Swine flu: Should we be worried?

Jun 4 2009

Everyone is equal in the eyes of swine flu. Whether you're a Scottish football fan or a student at Eton, the virus does not discriminate.

Confirmed cases of the bug have steadily crept up in the UK, with 278 at the last count (including 13 Rangers fans) but despite mass fear about its lethal effects, many of those who have suffered and survived claim it's no worse than catching a cold.

In Mexico, where the virus originated in pigs, the death toll has been recalculated from 159 cases to just 56.

So have we overreacted to the threat of swine flu? Or is a more dangerous strain developing, ready to hit us this winter?

According to the World Health Organisation (WHO), swine flu is currently rated as a level five threat. A "flu pandemic" is declared at level six.

This might sound bad, but the Professor of Virology at the University of Reading, Ian Jones, says it's not an indication of the flu's severity.

"There is still confusion in the public mind about the word pandemic. It doesn't mean severe infection, it simply means a very widespread infection, freely transmitting on a global scale."

Swine flu outbreaks have already forced several schools to close, including Eton College, and there are fears it could spread when children go back after the summer holiday.

Virology expert Professor John Oxford warned this week that the return to school, work and university in September could give the virus an "opportunity" to become a pandemic, before a vaccine becomes available from October.

But Prof Jones believes it's more likely to spread in November, the start of our normal flu season.

"There's no doubt that we can't eradicate the virus and so the spread will continue and probably will accelerate as we go into the traditional flu season.

"But I don't think there's any evidence that it will be any more severe in its second wave.

"Professor Oxford's point about children going back to school, the congregation of people, is correct, but the normal flu season is thought also thought to be related to the fact that people tend to crowd together in wetter, colder times of the year, they're indoors rather than outdoors, and that accelerates transmission."

:: GAINING IMMUNITY

How quickly swine flu will spread this winter will depend on how many people have already caught it and built up an immunity, say the experts.

"Once a person is infected and has cleared the infection, they're immune, the virus can't go there. So once 'herd immunity', as it's called, in the population, builds up, then the virus will be less and less of a problem," says Prof Jones.

The current outbreak is a new strain of influenza A virus subtype H1N1, a relative of pig flu that has already existed in America for the past 10 years, he explains.

Unlike the lethal H5N1 strain of bird flu, which reared its ugly head here in 2005, swine flu doesn't have to adapt itself to infect humans, meaning we might not see a stronger, mutated version appear later this year.

"In past epidemics, the virus has been adapting to human transmission because it was effectively a bird virus. But in this case, it's definitely a pig virus, a mammalian virus.

"Having said that, were it to come back in a slightly more dangerous form, then there's no doubt if you've been infected with the mild form, you'd be resistant. You would almost certainly be protected come the winter."