(Adds new WHO toll with more cases in Spain, Canada, Germany)
GENEVA, May 3 (Reuters) - The World Health Organisation said on Sunday its laboratories had identified a total of 898 H1N1 flu infections in 18 countries, including one case in Italy, and said there have been 19 confirmed deaths in Mexico.
The WHO's toll lags national reports about the virus but is considered more scientifically secure.
Its most recent figures say that 506 people have been infected in Mexico, and 226 people have been infected in the United States, the two countries most affected by the virus widely known as swine flu. There has also been one U.S. death, identified by authorities there as a Mexican infant.
The WHO has also confirmed flu infections, without deaths, in the following countries: Austria (1), Canada (85), Hong Kong - China Region (1), Costa Rica (1), Denmark (1), France (2), Germany (8), Ireland (1), Israel (3), Italy (1) Netherlands (1), New Zealand (4), South Korea (1), Spain (40), Switzerland (1) and Britain (15).
The WHO is waiting to see evidence of sustained spread of the virus outside the Americas region before raising its global alert level from 5 to the highest level, 6, and declaring a full pandemic.
Asked earlier on Sunday about the rising number of cases confirmed in Spain, WHO spokesman Gregory Hartl said most of those appeared to be "imported" cases involving people returning from Mexico, the disease epicentre, and not a situation where the virus was spreading widely through the Spanish population.
In its latest toll, the WHO also referred to the H1N1 virus identified in a swine herd in Alberta, Canada -- the first known case of animal infection with the new strain that is a mix of human, avian and swine flus.
"It is highly probable that the pigs were exposed to the virus from a Canadian farm worker recently returned from Mexico, who had exhibited flu-like symptoms and had contact with the pigs. There is no indication of virus adaptation through transfer from human to pigs at this time," the WHO said. (For more Reuters swine flu coverage, please click here: http://www.reuters.com/news/globalcoverage/swineflu )