More than 10,600 people were poisoned by mushrooms and 22 deaths were reported from 2010 to 2017 in France.

A total of 10,625 cases of unintentional poisoning because of ingestion of mushrooms were recorded by French poison control centers (PCCs), according to a study published this month.

The poisonings involved two or more people during the same meal in more than half of the cases. The peak of cases was in October although there was a monthly peak in August for two years. Intoxications occurred mostly in the west, south and east of France.

Ages of patients ranged from 9 months to 96 years old. Almost two-thirds of cases were between 30 and 69 years of age and 3.3 percent were younger than 5 years old. More than 90 percent of the people poisoned had one or more digestive symptoms, followed by general and/or neurological signs.

Almost all had been intoxicated during a meal, but 5 percent were intoxicated by what researchers determined to be ignorance of the risk, such as biting into a mushroom after picking it up. One third of children under 5 had eaten the poison mushrooms during a meal.

Severe illness and death
Mushrooms most often involved were boletus at 26.3 percent of cases, followed by agarics, clitocybes, lepiotas, amanita, chanterelles or tricholomas. In about 30 percent of cases the species was not identified.

For the eight years of study, 239 cases of high severity were identified, varying from 11 in 2016 to 44 in 2010. Twenty-two deaths were observed from zero to five each year. Deaths were due to phalloid (68.2 percent) or sudorian (31.8 percent) syndromes. Ten men and 12 women aged 38 to 88 died.

Seasonal surveillance was set up in 2010 by l’Institut de veille sanitaire (InVS, which is now Santé Publique France) following a report of poisoning caused by phalloid amanita in Pays de la Loire.  The French Agency for Food, Environmental and Occupational Health and Safety (ANSES) has been monitoring the situation since 2016.

Surveillance from July to December consists of monitoring how many poisoning cases come from mushrooms recorded by French poison control centers, as well as the number of severe cases and deaths. The objective is to detect in real-time any increase in poisonings so health authorities can be alerted and recommendations for mushroom picking and consumption disseminated to the public.

Apart from a lower number of cases in 2016 with 877, probably linked to a relatively hot and dry summer, the annual distribution of poisoning by mushrooms varied between 1,248 cases in 2014 and 1,596 in 2017.

The rate of mushroom poisonings decreased from 2010 to 2014, then increased in 2015 before being strongly dropping in 2016. However, it went back up in 2017 as this was the year with the most cases in the period covered by the report.

Preventing poisoning
Each year, a public alert was put out by health authorities at the first peak of poisoning. A second or third alert was published when the number persisted such as in 2010 and 2015 or when cases were severe or deaths were recorded.

The number of cases tended to decline after each alert but it was not possible to tell whether that was due to the natural fall in the epidemic peak, linked to a decrease in the growth of mushrooms or if it was prevention messages from authorities being heard. The number of cases seems more linked to weather conditions favoring growth than to communication measures.

More than 1,000 mushroom poisonings are recorded every year by French poison control centers. They represent 2 percent of all poisonings and are at the same level as poisonings by plants at 3.1 percent.

In 2017 in Switzerland, 1.8 percent of poisoning cases were due to mushrooms and 2.5 percent in Sweden. In Belgium, 5.1 percent of poisonings were associated with plants and/or mushrooms while in the United Kingdom, 2.8 percent of requests for toxicological investigations in 2016 to 2017 were linked to exposure to plants and/or mushrooms.

Many factors are involved in poisonings: confusion of an edible species with a toxic one; eating edible mushrooms that are in poor condition; failure to cook species that have heat-labile toxins; too many consumed; and individuals’ sensitivity.

The researchers wrote that while surveillance is necessary to disseminate national recommendations when peaks of poisoning occur, local intermediaries such as an associations of mycologists and pharmacists are essential to help identify the mushroom and limit the number of cases. The public is advised to take a photo of mushrooms before cooking an not to give wild mushrooms to young children.

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