H1N1 influenza

This item appears on page 21 of the June 2009 issue.

At press time, the World Health Organization had raised the alert level of the fast-spreading H1N1 “swine flu” from phase 4 to 5 out of a possible 6 alert levels. Phase 5 indicates that human-to-human transmission of the virus is confirmed in at least two countries. WHO advised that all countries put their preparations for a pandemic into effect.

Twenty countries confirmed cases of H1N1 as of May 4. In Mexico, the country with the most suspected cases (727), 26 were believed to have died of the virus or complications from the virus. The CDC had advised travelers to avoid unnecessary trips to Mexico.