Carbon monoxide poisoning monitoring network: a five-year experience of household poisonings in two French regions.

Background: In France, the epidemiological situation of acute carbon monoxide (CO) poisoning is only partially known. The purpose of this study was to assess the epidemiological situation of household poisonings in two French regions where a regional toxicovigilance network was active.

Methods: During five years, we studied, by means of a standardized data collection form, cases of acute CO poisoning admitted to regional hospitals and notified by hospital physicians.

Results: From 1997 to 2001, 1,458 people were involved in 489 places. Household poisonings represented the first circumstance of CO poisoning with 811 people involved in 293 places. So, analysis was performed only for household poisonings. The mean age was 33.3 years. Twenty patients died (2.6%), 16 patients were in coma (2.1%), and 11 patients had an initial isolated loss of consciousness (14.4%). Responsible appliances in household poisonings were identified in 84% of places. The appliances most often involved were vented heating systems (46.4%), mobile heaters (13.2%), and thermal motors (8.7%). In 63% of the 293 places, investigation showed that poisoning occurred because of a faulty installation. Vented gas heaters and mobile heaters were responsible for half of the severe household CO poisonings.

Conclusion: In the countries of Rhône-Alpes and Auvergne, most of household CO poisonings are no longer caused by waterheaters but by gas heating systems. Poisonings caused by mobile heaters more frequently led to coma and death and thermal motors played a large part in moderate poisonings. These recently emerging trends justify the efforts focused on ongoing monitoring and the introduction of preventive measures.