For the moment the symptoms are fairly mild and the same as those of seasonal flu, affecting the respiratory system (coughing and difficulty breathing) and causing high temperature, fatigue and muscle pain. Many may catch the virus without actually showing any of the symptoms.
Pregnant women, especially in the later stages of pregnancy, are particularly vulnerable and any fever with associated respiratory problems should be considered a medical emergency.
Children, the chronically ill and health workers, who are more exposed to the virus, are also more vulnerable.
The elderly are less at risk because of a similar virus that swept the world in 1948-1950.
The Chinese government has recently approved production of a vaccine made by Sinovac China. New vaccines may cause unexpected side effects and will be closely monitored. The French medicines agency (AFSSAPS) has said it will publish a website for people to report these side effects.
The WHO also recommends Tamiflu, which can be used as a preventive in case of exposure to the virus. Manufacturers Roche had a stock of 100 million courses of the drug in March in preparation of a new influenza outbreak. As of December the company plans to increase its stock by 33 million per month or 400 million per year.
The best way to avoid getting the virus is to pay attention to personal hygiene and to use common sense. Washing hands regularly with soap or with alcohol-based cleansers, using handkerchiefs for coughs and sneezes and making sure homes are well ventilated are the best means to control the spread of the virus.
For more information
Many health ministries and NGOs have published advice on their websites. These include the WHO and the European Centre for Disease Prevention and Control.
The Internet has a huge amount of information, including Google Maps which can show the location of H1N1 cases by country. Google has also launched Google Flu Trends to follow flu epidemics, including the current one.
Other diverse initiatives around Influenza A (H1N1)
- Apple has launched an iPhone application to track real-time development of global disease pandemics, including Influenza A(H1N1). Called, "Outbreak Near Me", it was developed by researchers at Children's Hospital Boston and at the Massachusetts Institute of Technology (MIT), with the support of Google.org, the philanthropic arm of the Internet giant.
- Some sites have games based on the spread of global pandemics.
- The Archbishop of Naples has forbidden the faithful from kissing a vial said to contain the blood of St Januarius in a ritual that takes place every year on September 19 in order to limit the spread of infections.
- The US department of health has organised a competition to find the most effective way of warning people about the virus. Among the seven finalists is Dr Clarke, rapping about the risks.