Sunday, December 9, 2007


Hey guys, here's an interesting article I found on the genetic change of the Chikungunya Virus.

Scientists from the University of Texas Medical Branch at Galveston
(UTMB) have reported their discovery of the reason behind a
mysterious epidemic on the island of La Reunion in the Indian Ocean.
An outbreak in 2005 and 2006 resulted in the 1st deaths from a virus
called chikungunya, a mosquito borne virus that mutated and became lethal.

In all, 266 000 people were infected, and at least 260 deaths
resulted. Researchers proved the epidemic was caused by a single
mutation and the virus was carried by a mosquito not previously known
to be a carrier. The species, _Aedes albopictus_, also called the
Asian tiger mosquito, has been established in the U.S. for around 20
years and has recently started spreading to Europe.

The researchers say the mutation gives the new strain of virus an
evolutionary edge over its predecessor and was predominantly
transmitted versus the original strain. The new strain evolved when a
single amino acid chain changed, leading to the ability for the virus
to infect the new mosquito. One of the authors created the same
change in a strain collected in Africa in 1983, which then also
showed a greater ability to infect _Aedes albopictus_.
In its non-lethal form, chikungunya causes extreme arthritis-like
pain, sometimes lasting for months or years. Many tourists became
infected at La Reunion and carried that [La Reunion] strain home with
them. Although no epidemics broke out in Europe [with the La Reunion
strain], the possibility was there. Another strain of the virus
causing an ongoing epidemic in India has spread to humans in Italy
through the Asian tiger mosquito.


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