Food-borne streptococcal pharyngitis in a hospital pediatrics clinic.

After a potluck luncheon, more than half the staff of a hospital pediatrics clinics became ill. Group A Streptococcus (M precipitin, nontypable; T agglutination type, 8/25; and serum opacity reaction, positive) was isolated from 12 of the 20 ill persons. Food-consumption analysis implicated a rice dressing as the vehicle of transmission. The dressing was prepared by a clinic employee in whom pharyngitis had developed three weeks before the luncheon. This is an unusual outbreak in that the implicated food product was not institutionally or commercially prepared and was not preponderantly composed of milk, eggs, or meat.