Public Health: WHO renames virus, raises alert, says no benefit in travel restrictions

Mexico has stopped counting suspected cases - and the result is that the number of reported cases is now officially down from more than 2500 to less than 700.

But that is not preventing countries from taking measures to try to prevent it arriving on aircraft - and being brought home by travellers.

After two groups of students visiting Mexico from New Zealand each brought back the virus, and a traveller from Mexico carried it to Hong Kong, airports across Asia Pacific have brought their passenger sensors out of storage and are recording temperatures of arriving passengers. In Hong Kong some 300 people are quarantined in a Wanchai hotel - the city suffered massive disruption under SARS and is taking no chances.

More countries are adding advice not to travel to Mexico unless the journey cannot be avoided.

The pork industry around the world is criticising the naming of the virus as swine flu - and saying that there is no evidence that it is passed within the pig industry either between animals or on to humans.

And now the WHO says that the name was wrong, or wrongly applied. And in a number of countries where pork is not permitted, the virus had in any case been known as Mexican Flu. From now, the WHO says, it is to be known by a rather more prosaic, technical and complicated name: influenza A (H1N1).

If that sounds horribly similar to the name given to variations of bird flu, that's because it is. How confusion will be avoided is something the WHO appears not to have given much thought to.

As of today, the official WHO position is summarised by the following statement:

20 countries have officially reported 985 cases of influenza A (H1N1) infection.

Mexico has reported 590 laboratory confirmed human cases of infection, including 25 deaths. The higher number of cases from Mexico reflects ongoing testing of previously collected specimens. The United States has reported 226 laboratory confirmed human cases, including one death.

The following countries have reported laboratory confirmed cases with no deaths - Austria (1), Canada (85), China, Hong Kong Special Administrative Region (1), Costa Rica (1), Colombia (1), Denmark (1), El Salvador (2), France (2), Germany (8), Ireland (1), Israel (3), Italy (1), Netherlands (1), New Zealand (4), Republic of Korea (1), Spain (40), Switzerland (1) and the United Kingdom (15).

There is no risk of infection from this virus from consumption of well-cooked pork and pork products.

It is considered prudent for people who are ill to delay international travel and for people developing symptoms following international travel to seek medical attention, in line with guidance from national authorities. Individuals are advised to wash hands thoroughly with soap and water on a regular basis and should seek medical attention if they develop any symptoms of influenza-like illness.

WHO advises no restriction of regular travel or closure of borders.

That's not preventing countries, and organisations and individuals, from taking action.

US Airlines are cancelling flights into Mexico due to a collapse in demand.

Mexico itself is putting in place measures to reduce the risk of people meeting in confined spaces e.g. restaurants.

And the WTO's statement on 1 May does not instil confidence amongst countries that have had to deal with rapidly spreading outbreaks - and the devastating effect that e.g. SARS had on their economies.

The WTO said " WHO is not recommending travel restrictions related to the outbreak of the influenza A(H1N1) virus. Today, international travel moves rapidly, with large numbers of individuals visiting various parts of the world. Limiting travel and imposing travel restrictions would have very little effect on stopping the virus from spreading, but would be highly disruptive to the global community.

Influenza A(H1N1) has already been confirmed in many parts of the world. The focus now is on minimizing the impact of the virus through the rapid identification of cases and providing patients with appropriate medical care, rather than on stopping its spread internationally. Furthermore, although identifying the signs and symptoms of influenza in travellers can be an effective monitoring technique, it is not effective in reducing the spread of influenza as the virus can be transmitted from person to person before the onset of symptoms. Scientific research based on mathematical modelling indicates that restricting travel will be of limited or no benefit in stopping the spread of disease. Historical records of previous influenza pandemics, as well as experience with SARS, have validated this point.

The fact is that the WHO's idea that anyone who feels ill should delay travel is not widely seen as a valid means of protecting societies.

And whilst its warnings of impending problems are widely respected, the current events are showing that talking down a problem is not gaining much traction.