Methanol poisoning caused by adulteration of alcohol at the production stage in a factory in northwestern Uganda, August 2022

Background Methanol ingestion can cause vision loss, severe illness, and death. Poor regulation of alcohol production can lead to methanol contamination of alcohol and methanol poisoning outbreaks. In August 2022, multiple sudden deaths occurred in Arua City and Madi-Okollo District, Uganda among persons who consumed a gin (Gin X) produced by a local manufacturer (Manufacturer A). We investigated to determine the scope of the problem, identify risk factors, and recommend control and prevention measures. Methods We defined a suspected case as acute onset of blurred vision with abdominal pain, weakness, headache, or profuse sweating in a resident of Arua City or Madi-Okollo District from 16–26 August 2022. We conducted a retrospective cohort study and used modified Poisson regression analysis to evaluate the association between quantity of Gin X consumed and risk of death, and conducted key informant interviews to identify possible sources of adulteration. We conducted a site visit to Manufacturer A and collected Gin X samples for toxicology analysis at the Government Analytical Laboratory. Autopsies were carried out on 8 deceased case-patients. Results Among 48 cases (47 males and 1 female), 18 (38%) died; median case-patient age was 32 (IQR 26–46) years. Onsets ranged from 17–24 August 2022. The risk of death was 11 times higher (RR = 10.7, 95% CI: 1.5–75, p = 0.02) among case-patients consuming ≥ 3-200ml bottles of Gin X than those consuming ≤ 1 bottle. Out of the eight samples of Gin X tested, five were positive, with a mean methanol concentration of 594 mg/L (range 259–809 mg/L), higher than the maximum ‘safe’ limit of 50mg/L. All eight autopsies showed signs consistent with methanol poisoning. Cases were clustered around the four bars that received Gin X from the unauthorized manufacturer A who had been denied a production license by Uganda National Bureau of Standards in April 2022. The chemist responsible for Gin X production had disappeared after a dispute with the proprietor, four days before the outbreak and immediately after the last production. Conclusion Gin adulterated with methanol, likely during production, caused a methanol poisoning outbreak in Uganda. Stricter enforcement of laws around alcohol production might prevent similar outbreaks.