GENEVA -- The world's total number of lab confirmed A(H1N1) flu cases has risen to 10,243, including 80 deaths, the World Health Organization (WHO) said in a latest update on Wednesday.

There is an overall increase of 413 cases compared with the accumulated number on Tuesday. A total of 41 countries have been affected by the new flu virus.

The United States has reported a total of 5,469 confirmed cases, of which 346 were reported in the past 24 hours. Mexico's total number of cases remains at 3,648, without change compared with Tuesday. Canada's total number of cases also remains at 496.

In the meanwhile, Japan reported 51 new cases and its total number of cases has risen to 210. Spain reported four new cases, with its total now standing at 107. Panama reported six new cases with a total of 65 cases.

So far most of the deaths have occured in Mexico, where the virus was first identified. Infections in countries outside of Mexcio are mostly mild ones.

But the WHO has repeatedly warned that the severity of the disease might increase and the world should remain highly vigilant of a possible pandemic.