Published online by Cambridge University Press: 18 December 2015
To describe an outbreak of severe Group A Streptococcus (GAS) infections that appeared to be associated with use of a biologic dermal substitute on foot wounds
Retrospective cohort study of cases and similar uninfected patients
Patients attending the podiatry clinic at a Veterans Affairs Medical Center between July 2011 and November 2011
Microbiology laboratory data were reviewed for the calendar year, a case definition was established and use of the biologic dermal substitute was discontinued. Staff were cultured to identify potentially colonized employees. A case–cohort study was designed to investigate risk factors for disease. Emm typing and pulsed field gel electrophoresis (PFGE) were performed to identify strain similarity.
In 10 months, 14 cases were identified, and 4 of these patients died. All strains were emm type 28 and were identical according to PFGE. Discontinuation of biologic dermal substitute use halted the outbreak. A prior stroke was more common in the case cohort vs uninfected patient cohorts. The number of patients attending the clinic on 13 probable transmission days was significantly higher than on nontransmission days. We identified 2 patients who were present in the clinic on all but 1 probable transmission day. Surveillance cultures of podiatry clinic staff and cultures of the same lot of retained graft material were negative.
A carrier was not identified, and we believe the outbreak was associated with inter-patient transmission likely due to lapses in infection control techniques. No additional cases have been identified in >3 years following the resumption of dermal substitute use in May 2012.
Infect. Control Hosp. Epidemiol. 2016;37(3):306–312
PRESENT AFFILIATIONS. At the time of the case–cohort study, Dr. Ibrahim was a fellow in the Division of Infectious Diseases at the University at Buffalo, Buffalo, New York; she now is in private practice in Hartford, Connecticut. Ms. Watson is now with the Genessee County (New York) Health Department, and Ms. McCabe is with Catholic Health System in Buffalo. Dr. Martinello is no longer affiliated with the Veterans Health Administration.
PREVIOUS PRESENTATION. The epidemiologic investigation described in this paper was presented at ID Week 2012, October 17–21, 2012, San Diego, California (Abstract no. 255).