Group A β-Hemolytic Streptococcal Bacteremia: Historical Overview, Changing Incidence, and Recent Association With Varicella

Abstract

Objective. To quantitate the increase in invasive group A β-hemolytic streptococcal (GABHS) infections and to define a possible association between GABHS bacteremia and primary varicella zoster virus (VZV) infections. Methods. This was a retrospective chart review conducted at Children's Hospital. Participants were patients with documented GABHS bacteremia occurring from January 1977 through December 1993. Measurements/Main Results. We identified 63 episodes of GABHS bacteremia in 62 patients. From 1977 to 1992, a mean of 3.2 ± 2 cases occurred per year (range, 0 to 6), increasing by a factor of 3 (10 cases) in 1993. The median age was 4 years (range, 1 day to 20 years; mean, 8 years ± 3 months); 36 were male; five children were immunocompromised. One child was dead on arrival and one had a cardiac arrest during evaluation in the emergency department. Primary sites of infection (oropharynx, skin, or middle ear) were identified in 40 (75%) of the cases; in addition, 10 cases occurred in patients with primary VZV. From 1977 to 1992, we identified five VZV-associated cases; an average of 7 ± 11.5% of the patients with GABHS had concurrent VZV infection annually, with no more than one case per year. In 1993, 50% of the 10 new GABHS cases were in children with VZV infection (P = .003, Fisher's exact test). The diagnosis of invasive GABHS infection in patients with VZV was not readily recognized, requiring a median of two (range, one to four) physician visits before admission and the administration of antibiotics. All 10 children were diagnosed on the fourth or fifth day of the exanthem and were febrile (39.6 ± 1.1°C, range, 38.3 to 40.8°C), with a mean white blood cell count (WBC) of 11 500 ± 8 400/mm3 (8 of 10 cases had a WBC less than 15 000/mm3). None of the five VZV-associated cases in 1993 had signs of cutaneous bacterial superinfection; among these were two cases of streptococcal toxic shock syndrome (one death), one case of osteomyelitis, and two cases of occult bacteremia. Of the five VZV-associated cases before 1993, one patient was diagnosed with supraglottitis, one with septic arthritis, one with orbital cellulitis, and two solely with impetiginized or cellulitic lesions. Conclusions. We found that the incidence of invasive GABHS infections has risen dramatically, increasing by a factor of 3 over the past year. In 1993, 50% of new cases of invasive GABHS disease were associated with VZV infection. Invasive GABHS should be considered in children with VZV who manifest fever on or beyond the fourth day of the exanthem. The absence of an elevated WBC and impetiginized or cellulitic lesions should not eliminate this diagnosis from consideration.