A study of methanol poisoning outbreak from infused liquor in three communities, Chonburi, Thailand

Abstract

Objective : On October 20, 2019, the Department of Disease Control was notified that 14 patients had experienced chest tightness, nausea, and hematemesis after ingesting a new formula-infused liquor believed to be mixed with a toad and had gone to Chonburi Hospital. One of them died. Subsequently, the Joint Investigation Team conducted an investigation on October 21–22, 2019, to verify the diagnosis, perform active case finding, identify severity factors, and provide recommendations.

Methods : We reviewed medical records and conducted a descriptive study. The implicated liquor was sent for the determination of toxic substance levels. An analytic study was performed to identify factors associated with the severity among the patients. The distribution point and the production process of the liquor were also investigated.

Results : Of 25 liquor drinkers living in 3 communities in Chonburi, 22 cases (88.0%) were identified; 5 of them died. Fifty percent of them were hospitalized; 31.8% required hemodialysis. The median age was 42 years old (IQR=16.3). The median latent period was 17 hours. The most common symptom was confusion (40.9%), followed by nausea/vomiting (36.4%) and abnormal vision (18.2%).  Most of the cases exhibited a high anion gap. Methanol levels in two liquor samples were extremely high (36.2 g/dl). A high amount of liquor drinking was significantly associated with the severity of cases (Coefficient 833.4, 95%CI 207.9-1459.0). The maker illegally mixed the infused liquor and distributed the liquor door-by-door. The components of the infused liquor cannot be identified.

Conclusion : A confirmed cluster of methanol poisoning was caused by the ingestion of methanol-contaminated infused liquor. No toad was involved. The case fatality rate was within the average range of previous outbreaks. Permanent visual impairments were detected. The amount of infused liquor consumed was statistically significant among severe and non-severe cases. Health education on methanol poisoning and strengthened enforcement on selling illegal liquor are recommended.