The worst is yet to come

As the annual flu season draws near, the rise in the number of swine flu cases is a worrying sign.

In New Zealand, winter is in full swing, and locals are facing a particularly bad flu season. The swine flu is also doing well. Researchers think the new H1N1 strain is spreading even more easily in New Zealand than it did in Mexico. They estimate that each carrier of the virus will infect two others. This is a little more contagious than seasonal flu, but much less so than the Spanish flu pandemic of 1918.

The UK, too, is facing the worst flu season in a decade. According to official figures, swine flu cases in the country rose by 100,000 last week.

The WHO says the swine flu spreads fastest in people aged between 10 and 45, which covers virtually the entire school- and office-going population.

In India, schools have had to take steps to limit exposure when one or more students returned from abroad with the swine flu. Two Indian school groups visiting NASA sites on study tours have come back with the disease. There’s no information on the effect of swine flu on office attendance; but anecdotally it appears to be the case that colds and coughs are doing the rounds. This may be worrying because although the total number of confirmed swine flu cases in India so far is very low — only 371 on July 23, according to government figures — the annual flu season has yet to start.

US estimates suggest that between 12 and 24 per cent of Americans will catch the swine flu this autumn and winter, if no vaccine is available by then. Overuse of the standard treatment for flu, the Tamiflu pill, may lead to the virus becoming resistant to it. There are signs that this may be happening, which scientists are watching closely. It particularly worries them that, unlike with ordinary flu, during summer the spread of swine flu did not come to a halt.

Being close relatives, flu viruses tend to exchange genetic material — in effect, they learn from each other. A new flu can learn from and replace a seasonal flu, or the two can fuse to form another one. Either way or neither, scientists are waiting nervously for the flu season.

There’s no safeguard but prevention. Sleep well, eat wisely, keep your hands clean. If you’re ill, stay away from school or office, and cough or sneeze into your elbow, not the open air.