ABSTRACT
BACKGROUND: Conflicting recommendations regarding antibiotic prophylaxis for contacts of patients with invasive group A streptococcal (GAS) infection exist. Close contacts of patients with such severe and rapidly progressive disease often strongly appeal to the treating clinicians for antimicrobial treatment to prevent additional cases. We aimed to use an approach based on pharyngeal culture testing of contacts and targeted antibiotic prophylaxis. METHODS: A large throat swab survey including 105 contacts was undertaken after a fulminant and fatal case of GAS necrotizing fasciitis. GAS strains were characterized by emm typing and antimicrobial susceptibility to 7 antibiotics. The presence of 30 virulence determinants was determined by polymerase chain reaction and sequencing. RESULTS: The GAS isolate recovered from the index patient was an M1T1 GAS clone susceptible to all antimicrobial agents tested. The same clone was present in the throat of 36% of close contacts who had exposure to the index patient (family households and classroom contacts) for >24 hours/week, whereas the strain was present in only 2% of the other contacts. CONCLUSIONS: Although the study does not allow firm conclusions to be drawn as to whether antibiotic prophylaxis is effective, we describe a practical approach, including an educational campaign and targeted antibiotic treatment to close contacts who have been exposed to an index patient for > 24 hours/week before the initial disease onset.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Antibiotic Prophylaxis , Fasciitis, Necrotizing/microbiology , Streptococcal Infections/prevention & control , Streptococcal Infections/transmission , Streptococcus pyogenes , Adult , Anti-Bacterial Agents/pharmacology , Antigens, Bacterial/genetics , Bacterial Outer Membrane Proteins/genetics , Bacterial Typing Techniques , Carrier Proteins/genetics , Child , Child, Preschool , Community-Acquired Infections/drug therapy , Community-Acquired Infections/pathology , Community-Acquired Infections/prevention & control , Community-Acquired Infections/transmission , Fatal Outcome , Female , Humans , Male , Microbial Sensitivity Tests , Patient Education as Topic , Pharynx/microbiology , Streptococcal Infections/drug therapy , Streptococcal Infections/pathology , Streptococcus pyogenes/classification , Streptococcus pyogenes/drug effects , Streptococcus pyogenes/isolation & purification , Streptococcus pyogenes/pathogenicity , Virulence , Virulence Factors/geneticsABSTRACT
OBJECTIVE: To characterize the epidemiologic burden and the molecular determinants of group A streptococcal (GAS) meningitis among the pediatric population of the state of Paraná, Brazil. METHODS: Clinical and epidemiologic data were gathered by a compulsory notification system during the period 2003 to 2011. Bacterial identification, antibiotic resistance profile, emm-typing, pulsed-field gel electrophoresis typing and virulence profile were analyzed by a central reference laboratory. A review of published pediatric cases of GAS meningitis from the last 45 years was undertaken and compared with the Brazilian series. RESULTS: The incidence of GAS meningitis among the pediatric population was 0.06 cases per 100,000 children per year and was associated with a case fatality rate of 43%. Neonatal age and the presence of an associated toxic shock syndrome were identified as risk factors for death. A distant focus of infection was present in more than half of the patients in the literature and in 36% in the Brazilian case series. A high diversity of emm-types was associated with GAS meningitis in Brazil. No single virulence determinant could be associated with death. CONCLUSIONS: GAS meningitis is associated with high mortality and with a high diversity of GAS emm-types and virulence determinants in Brazil.
