With the spread of Severe Acute Respiratory Syndrome, the Government has warned against travel to Toronto, Hong Kong, Beijing, Guangdong and Shanxi.

The Department of Health and the Foreign Office issued new warnings after the World Health Organisation strengthened its own advice about the Sars virus.

Sir Liam Donaldson, the UK's Chief Medical Officer, said: "The virus is likely to be here to stay. It is likely it will take its place as one of a range of known infections which cause serious outbreaks in different parts of the world which will need to be tackled."

How did this virus come into being?

There are countless filthy places in the world where people live in poverty. Many are host to different infections such as typhoid, hepatitis, cholera and polio.

But, so far, there has not been any evidence of respiratory viruses spreading from such places.

Many questions remain unanswered. Is it possible that pollution of the Earth's atmosphere through wars, nuclear testing, bombs, oil fumes, aeroplane fuel, car exhausts, air-conditioners and industrial waste may be responsible for these more sophisticated viruses?

Perhaps they are the result of experiments going wrong.

The natural way to prevent such infections is to stop polluting the environment and governments should be made to control their activities and focus on strategies to improve our air quality, general levels of hygiene, standards of living and promote safe disposal of domestic and industrial waste.

They should be encouraging organic farming and the planting of more trees.

People who are vulnerable to infections because they are run down, overworked or suffering from conditions such as asthma, diabetes or heart disease, can be helped by chyavanprash, a herbal formula originally developed by Ayurvedic physicians to treat tuberculosis, chronic bronchitis and other chest infections.

Clinical trials have shown it increases iummunity by enhancing the function of T-lymphocyte cells in the blood.

Another powerful anti-viral herb is curcumin, which has been shown to inhibit replication of viruses in the body.

Fresh root ginger, black pepper, long pepper, adhatoda vesica and buttercup will all help you breathe better when you have a chest infection.

Dasmool arishtha is a herbal medicine made from ten roots.

It has been shown to relieve breathing problems in asthma sufferers and those with chest/lung infections.

Steam inhalation with essential oil of curcumin and frankincense can also help as it has an anti-inflammatory effect on the lungs.