[Clustered cases of intrafamily invasive Streptococcus pyogenes infection (or group A streptococcus)].

Streptococcus pyogenes or group A streptococcus (GAS) is responsible for serious invasive infections with a risk of secondary infection in patients with more contact than in the general population. Regardless of clustering, few intrafamilial invasive infections have been reported despite a recent increase in the incidence of invasive GAS disease. We report the cases of two brothers, one a boy of 8.5 years with toxic shock syndrome with no bacteria identified and the second, 1 week later, his 14.5-year-old brother in hospital for sepsis due to GAS. The occurrence of a confirmed case of invasive GAS and a probable case within such a short period met the definition of clustered cases. Both brothers showed no risk factors for invasive disease and no gateway including skin was found. Antibiotic therapy was initiated in the family as recommended by the French Higher Council of Public Hygiene.