Unsafe food continues to pose a major but under-recognised public health challenge in India, particularly among young children. According to the World Health Organization (WHO), contaminated food caused an estimated 866 million illnesses and 1.52 million deaths globally in 2021. Children under the age of five account for nearly 29% of the disease burden, despite representing a much smaller proportion of the world’s population. WHO estimates also indicate that South-East Asia bears one of the highest burdens of foodborne disease worldwide. These illnesses are caused by more than 200 diseases linked to bacteria, viruses, parasites and chemical contaminants.

The Indian scenario

India is estimated to record over 100 million cases of foodborne illnesses every year, although experts say the true burden is likely to be much higher because many cases go undiagnosed or unreported.

“India carries one of the highest burdens of foodborne illnesses and deaths, owing not only to its large population but also to factors such as poor sanitation, contamination and undernutrition,” said S. Satyamanasa Gayatri Vinay, senior consultant, paediatrics, SRM Global Hospital, Chennai.

Common pathogens responsible for infections include Escherichia coli, Shigella, Salmonella and Campylobacter, along with viruses such as rotavirus and adenovirus. Pesticide residues and heavy metals also contribute to the disease burden, she said.

Young children most affected

Children under five remain particularly vulnerable because of their immature immune systems, undernutrition and incomplete vaccination status.

Sindhu Sivanandan, chief neonatologist, Kauvery Hospital, Chennai, noted that children account for roughly 30% of the total public health burden from foodborne diseases. In India and across the WHO South-East Asia Region, an estimated 18 children under five die from foodborne illnesses for every 100,000 children in this age group.

“Many foodborne illnesses are mild and self-limiting and people often recover without seeking medical care. Consequently, surveillance systems capture only a fraction of the actual disease burden,” she said.

Poor sanitation, lack of access to safe drinking water and malnutrition further amplify risks. Malnutrition compromises immunity; once infection sets in, the body’s ability to recover is affected, creating a vicious cycle, Dr. Gayatri Vinay said.

Experts say improperly stored foods and the growing availability of highly processed and junk foods also increase children’s exposure to pathogens.

Globally, diarrhoeal diseases remain the leading cause of foodborne illness, with pathogens such as E. coli, norovirus, Campylobacter and non-typhoidal Salmonella accounting for a substantial share of infections.

Chemical hazards and long-term effects

While infectious diseases account for most foodborne illnesses, chemical contaminants are increasingly emerging as a serious concern. Dr. Gayatri Vinay said arsenic contamination, especially in eastern India, has entered the food chain through groundwater used for irrigation and drinking. Rice cultivated in contaminated regions may also contain elevated arsenic levels.

Lead exposure can occur through contaminated spices, environmental sources and certain types of cookware, while methylmercury exposure is linked to the consumption of some fish species.

“These contaminants are not only associated with acute poisoning but also with long-term complications, including cardiovascular disease, cancers and neurodevelopmental impairment leading to lower IQ,” she said.

WHO’s latest burden estimates incorporated four major heavy metals – arsenic, cadmium, lead and methylmercury reflecting growing concern over chemical hazards in food systems. Chemical contaminants account for a relatively smaller number of cases but contribute disproportionately to severe disease, disability and mortality, Dr. Sivanandan said.

Exposure risks and challenges

Changing food habits and the rapid growth of informal food businesses may also be contributing to rising foodborne illnesses, experts said. Vijayshree N., chief dietician, MGM Healthcare, Chennai, said increasing dependence on restaurant food, street food and fast food has altered exposure patterns.

“People eat outside often. Whether it is a restaurant, fast-food outlet or street vendor, crowds are everywhere,” she said. She pointed to the emergence of mobile food vendors and roadside grills as examples of a rapidly expanding sector where regulatory oversight may be limited.

“We still lack in proper facilities for food storage and handling. If contaminated water is used for cooking, washing vessels or maintaining hand hygiene, bacteria can spread very easily,” she added.

According to WHO, unsafe food and water are closely linked, with contamination possible at every stage of production, processing and consumption. Initiatives such as Eat Right India and expanded laboratory surveillance have strengthened food safety systems in the country,. but experts say significant gaps remain.

“India has made substantial progress in outbreak management and diarrhoeal disease control, but the reporting system needs strengthening,” said Dr. Gayatri Vinay. “The chronic disease burden arising from foodborne exposure is likely underestimated.”

Dr. Sivanandan said India’s vast and largely informal food sector presents additional challenges. “A significant proportion of food comes from small-scale manufacturers, street vendors and informal businesses, where compliance with food safety regulations can be inconsistent,” she said.

Limitations in surveillance, enforcement and comprehensive data collection hinder accurate assessment of the country’s food safety burden, she added.

Preparing for emerging threats

Experts warned that climate change and antimicrobial resistance (AMR) are likely to intensify foodborne risks. Rising temperatures favour bacterial growth, while floods and heavy rainfall can contaminate crops, groundwater and sewage systems, increasing human exposure to pathogens, Dr. Gayatri Vinay said.

She also highlighted the growing problem of antibiotic-resistant bacteria. “The irrational use of antibiotics has resulted in resistant strains of organisms such as Shigella and Salmonella, which can cause life-threatening diarrhoeal diseases and dysentery in children,” she said.

Experts say improving surveillance, strengthening regulation across the food chain and increasing awareness among consumers and food handlers will be crucial to reduce the burden of diseases caused by unsafe food.