Research – Annual report concerning Foodborne Diseases in New Zealand 2022

NZFS

Human health surveillance and its relationship to foodborne illness is essential for informing
the strategic direction that New Zealand Food Safety (NZFS) takes and regulatory measures
it puts in place to minimise foodborne illness in New Zealand and overseas consumers. The
annual ESR foodborne disease reports are critical, allowing NZFS to monitor trends in
foodborne illness in New Zealand by describing in a consistent manner evidence from case
notifications, case enquiries, outbreak investigations, and other epidemiological studies of
human enteric disease.
This report is the latest in a series providing a consistent source of data annually to monitor
trends in foodborne illness in New Zealand. The series can be found here.
When reading these reports, it is necessary to bear in mind that notified cases of illness
represent only a subset of all the cases that occur in New Zealand each year.
• Many sick individuals do not visit a GP or otherwise come to the attention of the
health system.
• Multiple factors (e.g., change in sensitivity of testing methods, proportion of human
faecal specimens being tested) affect the notification rates on top of any underlying
changes to disease incidence happening in New Zealand. Some cases notified in
New Zealand are due to exposure to a pathogen or toxin while they were overseas.
Most cases of foodborne diseases in New Zealand are sporadic, which makes attribution to a
source or event difficult. In contrast, outbreaks offer a better opportunity to identify the source
and most of the 271 outbreaks (253 cases) of potential foodborne disease in 2022 were
associated with commercial food operators and only five outbreaks in 2022 were associated
with food prepared in consumer’s homes. Despite robust investigation, some outbreaks
reported as “foodborne with an unidentified food source” could also be attributed to other
routes of transmission, such as water, animal contact, or person to person contact.
Listeriosis is perhaps the only disease fully attributable to consumption of contaminated food.
Campylobacteriosis, yersiniosis, infection by shiga toxin-producing E. coli (STEC), and
salmonellosis remain the predominant notified foodborne illnesses. Notification rates per
100,000 population are generally stable, being highest for very young children (0 to 4 years
age group) and for elderly people (70+ years)