Hong Kong - Hong Kong researchers are claiming a breakthrough in bird flu treatment with a cocktail of drugs they say may be effective in treating the deadly virus in humans. The findings, published Wednesday in a US science journal, claim the cocktail increased survival rates by fourfold when tested on mice infected with H5N1.
The cocktail includes an antiviral called zanamivir, or Relenza, and two anti-inflammatory agents celecoxib and mesalazine.
The researchers claim the antiviral agent successfully suppressed the virus while the other two drugs reduced the effects of the so-called "cytokine storm" -the severe immune response triggered by the virus that can kill H5N1 patients.
Professor Yuen Kwok-yung, head of microbiology at the university who led the research, said it was the first breakthrough in 10 years and the first time a treatment had worked on mice when treatment was delayed for more than 48 hours.
"Tamiflu has been used on many patients but the mortality rate is still high at 50 to 80 per cent. This study suggests a new cocktail treatment is effective in mice," he said.
"Hong Kong does not have any [bird flu] patients so we can't test it on humans, but experts elsewhere can consider using it in a human trial."
In an account in this month's issue of the Proceedings of the National Academy of Sciences, Professor Yuen and colleague Zheng Bojian, detail how the team injected 1,000 lethal doses of the H5N1 virus into each mouse.
The dose normally kills 50 per cent within 14 days.
More than 48 hours later some of the mice were given the cocktail of drugs while some were just given the antiviral treatment and others left untreated.
The infected mice that were given the cocktail showed a survival rate of 53.3 per cent and a survival time of 13.3 days.
This compared to a 13.3 per cent survival rate and a 8.4 days survival time for those treated with zanamivir alone and zero per cent and 6.6 days for those given no treatment.
Those treated with the cocktail also experienced less damage to the lungs and suffered less general inflammation, said the researchers.
Professor Yuen said all three drugs were readily available and had very few side effects if taken for only 14 days.
The cocktail, if tested successfully on humans, would be an alternative to Tamiflu, the antiviral agent recommended by World Health Organisation.
The H5N1 strain of bird flu first jumped the species barrier to humans in 1997 in Hong Kong, infecting 18 people, of whom six died.
Since 2003, it has infected 383 and killed 241, most of them in Asia.
