Outbreaks of swine flu in Mexico and the United States have the potential to cause a worldwide pandemic but it is too early to say whether they will, Reuters cited the head of the World Health Organisation as saying today. WHO director-general Margaret Chan urged health authorities in all countries to be on high alert for unusual patterns of disease and any rise in severe flu or pneumonia cases. "This is clearly an animal strain of the H1N1 virus and it has pandemic potential because it is infecting people," Chan said on a teleconference. "However, we cannot say on the basis of currently available laboratory, epidemiological, and clinical evidence whether or not it will indeed cause a pandemic." The United Nations health agency has warned for several years that a new virus strain could spark a human influenza pandemic that could sweep around the globe and kill millions. The new H1N1 flu strain -- a mixture of swine, human and avian flu viruses which has killed up to 68 people among 1,004 suspected cases in Mexico and infected eight in the United States -- is still poorly understood and the situation is evolving quickly, Chan said.
