An Outbreak of Group A Streptococcal Bacteremia in an Intensive Care Unit

Abstract

Admission of a patient with group A streptococcal cellulitis and bacteremia to the intensive care unit of a tertiary care teaching hospital was followed by two subsequent cases of group A streptococcal bacteremia with pneumonia in the unit. All streptococcal isolates were the same M- and T-type. Endotracheal intubation with respiratory ventilation was a risk factor for disease acquisition. The characteristics of onset of the two nosocomially acquired cases suggested that a staff member may have been, at least transiently, a streptococcal carrier, but no such carrier was identified. No further cases occurred subsequent to a period when all patients in the unit received antibiotics effective for group A streptococcal therapy.

Outbreak of Streptococcus pyogenes infection in healthcare workers in a paediatric intensive care unit: transmission from a single patient

“…Although outbreaks outside the familial setting have markedly decreased in frequency and magnitude, they continue to occur, especially in closed communities such as daycare centres or military units [1, 2]. Nosocomial S. pyogenes transmission has been also well documented and, although most reports describe transmission from asymptomatic healthcare workers (HCWs) to patients [3–5], transmission from patients to HCWs has also been described [6–8]. Paediatric intensive care units (PICUs) are a recent creation where hygiene standards are high, explaining why, with some exceptions [9], no S. pyogenes outbreaks have hitherto been described in these units.…”

“…There were no asymptomatic infections, probably because the infecting dose transmitted by the patient was very high. The high transmissibility of S. pyogenes has been shown by the frequent occurrence of secondary cases detected in asymptomatic individuals [3–5], who probably have an infecting dose or bacterial load far lower than that of persons with symptomatic infection. The fifth HCW, with a distinct S. pyogenes strain than that detected in the index case, probably acquired the infection in the paediatric ED where she worked.…”