings showing the numbers of foreign-born individuals diagnosed with tuberculosis 10 years or more after arriving in the U.S. now exceeding the numbers of those diagnosed within 10 years of their arrival. Most cases of tuberculosis disease in the U.S. are believed to be attributable to the activation of infections acquired years earlier and rates of tuberculosis disease among foreign-born residents of the U.S. are about 14 times that among U.S.-born individuals. While efforts to detect and treat infection and illness among foreign-born U.S. residents have largely focused on opportunities before, and immediately following their arrival, the increasing trend of diagnosis 10 years or more after arrival indicates the interplay of other risk factors, the authors note. Those include living in settings where large numbers of people live in close quarters, including shelters for people who are without homes, long-term care facilities, and correctional institutions, and in addition to HIV, having immune compromising conditions that include diabetes and end-stage kidney disease. Foreign-born individuals diagnosed with tuberculosis 10 years or more after their arrival in the U.S. were “significantly more likely” to be at least 40 years old, have lived in a long-term care facility, have a history of non-HIV immune compromising conditions including diabetes, kidney disease, and organ transplant, and have reported excess alcohol use in the preceding year. At the same time, new tuberculosis patients who had been in the U.S. 10 years or longer were less likely to be incarcerated when diagnosed. What is not known is whether the numbers of foreign-born patients diagnosed with tuberculosis after 10 years or more in the U.S. may have become infected during more recent travel outside of the the U.S., the authors note.
The findings, they write, indicate needs to make screening and testing for tuberculosis infection and illness routine among people whose risks are higher, and to expand those efforts beyond current public health programs into private practice and community care settings.
*This post has been updated to reflect an update to the preliminary number reported last year.