Recurrent group A streptococcal carriage in a health care worker associated with widely separated nosocomial outbreaks.

Nine postpartum infections (five bacteremias, three cases of endometritis without bacteremia, and one infected episiotomy site) caused by an M-nontypable, T-28 strain of group A Streptococcus occurred during a 9-week period in 1987. Seven cases were cared for by one obstetrician, who was also present in the delivery suite when the remaining patients delivered. This individual was found to be an anal carrier of group A Streptococcus with the same M and T types. During the cluster, the attack rate for vaginal deliveries performed by this individual was 18% (6 of 34 patients). The individual was treated with penicillin V (500 mg four times a day for 10 days), rifampin (600 mg twice a day for 5 days), and hexachlorophene showers. Surveillance cultures of the physician were negative 1 week, 1 month, and 3 months after completion of therapy. No additional cases were identified among the next 210 vaginal deliveries performed by this individual. Fourteen months after therapy, four new cases occurred during 2 days. The physician was found to be heavily colonized once again with the original strain of group A Streptococcus and was treated with rifampin (600 mg twice a day) and oral vancomycin (250 mg four times a day) for 7 days. An open-ended regimen of penicillin V (250 mg/day) and periodic surveillance cultures was begun. During the next 19 months, this physician performed 275 vaginal deliveries, one of which resulted in an M-nontypable, T-28 group A streptococcal infection, at a time when the physician's surveillance cultures were negative. It is unclear how long a colonized health care worker who causes nosocomial group A streptococcal disease must be treated or monitored, but there is some risk after more than a year. Long-term surveillance or prophylaxis may be useful in some circumstances.