The World Health Organization kept its global pandemic alert at 5 out of 6 today because the new H1N1 virus was not spreading rapidly outside North America, while Asian nations promised a common fight against the new flu.
At the epicenter of the outbreak in Mexico, authorities reported one more death, based on lab tests of patients who died in days past, to raise the total to 45. A quarter of the dead were obese, the government said.
The virus has also killed two people in the United States and infected more than 3,000 people in 25 countries. US officials expect it to spread to all 50 states.
Swine flu briefly rattled financial markets after Mexico announced it had detected a new virus on April 23rd, and it temporarily depressed hog futures as some countries banned imported swine and pork.
Studies show the virus is a strange coupling between a triple-hybrid virus with pig, human and bird elements and a European swine virus not seen before in North America. Researchers have yet to determine where it originated.
The US Centers for Disease Control and Prevention reported 1,639 US cases on Friday, up from 896 on Thursday, a jump that has been expected as a backlog of lab tests were confirmed. The Mexican case total climbed to 1,364 from 1,204.
In Asia, countries whose health diplomacy skills were honed by SARS in 2003 and ongoing outbreaks of H5N1 avian influenza pledged to boost drug stockpiles, share essential supplies and tighten surveillance against what they called an "imminent health threat" to the region.
Health ministers from the 10-member Association of South East Asian Nations or ASEAN, plus China, Japan and South Korea also agreed to set up a "red alert" hotline and rapid response teams to fight the spread of the virus.
"We cannot afford to let our guard down," Asean secretary general Surin Pitsuwan told the meeting.
In Hong Kong, authorities freed nearly 300 guests and staff of a hotel after quarantining them for a week.
Sylvie Briand, acting director of the WHO's global influenza program, said most people infected with the new strain around the world had either traveled to Mexico or been close to someone who had.
The WHO increased its pandemic alert warning to its second-highest level last week, Phase 5, indicating a pandemic was "imminent" but had held off declaring a full pandemic until more cases are seen either in Europe or Asia.
"We still remain in stage five. We have no evidence of community transmission," Ms Briand told a news conference.
Asked why the H1N1 strain has killed young adults in Mexico but caused relatively mild symptoms elsewhere, Briand said it appeared those patients did not seek medical care in time.
In Mexico, where diabetes is the nation's leading cause of death, officials said 24 per cent of the dead were obese and half of those were morbidly obese, meaning the patients were at least twice their ideal weight.
Diabetes was associated with many of the victims, as were cardiovascular problems such as angina and high blood pressure, Health Minister Jose Angel Cordova told a news conference.
These conditions can raise the risk of complications and death from seasonal influenza, which kills 250,000 to 500,000 people every year globally and 36,000 in the United States alone.
Mexico has largely returned to normal after a five-day shutdown of non-essential businesses ended on Wednesday.
Officials said their fast implementation of social distancing, disinfecting public spaces and education about hand hygiene helped control the spread of the virus, which is acting much like a typical seasonal flu.
Reuters