A family outbreak due to an emm-type 11 multiresistant strain of Streptococcus pyogenes.

Four cases of Streptococcus pyogenes infection due to an emm-type 11 strain, including one with a fatal outcome, occurred within a seven-member family. All strains shared biotype 5, pyrogenic exotoxin genes speB and speC, and resistance to kanamycin, tetracycline, macrolides and lincosamides. The identity of SmaI pulsed-field gel electrophoresis patterns confirmed their clonal origin. This highlights the ability of S. pyogenes to spread rapidly among family members. This first report of a family outbreak due to emm11 S. pyogenes reinforces the importance of surveillance of close family contacts of individuals with invasive streptococcal disease, and provides further support for antibiotic prophylaxis among the elderly.