Key points for Weeks 11 and 12 (March 14–27, 2011)

• The number of reported cases of carbon monoxide (CO) poisoning during weeks 11 and 12 (n=43) showed a slight decrease (-10%) compared to the number of reports from the previous two-week period (n=48).

• During the same period the previous year, the number of reports was higher (n=65).

• Three cases of poisoning in public buildings were reported to the surveillance system, one of which was a mass poisoning incident. In total, 10 people were exposed to CO fumes in a public building. The mass poisoning incident involved 8 people. In one incident, the poisoning was linked to a malfunction in a propane-powered radiant panel heating system. For the other two incidents, the cause of the poisoning was unknown at the time of reporting.

• No deaths were reported to the surveillance system during weeks 11 and 12.