Mexico stirred back to normal life after a five-day shutdown of businesses due to the swine flu virus, which has claimed a second life in the US.
The Mexican government reported that the confirmed death toll from swine flu has increased to 42. Most of the additional fatalities had died several weeks ago.
Elsewhere, Sweden and Poland joined the list of affected countries.
Sweden said a woman in her 50s who visited Chicago had tested positive for the virus known as swine flu or A(H1N1) .
The 30-year-old had chronic health problems. A Mexican toddler also died in Texas.
The US now has 642 cases, the Centers for Disease Control and Prevention reported and is on alert after a Texan woman died this week.
The Mexican government last week ordered all non-essential businesses to close to prevent infection but now says the outbreak seems to be slowing.
President Felipe Calderon cautioned against complacency.
There have been 1,516 officially reported cases in 22 countries, the World Health Organisation said in Geneva.
It confirmed more infections in Britain, Spain, Italy and Germany.
Most cases outside Mexico remain in North America.
WHO experts will meet next week to consider whether drug makers should switch from seasonal to pandemic flu production in response to the new strain.
