ZURICH (Reuters) - The number of confirmed cases of the new H1N1 flu has climbed to 8,451, including 66 deaths, the World Health Organisation said Saturday.
The number of countries reporting confirmed cases of H1N1, commonly known as swine flu, has risen to 36 with Ecuador and Peru confirming their first cases, the WHO said.
The vast majority of cases have been in Mexico and the United States.
The spread of the disease has led the WHO to declare a pandemic is imminent. On April 29 it raised its pandemic alert to 5 on a 6-level scale.
WHO Director-General Margaret Chan said Friday there remained "great uncertainty" about the new strain, which continues to spread and could pose particular threats in Southeast Asia.
U.S. health officials later Friday announced they were easing their warning on travel to Mexico.
The virus is behaving much like a seasonal influenza strain -- spreading rapidly and causing mainly mild disease, but severe illness in some people.
Seasonal flu kills 500,000 people a year, mainly the elderly or those with respiratory problems like asthma.
The WHO said Mexico has reported 2,895 confirmed cases including 60 deaths. The United States has reported 4,714 confirmed cases including four deaths. Canada has 496 confirmed cases and Costa Rica nine cases, both with one death.
The WHO's tally lags national reports but is considered more secure. Rising numbers can indicate that a backlog of cases is being processed, as well as the spread of the disease.
(Reporting by Jason Rhodes; editing by Myra MacDonald)