SEATTLE, United States: The number of H1N1 flu-related deaths outside of Mexico rose after the US reported its third fatality and Costa Rica its first, but both men also suffered from complicating illnesses, health officials said.

In Mexico, the center of the outbreak where 48 people with H1N1 flu have died, most of the victims have been adults aged 20 to 49, and many had no reported complicating factors.

Elsewhere, five others have died while infected with the virus, including the two fatalities reported on Saturday, but each of them had additional health issues. People with chronic illnesses usually are at greatest risk for severe problems from flu, along with the elderly and young children.