Avian pox in California quail from Oregon

A Review on the Prevalence of Poxvirus Disease in Free-Living and Captive Wild Birds

Avian pox is a widespread infection in birds caused by genus Avipoxvirus pathogens. It is a noteworthy, potentially lethal disease to wild and domestic hosts. It can produce two different conditions: cutaneous pox, and diphtheritic pox. Here, we carry out an exhaustive review of all cases of avian pox reported from wild birds to analyze the effect and distribution in different avian species. Avian poxvirus strains have been detected in at least 374 wild bird species, a 60% increase on a 1999 review on avian pox hosts. We also analyze epizootic cases and if this disease contributes to wild bird population declines. We frequently observe very high prevalence in wild birds in remote island groups, e.g., Hawaii, Galapagos, etc., representing a major risk for the conservation of their unique endemic avifauna. However, the difference in prevalence between islands and continents is not significant given the few available studies. Morbidity and mortality can also be very high in captive birds, due to high population densities. However, despite the importance of the disease, the current detection rate of new Avipoxvirus strains suggests that diversity is incomplete for this group, and more research is needed to clarify its real extent, particularly in wild birds.

An epornitic of avian pox in houbara bustards (Chlamydotis undulata macqueenii)

An epornitic of avian pox occurred in a flock of 123 houbara bustards (Chlamydotis undulata macqueenii) received at the Sulman Falcon Hospital in the State of Bahrain in February 1993. Birds displayed conjunctivitis, excessive lacrimation and papilloma-like growths forming amorphous clusters on the third eyelid and on the conjunctiva. Examination of eyelid samples under transmission electron microscopy revealed pox virus particles displaying the classical morphology of vaccinia-avipox virions. Typical pox lesions were also detected 5 days post infection (p.i.) on chorioallantoic membrane (CAM). The virus titre on CAM was 10(7) focus-forming units (FFU)/ml. In tissue culture, only a slight cytopathogenic effect (CPE) was detected 5 days p.i. the virus titre on cell cultures was 10(4.5)FFU/ml. The virus infection in cell culture appeared to be abortive and no CPE was seen after three passages in secondary chicken embryo fibroblasts. No neutralization of the cell-grown virus was detected on serological studies using antisera directed against fowl, pigeon, canary and sparrowpox viruses. The discussion is framed around the different cultural properties of the houbara bustard pox virus isolate and its relationship to other known viral strains.

Cutaneous tumour-like lesions due to poxvirus infection in Chilean flamingos

Cutaneous tumour-like growths were observed on the face and other areas of the body surface of young Chilean flamingos. In the cells of these lesions, avian pox-specific cytoplasmic inclusion bodies were observed by light microscopy and virus particles were detected under an electron-microscope. It was diagnosed as avian pox.