RESUMO
OBJECTIVES: To assess changes in hospitalization rates for invasive group A streptococcal (IGAS) and varicella-associated IGAS (VA-IGAS) infections at a pediatric hospital over a period of 9 years, to characterize clinical features of patients with IGAS infections, and to assess frequency of macrolide-resistant IGAS isolates. Study design Medical records of all hospitalized patients with group A streptococcus isolated from a normally sterile site from 1993 to 2001 were reviewed. Data collected included demographics, clinical course, microbiologic features, outcome, and presence of streptococcal toxic shock syndrome (STSS) or necrotizing fasciitis (NF). Annual hospitalization rates for IGAS were determined. RESULTS: There were 144 patients with IGAS infections, including 11 (8%) with STSS or NF. Overall mortality rate was 2% (3/144) but 18% (2/11) among patients with STSS or NF. Preexisting varicella was present in 16% (23/144); 4 of 23 VA-IGAS cases had STSS or NF. Although there was no change in annual hospitalization rates for IGAS infections during the study period, the percentage of VA-IGAS hospitalizations decreased from 27% in the prevaccine era (1993 to 1995), to 16% during vaccine implementation (1996 to 1998) and 2% during widespread vaccine use (1999 to 2001) (linear-by-linear association, P=.001). Macrolide resistance was low in 1993 to 1995 (5%, 1/19) and 1996 to 1998 (0%, 0/42) among tested IGAS isolates and increased significantly in 1999 to 2001 (13%, 5/38) (Fisher exact, P=.035). CONCLUSIONS: A decline in pediatric varicella-related IGAS hospitalizations was temporally associated with utilization of varicella vaccine. These data reinforce the importance of universal varicella vaccination for children. Increasing macrolide resistance among IGAS isolates indicates a need for continued surveillance.
Assuntos
Vacina contra Varicela/administração & dosagem , Hospitalização/estatística & dados numéricos , Infecções Estreptocócicas/epidemiologia , Streptococcus pyogenes , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos , Fatores de Risco , Infecções Estreptocócicas/virologia , Vacinação/estatística & dados numéricosRESUMO
A random-amplified polymorphic DNA assay using partially degenerate oligonucleotides as primers was used for the characterization of 78 epidemiologically related and unrelated clinical isolates of Streptococcus agalactiae belonging to different serotypes. Thirty distinct amplification profiles were obtained among 52 unrelated S. agalactiae isolates assigned to nine groups by serotyping (including 3 nontypeable strains), uncovering the extent of genomic heterogeneity existent within serotypes. This method was particularly useful in providing evidence for or against vertical transmission of a given clone of this microorganism, as well as for relapsing or reinfection in related cases, and suggested clonal relatedness between unrelated S. agalactiae isolates associated with some invasive infections. Thus, this simple methodology represents a suitable tool for the epidemiologic study of S. agalactiae infections.