A Vibrio outbreak that sickened more than 250 people in Australia was linked to oysters, but a specific grower could not be identified. The nationwide outbreak caused by Vibrio parahaemolyticus occurred during September 2021 to January 2022. A total of 268 people were sick, and 97 percent reported consuming Australian-grown oysters.
Cases were reported from all states and territories. The outbreak included two distinct strains of Vibrio parahaemolyticus. Implicated oysters were traced back to a common growing region in South Australia.
The incident prompted a national recall and improvements in postharvest processing of shellfish. According to a study published in the journal Emerging Infectious Diseases, foodborne outbreaks of Vibrio parahaemolyticus have been rare in Australia until recently. Only four were recorded from 2002 to 2019, with 24 cases.
Only 29 locally acquired, sporadic foodborne cases were reported in 2016 to 2020, with 22 infected people reporting oyster consumption. A link to oysters Vibrio parahaemolyticus infections might be underreported because pathology laboratories rarely include them in routine fecal testing procedures, and the infection is notifiable in only four of Australia’s eight states and territories. In September 2021, at the end of the winter season, health officials identified an increase in locally acquired Vibrio parahaemolyticus cases in South Australia, and a similar trend was later noted in other parts of the country.
In November 202.