As Kerala battles Shigella threat, WHO warns unsafe food sickens 866 million people worldwide

Unsafe food causes an estimated 866 million illnesses and 1.5 million deaths worldwide each year, with young children bearing a disproportionate share of the burden, according to the latest report from the World Health Organization. The report found that children under the age of five, who make up just 9 per cent of the global population, account for nearly one-third of all foodborne disease cases. It also warned that chemical contaminants are responsible for nearly three-quarters of food-related deaths, while emerging challenges such as climate change and antimicrobial resistance are making food safety risks increasingly difficult to manage. 

For India, which is already recording about 100 million foodborne illness cases every year, the WHO findings are less of a warning than a confirmation. With that number set to rise to 150-177 million by 2030, the cost of inaction is only growing.  

The report states that over 866 million cases of illnesses and 1.5 million deaths were recorded globally due to unsafe food as of 2021. It also reveals that the total number of foodborne diseases has declined since 2000, but there are major regional disparities, with the greatest burden being borne by the African and Southeast Asian countries.  

According to the report, children aged less than five years are at a three times higher risk of falling ill. Young children account for only about 9 per cent of the global population but suffer nearly one-third of all foodborne disease cases, particularly diarrhoeal illnesses that can be fatal for this vulnerable age group. 

For India, this is less of a warning and more of a confirmation, according to a report from the Food Safety and Standards Authority of India (FSSAI) from 2021. According to the report, India records an estimated 100 million cases of foodborne diseases each year. The burden is expected to rise sharply, with annual cases projected to reach between 150 million and 177 million by 2030. 

Reasons for the illness

The majority of foodborne diseases were caused by exposure to biological hazards like foodborne bacteria and viruses, as well as parasitic infections. Chemical exposures from natural sources and human activities led to a disproportionate share of deaths. More than a million deaths happen per year due to these chemicals. Most of these chemical-related deaths were linked to inorganic arsenic (42 per cent) and lead (31 per cent).  

Once these chemicals enter the food chain, they often become impossible to remove. Chemical hazards accounted for about 73 per cent of deaths due to contaminated food in 2021. Exposure to chemicals such as methylmercury and lead in food can harm the developing brain of a child, causing lifelong neurological and developmental problems  

Prevention of illnesses

The report suggests that many of the deaths could be prevented with measures like improved water, sanitation, hygiene, food safety practices such as pasteurisation and access to health care for vulnerable populations. WHO called on governments to prevent contamination at source through better agricultural practices, stricter industrial controls and stronger environmental regulations.  

In low- and middle-income countries, children and people living in low-resource communities are facing the greatest health burden.  

“The data show that foodborne diseases are not only persistent but are being made worse by climate change, which increases contamination risks, and by antimicrobial resistance, which makes infections harder to treat,” Yuki Minato, WHO technical officer for food safety and senior author of The Lancet Global Health, said. 

The WHO's latest analysis also expands the evidence base by examining 42 foodborne hazards, including bacteria, viruses, parasites and chemicals, across 194 countries between 2000 and 2021.  This estimate also includes new hazards like metals, rotavirus and Trypanosoma cruzi (the parasite causing Chagas disease).

The economic wound

Not only does this impact the health of the people, but it also dents the economy of countries. The study estimated that foodborne diseases led to about $310 billion in lost productivity in 2021, as people were not able to work due to illness.  

When this economic impact was adjusted to the cost-of-living differences between countries, the estimate increased to $ 647 billion in lost productivity. According to FSSAI, foodborne diseases cost India 15 billion dollars every year.  

“When the economic impact was adjusted for cost-of-living differences between countries, the estimate increased to $647 billion in lost productivity,” the report added.  

The India picture

A study published in the Indian Journal of Public Health documented a 2018 outbreak in Makunsar village in Maharashtra's Palghar district, where 75 people fell ill after eating gaajar halwa at a wedding, with over half of them requiring hospitalisation. The likely culprit was Staphylococcus aureus, a bacterial toxin that multiplies in khoa, a perishable milk product stored at room temperature for nearly 12 hours. 

The study also found that most foodborne disease outbreaks in India go uninvestigated due to resource constraints, suggesting that the 100 million annual cases estimated by the FSSAI are almost certainly an undercount. The informal food economy, where most Indians eat, remains the least regulated. 

The informal food economy is not just poorly regulated; it is actively hazardous. A study published in the Indian Journal of Microbiology Research, which tested 300 street food samples across five zones of Hyderabad, found dangerous pathogens in a significant share of commonly eaten foods. Shigella was detected in over 45 per cent of bhelpuri samples, while Bacillus cereus, which produces toxins linked to food poisoning, was found in 90 to 92 per cent of Chinese fast food samples tested. 

What makes this finding harder to dismiss is the antibiotic resistance dimension. Several Shigella isolates from the same samples showed resistance to commonly prescribed antibiotics, a pattern that tracks closely with what WHO has identified as one of the accelerating factors behind foodborne disease burden globally. The bacteria may be in the food, but the tools to fight them are weakening. 

The contamination problem does not stop at unlicensed vendors or poorly stored milk and milk products. A 2024 study published in the Journal of Pioneering Medical Sciences examined food adulteration across India and found that the threat runs deeper into the food supply chain itself. Adulteration, defined as the deliberate substitution or contamination of food with inferior or harmful substances for economic gain, affects everything from spices and oils to dairy and fish. Hazardous chemicals like formalin in fish, synthetic dyes in spices and detergents in milk are routine practices, the study found. 

The long-term consequences go well beyond a stomach upset. The study recognised chronic exposure to adulterated food as a driver of non-communicable diseases, including cardiovascular conditions, diabetes and cancer. In a country already dealing with a rising burden of both infectious and lifestyle diseases, the two threats are not separate; they complement each other.  

This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS