A report published by the FSA has found it is not possible to compare foodborne disease rates effectively between countries. This is due to the hugely different methodologies and recording systems employed.
Researchers compared the ways different countries estimate how many people suffer from food poisoning each year, in an effort to determine whether these rates can be reliably compared.
The study, commissioned by the FSA and carried out by Public Health England, uncovered three broad approaches used globally:
- Prospective cohort studies – a sample population is recruited in advance, then report weekly on any symptoms of illness and may also submit samples so specific causes can be determined.
- Surveillance pyramid studies – an estimation of the number of cases missed through under-diagnosis and under-reporting, by using multipliers to extrapolate from laboratory confirmed illnesses.
- Retrospective cross-sectional surveys – a representative sample of the population is contacted and asked about their symptoms in the recent past.
Countries need to calculate foodborne disease estimates due to under-reporting, as not everyone who suffers from infectious intestinal disease (IID) will seek medical help and those who do will not always get a confirmed diagnosis. The data can then inform a country’s own food policy and prioritisation of resources.
Researchers concluded that the UK is using the most accurate approach available (prospective cohort studies).
FSA Head of science, evidence and research, Rick Mumford, said:
“The report concludes that attempting to accurately compare different countries’ foodborne disease rates is an almost impossible task. The only way you could attempt this would be for different countries to have the same type of study with the exact same study specifications, over the same time period. Even then, differences in underlying surveillance data available in each country could cause issues, particularly in terms of determining what proportion of IID cases are due to food.
“We have a much greater understanding of the different approaches taken across the globe and will continue to look and learn from this.”
Read the full report here.