Bird Flu Explained

Bird Flu or more correctly, avian flu, is much in the"These H5N1 viruses might be acquiring the ability
news and causing a lot of anxiety. Many peopleto adapt to humans, increasing their pandemic risk
are worried that they may get it, and the papers... there is a suggestion there may be some
are full of horror scenarios.parallel evolution going on."
There are over 100 strains of avian flu, but mostScientists still do not understand completely how a
of them do not infect humans. The current strainbird virus becomes a human virus, but H5N1 is
H5N1 can infect humans, but not easily. Thealready showing some of the mutations
number of cases of avian flu in humans in thenecessary for it to become a human flu, but at
current outbreak is very small, and almost all havethe moment, in spite off all the panic, there is no
come about by direct contact with infected orpandemic flu strain.
dead birds something that most of us are unlikelyResearch in the Netherlands and the USA has
to experience. So far, the spread of H5N1 virusshown that while human influenza viruses are able
from person-to-person has been rare and has notto bind with receptors in the windpipe, H5N1 binds
continued beyond one person. In fact according toonly much deeper inside the lungs. This makes it
The Times (London, 23rd March 2006) only 184more difficult for the virus to infect humans,
confirmed cases have been reported worldwidebecause the virus is less likely to reach the inner
so far from this strain, with 103 deaths. Theselungs than the windpipe. The H5N1 virus is also
have been in Cambodia, China, Indonesia, Thailand,less likely to spread from human to human.
Vietnam, and most recently, several cases inCoughing and sneezing easily transmits viruses
Turkey.that have multiplied in the windpipe, but not those
What the authorities are much more concernedlocated deep in the lungs. If H5N1 manages to
about is the strain mutating into a variation thatmutate so that it can replicate in the upper
can be transmitted between human beings, ratherrespiratory tract, a pandemic becomes more
than just from bird to human. This has beenlikely. Scientists are constantly monitoring the virus
designated as influenza A/H5N1. Humans do notfor this mutation.
have any resistance to this strain, because theseSo should we be concerned? There have been
viruses do not commonly infect humans. If amany scares over the years that have not come
strain developed that could infect the humanto anything, and this could turn out to be one of
population, a pandemic would be likely with manythose too, but it is worth taking some sensible
people being infected and dying. The 1918 Spanishprecautions rather than just relying on the
flu is estimated to have killed 50 million peoplescientists to find a powerful enough solution.
worldwide. At least four of the eight genes ofHaving a strong immune system has to be the
H5N1 avian flu now contain mutations seen in thatfirst line of defence. Eating a good diet, taking
deadly strain.exercise, getting plenty of sleep, and reducing
Jeffery K. Taubenberger, a molecular pathologiststress can all lead to a stronger immune system
at the Armed Forces Institute of Pathology inthat can fight more effectively against the bugs
Rockville, USA has said:of this world and any dangerous mutations.