The epidemiology, molecular characterization and clinical pathology of circovirus infections in pigeons – current knowledge

Abstract

The first cases of circovirus infections in pigeons were documented less than 25 years ago. Since then, circovirus infections have been reported on nearly all continents. The specificity of pigeon breeding defies biosecurity principles, which could be the reason for the high prevalence of PiCV infections. PiCV infections in pigeons lead to atrophy of immune system organs and lymphocyte apoptosis. Infected birds could be more susceptible to infections of the respiratory and digestive tract. PiCV has been associated with the young pigeon disease syndrome (YPDS). PiCVs are characterized by high levels of genetic diversity due to frequent point mutations, recombination processes in the PiCV genome and positive selection. Genetic recombinations and positive selection play the key role in the evolution of PiCV. A protocol for culturing PiCV under laboratory conditions has not yet been developed, and traditional vaccines against the infection are not available. Recombinant capsid proteins for detecting anti-PiCV antibodies have been obtained, and these antigens can be used in the production of diagnostic tests and subunit vaccines against PiCV infections. However, YPDS has complex etiology, and it remains unknown whether immunization against PiCV alone will contribute to effective control of YPDS.

Recombinant Goose Circoviruses Circulating in Domesticated and Wild Geese in Poland

“…Subsequently, GoCV has been found infecting domesticated geese in other European and Asian countries [ 9 , 10 , 11 , 12 , 13 ] and, more recently, the virus has also been found in wild geese [ 14 ]. Based on published data, the prevalence of GoCV infections in domesticated geese (~20–56%) is similar to that noted for circovirus infections in pet/wild parrots (~20–64%) but generally lower than that for circoviruses infecting pigeons (~36–100% depending on age and health status) [ 9 , 12 , 15 , 16 , 17 , 18 ].…”

A novel group A rotavirus associated with acute illness and hepatic necrosis in pigeons (Columba livia), in Australia

“…Histologically, there was no indication of splenic or bursal depletion, where the tissue was available, although inclusion bodies typical of circovirus were seen in two birds and pigeon circovirus was reportedly present in about half the birds (n = approximately 17 birds tested) tested by PCR for that agent. Circoviral infection is widespread and common in racing pigeons [ 54 ] and it has been associated with disease susceptibility in young pigeons [ 54 – 56 ]. The inconsistent finding of circovirus infection and the wide range of ages of birds affected make the role of circovirus uncertain in our cases.…”

Immunogenicity of Pigeon Circovirus Recombinant Capsid Protein in Pigeons

“…Belonging to the genus Circovirus and the family Circoviridae , the pigeon circovirus (PiCV) [ 1 ] is thought to be one of the causative factors of the greatest health problem in global pigeon breeding: young pigeon disease syndrome (YPDS) [ 2 ]. PiCV infections are spread worldwide due to the specificity of pigeon breeding [ 3 ] like, e.g., inability to follow biosecurity procedures, especially in the case of racing birds. These birds usually take part in pigeon races or shows where hundreds or thousands of birds originating from different geographic areas have direct or indirect (watering during transport) contact with each other.…”