WHO raised the pandemic alert level from 4 to 5 last night, based on increasingly rapid spread of the new influenza A/H1N1 especially in the United States.
30 April 2009 -- The situation continues to evolve rapidly. As of 17:00 GMT, 30 April 2009, 11 countries have officially reported 257 cases of influenza A (H1N1) infection.
The United States Government has reported 109 laboratory confirmed human cases, including one death. Mexico has reported 97 confirmed human cases of infection, including seven deaths. Source:W.H.O. and WHO pandemic preparedness plan
The following countries have reported laboratory confirmed cases with no deaths - Austria (1), Canada (19), Costa Rica (2),Germany (3), Israel (2), Netherlands (1), New Zealand (3), Peru (1), Spain (13), Switzerland (1) and the United Kingdom (8). Source: W.H.O. Influenza A(H1N1) - update 6
United States As of 10.30 (ET) the US reported 109 cases with 1 fatality. New states were added like Massachusetts (2), South Carolina (10), Indiana (1), Nevada (1) and Indiana (1). Source: CDC
Comment The virus continues to spread. Data from Mexico is very sparse, but if the reported number of cases in anyway reflects what is happening, the outbreak in Mexico has peaked. Secondary cases are now reported from Spain, but are still few.
All previous influenza strains including pandemic strains have not been infective during the summer months on the northern hemisphere, where transmission has ended by mid May. If the new influenza A/H1N1 showed the same pattern, the number of new cases will decrease over the next few weeks. If the virus has pandemic potential, which it looks like, new cases will appear on the southern hemisphere from now until October and the virus will reemerge on the northern hemisphere by September or October.