[A cluster of methanol-related poisonings in Sicily: case characterization and identification of unexpected sources of exposure]. / Un cluster di intossicazioni da metanolo in Sicilia: descrizione dei casi e identificazione delle fonti di esposizione.

ABSTRACT

OBJECTIVE: To describe methanol poisoning exposures in Italy and to investigate a cluster of methanol-related deaths due to abuse occurred in Sicily among immigrants from East Europe. DESIGN: the human methanol exposures handled by the Poison Control Centre of Milan, the major national centre for toxicological advise active in Italy, were reviewed retrospectively (January 2004-September 2006) and prospectively (October 2006-October 2008). SETTING: For each case of managed human exposure, the Poison Control Centre of Milan uses a standard format to collect patient information, substance/exposure information, clinical effects, therapy, outcomes. The database arising from that procedure was searched for all cases exposed to methanol and/or reporting selected clinical signs (i.e., metabolic acidosis with ocular effects and/or central nervous system depression and/or respiratory depression). Each case was reviewed and classified according to standard criteria. MAIN OUTCOMES: Three commercial products containing more than 70% methanol available on the market in Sicily and associated with lethal exposures due to abuse among immigrants were identified. RESULTS: In the period under study, the Poison Control Centre of Milan examined 29 methanol poisoning exposures (none in 2004, 6 in 2005, 6 in 2006, 15 in 2007, and 2 in 2008). Among them, 17 occurred in Sicily, with a peak of 11 cases in 2007, and 12 in other regions. The patients included 16 men and 13 women with a median age of 49,5 years (range 1-81 years). Fifteen cases were immigrants from East Europe (14 Rumanian and one Polish). Eleven cases reported minor effects, two cases moderate effects, four cases major effects, and 12 cases died. Twelve cases were accidental exposures (5 occurred at work, 3 at home and 4 in other places), while 17 cases were intentional exposures (14 due to abuse, 2 to attempted suicide and 1 to misuse). Minor effects were reported in 11 cases, moderate effects in two cases, major effects in four cases and death in 12 cases. The most frequently reported clinical effects included coma (13 cases), metabolic acidosis (10 cases), mydriasis (4 cases), visual loss (3 cases), gastric pyrosis (2 cases), constriction of the visual field (2 cases), and vertigo (2 cases). Blood methanol level was reported for 15 cases (< 50 mg/dL in 2 cases; 50-99 mg/dL in 2 cases; 100-499 mg/dL in 4 cases; >500 mg/dL in 1 case; positive, unknown value in 6 cases). All cases due to abuse (n. 14) and, among them, lethal (n. 12) occurred in Sicily and involved immigrants. On the other hand, all methanol poisonings occurring in the other Italian regions involved Italian citizens unintentionally exposed and with minor effects, except for one case of attempted suicide with consequent major effects. The investigations performed in Sicily lead to identifying three locally produced and marketed detergents containing more than 70% methanol, improperly labelled and packaged. Furthermore, a detergent for domestic use was identified containing 25-30% methanol without any labelling information. Two of the detergents containing more than 70% methanol were withdrawn from the market in November 2007, while the other, that was identified later, was withdrawn in July 2008. The detergent for domestic use, containing 25-30% methanol was withdrawn in December 2007. Starting from July 2008, no new cases of methanol poisonings were observed. CONCLUSION: The availability in Sicily of products containing high concentrations of methanol, improperly packaged and labelled, determined a generalised risk of accidental exposures and favoured voluptuary assumption of methanol among selected groups. The observations highlight the importance of a surveillance system of toxic exposures based on the information collected by the Poison Control Centres and its ability to provide timely identification of unexpected and dangerous events and to support preventive actions.