SEATTLE (AP) -- The number of swine flu-related deaths outside Mexico has inched up to five with the U.S. reporting its third fatality and Costa Rica its first, both involving men who also had underlying illnesses.
The number of confirmed cases of the infection in the U.S. has risen to 2,532 in 44 states, the Centers for Disease Control and Prevention reported Sunday.
Washington state health officials said the victim there was a man in his 30s who had underlying heart conditions and viral pneumonia when he died Thursday from what appeared to be complications from swine flu. The state Department of Health said in a statement Saturday that swine flu was considered a factor in his death.
"We're working with local and federal partners to track this outbreak," said Washington State Secretary of Health Mary Selecky.
The man was not further identified. He began showing symptoms on April 30, and was treated with anti-viral medication. Dr. Gary Goldbaum, Snohomish Health District medical director, said medical officials hadn't been able to isolate any "risk factors" for the man to identify where he might have been exposed.
The death of a 53-year-old man in Costa Rica on Saturday was the first involving swine flu outside North America. He also suffered from diabetes and chronic lung disease, the Health Ministry said.
Most of the victims in Mexico, the center of the outbreak where 48 people with swine flu have died, have been adults aged 20 to 49, and many had no reported complicating factors.
Previously, U.S. authorities reported swine flu deaths of a toddler with a heart defect and a woman with rheumatoid arthritis, and Canadian officials said the woman who died there also had other health problems but gave no details.
Mexico, which raised its count of confirmed cases to 1,626 based on tests of earlier patients, has been gradually lifting a nationwide shutdown of schools, businesses, churches and soccer stadiums.
But an upswing in suspected - though not confirmed - cases in parts of Mexico prompted authorities in at least six of the country's 31 states to delay plans to let primary school students return to class Monday after a two-week break.
"It has been very stable ... except for those states," Health Department spokesman Carlos Olmos said, referring to states in central and southern Mexico.
Mexican health authorities released a breakdown of the first 45 of the country's 48 flu deaths that showed that 84 percent of the victims were between the ages of 20 and 54. Only 2.2 percent were immune-depressed, and none had a history of respiratory disease.
Marshall reported from Seattle; Jimenez reported from San Jose, Costa Rica.