Nontoxigenic corynebacterium diphtheriae: an emerging pathogen in England and Wales?

Confirmed isolates of nontoxigenic Corynebacterium diphtheriae in England and Wales increased substantially from 1986 to 1994. Ribotyping of 121 isolates confirmed in 1995 showed that 90 were of a single strain isolated exclusively from the throat; none had previously been identified in toxigenic strains from U.K. or non-U.K. residents. The upward trend in nontoxigenic C. diphtheriae probably represented increased ascertainment, although dissemination of a particular strain or clone may have been a factor.