Evolving epidemiologic characteristics of invasive group a streptococcal disease in utah, 2002-2010

Abstract

Background. Invasive group A Streptococcus (GAS) infections are associated with substantial morbidity and mortality. Recent national surveillance data report stable rates of invasive GAS disease, although these may not capture geographic variation. Methods. We performed a population-based, retrospective laboratory surveillance study of invasive GAS disease among Utah residents from 2002-2010. We used Intermountain Healthcare's electronic medical records and data warehouse to identify patients from whom GAS was isolated by culture. We defined clinical syndromes of invasive GAS disease on the basis of International Classification of Diseases, Ninth Revision codes. We abstracted demographic information, comorbidities, and microbiologic and laboratory findings. Results. From 2002-2010, we identified 1514 cases of invasive GAS disease among Utah residents. The estimated mean annual incidence rate was 6.3 cases/100 000 persons, which was higher than the national rate of 3.6 cases/100 000 (P <18 years, the incidence of invasive GAS increased from 3.0 cases/100 000 children in 2002 to 14.1 cases/100 000 children in 2010 (P