|An employee at a mask-making plant inspects surgical masks in Richland Hills, Texas.|
The Americas are back in the spotlight over swine flu fears after Canada announced its first death, the number of US infections almost doubled, and more cases were found in Latin America.
On the other side of the world, Japan and Australia announced their first confirmed infections.
Brazil on Friday also confirmed its first case transmitted from person to person while Mexico said it was investigating 10 more possible swine flu deaths.
US President Barack Obama warned the United States was not out of the woods yet, as across the nation's northern border a woman in western Alberta province became the first person in Canada to succumb to the disease.
"We have our first fatality in Alberta that is associated with the H1N1 flu," said Andre Corriveau, the province's chief medical officer.
Canada has the third highest number of swine flu infections with 224 cases, but the United States overtook Mexico on Friday to become the country with the highest number of patients, recording 1,639 cases in 43 states.
Mexico, which was the epicentre of the worldwide epidemic, raised its swine flu death toll to 45, with confirmed cases going up to 1,319, of which more than half were younger than 20. Two people have also died in the US.
The World Health Organization (WHO) said that 2,500 people in 25 countries had tested positive for the A(H1N1) virus, with 46 deaths.
As the number of US cases jumped overnight with more tests put in place, Obama warned Americans to remain vigilant.
"We are seeing that the virus may not have been as virulent as we at first feared," Obama said at a Spanish-language town hall-style meeting at the White House.
"But we are not out of the woods yet. We still have to take precautions."
The US president warned the autumn and winter flu season later in the year could be "even worse" and see cases spike again.
Brazil confirmed its first case of swine flu transmitted from person to person within the country.
Health Minister Jose Gomes Temporao said a new case, one of two found on Friday, was "up to now the only case of person-to-person transmission (of the virus) in Brazil."
The discovery brought to six the total number of cases detected in Latin America's largest nation.
Earlier, Panama confirmed a case of the virus while Guatemala said it had two people who had caught the disease.
However, life in Mexico was slowly returning to normal after a week-long shutdown with the reopening of schools and tourist sites, Mexico City eateries, theatres and cinemas. Primary schools were due back on Monday.
In the Asia-Pacific region, Australia and Japan became the latest countries to confirm cases of the A(H1N1) virus.
An Australian woman tested positive for the disease as she returned from a trip to the United States, the government said.
"We have a person who had contracted the disease overseas and has fully recovered by the time they returned to Australia," Health Minister Nicola Roxon said.
She said authorities were contacting other passengers who were on the woman's flight from Los Angeles, which arrived in Brisbane on Thursday.
In Japan a teacher and two students returning from North America tested positive for swine flu in the first confirmed cases of the virus in the island nation, the government said.
Japanese authorities quarantined the three males, who had been on a high school trip to Canada, and 49 others who were aboard their flight, which arrived Friday at Tokyo's Narita international airport from the US city of Detroit.
Health Minister Yoichi Masuzoe said the government was trying to contact for testing all of the 391 passengers and 21 crew who were on the Northwest Airlines flight that arrived around 4:30 pm (0730 GMT) Friday.
In Hong Kong, still haunted by memories of the 2003 SARS epidemic that killed nearly 300 people there, more than 280 guests and staff were finally allowed to leave a hotel after spending a week in quarantine.
The Mexican guest who tested positive for swine flu and had stayed at the hotel was also released from hospital Friday.
Swine flu and preparation for possible pandemics will top the agenda when health officials meet from May 18 during the World Health Organization's annual gathering in Geneva.