Preplanned Studies: Mushroom Poisoning Outbreaks — China, 2024

Introduction: Mushroom poisoning represents a significant food safety concern in China. Over the past decade, China has established an effective mushroom poisoning control and prevention system involving government agencies, clinicians, CDC experts, and mycologists.

Methods: Under the system of mushroom poisoning control and prevention, information of mushroom poisoning incidents were systematically collected, with identifing species, detecting toxins, and analyzing the spatial and temporal distribution characteristics and species diversity.

Results: In 2024, the China CDC investigated 599 mushroom poisoning incidents across 28 provincial-level administrative divisions (PLADs), involving 1,486 patients and resulting in 13 deaths, with a case fatality rate of 0.87%. The number of cases per incident ranged from 1 to 14 (median=2), with 11 incidents involving more than 10 patients. Among these cases, 50 patients (including 2 fatalities) from 17 incidents consumed poisonous mushrooms purchased from markets, 37 patients from 14 incidents were poisoned after consuming dried mushrooms, and 15 patients from 10 incidents consumed uncooked wild mushrooms. Temporal analysis revealed that mushroom poisoning incidents occurred throughout the year, with the highest frequency between June and October, peaking in June. Geographically, incidents were reported in 28 PLADs, with 13 PLADs reporting more than 10 incidents. Sichuan, Yunnan, Hunan, Guizhou, and Chongqing were the five most affected regions. Deaths were reported in Guizhou (5 deaths), Sichuan (2 deaths), Chongqing (2 deaths), Heilongjiang (2 deaths), Hunan (1 death), and Jiangsu (1 death). A total of 110 poisonous mushroom species causing 7 distinct clinical syndromes were identified, including 8 newly documented poisonous species, bringing the total number of mushroom species involved in poisoning incidents in China to approximately 246 by the end of 2024. The five most lethal mushrooms were Amanita exitialis, A. molliuscula, A. subpallidorosea, Lepiota brunneoincarnata, and Russula subnigricans, each causing 2 deaths. Chlorophyllum molybdites was responsible for the highest number of poisoning incidents (147 incidents affecting 269 patients). Paxillus obscurosporus, which causes hemolysis, was identified in a poisoning incident for the first time.

Conclusions: The persistent severity of mushroom poisoning in China underscores the need for continued public education efforts, strengthened market supervision, and enhanced collaboration across departments and disciplines to reduce the incidence of mushroom poisoning.

Mushroom poisoning represents a significant food safety challenge in China. Over the past decade, China has established an effective mushroom poisoning control and prevention system that integrates government agencies, clinical physicians, China CDC experts, and mycologists (1–5). Within this system, CDC personnel and hospital staff promptly collect mushroom specimens, photographs, and biological samples such as blood and urine immediately following poisoning incidents. Mushroom specimens and photographs are forwarded to mycologists for species identification, while mushroom and biological samples are sent to CDC experts and hospital professionals for toxin detection. Based on species identification, toxin analysis, and clinical manifestations, patients receive accurate diagnoses and timely treatment (1–5). In 2024, the China CDC investigated 599 mushroom poisoning incidents across 28 provincial-level administrative divisions (PLADs), involving 1,486 patients and resulting in 13 deaths, yielding a case fatality rate of 0.87%. Investigators successfully identified 110 poisonous mushroom species, including 8 newly documented species, associated with 7 distinct clinical manifestations. This brings the total number of mushroom species linked to poisoning incidents in China to 246 by the end of 2024.

In 2024, the number of cases per mushroom poisoning incident ranged from 1 to 14, with a median of 2 cases per incident. Among these incidents, 11 involved more than 10 patients. Notably, 50 patients (including 2 fatalities) from 17 incidents consumed poisonous mushrooms purchased from markets, while 37 patients from 14 incidents were poisoned after consuming dried mushrooms. Additionally, 15 patients from 10 incidents became ill after consuming uncooked wild mushrooms (Supplementary Table S1).

Temporal distribution analysis revealed that mushroom poisoning incidents occurred throughout the year, with the highest frequency observed between June and October (498 incidents, 1,254 patients, and 9 deaths), peaking in June (135 incidents, 332 patients, and 2 deaths). The first death occurred on May 2 in Chongqing. The highest mortality was recorded in August (4 deaths), followed by May, June, October, and November (2 deaths each) (Figure 1).

Figure 1. 

Monthly distribution of mushroom poisonings in China, 2024.

