Summary

The Enteric Reference Laboratory (ERL) typed a total of 68 Vibrio parahaemolyticus and cholerae isolates with the confirmation of one toxigenic cholera case (sequence type 69, serotype O1 Biotype El Tor subtype Ogawa). This case was associated with travel to Pakistan. Overall, the number of V. cholerae isolates typed by ERL increased from 4 in 2021 to 11 in 2022 and there were no identifications of toxigenic V. cholerae in 2021. The number of V. parahaemolyticus typed in 2022 increased from 39 in 2021 to 57 in 2022. Nearly two-thirds (64.9%, 37/57) of the 2022 Vibrio parahaemolyticus isolates, 37 (64.9%), were identified as sequence type 50 (ST50), a tdh (thermostable direct haemolysin) and trh (tdh related haemolysin) positive variant that was first identified in New Zealand in 2021 and resulting in a subsequent nationwide outbreak investigation in 2022. Various recreationally caught seafoods were implicated as the source of illness for the majority of cases. Most of the ST50 isolates identified in 2022, 18/37 (48.6%), were from cases in the Christchurch region.