July 23, 2007

Italian study finds turkeys and chickens react differently to bird flu

While Turkeys may produce antibodies to fight against bird flu infection, chickens are defenceless against the virus, an Italian study has found.

In experimentally infected turkeys, antibodies were produced against the bird flu's nonstructural 1 protein (NS1), Biotech Business Week reported.

Bird flu prevention authorities are working on a way to differentiate bird flu strains in infected birds and those in vaccinated birds called "differentiation of infected from vaccinated animals" (DIVA). 

A promising system, based on the detection of antibodies to the nonstructural 1 (NS1) protein of AI, has been worked out. However, there are presently no data available on antibody production against the NS1 proteins.

The study, by W.G. Dundon and colleagues from the FAO and National Reference Laboratory for Newcastle Disease and Avian Influenza (Istituto Zooprofilattico Sperimentale delle Venezie, Italy) aimed to track the appearance of anti-NS1 antibodies in a native poultry population.

In turkeys, antibodies to a peptide in the NS1 protein were detected starting between day 3 and day 5 postinfection.

However, no antibodies to the NS1 peptide could be detected in chickens over the test period.

Both turkeys and chickens reacted differently to the infection by the H9N2 challenge virus. The findings indicate that there is a significant difference in the viral replication in turkeys and chickens, resulting in a variation in the production of antibodies to NS1.

Dundon and colleagues published their study in Avian Diseases (Appearance of serum antibodies against the avian influenza nonstructural 1 protein in experimentally infected chickens and turkeys. Avian Diseases, 2007;51(1 Suppl):209-12).