猪流感将波及世界人口三分之一The swine flu virus will infect a third of the world’s population if it continues to spread at its current rate, scientists warned today, as three more cases were confirmed in the UK.
In what the journal Science described as the "first quick and dirty analysis" of swine flu, a study by researchers at Imperial College London predicted the virus was likely to cause an epidemic in the northern hemisphere in the autumn.
One of the authors, the epidemiologist and disease modeller Neil Ferguson, who sits on the World Health Organisation’s emergency committee for the outbreak, said the virus had "full pandemic potential".
Speaking on BBC Radio 4’s Today programme, he said: "It is likely to spread around the world in the next six to nine months, and when it does so, it will affect about one-third of the world’s population.
"To put that into context, normal seasonal flu probably affects around 10% of the world’s population every year, so we are heading for a flu season which is perhaps three times worse than usual--not allowing for whether this virus is more severe than normal seasonal flu viruses."
The Health Protection Agency announced three more confirmed cases of the virus in the UK, bringing the total to 68. The three patients--two children and one adult from London--all had close contact with previously confirmed cases.
Today’s study estimated the contagiousness of the disease by analysing the number of people travelling to Mexico who became infected, and comparing that with a study of a Mexican village where the disease has spread. The research also examined how the virus was mutating.
It estimated that swine flu had killed between 0.4% and 1.4% of its victims in Mexico. The report’s lead author, Christophe Fraser, said it was too early to predict what the death rate was likely to be outside Mexico. "My hunch is that the death rate will be lower elsewhere--Mexico has underlying issues with respiratory disease," he said.