GAINESVILLE, Fla., Dec. 4 (UPI) -- Roughly one in 10 people worldwide contract a food-borne disease each year, most of whom live in poor and developing countries, reported a World Health Organization task force in a series of new studies published in the journal PLOS ONE.
Researchers found as many as 600 million people are sickened each year by food contaminated by one or more of 31 agents identified by the agency. Of those who contract a disease, 420,000 die annually, including 125,000 children under the age of 5.
The WHO's Foodborne Disease Burden Epidemiology Reference Group has spent the last eight years identifying health hazards that can have effects on people years after surviving an infection, including chronic diseases such as cancer or kidney or liver failure.
The goal of the task force was not only to quantify and rank disease incidence, but to create tools that may help improve national food systems and start lowering the number of people affected -- which researchers said rival the "big three" infectious diseases: HIV and AIDS, malaria, and tuberculosis.
The effort took nearly a decade because of the high number of food-borne illnesses that exist, as well as the fact that a fraction of people made sick by food report it, and only a fraction of those cases are recognized as being caused by food, treated as such, and reported to authorities.
"Estimating the burden of foodborne diseases is highly complex due to the many diseases involved," said Dr. Arie Havelaar, a researcher at the University of Florida and leader of the WHO task force, said in a press release. "The full extent of chemical and biological contamination of food, and its burden to society, is still unknown."
Diarrheal diseases were the most frequent, affecting as many as 550 million people per year, especially norovirus and Campylobacter, as well as non-typhoidal salmonella enterica. The researchers also said major causes for diseases were Salmonella typhi, tapeworm found in pork products called taenia solium, and hepatitis A.
While Salmonella strains are of concern in all regions of the world, and Campylobacter is a pathogen affecting mostly high-income countries, the researchers said many diseases are seen in low-income countries, including food-borne cholera and E. coli. The risk is higher in these countries because of unsafe water, inadequate hygeine, inadequate storage and production methods for food, and lack of food safety or oversight by government agencies.
"Until now, estimates of foodborne diseases were vague and imprecise. This concealed the true human costs of contaminated food. This report sets the record straight," said Dr. Margaret Chan, Director-General of the WHO, in a press release. "Knowing which foodborne pathogens are causing the biggest problems in which parts of the world can generate targeted action by the public, governments, and the food industry."