A serological survey on classical swine fever (CSF), Aujeszky's disease (AD) and porcine reproductive and respiratory syndrome (PRRS) virus infections in French wild boars from 1991 to 1998

In early 1992, a CSF epizootic was clinically recognised in a wild boar pop ulation of approximately 1300 animals within an area of 250 km(2) located i n the east of France. In order to check the CSF situation in wild boars out side this area, a serological survey was carried out in the rest of France, for 8 consecutive years (1991-1998). This paper reports on the results obt ained during this survey which included wild boars shot during the hunting period but also boars reared within fences. Around 1000-2700 sera a year we re tested for the presence of antibodies to classical swine fever virus (CS FV) and also to Aujeszky's disease virus (ADV). Out of 12 025 sera tested o ver the whole period, 80 wild boars were found positive for CSF antibodies. Sixty of them were collected on wild boars shot during the years 1992-1994 in the epizootic area located in east of France and 10 were collected in C orsica during the years 1994-1996. The last four positive samples were sing le reactors coming from areas or farms, which were thereafter confirmed to be serologically negative. These results together with the fact that no dis ease has been reported so far illustrate that the French wild boar populati on is probably not concerned by CSF infection (excepted in the east of Fran ce where the disease has now become enzootic). Two hundred and forty nine s era were initially detected as CSF positive but confirmed secondarily as po sitive for border disease (BD) antibodies. This finding shows that wild boa rs are also susceptible to infection by ruminant pestiviruses. Four hundred and twenty three wild boars have been found positive for ADV antibodies. I n addition, from 1993 to 1995, 909 samples were tested for the presence of antibodies to porcine reproductive and respiratory syndrome virus (PRRSV). Thirty three of them were positive. The results on AD and PRRS antibody det ection show that wild boars may constitute a reservoir for various infectio us diseases of pigs. (C) 2000 Elsevier Science B.V. All rights reserved.