An outbreak of food-borne illness associated with methomyl-contaminated salt.

Context: On January 5, 1999, the California Department of Health Services was notified of the repeated occurrence (December 21, 1998, and January 2, 1999) of gastrointestinal tract illness among patrons at a Thai restaurant in central California.

Objective: To identify the source of the outbreak.

Design: Case-control study; microbiological and toxicological laboratory testing of samples of food, stool, and vomitus.