Immigration and tuberculosis among children on the United States-Mexico border, County of San Diego, California

Objective. To identify factors contributing to a 400% increase in tuberculo sis among children in San Diego County, California, from 1985 to 1993. Design. Review of medical records of reported cases in 1989, 1991, and 1993 and their source case. Results. Of 192 children with tuberculosis, the largest increase was observ ed in children younger than 5 years old, of whom 77.4% were born in the Uni ted States, 67.8% had a foreign-born parent, 73.1% came from a non-English- speaking household, and 46.2% were known to visit Mexico. Of 28 source case s, 82.1% were born outside the United States, primarily in Mexico (67.9%). Resistance to at least one first-line antituberculous drug was identified i n 27.5% of isolates from children and in 33.3% of isolates from source case s. Conclusions. The increase in tuberculosis and high level of drug-resistance among children born in the United States may be attributed to transmission outside of the United States or within the United States from household co ntacts born in countries in which tuberculosis is highly endemic.