More than 10,000 outbreaks caused by mushroom poisoning were reported across a decade in China, according to a recently released study.

Mushroom poisoning is the leading cause of foodborne disease outbreaks and outbreak-associated deaths in the country despite people being advised to not collect or eat wild mushrooms.

The 10,036 outbreaks resulted in at least 38,676 illnesses, 21,967 hospitalizations and 788 deaths from 2010 to 2020. The number of recorded outbreaks increased each year, from 37 in 2010 to 2,705 in 2020.

A large proportion of outbreaks occurred between May and October, according to data from the Foodborne Disease Outbreaks Surveillance System, which is managed by the China National Center for Food Safety Risk Assessment.

Risk of picking wild mushrooms
Among all reported outbreaks, 84.7 percent were associated with food prepared in private homes, followed by 8.8 percent from food prepared in street stalls, and 2.5 percent in canteens. The major cause of domestic outbreaks was self-harvest of wild mushrooms. Non-expert wild mushroom picking increases the risk of poisoning because of the difficulties of distinguishing between poisonous and edible mushrooms.

Most outbreaks involved fewer than 10 patients but 12 had more than 30 patients, according to the study published in the journal China CDC Weekly.

A rise in incidents between 2010 and 2020 is associated with implementation of compulsory surveillance in 2011, increasingly strict requirements for outbreak reporting, and enhancement of reporting awareness.

Mushroom poisonings were reported throughout the country, but was highest in the southwest and central areas, likely due to the warm and damp conditions, said researchers.

only 3,872 outbreaks were reported with mushroom names. Absence of relevant mushroom samples and ingestion of multiple mushrooms increased the difficulty of identifying causative species. More than 180 mushroom names were reported. Accurate and prompt species identification is crucial for diagnosis and treatment.

Educating people
Mushroom poisoning occurred every month, the study found, with peaks in summer and autumn. Seasonality suggests health education is crucial in those periods. Mushroom picking is more frequent in rural environments so education targeted for specific groups in such areas is also essential to reduce poisonings.

Researchers said efforts should be made to improve investigative procedures, reporting practices, and data collection as some of the epidemiological information is not complete or accurate.

Another study found the amount of mushroom poisonings and number of people affected doubled this past year in China compared to 2019.

Other work revealed poisonous mushrooms were the most common cause of outbreaks in China during a 14-year period.