Assessment of antibodies to rabbit haemorrhagic disease virus in fox serum as an indicator of infection in sympatric rabbit populations.
OBJECTIVE
To assess the value of foxes as indicators of rabbit haemorrhagic disease virus in sympatric populations of rabbits.


METHODS
Serum samples from 341 foxes in central western New South Wales were tested for exposure to rabbit haemorrhagic disease virus using antibody cELISAs. Selected samples were tested for viral antigens by ELISA, viral nucleic acids by reverse transcriptase PCR and viral infectivity by rabbit inoculation.


RESULTS
Antibodies against rabbit haemorrhagic disease virus were first detected in foxes 4 months after rabbit haemorrhagic disease was observed in rabbits in the same area. There was evidence of exposure of foxes to the virus in two subsequent years. A proportion of antibody positive, inconclusive and negative serum samples from foxes gave false positive results in an antigen ELISA for rabbit haemorrhagic disease virus. These serum samples were negative for viral nucleic acid by reverse transcriptase PCR and for infectious virus by rabbit inoculation. Liver samples from foxes were negative for viral antigens.


CONCLUSIONS
Antibodies against rabbit haemorrhagic disease virus in fox serum can serve as an index of the occurrence of rabbit haemorrhagic disease in rabbit populations. Some fox serum samples exhibit false positive reactivity in an antigen ELISA for rabbit viral haemorrhagic disease virus.
Philbey
A W
AW
Department of Veterinary Pathology, University of Glasgow, Bearsden Road, Glasgow G61 1QH, Scotland, United Kingdom. Adrian.Philbey@vet.gla.ac.uk
Kirkland
P D
PD
Saunders
G R
GR
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis* / Q000097:blood; D017250:Caliciviridae Infections / Q000453:epidemiology / Q000517:prevention & control / Q000662:veterinary*; D004279:DNA, Viral / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005589:Foxes; D017929:Hemorrhagic Disease Virus, Rabbit / Q000235:genetics / Q000276:immunology*; D009517:New South Wales / Q000453:epidemiology; D015995:Prevalence; D011817:Rabbits / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary
D000914:Antibodies, Viral; D004279:DNA, Viral