A long-term serological survey on Aujeszky's disease virus infections in wild boar in East Germany.

Between 1985 and 2008, a total of 102,387 wild boar sera originating from Eastern Germany covering an area of 108 589 km2 were tested for the presence of Aujeszky's disease virus (ADV)-specific antibodies. From 1985 until 1991 and from 1992 until 2008, wild boar sera were exclusively investigated using either conventional seroneutralization assays (n=39 621) or commercial gB and full antigen ELISAs (n=62,766), respectively. Spatial-temporal analysis revealed an increasing ADV seroprevalence from 0·4% to 15·9%, on average, during the 24-year observation period that went along with a continuous spread of the infection in a western direction. During 2006 and 2008, 18% of the 66 affected districts had ADV seroprevalences >30%. There was a significant correlation between ADV seroprevalence and the hunting index of population density (HIPD) of wild boar in the entire study area, although this did not hold true for some regions. Seroprevalences did not differ between sexes but were age-dependent. East Germany has been officially free of Aujeszky's disease (pseudorabies) in domestic pigs since 1985. Although a risk for domestic pigs cannot be completely ruled out, experience has shown that ADV in domestic pigs could be eliminated although the virus was present in the wild boar population. Despite increasing ADV seroprevalence in the East German wild boar population no spillover infections from wild boar to domestic pigs have been reported. To further trace ADV infections in the wild boar population in Germany, a nationwide serological monitoring programme should be implemented.

Apparent seroprevalence of Salmonella spp. in harp seals in the Greenland Sea as determined by enzyme-linked immunosorbent assay.

An indirect ELISA was developed as a possible tool for surveillance of the seroprevalence of Salmonella spp. in harp seals. This species is hunted for human consumption and thus transmission of disease to humans cannot be excluded. To cover a broad spectrum of serogroups, a mixture of the lipopolysaccharides (LPS) of S. typhimurium and S. choleraesuis was used as the antigen in this pilot study. Chicken anti-harp-seal immunoglobulin horseradish peroxidase conjugate served as the immunoconjugate. Sera from four captive harp seals, which were Salmonella culture-negative and had no clinical or historical evidence of salmonellosis, were used as negative controls. After immunization with an inactivated S. typhimurium vaccine, further sera from these seals were used as positive controls, as no serum from naturally infected animals was available. Serum samples from 93 harp seals caught in the Greenland sea in 1999 were examined, and anti-Salmonella antibodies were found in the samples from two individuals (seroprevalence 2.2%). Although Salmonella has been isolated from other pinniped species, this is the first documentation of Salmonella-seropositive harp seals. This study contributes to the evaluation of the importance of salmonellosis in arctic marine mammals and thus to the prevention of potential outbreaks of this important zoonosis.

On the move? Echinococcus multilocularis in red foxes of Saxony-Anhalt (Germany).

Echinococcus multilocularis is a cestode parasites that frequently occurs in the red fox (Vulpes vulpes), which is the main definitive host in Central Europe. The parasite may infect humans as accidental intermediate hosts and cause alveolar echinococcosis. In the German federal state of Saxony-Anhalt, the occurrence of E. multilocularis in red foxes as a possible source of infection for humans was studied from 1998 to 2010. A significant shift in the geographical centroid of the occurrence of E. multilocularis from a long-known highly endemic area in the southwest of the state towards the north-northeast (3.2 km/year) was found. The overall prevalence in the state increased significantly from 13.6% (1998-2005) to 23.4% (2006-2010). No autochthonous cases of alveolar echinococcosis have been reported to date in Saxony-Anhalt, but this might change in the near future with the spread and increasing biomass of the parasite.

Occurrence and geographical distribution of Canine Distemper Virus infection in red foxes (Vulpes vulpes) of Saxony-Anhalt, Germany.

Canine Distemper Virus (CDV) infects dogs and a variety of carnivore species. In Saxony-Anhalt, a federal state of Germany, 761 foxes were examined for CDV infection, using real-time polymerase chain reaction (PCR), in the years 2010 and 2011. A prevalence of 30.5% was found for the whole time period without significant changes in prevalence between 2010 and 2011. The relative risk (RR) of a fox to test positive for CDV varied markedly within the area of the state and was significantly increased in some regions. The latter was confirmed by a spatial cluster test that identified a significant cluster (p<0.001) with a diameter of 44 km in the west of the state. To protect hounds and domestic dogs from CDV infection, vaccination is recommended in Saxony-Anhalt.

Toxoplasma gondii in foxes and rodents from the German Federal States of Brandenburg and Saxony-Anhalt: seroprevalence and genotypes.

Data on the genotypes of Toxoplasma gondii circulating in wildlife are scarce. In the present study, foxes and rodents from two Federal States in Central or Eastern Germany were examined for T. gondii infections. Body fluids were collected at necropsy or fluids were obtained from frozen tissues of naturally exposed red foxes (Vulpes vulpes), voles (Microtus arvalis), shrews (Neomys anomalus) and a striped field mouse (Apodemus agrarius) and tested for T. gondii by serology. DNA isolated from tissues of seropositive foxes and all the rodents was examined by PCR. In the German Federal States of Brandenburg and Saxony-Anhalt 152/204 (74.5%) and 149/176 (84.7%) of foxes, respectively, but none of the rodents (0/72) had antibodies to T. gondii. Only 28/152 (18.4%) and 20/149 (13.4%) of seropositive foxes from Brandenburg and Saxony-Anhalt, respectively, but none of the rodents tested PCR-positive for T. gondii. The complete T. gondii genotype could be determined for twelve samples using nine PCR-restriction fragment length polymorphism (PCR-RFLP) markers (newSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, PK1, L358 and Apico). In addition to T. gondii clonal type II (Apico II) and type II (Apico I), type III and T. gondii genotypes showing non-canonical allele patterns were observed in foxes. This suggests that, while T. gondii type II prevails in foxes, other genotypes circulate in wildlife. The population structure of T. gondii in Germany may be more diverse than previously thought.