Hong Kong, with a clear memory of the searing experience of severe acute respiratory syndrome, has given a strict lesson in how to try to contain the disease. More than 300 people who stayed in the same hotel as the Mexican traveller infected with swine flu were quarantined, as was the taxi driver who drove him, and others who sat close to him on the flight. Immigration has been notified, so that people who may have been infected cannot fly off and spread the flu.

Other countries with cases of swine flu have ordered victims to stay at home, closed schools and prepared millions of face masks to protect against transmission.

One cynical commentator in Britain said that if Tony Blair had still been prime minister, he and his cabinet would have been seen on television going to the bunker kitted up in full germ-warfare suits to prepare their battle plans. Instead, schools attended by victims have been closed, warning leaflets delivered to every household, and the media have been bombarded with advertisements giving telephone numbers to call, recommendations what to do if someone felt they had flu, and advising frequent washing of hands.

Is this an overreaction? The mainstream press in the west has seized on the outbreak of swine flu as a great chance for headlines that will sell newspapers.

So far, the predictions have been far scarier than the disease. Although it has spread to more than 20 countries, by the middle of the week 1,500 people had been infected, and the confirmed death toll was 29 in Mexico and two in the US, though one of the US cases was a woman with chronic health problems. The death rate even in Mexico has been about the same as for normal flu. Moreover, health workers caring for the sick have not caught the disease, a sign that it is a mild variant.

The World Health Organisation warned that it may have to raise the alert to the highest level, six, signalling that a global pandemic was in full effect. But at mid-week, the organisation said: 'WHO advises no restriction of regular travel or closure of borders.'

However, international and national health experts warned that the outbreak might mutate and strike back more violently. Already, the disease has been transmitted to pigs from humans, and has demonstrated frightening power to spread quickly across the globe. Even though almost all the cases so far have a Mexican connection, cases of human-to- human transmission by those who have not been to Mexico but just shared drinks with infected people shows the potential for a pandemic.

The 1918 flu outbreak, which killed some 50 million people, was of the same H1N1 strain and passed from humans to pigs, though in a mild form, until in 1998 a variant evolved into a triple hybrid combining bird, human and swine flu that made US pigs violently ill.

The origins of the disease are not properly understood, and its potential for scary mutations that can occur faster than scientists can follow is alarming. So, too, is the potential for panic.

Egypt's mass slaughter of pigs - when the WHO was quite firm that properly cooked pork was no danger to anyone - was one such over-reaction. More contentiously, Mexicans in China were angered by what they claimed was discrimination against them; Beijing, with the experience of avian influenza and Sars, replied that it was just being professional in preventing the spread of a potentially lethal disease.

Reports from the area in Mexico where the swine flu originated describe in graphic detail immense lagoons of foul-smelling pig waste produced by massive factory farming. Pig producers naturally swore that they abided by all health regulations.

Even so, there are two obvious questions: is enough known about the repercussions and side-effects of vast factory farming and waste? And are there sufficient checks to ensure everyone at all times follows every correct health and safety procedure?

In developed countries, people are protected by a profusion of rules and regulations - health and safety and environmental rules that intrude into every aspect of life, so that it seems you cannot breathe without asking for permission from the ever-vigilant Nanny State.

Nanny offers abundant employment for bureaucrats, but is still vulnerable to the stupid, careless or sleeping officials, as well as to smart diseases that can move faster than ponderous officialdom.

By contrast, in many developing countries, health and safety concerns are few and far between and can be swept aside by people with money or connections.

In a globalising world, we are all as safe - or as vulnerable - as the weakest person on the planet, which is why there is a need for more information and co-operation across national borders - and more concern to see that the weakest person is better fed, healthier and educated, or he, his sister or cousin may be carrying a lethal disease across the world.

A small tragic footnote is that there are millions of vulnerable people on this planet who live in poverty and die in vast numbers every day and are never noticed; 1 million a year from malaria, 15 million children from malnutrition.

What a commentary on modern humanity.

Kevin Rafferty is editor-in-chief of PlainWords Media