Scientists have called for Chagas disease to be included in new estimates of the global burden of foodborne disease. 

Chagas disease, caused by infection with the parasite Trypanosoma cruzi, has a complicated transmission cycle with many infection routes. The disease mainly occurs in Latin America but is rising in other regions, such as North America and Europe.

Foodborne transmission may occur from consuming meat or blood from infected animals or ingesting other contaminated foods, such as fruit juice.

Researchers said it was important that Chagas disease was not overlooked in work on the health burden of foodborne infections simply because of its relatively restricted geographical area.

It was omitted from the original World Health Organization (WHO) estimates of foodborne disease published in 2015 due to a lack of resources. These figures are being updated by the Foodborne Disease Burden Epidemiology Reference Group (FERG), with publication expected in 2025.

Higher burden than other pathogens
Preliminary calculations suggest a burden of at least 137,000 Disability Life Years (DALYs), but this does not consider the greater symptom severity associated with foodborne transmission, said scientists in the PLOS journal Neglected Tropical Diseases.

This burden is lower than the previously estimated figure of 273,000 DALYs. Still, it exceeds the DALY burdens in the 2015 estimates for 11 of 15 pathogens, including Bacillus cereus, Clostridium botulinum, Clostridium perfringens, Fasciola spp., Giardia, Listeria monocytogenes, Shiga toxin-producing E.coli, Staphylococcus aureus, and Trichinella.

Researchers said using source attribution alone to determine the foodborne proportion may underestimate the higher disability and mortality associated with this infection route.

An estimated 6 to 7 million people are infected with Trypanosoma cruzi worldwide, with about 10,000 deaths annually. Mortality from vector-borne Chagas disease is estimated to be between 5 and 10 percent, while the foodborne infection route is said to be associated with 8 to 40 percent mortality.

Increasing evidence
Growing evidence suggests that foodborne transmission of Trypanosoma cruzi occurs as commonly as vector-borne infection, and foodborne infection results in more severe disease.

However, although foodborne Chagas disease is gaining recognition, the importance of this infection route is not widely understood. Many articles continue to be published in which foodborne transmission is not included in the introductory text, or oral transmission is described as infrequent.

In foodborne disease, acute symptomatic Chagas disease occurs in nearly all patients, with nearly 100 percent experiencing fever; other common symptoms include muscle pain, headache, leg and/or facial swelling, pericardial effusion, and abdominal pain. Other issues, such as diarrhea, skin rash, palpitations, and hemorrhagic jaundice, have also been reported.

The reasons for differences in clinical outcomes based on transmission route may be due to a greater parasitic load associated with oral infection, according to the study.

“Even preliminary conservative estimates suggest that the burden from foodborne Chagas disease is greater than other foodborne diseases with a global distribution. Exclusion of foodborne Chagas disease from the etiology-based burden of foodborne disease estimates may result in errors when risk ranking these diseases to prioritize interventions in endemic countries,” said scientists.