(PhysOrg.com) — A new, highly detailed study of the H1N1 flu virus shows that the pathogen is more virulent than previously thought.

And it is possible, he adds, that the virus could become even more pathogenic as the current pandemic runs its course and the virus evolves to acquire new features. It is now flu season in the world’s southern hemisphere, and the virus is expected to return in force to the northern hemisphere during the fall and winter flu season.

The United States has reported 403 laboratory confirmed human cases, including one death.

The United States has reported 403 laboratory confirmed human cases, including one death.

As of 06:00 GMT, 6 May 2009, 22 countries have officially reported 1516 cases of influenza A (H1N1) infection.
The following countries have reported laboratory confirmed cases with no deaths – Austria (1), Canada (165), China, Hong Kong Special Administrative Region (1), Colombia (1), Costa Rica (1), Denmark (1), El Salvador (2), France (4), Germany (9), Guatemala (1), Ireland (1), Israel (4), Italy (5), Netherlands (1), New Zealand (6), Portugal (1), Republic of Korea (2), Spain (57), Switzerland (1) and the United Kingdom (27).