Foodborne parasites rarely receive the same attention as major viral or bacterial outbreaks, yet their global impact remains substantial. A new World Health Organization analysis estimates that around 171 million illnesses worldwide are linked to foodborne transmission of 14 invasive parasites.

The updated assessment incorporates more than a decade of additional research and is intended to give health authorities a clearer picture of where the burden remains greatest.

Although sanitation, hygiene and prevention have improved in many regions, these infections continue to affect vulnerable populations disproportionately.

Measuring More Than Case Numbers

The analysis forms part of the work of the WHO Foodborne Disease Burden Epidemiology Reference Group, which evaluates the health impact of foodborne diseases globally.

Researchers did not rely only on numbers of infections and deaths. They also used disability-adjusted life years, or DALYs, a measure that combines years of life lost because of premature death with years lived with illness or disability.

This makes it possible to compare diseases that may differ greatly in severity. One infection may cause many short-lived illnesses, while another may occur less often but lead to long-term neurological or physical complications.

Texas A&M University professor Christine Budke, who contributed to the updated estimates, explained that DALYs give policymakers a fuller picture because they reflect both the duration and severity of disease, not simply how many people become infected.

Some Infections Have Lasting Effects

The disease can lead to serious neurological problems and is recognised as an important preventable cause of seizures in some parts of the world.

Budke worked with international researchers to update estimates for neurocysticercosis. She noted that more accurate burden estimates can help governments decide where limited public-health resources are likely to have the greatest impact.

The updated analysis benefits from newer evidence about how these infections affect patients over time, allowing previous WHO estimates to be refined.

Why These Diseases Have Not Disappeared

Improved sanitation, food safety and education have reduced the burden of some parasitic diseases, but progress has been uneven.

The greatest problems remain in settings where surveillance is limited, diagnostic services are difficult to access and prevention programmes receive insufficient funding.

Many foodborne parasitic infections are also classified among neglected tropical diseases, a group that disproportionately affects poorer communities while historically receiving less research investment and public attention.

The consequences can extend well beyond immediate symptoms. Chronic illness may reduce a person’s ability to work, study or care for family members, while medical costs can deepen existing financial hardship.

Budke emphasised that these infections should not be dismissed simply because they receive less media attention, as reduced vigilance can allow preventable disease burdens to persist.

Diagnosis Is Still a Major Challenge

Important knowledge gaps remain.

For neurocysticercosis, researchers are still investigating the full range of possible neurological effects beyond seizures, including severe headaches and other long-term complications.

Diagnosis can also be difficult in countries where advanced imaging, such as CT scanning, is not widely available. That means some infections may go undetected, making the true burden harder to measure.

These limitations are one reason WHO periodically revises its estimates as better data become available.

Why Updated Estimates Matter

The practical purpose of the analysis is to help countries set priorities.

When health budgets are limited, reliable estimates allow policymakers to compare competing risks and decide whether more resources should go toward food-safety systems, diagnosis, treatment, education or surveillance.

Budke said the value of the WHO process lies in giving countries the strongest available evidence so that public-health decisions can be based on actual disease burden rather than visibility or headlines.

A Persistent Global Problem

The estimate of 171 million illnesses shows that foodborne parasitic disease remains far from solved.