Responding to Foodborne Illness Outbreaks
Surveillance and control of foodborne illness involves public health agencies, food safety agencies, laboratories and local government working together. Which agency or agencies participate in an investigation depends on the size and scope of the outbreak.
- OzFoodNet, a member of the Communicable Diseases Network Australia (CDNA), is the national network of foodborne disease epidemiologists and surveillance officers. The network is coordinated nationally by the OzFoodNet Central team within the Australian Government Department of Health. OzFoodNet epidemiologists are located within each state and territory health department.
- When foodborne illness outbreaks are identified, health departments collaborate with food safety agencies. Each state and territory health department has public health units that focus on surveillance, monitoring and control of notifiable illnesses. They conduct epidemiological investigations to help identify which food is the source of illness. Food safety agencies work to find out why the outbreak occurred, take steps to control it, and look for ways to prevent future outbreaks.
- When an outbreak crosses multiple jurisdictions, a collective national response is required. The multi-jurisdictional epidemiological investigation is coordinated by OzFoodNet Central. The multi-jurisdictional food and environmental investigation is coordinated by food safety agencies under the bi-national Food Safety Network.
- The bi-national Food Safety Network is made up of state and territory (and New Zealand) food safety agencies, the Australian Government Department of Health, Department of Agriculture and Water Resources and Food Standards Australia New Zealand (FSANZ). FSANZ provides the secretariat for the bi-national Food Safety Network and its role is to coordinate activities, collate and share information. The National Food Incident Response Protocol may be activated to ensure the national response is timely, appropriate and consistent.
- Most foodborne illness outbreaks are local events. Local government Environmental Health Officers (EHOs) work with their local public health unit to respond to outbreaks of foodborne illness within their district.
Identifying an outbreak
Foodborne illness outbreaks can be identified by health and/or food safety agencies and/or local government through a range of mechanisms, including reports from the public, general practitioners, food businesses and via the analysis of surveillance data.
Surveillance data on foodborne illness is collected and analysed at the national, state and local levels. OzFoodNet epidemiologists communicate frequently about these analyses, such as unexpected clusters of foodborne disease, and enable the network to identify outbreaks, particularly those that cross state and territory borders.
Investigations into outbreaks of foodborne illness are coordinated by public health and food enforcement agencies in each jurisdiction. The purpose of an outbreak investigation is to work out what is making people sick, stop it continuing and prevent the likelihood of future outbreaks. Each agency determines what needs to be done in their jurisdiction and responds according to their food law, response plans and protocols.
A successful outbreak investigation involves three main components – the laboratory, epidemiological and environmental investigations. These may occur in sequence or simultaneously throughout the outbreak investigation.
- Gathering laboratory evidence involves the testing of clinical specimens from ill individuals as well as food and environmental samples to detect the presence of the microorganism or its toxin that is making people sick.
- The Public Health Laboratory Network (PHLN) is a group of state and territory laboratories that provide expertise in public health microbiology in clinical specimens. PHLN are members of OzFoodNet and provide advice on case definitions and testing of clinical samples of ill individuals.
- Interviews with sick people (confirmed and suspected cases) are conducted to identify a common food or food business, or other source of exposure.
- The information collected is summarised and statistically analysed. This includes information about the sex and age of ill people; date of illness; symptoms; duration of illness; what foods were eaten and when; and where foods were purchased or food venues attended.
- Food safety agencies conduct onsite investigations into the potential sources or processes that caused the outbreak. They may trace foods to their origins, take food and environmental samples for testing, assess food safety measures in a food business or lead on-farm investigations.
A successful investigation needs ongoing communication and review of findings from all the three components of the investigation.
Based on findings of an outbreak investigation, action is taken to help stop the outbreak and avoid a similar one in the future. Outbreak control measures may include:
- Removing unsafe food from sale. This may require a food recall or stopping a business from producing and selling food until factors that caused the outbreak are remedied.
- Enhance food safety management practices by changing processes or equipment, cleaning and disinfecting facilities and equipment, training or retraining employees.
- Changing industry-wide practices.
Food Industry's Role
The food industry itself plays an important role in preventing and responding to outbreaks of foodborne illness.
It is vital that government agencies and food businesses work together during a food incident so they can act quickly to stop people getting sick and keep the confidence of consumers in a safe food supply.