(AP) -- The worldwide death toll from swine flu has doubled in the past month, reaching over 700 since the start of the outbreak last spring, the World Health Organization said Tuesday.
The U.N. health agency also said it is examining how countries can tackle the expected explosion in cases predicted this fall, when students and workers in the northern hemisphere return from summer vacation.
Closing schools can help break the chain of swine flu transmission, though at risk of considerable economic cost, the British medical journal The Lancet reported Tuesday. The study is to be published in next month's edition.
"School closures is one of the mitigation measures that could be considered by countries," WHO spokeswoman Aphaluck Bhatiasevi told reporters in Geneva.
The agency has stressed that although the disease is "unstoppable" in the long term, slowing its spread is important to prevent hospitals being overwhelmed by the sheer number of new cases.
WHO stopped asking governments to report infections last week, saying it was "extremely difficult, if not impossible" for countries with large numbers of cases to keep track of each new one.
But the Stockholm-based European Center for Disease Prevention and Control, ECDC, said Monday there had been over 2,300 new reported cases in 24 hours, taking the global total to almost 140,000. Many more could have gone undetected, since the virus causes only mild illness in most cases that does not require medical treatment.
WHO did not give a breakdown of the deaths Tuesday. But as of last week, the United States reported 263 deaths, Canada reported 45 deaths and Britain had 29. According to WHO's last update on July 6, there were 119 deaths in Mexico.
Yet even Tuesday's figure of 700 deaths may seriously underestimate the true toll, experts say, because not all swine flu cases are being picked up due to testing limitations.
The Lancet paper, written by researchers at London's Imperial College, argues that school closures would allow more time for a vaccine to be produced and administered widely. Estimates for when this might be the case vary from September to the end of the year.
Slowing the pandemic would also limit the burden on national health care systems and reduce the peak in worker absenteeism, the paper argues.
France is among the countries reportedly considering school closures, though decisions would be made on a a case-by-case basis, Le Parisien daily reported Thursday.
France's Education Ministry has already prepared nearly 300 hours of educational programming for radio and television to allow those affected by school closures to follow their lessons, it said.
Associated Press writers Bradley S. Klapper in Geneva, Maria Cheng in London and Jenny Barchfield in Paris contributed to this report.
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