AsiaLIFE

So it did become a pandemic – and quickly. Swine flu seems to have originated in California and Mexico, though it may have been circulating for a while before it was picked up earlier this year. Influenza H1N1 is a result of mixing (reassortment) two pig, one human and a bird influenza virus.

There are several theories as to how this happened. One is that an animal (presumably a pig) became infected with these four types of influenza or at least a combination of viruses containing these strains. Another is that other swine flu variants circulating in the general population have combined to form this current strain. Regardless, as a consequence of the multiple species of origin it can infect and be transmitted among and between all three animal groups increasing the rate of distribution and transmissibility.

As a new strain there are implications for humans – we have little immunity. However, though easily transmitted, it is not particularly dangerous. Out of the 150,000 cases worldwide (at time of writing), there were only 900 confirmed deaths, though the death rate may be higher. Normal (seasonal) flu mortality rate is 0.1 percent, the Spanish flu mortality rate was 2.5 percent. SARS was about 50 percent and ‘bird flu’ higher.

The mortality rate for swine flu may be even lower than common flu. Initially it was thought that the mortality rate was about 7 percent but it’s probably less than 1 percent. However, 1 percent of say 40 million people is still a lot of people! And the deaths have been in young healthy people and those with other chronic illnesses rather than the typical very old and very young. Compare this to seasonal influenza epidemics, which result in about 3 million to 5 million cases of severe illness worldwide annually. About 250,000 to 500,000 of the people with severe illness die each year from complications of influenza.

Swine Flu in Cambodia

The first swine flu case in Cambodia was diagnosed in late June. It is currently unclear how many cases there are, although at least 14 have been confirmed – all from individuals returning from other countries. Scientists in the U.S. believe that the spread of swine flu is much more widespread that the reported number of confirmed cases – more than 1 million perhaps, so it is likely there is more H1N1 in Cambodia than we know about. Currently this particular virus is sensitive to antiviral medication both for prophylaxis and treatment. Symptoms develop one to two days after contact with a person with flu. Those infected run a fever of more than 38 Celsius for several days. Symptoms include a runny nose or sore throat or cough, body aches and pains. You won’t feel too good. The Ministry of Health and WHO have H1N1 pandemic plans. Calmette is the designated hospital for the public. Testing for both seasonal flu and H1N1 can be completed in Cambodia, with the results usually available within 24 to 48 hours.

Transmission and Prevention

Prophylaxis is recommended for contacts of confirmed cases if contact has been less than 48 hours. Treatment with antiviral medication is only effective if taken within 48 hours of the onset of symptoms. The seasonal flu vaccine does not prevent H1N1, but H1N1 vaccines have almost been developed in other parts of the world and clinical trial will begin soon. Vaccination programmes are likely to start before the end of the year. It is unclear when these will be available in Cambodia.

How to Prevent Transmission

Transmission is by droplets instead of air. Therefore you need to stand at least one metre away from someone to reduce transmission risk. It is hard to catch by just breathing the same air. Both the infected person and others in the vicinity should wear a mask. The N95 mask is the most effective, though a normal surgical mask is probably adequate. As it is easily transmitted by hand contact, it is important that those who are infected wash their hands regularly.

If you or your family contact the flu this year, stay home until you are better, so you do not transmit it to you workplace or school. If you are pregnant you need to be particularly careful to avoid H1N1 and seek treatment early.