Outbreaks of infections with erythromycin-resistant group A streptococci in child day care centres.

Erythromycin-resistant group A streptococci (ERGAS) are considered rare in Sweden. In the county of Halland (240,000 inhabitants) in southern Sweden, we had 294 isolates of ERGAS between January 1984 and June 1985. Almost all strains were of T-type 12 and only resistant to erythromycin (MIC values approximately 8 g/l). Seven child day care centres (DCC) were involved in the outbreaks and on average 49% of all children were infected in each outbreak. Employees were seldom infected (8%), but parents and siblings more often (23% and 36%). One course of phenoxymethylpenicillin succeeded in eradicating ERGAS from 75% of those infected. The ERGAS strains are now established in southern Sweden and account for about 2% of all group A streptococcal infections in the county of Halland.