The Epidemiological Characteristics of Mushroom Poisoning Outbreaks in Thailand,2013 and 2023

Abstract

This study is a cross-sectional study that retrospectively collected secondary data from the Outbreak Investigation Reporting System of the Department of Disease Control. The objective was to describe the magnitude of the problem, distribution and types of mushrooms associated with the severity of death from mushroom poisoning in Thailand from 2013 to 2023. Descriptive statistics, including frequency, percentage, median, maximum, and minimum values and Inferential statistics were applied using univariate logistic regression analysis to present odds ratios. The study identified 214 outbreak events, involving 931 patients and 81 deaths (case-fatality rate of 8.73%). The median number of patients per outbreak was 3 (range: 1-30). The proportion of male and female patients was nearly equal. The most common symptoms were gastrointestinal-related (66.10%). The highest number of outbreaks occurred between May and July, with a median of 2 outbreaks (range: 0-14), while the lowest occurred between January and April, with a median of 0 outbreaks (range: 0-1). The highest number of outbreaks was reported in Health Region 1 (57 events), followed by Health Region 10 (51 events) and Health Region 12 (20 events). Regarding the identification of mushrooms causing outbreaks, 159 events (74.30%) involved mushrooms definitively identified as poisonous. There were 89 events (41.59%) where the species of mushroom was either unspecified or unknown, and 21 events (9.81%) where mushrooms were identified as edible or with unclear classification. Analysis of symptoms by mushroom poison groups revealed that gastrointestinal symptoms were the most commonly reported events across all mushroom types. Secondary symptoms, particularly in cases involving mushrooms with unclear or erroneous classification, included neurological symptoms (13.33%). The study identified specific mushroom species that were significantly associated with the severity of mortality. These included Amanita hemibapha (OR=9.00, 95% CI=1.38-58.44), Astraeus odoratus (OR =10.00, 95% CI=1.44-69.26), Gyrodon spp. (OR=17.50, 95% CI=1.96-155.59), and Termitomyces spp. (OR=10.00, 95% CI=1.02-97.50). The quality of data in outbreak investigation reports is critical for comprehensive analysis. Therefore, improving data management, including complete and accurate tracking of poisonous mushroom species, is essential for planning and implementing effective surveillance and control measures at the local level.