The study was performed to determine the effects of physical and chemical agents on infective potential of highly pathogenic avian influenza (HPAI) H5N1 (local strain) virus recently isolated in Pakistan during 2006 outbreak.

H5N1 virus having titre 108.3 ELD50 /ml was mixed with sterilized peptone water to get final dilution of 4HA units and then exposed to physical (temperature, pH and ultraviolet light) and chemical (formalin, phenol crystals, iodine crystals, CID 20, Virkon-S, zeptin 10%, Kepcide 300, Kepcide 400, Lifebuoy, Surf Excel and caustic soda) agents.

Harvested amnio-allantoic fluid (AAF) from embryonated chicken eggs inoculated with H5N1 treated virus (0.2 ml/egg) was subjected to haemagglutination (HA) and haemagglutination inhibition (HI) tests.

H5N1 virus lost infectivity after 30 minutes at 56°C, after 1 day at 28°C but remained viable for more than 100 days at 4°C.

Acidic (pH 1 and 3) and basic (pH 11 and 13) conditions were virucidal after six hours contact time. However, the virus retained infectivity at pH 5 (for 18 hours), and pH 7 and 9 (for more than 24 hours).

UV light was proved ineffectual in inactivating virus completely even after 60 minutes.

Soap (Lifebuoy), detergent (Surf Excel) and alkali (caustic soda) destroyed infectivity after 5 minutes at 0.1, 0.2 and 0.3 per cent dilution.

All commercially available disinfectants inactivated virus at recommended concentrations.

The authors suggest that their results would be helpful in implementing biosecurity measures on farms and hatcheries levels in the wake of possible future AI outbreaks.

Reference

Shahid M.A., M. Abubakar, S. Hameed and Shamsul Hassa, 2009. Avian influenza virus (H5N1): effects of physico-chemical factors on its survival. Virology Journal 2009, 6:38doi:10.1186/1743-422X-6-38

Further Reading

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You can view the provisional report by clicking here.

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You can visit the Avian Flu page by clicking here.