Genomic epidemiology reveals low toxigenic diphtheria cases among rising nontoxigenic infections in Ontario, highlighting concerns for public health responses.
Key Points
The study examines the genomic epidemiology of toxigenic and nontoxigenic C. diphtheriae in Ontario.
Analysis of isolates submitted to the Public Health Ontario Laboratory
Utilization of whole-genome sequencing
Core genome multi-locus strain typing using BIGSdb-Pasteur
Toxigenic C. diphtheriae cases were 2.7% of total infections observed
A significant increase in nontoxigenic C. diphtheriae isolates over the study period
Most nontoxigenic isolates showed local transmission patterns