Home > Plasmid: Science and bio-tech research blog > Archives > 2006 > June > 02 > Entry
Dangerous mutation to Bird Flu developing?
The British scientific journal Nature reports that a variant of the H5N1 bird flu has developed a mutation that may allow the virus to survive at lower temperatures, such as those in the human body’s nasal region.
Why does that matter? Because it may mean H5N1 is becoming somewhat easier for humans to catch.
Most of the bird flu that’s been studied so far multiplies in the deepest part of the lungs. That’s probably the main reason that since 1997, it has only infected 227 people worldwide (that we know of) and caused just 127 deaths.
But the recent outbreak in Indonesia requires a closer look.
On the northern part of the island of Sumatra, World Health Organization officials have put 54 people under home quarantine, and are giving them the antiviral drug Tamiflu.
A medical worker checks the health condition of Johannes Ginting, 25, a surviving member of an Indonesian family infected with bird flu, on Monday, May 29, 2006. The case has drawn much attention because the infections have not been linked to contact with birds. (AP Photo/Binsar Bakkara)
That’s because the people are relatives of eight family members in a village called Kubu Simbelang who have died from H5N1. (One case was never confirmed.) Most of those family members lived in houses next door to each other.
According to Nature’s Declan Butler: “What caused the suspected human-to-human transmission at Kubu Sembelang is still a mystery. Nature has learned that the cases differed from past Indonesia cases, in that they had much higher viral loads in the throat and nose.”
Let’s look for a moment at the makeup of the flu virus: It looks like a burr, a hollow ball of spikes, with eight genes in the middle. Once injected into a host cell, those genes take over so that eight proteins are made, and assembled into more viruses. Each of those viral proteins is made of hundreds, sometimes thousands, of amino acids.
According to Butler, an H5N1 sub-type found in Turkey has a substitution of a single amino acid in the flu’s polymerase protein.
“This mutation is thought to allow the virus to survive in the cooler nasal regions,” Butler writes.
In August 2005, he adds, that mutation also appeared in a sub-type that was found in Indonesia.
So that begs the question: Is that mutation the reason that the bird flu appears to have hopped from person to person in that family?
It would be helpful to know, but the World Health Organization isn’t saying.
“We will leave that to the government of Indonesia, the owner of the data,” Steven Bjorge, a WHO official based in Indonesia, told Nature.
What WHO is saying is the following:
“As of (May 31) no new cases suggestive of H5N1 infection have been detected since 22 May. This finding is important as it indicates that the virus has not spread beyond the members of this single extended family. No hospital staff involved in the care of patients, in some instances without adequate personal protective equipment, have developed the disease. The last person in the cluster, who developed symptoms on 15 May and died on 22 May, refused hospitalization. He moved between two villages while ill, accompanied by his wife. The wife is under surveillance and has not developed symptoms.
Despite multiple opportunities for the virus to spread to other family members, health care workers or into the general community, it has not, on present evidence, done so.”
If you want to stay aware of the bird flu situation, keep visiting www.who.int/ but also consider subscribing to Nature. It’s quickly becoming indispensable reading.
So what do you think? Will you trust the Indonesian government to tell us if they have a sub-type of bird flu that could be developing pandemic potential?
Comments
By Glad to be out of WPB
June 5, 2006 4:09 PM | Link to this
Probably not, it will probably be a wide spread disease killing millions of people in a short amount of time. One of the many plagues that will almost wipe out all life. It is inevitable…