An outbreak of group A food-borne streptococcal pharyngitis

A food-borne outbreak of pharyngitis from group A streptococcus developed in people attending wedding banquets in the same restaurant on July 5-8, 1986. Of the 300 people interviewed, 179 reported illness; pharyngeal swabs were taken from 115 ill people; from 63 (53%) of them group A streptococci, belonging to serotype T28, M28, were isolated. Statistical analysis performed using chi-square and Cochran's test showed that a prawn hors-d'oeuvre served on July 5 and squills or/and custard cake served on July 7 could have been a possible source of infection. Six people on the staff, 5 of whom belonged to the family of the restaurant manager, and the manager's three young daughters were colonized by the same group A serotype. A possible previous diffusion of the strain among the staff followed by contamination of the food was suspected.