Scientific body touts bird flu cure
influenza virus have been shown to be effective, in laboratory
tests, against a sample of an H5N1 influenza virus currently
infecting chickens in Asia.
The findings may give hope to poultry producers in Asia who are currently fighting a battle to control the spread of the disease. Latest reports suggest that now pet cats are thought to be spreading the disease in Thailand - an alarming development that now makes the hunt for a solution to the problem all the more pressing.
CSIRO Health Sciences and Nutrition scientist Dr Jenny McKimm-Breschkin has tested the ability of the flu drug Relenza to inhibit the virus, known as H5N1 strain, which has killed millions of chickens in Asia and has been responsible for 22 human deaths so far this year.
The tests, used to monitor virus sensitivity to drugs, have shown that the drug is as effective, in laboratory experiments, against this bird flu as it is against other strains of flu that affect humans.
"There is a direct correlation between enzyme sensitivity as measured by these laboratory tests and the ability of the drug to prevent the virus from multiplying," said Dr McKimm-Breschkin.
In 1999, the world's first drug effective against all strains of influenza was released onto the world market. Relenza was designed based on CSIRO's discovery that there was a small section on the surface of the influenza virus that does not change between strains of flu. Designing a drug to inhibit the action of this part of the virus meant it would be very difficult for the virus to mutate to avoid binding the drug. No drug resistance has been seen globally in any previously healthy patient treated with Relenza, claims CSIRO, which also receives royalties from the sale of the drug.
Subsequently a second drug, Tamiflu, was developed based on CSIRO research. Its manufacturers claim that pre-clinical trials provide reassurance that it could be effective against bird flu.
The Asian bird flu has not been shown to be passed from human to human. All those who have died from this disease have caught it directly from infected birds. The current strategy for preventing this virus from spreading further and endangering more humans has been to cull tens of millions of chickens in Asian farms and markets.
"In the event that the disease does mutate into a form which can be passed from human to human it is important to know that we already have a treatment available," said Dr McKimm-Breschkin. "The fact that our experiments show that in the laboratory this Australian designed drug is effective against bird flu again shows just how important a discovery this was."
In order to establish that Relenza is effective in humans infected with bird flu, clinical data from humans will be needed, CSIRO says.