Veterinary session

Nowadays there are no surveys based on data about the spread of the pigeon circovirus (PiCV) infection, but the examined stocks seem like infected in 80-100%. The significance of the infection is just estimated. Despite of the mild clinical symptoms, the damage of the immune system causes indirectly the severe health destruction and even the death of the pigeons. These take part particularly by the 1 year old younger pigeons. The PiCV infection is the most important development factor of the”young pigeon desease syndrome” (YPDS). By older pigeons will be outstanding, if there are parallel other predismoning factors next to the PiCV, for example competiton, eggs-laying period, crowded keeping, inadequate loft-hygiene, parasites, active co-infection etc...

Consequently, the PiCV infection has significant impact not just on the meat- and raicing pigeon stocks' health-status but also on their performance and economic value.

The PiCV is a singlestranded DNA virus, the capsid is icosahedral, non enveloped.

The previous studies gaves evidences, that although the PiCV is a DNA virus, nevetheless it is really variable. One of the two main genes is the ORF1 (open reading frame), encodes the replication associated protein and it's significantly more conservative, than the ORF2, which encodes the only capsid protein.

So the ORF1 primarily has a role in the moleculare diagnostic, while the ORF2 gene analysis helps to follow up the variability of the virus or rather to produce effective vaccines.

The primary goal of our investigation was to examine the presence and prevalence of the PiCV in Hungary. We try to explore what kind of genetic relation of the hungarian viruspopulation has with the already known virusgenomes and are there any differences between the aminoacids of the capsids and which they are.

So after the first survey in the investigation the ORF2 gene analysis came to the front. As a result of the survey the presence of the PiCV was certified in Hungary and by right of the sequense data the viruses are classified into 5 groups. The significal sequence-differences between the capsid-proteins are established and it was found out at the first time that not just the point-mutation, but the base triplet delecions, addicions and the recombinations between the genes are liable for the variability of the PiCV capsids.