Rosângela Stadnick Lauth de Almeida Torres1, Talita Zajac dos Santos2, Robson Antônio de Almeida Torres3, Lygia Maria Coimbra de Manuel Petrini4, Marion Burger5, Andrew C Steer6, Pierre R Smeesters7. 1. Laboratório de Bacteriologia, Divisão de Laboratórios de Epidemiologia e Controle de Doenças, Laboratório Central do Estado do Paraná Universidade Positivo, Curitiba. 2. Pontifícia Universidade Católica do Paraná 3. Universidade Positivo, Curitiba. 4. Hospital Vita, Curitiba. 5. Secretaria Municipal de Curitiba Associação Hospitalar de Proteção a Infância Dr Raul Carneiro, Curitiba, Paraná, Brazil. 6. Centre for International Child Health, University of Melbourne Group A Streptococcal Research Group, Murdoch Children's Research Institute, Parkville, Melbourne, Victoria, Australia. 7. Centre for International Child Health, University of Melbourne Group A Streptococcal Research Group, Murdoch Children's Research Institute, Parkville, Melbourne, Victoria, Australia Laboratory of Bacterial Genetics and Physiology, IBMM, Faculté des Sciences, Université Libre de Bruxelles, Brussels, Belgium.
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.
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.