When Barack Obama went to the White House as a newly elected senator for an interview and welcome from the reigning President, George W. Bush was a kindly, attentive host. Apparently Obama was not only impressed by Bush's sen- sitive and kindly advice but surprised by his insistence that Obama should spray his hands with a disinfectant skin cleanser before he handled refreshments. Reports suggest that four years later Bush continues his campaign and at last week's dinner party for the victorious candidate he once again had his hands disinfected. Bush explained that this measure had reduced the number of coughs, colds and other infections that afflict all households.

About 15 years ago I was invited to spend a fortnight inspecting the hygiene regime on a Nile steamer and spent part of every day examining the steamer's kitchens, larders, bars, lavatories and the crews' quarters. Most Nile steamers are notorious for transmitting a range of organisms that ruin many a holiday, but this didn't apply to the craft owned by this company.

I interviewed every passenger daily and none had any infection during their trip. Other than the overall cleanliness, the most striking feature of the regime was that passengers, whenever they returned to the boat, were greeted by waiters bearing disinfectant mixtures, soap and clean towels. Grubby money from the outside world was collected and stored away before the passengers washed their hands.

Scientists studying the flu virus around the world have reported that resistance to Tamiflu (oseltamivir), the favoured treatment for flu, is beginning to increase. In some countries this degree of resistance would be a problem should the world suffer a flu pandemic similar to that of the 1918 Spanish flu, which killed more than 25 million people worldwide.

Fortunately there have so far been only a few instances in which the avian flu virus, H5N1, has been shown to have developed resistance to Tamiflu, but this fear is always present. The UK's state of preparedness for bird flu has recently improved and is now on a par with of other comparable European countries.

So far this year the number of cases of proven influenza in Europe has been strikingly low. Even though it is still early in the flu season, this is good news. Judging by previous years when the annual flu epidemic starts late, it is more likely to be less intense. If flu does strike, Tamiflu or Relenza are still indicated as the treatment of choice for patients whose general health makes them unusually vulnerable. Most run-of-the-mill patients will need only to take plenty of fluids and some simple remedy to lower the temperature and counter aches and pains.

Patients who swear by herbal products take such remedies as Sambucol, a mixture of the juice of black elderberries fortified by vitamin C. They claim that Sambucol reduces their chance of developing flu and if they do, it shortens the severity.

Even if the evidence so far supports the hope that the flu outbreak this year will be less severe than usual, everyone entitled to an NHS flu vaccination should have it. This immunisation is painless and exceptionally free of side-effects. Flu vaccination is not recommended for people with sensitivity to eggs, and those patients with any severe allergy problems should discuss them with their doctor before having immunisation.

Many other people, although they do not satisfy the criteria that would make them eligible for NHS flu immunisation, would also benefit. The chance to receive some protection against an attack of flu, or to reduce its severity should one occur despite injection, should never be rejected. As well as these obvious advantages there is also some suggestion that an annual flu jab provides some protection in later years, even though the strain of flu responsible will almost certainly have changed.

A hitherto unknown reason to have flu jabs has recently been revealed by research at Paris Descartes University. Scientists there have shown that flu vaccination reduces significantly the risk of travellers developing deep-vein thromboses and hence dangerous, sometimes fatal, pulmonary emboli - blood clots that may obstruct the blood supply to the lung.

This benefit of flu immunisation is especially obvious in younger people. The risk of developing a deep-vein thrombosis was reduced by more than 25 per cent by having a flu jab. For women on the Pill, whose risk is appreciably greater than in other travellers, the risk was cut by 59 per cent.