Regarding geographical distribution, mushroom poisoning incidents were reported in 28 PLADs, with 13 PLADs recording more than 10 incidents. Sichuan, Yunnan, Hunan, Guizhou, and Chongqing PLADs were the 5 most affected regions (Table 1). Deaths were reported in 6 PLADs: Guizhou (5 deaths), Sichuan (2 deaths), Chongqing (2 deaths), Heilongjiang (2 deaths), Hunan (1 death), and Jiangsu (1 death) (Table 1). Southwestern China (Sichuan, Yunnan, Guizhou, and Chongqing) was the most severely affected region, with 321 incidents, 882 patients, and 9 deaths, followed by Central China (Hunan, Hubei, Henan, and Jiangxi) with 126 incidents, 235 patients, and 1 death. East China (Zhejiang, Anhui, Jiangsu, Fujian, and Shanghai) reported 59 incidents, 130 patients, and 1 death; Northwestern China (Ningxia, Qinghai, Xinjiang, and Shanxi) had 31 incidents, 68 patients, and no deaths; Southern China (Guangxi, Guangdong, and Hainan) recorded 30 incidents, 77 patients, and no deaths; Northern China (Hebei, Shandong, Shanxi, Beijing, and Inner Mongolia) had 22 incidents, 62 patients, and no deaths; and Northeastern China (Heilongjiang, Liaoning, and Jilin) reported 10 incidents, 32 patients, and 2 deaths. Detailed information for each PLAD is presented in Table 1.

In 2024, a total of 110 species of poisonous mushrooms were identified in mushroom poisoning cases, resulting in 7 distinct clinical syndromes. Among these, 8 species (Lactarius trivialis, Lactifluus bertillonii, Ligymnopus moseri, Marasmius maximus, Russula insignis, Tricholoma olivaceum, T. ustaloides, and Tylopilus vinosobrunneus) causing gastroenteritis were newly documented as poisonous mushrooms in China (1–7) (Figure 2K–O, Supplementary Table S1).

Figure 2. 

Fifteen important poisonous mushrooms were discovered from mushroom poisoning incidents in China, in 2024, which caused deaths, resulting in the highest number of different types of poisoning or newly added to the Chinese poisonous mushroom list. (A) Amanita exitialis, (B) A. molliuscula, (C) A. subpallidorosea, (D) Lepiota brunneoincarnata, (E) Russula subnigricans, (F) A. pseudoporphyria, (G) Paxillus obscurosporus, (H) Cordierites frondosus, (I) Chlorophyllum molybdites, (J) Amanita subglobosa, (K) Lactarius trivialis, (L) Marasmius maximus, (M) Russula insignis, (N) Tricholoma olivaceum, (O) Tylopilus vinosobrunneus.

The five most lethal mushrooms were Amanita exitialis, A. molliuscula, A. subpallidorosea, Lepiota brunneoincarnata, and Russula subnigricans (Figure 2A–E), each responsible for 2 deaths (Supplementary Table S1). Chlorophyllum molybdites (Figure 2I) caused the highest number of poisoning incidents (147 incidents affecting 269 patients), either alone or in combination with other species. This species also exhibited the widest geographical distribution (found in 16 PLADs) and the longest active period (from late March to late November).

In 2024, 8 species of Amanita, 1 species of Galerina, and 1 species of Lepiota were identified as causes of acute liver failure in China (Supplementary Table S1). Among these, Amanita exitialis, A. molliuscula, A. subpallidorosea, and Lepiota brunneoincarnata (Figure 2A–D) were the most dangerous species, each causing 2 deaths. The three mushroom species responsible for the highest number of incidents were Galerina sulciceps (15 incidents with 26 affected patients), Lepiota brunneoincarnata (14 incidents with 32 affected patients and 2 deaths), and Amanita molliuscula (7 incidents with 19 affected patients and 2 deaths).

Two species, Amanita oberwinklerana and A. pseudoporphyria, were identified as causes of acute kidney injury in 2024 (Supplementary Table S1). A. oberwinklerana was the most prevalent species, present in 10 incidents involving 30 patients, either alone or in combination with other species. A. pseudoporphyria (Figure 2F) resulted in 1 fatality across 6 incidents affecting a total of 19 patients.

Russula subnigricans (Figure 2D) caused 15 cases of rhabdomyolysis, affecting a total of 37 patients and resulting in 2 fatalities, either independently or in conjunction with other mushrooms. Paxillus obscurosporus (Figure 2G) along with 4 other species caused hemolysis in one incident affecting 5 patients in late July in Chongqing. Additionally, Cordierites frondosus (Figure 2H) caused photosensitive dermatitis when consumed with edible Auricularia sp., resulting in 1 incident with 3 patients in Yunnan during mid-June (Supplementary Table S1).

A total of 70 mushroom species causing gastroenteritis were identified in China in 2024 (Supplementary Table S1). Among these, 8 were newly identified as poisonous mushrooms and have been added to the Chinese poisonous mushroom list (1–7). The three most commonly encountered species in this category were Chlorophyllum molybdites (Figure 2I, appeared in 147 incidents affecting 269 patients), Russula aff. japonica (appeared in 40 incidents affecting 92 patients), and Entoloma omiense (appeared in 31 incidents affecting 105 patients).

In 2024, 25 mushroom species associated with psycho-neurological disorders were identified in China (Supplementary Table S1). The three most frequently encountered species were Amanita subglobosa (Figure 2J, 14 incidents affecting 35 patients), Anthracoporus nigropurpureus (11 incidents affecting 24 patients), and Gymnopilus dilepis (8 incidents affecting 13 patients).

