23 countries

Influenza A(H1N1) - update 18
6 May 2009 -- As of 16:00 GMT, 6 May 2009, 23 countries have officially reported 1893 cases of influenza A (H1N1) infection.
Mexico has reported 942 laboratory confirmed human cases of infection, including 29 deaths. The United States has reported 642 laboratory confirmed human cases, including two deaths.
Related links
Map of the spread of Infuenza A(H1N1): number of laboratory confirmed cases and deaths [jpg 419kb]As of 6 May 2009, 18:00 GMT Influenza A(H1N1) web siteDaily updates will be posted on this site.

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 (5), Germany (9), Guatemala (1), Ireland (1), Israel (4), Italy (5), Netherlands (1), New Zealand (5), Portugal (1), Republic of Korea (2), Spain (73), Sweden (1), Switzerland (1) and the United Kingdom (28).
WHO is not recommending travel restrictions related to the outbreak of the influenza A(H1N1) virus.
Individuals who are ill should delay travel plans and returning travellers who fall ill should seek appropriate medical care. These recommendations are prudent measures which can limit the spread of many communicable diseases, including influenza.
Further information on the situation will be available on the WHO website on a regular basis.

http://www.who.int/en/