To identify factors contributing to a 400% increase in tuberculosis among children in San Diego County, California, from 1985 to 1993.
Review of medical records of reported cases in 1989, 1991, and 1993 and their source case.
Of 192 children with tuberculosis, the largest increase was observed in children younger than 5 years old, of whom 77.4% were born in the United 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 cases, 82.1% were born outside the United States, primarily in Mexico (67.9%). Resistance to at least one first-line antituberculous drug was identified in 27.5% of isolates from children and in 33.3% of isolates from source cases.
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 contacts born in countries in which tuberculosis is highly endemic.