Nosocomial Transmission of Invasive Group A Streptococcus from Patient to Health Care Worker

Background. Nosocomial transmission of group A streptococcus ( GAS) has been well described. Instances resulting in fulminant disease among health care workers have not been described. Contact and droplet precautions have been advised to minimize the risk of nosocomial transmission. We aimed to determine whether a case of invasive GAS pneumonia and streptococcal toxic shock syndrome in a respiratory therapist was acquired as a result of caring for a patient with GAS necrotizing fasciitis. Contacts of these patients were screened to determine if they were the reservoir of the GAS. Genetic testing to confirm clonal transmission was conducted. Methods. Contacts of the patients with GAS infection were screened using questionnaires and testing of pharyngeal specimens. Specimens from patients and carriers of GAS who were identified during screening were subjected to pulsed-field gel electrophoresis and emm gene typing. Results. We identified 705 contacts of the 2 patients; all contacts had oropharyngeal specimens collected for culture. Only the index patient and the respiratory therapist yielded identical pulse-field gel electrophoresis GAS isolates, with clonality indicated by emm typing. Conclusions. Nosocomial transmission of GAS from a patient to a health care worker who developed streptococcal toxic shock syndrome may have occurred after the index patient had received 48 h of antibiotic therapy and despite placement in contact isolation. Isolation guidelines for patients with severe GAS infection may need to be reviewed.