In 2024, the number of mushroom poisoning incidents and patients ranked second highest in the past six years, though with the fewest deaths (1–5). Among the 2024 poisoning incidents, 110 poisonous mushroom species were successfully identified, with 84 previously documented (1–5), bringing the total number of mushrooms involved in poisoning incidents in China to approximately 246 by the end of 2024. Unlike previous years (1–5), the most dangerous mushrooms causing fatalities in 2024 were more diverse, with 4 species each causing 2 deaths. Acute liver failure and rhabdomyolysis were the most lethal clinical presentations, with the remaining deaths attributed to acute renal failure and hemolysis. Most poisoning incidents resulted from mushrooms causing gastroenteritis and psycho-neurological disorders, from which patients typically fully recovered.

Our studies (1–5) found that patients from many incidents consumed mixed mushrooms, sometimes including poisonous species causing different clinical syndromes. This highlights the importance of comprehensive investigations by CDC staff, physicians, and mycologists to collect all suspicious mushroom samples to avoid missing potentially dangerous species.

The temporal distribution analysis revealed that mushroom poisonings in 2024 primarily occurred from June to October, a shorter period compared to 2019−2023 (1–5). Similar to 2022 and 2023, the peak of mushroom poisonings in 2024 was observed in June (1–5). Unlike previous years (1–5), Sichuan had the highest number of incidents among all PLADs in 2024.

In 2024, among species causing acute liver failure, Amanita exitialis was first discovered in Chongqing, resulting in 1 incident involving 4 patients and 2 deaths (1–6,8–9). Amanita molliuscula, first described in China in 2016 (8–9), was identified in mushroom poisoning incidents (7 incidents, 19 affected patients, and 2 deaths) for the first time, expanding its known distribution from its type locality in Shanxi to include Hubei, Henan, Jilin, and Heilongjiang.

In 2024, only Amanita oberwinklerana and A. pseudoporphyria were identified as causes of acute kidney injury, similar to findings in 2023 but fewer than observed during 2019–2022 (1–5). Russula subnigricans caused 15 incidents of rhabdomyolysis, equal to the number reported in 2019 and 2022, less than in 2021 (16 incidents), and more than in 2020 (12 incidents) and 2023 (14 incidents) (1–5). Notably, Paxillus obscurosporus was documented as a cause of hemolysis in poisoning incidents for the first time (2–4).

In 2024, we identified 70 species causing gastroenteritis, including 8 newly recorded poisonous mushrooms, exceeding the number identified in each of the previous five years (1–5). Additionally, 25 mushroom species associated with psycho-neurological disorders were documented, fewer than in 2020 (28 species), 2022 (32 species), and 2023 (33 species), but more than in 2019 (18 species) and 2021 (22 species) (1–5).

This study represents only incidents that were investigated through our collaborative system comprising CDC staff, doctors, and mycologists. It is important to note that numerous poisoning incidents lacked mushroom specimens or even photographic documentation, making it impossible to confirm the exact species of poisonous mushrooms involved and thereby hindering targeted treatment for affected patients.

To reduce the incidence of mushroom poisoning, we advocate for closer collaboration among CDC staff, physicians, and mycologists. This includes developing diverse and accessible educational materials about poisonous mushrooms and conducting extensive public education campaigns to raise awareness about mushroom safety.

Profs. Zhuliang Yang, Xianghua Wang, Gang Wu, Hong Luo, Zaiwei Ge, Yanchun Li (Kunming Institute of Botany, Chinese Academy of Sciences), Profs. Zuohong Chen, Ping Zhang (Hunan Normal University), Profs. Taihui Li, Wangqiu Deng, Drs. Ming Zhang, Chaoqun Wang (Institute of Microbiology, Guangdong Academy of Sciences), Profs. Yu Li, Tolgor Bau, Changtian Li, Haiying Bao (Jilin Agricultural University), Prof. Niankai Zeng (Hainan Normal University), Prof. Yuguang Fan (Hainan Medical University), Prof. Liping Tang (Kunming Medical University), Prof. Junfeng Liang (Research Institute of Tropical Forestry, Chinese Academy of Forestry), Profs. Yucheng Dai, Baokai Cui, Shuanghui He, Jing Si (Beijing Forestry University), Prof. Chuanhua Li (Shanghai Academy of Agricultural Sciences), Prof. Haisheng Yuan (Institute of Applied Ecology, Chinese Academy of Sciences), Prof. Xiaolan He (Institute of Agricultural Resources and Environment, Sichuan Academy of Agricultural Science) and Profs. Liangdong Guo, Lei Cai, Ruilin Zhao, Xiaoyong Liu (Institute of Microbiology, Chinese Academy of Sciences), Prof. Xiaoyong Liu (Shandong Normal University); involved CDCs and hospitals.

This study is not applicable for ethical review.