Typhoid fever in San Antonio, Texas: an outbreak traced to a continuing source.

Eighty cases of typhoid fever occurred in San Antonio, Texas, with dates of onset from August 18, 1981, to October 26, 1981. Preliminary epidemiological investigations of the first 24 cases suggested a Mexican food takeout restaurant as the common source. A case-control study confirmed this association (P less than or equal to .001). Barbacoa , a mixture of muscle, lips, ears, tongue, and eyes from steamed bovine heads, was identified as the source of Salmonella typhi (P = .03). S typhi was cultured from the stool of one of 31 restaurant employees. Closure of the restaurant resulted in termination of the outbreak within a single incubation period. The restaurant was allowed to reopen after the remaining employees had demonstrated lack of excretion of S typhi in stools. This outbreak represents the largest restaurant-associated typhoid fever outbreak reported in the United States in greater than 50 years.