Summary

The Enteric Reference Laboratory (ERL) typed 20 Vibrio cholerae and 28 Vibrio parahaemolyticus isolates in 2024 compared to 18 V. cholerae and 26 V. parahaemolyticus in 2023. The isolates were quite diverse with V. parahaemolyticus ST3 totalling five cases as the most abundant type with two V. parahaemolyticus ST2631 and two ST607 being the only other types with more than one isolate. There was one toxigenic V. cholerae ST69 associated with travel to India, which is the only sequence type associated with toxigenic cholera isolates in New Zealand since the start of sequencing of select isolates in 2014. In 2024 there were 29 confirmed cases of gastroenteritis caused by V. parahaemolyticus with two isolates not received by ESR resulting in 27 typed isolates. An additional blood isolate was a sequence type 2631, one of multiple isolates with this sequence type derived blood samples. Of the gastroenteritis cases with a typed V. parahaemolyticus isolate, 13 were associated with foreign travel (one unknown). Likewise, of the 20 V. cholerae isolates there were 12 cases with foreign travel during the incubation period, two cases without foreign travel, and six with no travel history recorded.