Researchers find a strain of tuberculosis that is particularly common in Mexican immigrants

The incidence of a strain of tuberculosis (TB) called Mycobacterium bovis, or M. bovis, associated more often with cattle than humans, is increasing in San Diego and is concentrated mostly in Hispanics of Mexican origin, according to a study conducted by researchers at the University of California, San Diego School of Medicine in collaboration with San Diego County public health officials. Their analysis shows that changing patterns of TB in the United States are increasingly being driven by conditions outside of the country, especially in binational communities. In their review of 3,291 culture-positive cases of TB covering 1994 to 2005, M. bovis accounted for 45% of TB cases in children under the age of 15, with almost all M. bovis cases from 2001 to 2005 found in persons of Hispanic ethnicity. The researchers found that more than 90% of M. bovis cases in San Diego occurred in Hispanics, most born in Mexico.