Whole genome sequencing-proven transmission of Corynebacterium diphtheriae-caused cutaneous diphtheria in two siblings, Germany, 2018

In September 2018, a Somalian child presented with cutaneous diphtheria by toxigenic Corynebacterium diphtheriae biovar mitis. A sibling was affected by multiple super-infected insect bites harbouring also toxigenic C. diphtheriae. Next generation sequencing (NGS) revealed complete identity of both strains suggesting very recent human-to-human transmission. Epidemiological and NGS-based data suggest that the two cutaneous diphtheria cases within one family are constitute the first diphtheria outbreak by toxigenic C. diphtheriae in Germany since the 1980s.