June 1, (Reuters) - At least 17,564 people have been confirmed infected with the new H1N1 flu strain in 64 countries.

Bulgaria confirmed on Monday its first case of H1N1 flu, in a man who had recently returned from the United States, the Health Ministry said.

Here are some details about the spread of the virus:

DEATH TOLL: 115

CONFIRMED CASES: The number of confirmed cases of H1N1 is 17,564 in 64 countries. The World Health Organisation includes Taiwan and Hong Kong in China for its country tally.

COUNTRIES WORST AFFECTED:

DEATHS CASES

MEXICO 97 5,029*

UNITED STATES 15 8,975***

CANADA 2 1,336

COSTA RICA 1 37

AUSTRALIA 0 401+

JAPAN 0 379

CHILE 0 276**

BRITAIN 0 229****

SPAIN 0 178

PANAMA 0 107

NOTE: * = Mexico Ministry of Health figures

** = Chilean health authorities.

*** = U.S. authorities estimate more than 100,000 cases; confirmed cases are only a sampling.

**** = British Health Protection Agency figures

+ = Australian government.

Sources: Reuters/WHO. WHO figures sometimes lag local confirmations covered by Reuters. (Writing by David Cutler, London Editorial Reference Unit;)

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