A 23-month-old US boy has become the first confirmed swine flu fatality outside of Mexico as authorities around the world struggle to contain a growing global health menace which has also spread to Germany and Austria.
The toddler was a Mexican child who died in Houston, said Kathy Barton of the Houston Health and Human Services Department.
The child, who had travelled with family from Mexico to Brownsville in south Texas, became ill in Brownsville and was taken to a Houston hospital, where he later died.
Germany has confirmed three cases and Austria one - joining Canada, New Zealand, Israel, Spain and Britain on the list of affected nations. Deaths reported so far have been limited to Mexico, and now the US.
The world has no vaccine to prevent infection but US health officials aim to have a key ingredient for one ready in early May, the big step that vaccine manufacturers are awaiting.
US President Barack Obama asked Congress for $1.5 billion (£1bn)in emergency funds to help build more drug stockpiles, monitor future cases and help international efforts to avoid a full-fledged pandemic.
"It's a very serious possibility, but it is still too early to say that this is inevitable," said the World Health Organisation's flu chief, Dr Keiji Fukuda.
The WHO has called a third emergency meeting in response to an increase in the number of cases and its expert panel will discuss whether to raise the worldwide flu alert level.
After the panel's first meeting Saturday, the outbreak was declared an international public health emergency. On Monday the pandemic alert level was raised from phase 3 to 4 to reflect the increase in risk of a global outbreak. Level 4 is two places below the top threshold - a full pandemic outbreak.
