Experimental infection of European wild boars and domestic pigs with pseudorabies viruses with differing virulence.
OBJECTIVE
To determine susceptibility of European wild boars (Sus scrofa) to infection with pseudorabies virus (PrV) and to characterize the virulence of a wildboar PrV isolate for wild and domestic pigs.


METHODS
18 wild boars and 16 domestic pigs.


METHODS
Three groups of 4 wild boars were inoculated with PrV Bartha, Kaplan, and a wild-boar isolate (BFW1) and housed with uninfected pigs. Two groups of domestic pigs (4 and 8 pigs/group, respectively) were inoculated with various doses of BFW1. Animals were observed daily for clinical signs, and samples were tested for PrV excretion and homologous antibodies. After reactivation of latent infection by induced immunosuppression, PrV was detected in tissues of necropsied animals, using cell culture and a polymerase chain reaction (PCR).


RESULTS
Clinical signs depended on virulence of the PrV strain and dose of inoculum. Only infection with PrV Kaplan resulted in severe disease and death. Virus was isolated from nasal and genital swab specimens. Antibodies were first detected on day 7 after inoculation; a specific humoral immune response was delayed in BFW1-infected animals. Virus was isolated from various tissues of Kaplan-infected wild boars, whereas mainly viral DNA was detected in a few tissues of Bartha- and BFW1-infected animals, using PCR after immunosuppression.


CONCLUSIONS
European wild boars are susceptible to transmission of PrV infection from domestic pigs and vice-versa. The PrV isolate BFW1 is of low virulence and seems to be adapted to the wild boar population from which it was isolated.
Müller
T F
TF
Institute for Epidemiological Diagnostics, Federal Research Centre for Virus Diseases of Animals, Wusterhausen, Germany.
Teuffert
J
J
Zellmer
R
R
Conraths
F J
FJ
D000818:Animals; D000829:Animals, Domestic / Q000821:virology*; D000835:Animals, Wild / Q000821:virology*; D000914:Antibodies, Viral / Q000032:analysis; D002478:Cells, Cultured; D004198:Disease Susceptibility / Q000662:veterinary; D004306:Dose-Response Relationship, Immunologic; D011558:Herpesvirus 1, Suid / Q000145:classification / Q000472:pathogenicity*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011557:Pseudorabies / Q000821:virology*; D013552:Swine; D013553:Swine Diseases / Q000821:virology*; D014774:Virulence
D000914:Antibodies, Viral