Continued focus needed to reduce Campylobacter and Salmonella

The research is an extension of the infectious intestinal disease 2 (IID) study, published in September 2011, which estimated the numbers of cases in the UK.

There are more than 500,000 cases of food poisoning a year from known pathogens and the figure would more than double if it included cases from unknown pathogens.

Campylobacter was the most common foodborne pathogen, with about 280,000 cases every year but ranked fourth as a cause of food-related hospital admissions.

The next most common was Clostridium perfringens with 80,000, and norovirus was third with an estimated 74,000.

Although C. perfringens outbreak reports to national surveillance have been declining it continues to cause a considerable illness burden and control is an important policy issue.

There were fewer than 10,000 estimated cases of foodborne E.coli O157 and fewer than 200 for listeriosis.

Salmonella causes the most hospital admissions – about 2,500 each year indicating the severity of illness.

The research aimed to estimate the burden of UK-acquired foodborne disease in 2009​, the date of the IID study, and to quantify the contribution of pathogens and food commodities to foodborne disease burden.

Food commodity​

Poultry meat was linked to the most cases of food poisoning, with an estimated 244,000 every year.

A person with typical patterns of consumption is nearly 40 times more likely to acquire foodborne illness through contaminated poultry than through grains and beans.

Produce including vegetables, fruit, nuts and seeds, caused the second highest number of cases of illness (estimated 48,000 cases), while beef and lamb were third (estimated 43,000 cases).

Eggs accounted for fewer cases, but were associated with greater disease severity; egg-related infections accounted for only 5% of cases of foodborne illness (31,000), but more than 30% of hospital admissions (1,800).

Steve Wearne, director of policy at the FSA, said: “This study is a very important part of the research we fund to increase our knowledge of food safety and the risks that all of us are exposed to. ​

“Reduction of campylobacter is our top food safety priority, and that is borne out by this research.”​

The researchers were able to identify about half a million cases of food poisoning every year attributable to 13 specific pathogens. However, 10 million cases of IID a year are not yet attributed to a specific pathogen.

If these cases had similar rates attributable to food then this would bring the overall figure to in excess of a million cases a year.

IID study extension​

The research is an extension of the IID2 study, published in September 2011, which estimated the numbers of cases of IID in the UK.

The IID2 extension was commissioned by the FSA to use the data generated from the IID2 study, and other sources, to estimate the burden of foodborne disease in the UK.

It applied mathematical modelling techniques to the results of the IID2 study, alongside data from outbreaks and a literature review of almost 200 international studies.

A Monte Carlo simulation and a Bayesian approach were used as modelling approaches. Three modelling simulations were generated – one using Monte Carlo and two using Bayesian methods.

The FSA is working to produce annual estimates for unknown agents, hospital occupancy and deaths.

Researchers suggested this could draw on methods by the WHO Foodborne Disease Epidemiology Reference Group study. However, deaths are associated with vulnerable patients and other underlying diseases. 

They also recommended estimates of disease burden (DALYS) and costs to prioritise food safety policy measures and say better data is needed to attribute illness to foods and for commodity attribution.