Swine Flu could be the next major disease epidemic. It appears to have emerged in Mexico has killed more than 100 people and infected more 1000 who have recovered. Cases and suspected cases have now been identified in the USA, New Zealand, France, Scotland, Israel, Spain, and elsewhere.
How many people have died from swine flu?
In the current outbreak of swine flu, just 20 deaths of 103 suspected fatal cases have actually been confirmed as having been caused by the new virus. That’s a lethality rate of just over 1%. Spanish Flu in 1918 had a lethality rate of 2.5%.
How many people infected?
Cases in Mexico number around 1600, according to Mexican Health Secretary Jose Angel Cordova.
Is this swine flu the same strain of flu that killed millions in 1918, the so-called Spanish flu?
No. The present strain is a type A influenza virus of class H1N1, certainly, but it is a different sub-species. Influenza viruses evolve very rapidly in response to changes in the immune systems of their hosts.
What does H1N1 mean?
The “H” refers to the viral hemagglutinin protein, and the “N” refers to the neuraminidase protein (enzyme). There are H1N2, H3N1, H3N2, and H2N3 strains of swine flu endemic in pig populations.
Whatever happened to bird flu?
Strains of avian influenza, or bird flu, are still around, these viruses exist in host species in Asia and potentially elsewhere and could still make the leap to humans at any time.
Why pigs?
Influenza viruses can exist endemically in pigs as well as birds and other species. The current strain of interest, swine flu, is endemic in pig populations in Mexico but has now spread to people.
Didn’t we have swine flu before?
Swine flu has been present for years and commonly infects people who work with pigs. An outbreak at the Fort Dix army base killed and hospitalized soldiers there and led to an ill-fated mass-vaccination campaign under President Ford. An outbreak of swine flu happened in the Philipines in 2007.
Was the new swine flu genetically engineered as a bioweapon?
It is perhaps possible to engineer a virus, but the precursors to this present strain of influenza has been seen in the wild for years and so it would seem highly unlikely that it was synthesised. Is there a lab that could synthesise a whole new viable viral species from combined segments of human, bird, and pig influenza viruses?
But how did porcine, avian, and human viruses get mixed together?
These flu viruses have a segmented genome containing eight pieces of RNA. If two strains infect a single cell their progeny undergo reassortment so that new strains emerge. Pigs are a particularly good biological mixing bowl for flu viruses, it takes just one lucky reassortment that can infect humans to then make the species leap. This has happened several times in the past.
What is WHO doing about the outbreak?
The World Health Organisation will meet in Geneva on Tuesday (April 28) to discuss whether to raise the pandemic alert level.
