WHO: global death toll from swine flu now over 700

The worldwide death toll from swine flu has doubled in the past month, reaching over 700 since the start of the outbreak, the World Health Organization said Tuesday.

The UN health agency also said it is examining how countries can tackle the explosion in cases predicted this fall, when students and workers in the northern hemisphere return from summer vacation.

Experts say closing schools can help break the chain of transmission, though at risk of considerable economic cost according to a paper to be published in next month's edition of the medical journal The Lancet.

"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 as in most cases the virus causes only mild illness that does not require medical treatment.