New flu virus may mutate further

May 13 (Reuters)-The World Health Organization (WHO) said 12th that the swine flu virus could continue to mutate into more virulent viruses, triggering an influenza pandemic that could cause three waves of disease globally, according to the WHO. The WHO report says the impact of any virus can be varied.　　The same virus, in countries with complete health-care systems, may have little impact, while countries with fewer medicines and poor medical facilities may have devastating effects. In a report entitled "Severity assessment of influenza outbreaks" (assessing the severity of influenza pandemic), who noted that the swine flu virus "appears to be more contagious than seasonal influenza",　　And almost all races have no immunity to them.　　A spokesman for who, Thomas Abraham, told reporters that the report aims to show in many ways the severity of the outbreak, not only its pathogenicity, but also its impact on health and social systems. According to the WHO data released 12th this month, the total number of new influenza viruses diagnosed in 30 countries worldwide has reached 5,251, of which 61 have died.　　The worst-affected Mexico has 2,059 cases, 56 deaths and 2,600 in the United States, of whom 3 are dead. The WHO says that, in addition to Mexico, the new flu virus infection in other countries is relatively mild.　　But influenza viruses often mutate abruptly without warning, and do not rule out the emergence of more virulent new variants. "The overall severity of the epidemic also depends on whether there are two or even three global trends," the W.H.O. said.　　"1918 years of flu outbreaks have killed tens of millions of people, but initially the outbreak was relatively flat, but six months later it became extremely lethal." The spread of new influenza viruses seems to be easier than seasonal flu. The average seasonal flu kills 25.5 million people a year, and the death rate is less than 0.1%. Seasonal influenza has a 5%-15% "Two attack rate" (that is, the percentage of people who are in contact with the total number of all susceptible contacts), and according to WHO, the new influenza has a two attack rate of 22-33%.