The world is facing a flu pandemic. On Thursday, the World Health Organisation raised the level of alert to phase 6, the highest phase. What does that mean?

There is no panic. The Netherlands says the current variant of H1N1 flu is not severe. Other countries are improving checks at airports to trace possible carriers of Mexican flu. 
In general people returning from foreign countries, who develop a fever of at least 38.5 degrees within 4 days, should contact their doctor immediately, so that the flu variant can be diagnosed quickly. 
 

This is the first time in 41 years that alarm phase 6 has been reached. The last flu pandemic was during the Hong Kong flu outbreak in 1968, in which around a million people died. Mexican flu is considered to be a much milder virus.

There's still a lot of uncertainty about the new flu variant that has appeared in Mexico. But people still want to know what precisely is happening and what can be done about it. Here's a selection of FAQs (frequently asked questions), and the answers.

1. What is swine flu?

Mexican flu would be a better name for this disease. The new virus is a mixture of influenza viruses from birds, pigs and humans. As a species, pigs constitute a big reserve of flu viruses. Because pigs are genetically very similar to humans, viruses are often exchanged between these two mammals. Now that the virus has spread from human-to-human, it is a “human virus”. The virus that caused the Spanish flu epidemic around the end of the First World War originated in birds and spread to humans via a swine variant. Strangely enough, the current 'swine flu virus' only affects humans.

2. Can people get swine flu?

Generally speaking, a bird or swine flu virus will not cause symptoms in humans. There are exceptions, however: usually people who have intensive contact with these animals. This was the case recently with the few individuals who became ill - some died - after infection with the bird flu virus. As a result of mutation, the virus evolves in a such a way that it not only causes illness in humans but also passes from person to person. This probably happens the same way as with 'normal' flu: through people coughing and sneezing when in close proximity to others.

3. What are the human symptoms of swine flu?

The symptoms are the same as for 'normal' flu: a high temperature (38.5 degrees Celsius or higher), muscle aches, tiredness, loss of appetite and coughing. Without treatment, it may develop into pneumonia, which, in turn, may prove fatal. Medical services are advising people to contact a doctor - preferably by telephone in the first instance - at the first sign of flu symptoms. Laboratory tests can be carried out to determine what variant of the flu virus is causing the symptoms.

4. Is this a new virus?

Yes, according to the World Health Organisation (WHO) it's a strain of virus that has not been encountered before. So, humans are unlikely to have built up a resistance to it. The flu jab that many 'at risk' people in richer nations receive each year also provides no protection. Therefore it's important that a doctor determines what form of flu is involved. In the case of an attack of 'normal' flu, people normally recover without any assistance since they have already built up a natural resistance to the known viruses.

5. Why are people between the ages of 20 and 45 the only ones getting ill so far?

That's one of the mysteries of this virus. Normally, young children, the elderly and the chronically ill are the groups most vulnerable to flu viruses. It could be that older people still have some resistance from a previous outbreak, but that somewhat contradicts the observation that this is a totally new virus. The Spanish flu of the early 20th century also hit hardest among people who were in the prime of their lives. There might possibly be some kind of overreaction involved on the part of the immune system, which is fully developed in people in this age category. Such an overreaction might be fatal even when there are no extremely serious symptoms such as pneumonia.

6. Can Mexican flu be treated?

So far, the anti-flu medicines Tamiflu and Relenza seem to be effective against new flu variants. Both medicines lessen the effects of the flu symptoms. But ultimately, each flu infection has to run its course. Moreover, Tamiflu and Relenza are not vaccines. So there's no sense in taking them in the hope they will ward off the flu. In the United States, they're currently working on a flu vaccine that will - hopefully - offer real protection. But the development of this vaccine will take at least five months.

7. Is it safe to eat pork?

Yes, the virus can be found in the bronchial tubes of pigs, and not in its blood or in the organs. Even if the virus was in the meat, it would be killed during cooking. A ban on importing pork would have absolutely no effect on the spread of the virus.

8. The World Health Organisation (WHO) is raising the level of alert. What does that mean?

The preparations for a worldwide flu epidemic are divided into six phases. The recent outbreak of the bird flu virus had already brought the level up to phase 3, which means there's a chance that a new virus will become transferable from human to human.

Phase 4 means that a new virus has indeed mutated in such a way that makes it communicable between humans. The phase 4 alert means the authorities need to dust off their emergency plans for dealing with a pandemic. It does not mean there will be a pandemic.

Phase 5 indicates that human-to-human transfer has taken place in at least two countries in a WHO region (in this case Mexico and the United States). The threat of a pandemic is closer and all countries have to tie up any loose ends in their emergency plans.

Phase 6 is the highest alert. This means there is an actual pandemic, when the epidemic has spread across whole continents or even worldwide. This is the first time in 41 years that Phase 6 has been reached. The last time there was a flu pandemic was during the Hong Kong flu outbreak in 1968. Mexican flu is considered to be a much milder virus.

9. I have just been to a country were there is a flu epidemic. Is there anything I should do?

People who have just been to these countries should be on the alert even if they are not sick. The incubation period - that is to say, the time between becoming infected and actually developing symptoms of flu - is short. The virus can be transmitted to others during this period. People who have returned from epidemic regions since 17 April and have developed a fever of at least 38.5 degrees Celsius within fours days of their return are advised to stay at home and contact their GP (family doctor). Those who become ill as a result of the new virus should alert those with whom they have been in recent contact.

10. What can I do to protect myself and those around me?

In areas where the flu virus occurs, the sensible thing to do is to avoid large groups or gatherings of people in order to avoid becoming infected.
Also avoid shaking hands and kissing. After all, most people say 'best stay away from me' when they have an ordinary head cold. Basically, it's best to do the same with this new form of flu.
Be careful about hygiene: wash your hands more often than you might normally do, using soap or a disinfecting agent
Simple face masks may provide a feeling of protection, but will not ward off the flu virus in the longer term. Laboratory masks are the only ones that offer any real protection.

11. Is a flu virus 'hype' being generated by the media?

Most people who have contracted have experienced mild form of flu and get better without medication. Even in normal circumstances, around 500,000 around the world die each year as a result of having influenza. The current outbreak is exceptional only inasmuch as it involves a new strain of the flu virus. There have been many new strains of influenza in the past, too, but rarely have they resulted in a pandemic. Compared with 30 years ago, when the last major flu outbreak occurred, there is now greater medical and medicinal know how about how to treat the disease and how it spreads. However, people also travel much more than they did then. There is, therefore, enough reason for people to be cautious and careful (about things such as hygiene), but there is no reason for panic.