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 Hospit al in the State of Bahrain in February 1993. Birds displayed conjuncti vitis, excessive lacrimation and papilloma-like growths forming amorph ous clusters on the third eyelid and on the conjunctiva. Examination o f eyelid samp under transmission electron microscopy revealed pox viru s particles displaying the classical morphology of vaccinia-avipox vir ions. 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 cytop athogenic effect (CPE) was detected 5 days p.i. The virus titre on cel l cultures was 10(4.5) FFU/ml. The virus infection in cell culture app eared to be abortive and no CPE was seen after three passages in secon dary chicken embryo fibroblasts. No neutralization of the cell-grown v irus was detected on serological studies using antisera directed again st fowl, pigeon, canary and sparrowpox viruses. The discussion is fram ed around the different cultural properties of the houbara bustard pox virus isolate and its relationship to other known viral strains.