Tuesday, 5 May 2009
Unless you've been living in a cave, or a sterile, sound proof bubble for the past few weeks, you've undoubtedly been subjected to the overwhelming hype and terror being propagated through the media about swine flu. While I'm sure most people are sick to death of reading about this, I still feel I should write this, providing a little scientific background and discussing once and for all how much we should REALLY be worried.
What is swine flu?
Swine flu is a respiratory disease, a reassortment of four different strains of influenza type A which infects pigs, subtype H1N1. This nomenclature refers to the structure of cell markers called antigens (hemagglutinin and neuraminidase) present on the protein coat of the virus, which confers specific cell interaction attributes on that particular strain, as well as requiring different treatment.
There are many types, and the infection is constantly changing. Until now it has not normally infected humans, but the latest form clearly does, and can be spread from person to person - probably through coughing and sneezing.
How does the infection spread?
Influenza mainly spreads from person to person through close contact. Coughing and sneezing within a metre or so of another person can expose them to infectious droplets.
Hands can become contaminated through touching someone who is unwell, or through touching door handles or other hard surfaces contaminated with the virus. If you then touch your mouth before washing your hands you can catch the infection.
How worried should we be?
When it comes to potential pandemics, there are two main features we should discuss regarding the virus in question, infectiousness and deadliness.
What really worried the WHO with this outbreak was how far the virus managed to travel in such a short time, but there are a few things to bear in mind here. For starters, any decent epidemiologist will caution that the number of cases reported in the early days of an outbreak can be very inaccurate and deceptive. This can be due to several causes, including selection bias, media bias, and incorrect reporting by governments.
One must also bear in mind that, biologically speaking, virus that can travel far is by definition not very deadly, as it allows the infected to live long enough to carry the virus across the planet. It is therefore not much of a shock to see very few deaths have been attributed to this virus, aside from Mexico. Why might this be? Well it could simply be attributable to that phenomenon I mentioned earlier, that the virus that transmits far, into other countries, is less deadly, or it could be related to a poorer quality of healthcare in Mexico.
In short, there's not much cause to be fretting too much just yet, and especially if you live in the developed world, like USA or UK, where antiviral stocks are plentiful.
