US reports third swine flu death

More than 2,200 cases of the virus have been reported across the US

The US has reported its third death from swine flu, as Costa Rica confirmed a fatality and three more countries found cases of the virus.

A man with a heart condition who died in the US state of Washington was found to have the virus, officials said.

A 53-year-old man became Costa Rica's first fatality from the flu.

On Saturday Australia, Norway and Japan all confirmed cases of the virus, which emerged in Mexico last month and has killed 48 people there.

Those who have died outside Mexico - three in the US, one in Canada and one in Costa Rica - are reported to have suffered from underlying ailments.

In the US, health officials said that the man in his 30s who died in Washington state last week had a heart condition.

The man who died in Costa Rica was also suffering from diabetes and lung disease, the country's health ministry said.

Studying trends

Globally, cases of the virus have now been reported in 30 countries.

On Saturday Norway confirmed two cases, a man and a woman who had been studying in Mexico, while Australia confirmed one, a woman who had been travelling in the US.

I think right now the numbers don't tell us as much as the trends Dr Anne Schuchat, CDC

In Japan, four people - a teacher and three students - who had recently returned from Canada were found to have the virus.

Forty-eight other people who were on the same flight as the four have been placed under a 10-day quarantine, Kyodo news agency said.

In the US, meanwhile, the number of confirmed cases rose to 2,254 on Saturday - up from 1,639 a day ealier. Of these, 104 people were in hospital, the Centers for Disease Control and Prevention (CDC) said.

CDC official Dr Anne Schuchat said that it was more important to focus on trends than numbers.

"Fortunately, the severity of illness that we are seeing at this point doesn't look as terrible as a category five kind of pandemic or the severity of impact that some had feared," she said.

But viruses were unpredictable, she said, and it was important to focus on how the virus was spreading and how it developed in the southern hemisphere, which was just beginning its flu season.

"So a lot of our emphasis ... is still understanding the epidemiology transmission, severity and viral characteristics, but also working with partners internationally to really prepare and evaluate issues in their countries," she said.