A couple tend to their child who is suspected to be infected with bird flu
© AFP/File

TOKYO (AFP) - The system has been improved from an earlier version which was shown in 2005 to have eliminated 99 percent of the H5N1 virus when airborne, Sharp official Kenji Ota told reporters.

The plasmacluster ion technology, developed in 2000, disables airborne micro-organisms by releasing positive and negative ions into the air.

Direct contact with infected poultry, or surfaces contaminated by their faeces, is currently considered the main cause of human infection with the H5N1 virus, according to the World Health Organization.

But influenza is a hard virus to beat and will need several lines of defence, said John Oxford, a University of London professor who heads Retroscreen Virology, a British research institute involved in the project.

"This kind of new technology will add something to (our) ammunition box," he told the same press conference.

Plasmacluster ions have also proved effective against 26 other kinds of harmful airborne substances, including bacteria and allergens, Sharp said.

During the tests, the H5N1 virus was sprayed in a one-cubic metre (1.3-cubic yard) box with a concentration of 50,000 ions per cubic centimetre. Samples were then taken 10 minutes later and injected into cell cultures.

The deadly H5N1 strain of bird flu has killed more than 240 people worldwide since late 2003, according to the World Health Organization.

The virus typically spreads from bird to human through direct contact, but experts fear it could mutate into a form easily transmissible between humans, with the potential to kill millions in a pandemic.

Plasmacluster technology can be installed in air conditioners, dehumidifiers and air purifiers for home and industrial use, although Sharp gave no indication of when the latest technology might be used commercially.

Sanyo Electric Co. has also developed a similar technology that proved 99 percent efficient in removing the bird flu virus using electrolysed tap water.

©AFP