MPI
New Zealand Food Safety, part of the Ministry for Primary Industries (MPI), leads New Zealand’s food safety system, protecting the health and wellbeing of consumers here and overseas. This includes reducing food-related risks to human health. Human health surveillance is an essential element of the monitoring and review component of New Zealand Food Safety’s risk management framework. In addition, evidence from notifications, case enquiries, outbreak investigations and other epidemiological studies of human enteric diseases are used as sources of data for risk profiles and assessments.
There is ongoing interest in foodborne disease statistics within New Zealand Food Safety and its stakeholders. This report for the calendar year 2020 is part of a series providing a consistent source of data and method of presentation to allow monitoring of foodborne illness in New Zealand. Human health surveillance data and foodborne disease The information in this report concerns reported cases of notifiable disease and reported outbreaks collected in the EpiSurv database.
Some notifiable illnesses may be caused by transmission of pathogens through foods, but it is important to remember that most of the information relates to the illness, not the mode of transmission.
The information needs to be considered with two caveats:
1. Notified cases of illness and reported outbreaks represent a subset of all the cases and outbreaks 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. By using these data as indicators, we are assuming that they are representative of all the cases and outbreaks that occur [1].
2. Foodborne transmission is only one of the routes by which humans are exposed to pathogens; other routes include water, animal contact and person to person. There are some indicators from which we can get information on the proportion of cases caused by foodborne transmission:
•Outbreak reports: the circumstances of an outbreak (multiple cases from a single event) mean that an investigation is more likely to identify a source of exposure to the pathogen than investigation of sporadic cases.
•Expert opinion: based on their experience in laboratories and epidemiological investigations, as well as knowledge of factors influencing the risk, experts can provide estimates of the proportion of cases caused by foodborne transmission.
Estimates for New Zealand have been developed for some foodborne diseases [2, 3], as presented in relevant report sections. These are not fixed values; future changes to the New Zealand food chain may require the values to be amended.
•Overseas analyses and estimates: information for countries with food supplies similar to New Zealand can be helpful, especially for illnesses where a foodborne estimate could not be developed f rom local studies. New Zealand estimates [2, 3] and published country-specific estimates, for the USA [4], Canada [5], Australia [6, 7], England and Wales [8] and the Netherlands [9] are given in Table 1.
In addition, a WHO project to estimate the global burden of foodborne diseases derived estimates for 14 international regions [10, 11]. The estimates for New Zealand, Australia, Canada, the Netherlands and the international WHO estimates are based on expert opinion, the estimates for England and Wales are based on outbreak analysis, while the US estimates are based on data from surveillance, risk factor studies and a literature review.
It is worth noting that, although for most of the diseases included in this report foodborne transmission is considered significant, there are several illnesses (shigellosis, giardiasis, cryptosporidiosis, hepatitis A) where foodborne transmission is considered to only contribute a small proportion of the total disease burden
