Kai Frölich

Epizootiological investigations of canine distemper virus in free-ranging carnivores from Germany

Canine distemper virus (CDV) infects a broad range of carnivores. To assess whether wild carnivores may play a role in the epidemiology of CDV in domestic dogs in Germany, the seroprevalence of CDV was determined. In sera from red foxes (30 of 591 (5%)) and stone martens (2 of 10 (20%)) antiviral antibodies were detected using a neutralization assay, whereas sera of raccoons, two mink, one pine marten and one raccoon dog were negative. In foxes, there was a significantly higher prevalence in urban and suburban compared to rural regions. When testing lung and spleen tissue samples (fox, badger, stone marten, polecat, raccoon dog) 13 of 253 (5.1%) foxes, 2 of 13 (15.4%) stone martens and 2 of 6 (33%) badgers were virus positive using RT-PCR. Phylogenetic analysis based on partial sequences of the F gene revealed a distinct relatedness to canine CDV isolates. Together, the data support the concept of transmission of CDV between domestic dogs and wild carnivores.

Bovine Virus Diarrhea and Mucosal Disease in Free-ranging and aptive Deer (Cervidae) in Germany

From 1990 until 1992, 355 bloodsamples of roe deer (Capreolus capreolus) (n =123), red deer (Cervus elaphus) (n = 60), fallow eer (Darna dama) (n= 87) and other cervid pecies (n = 85) from three different habitats (n = 180) and 11 wildlife parks or zoos (n = 75) in Germany were tested for prevalence of estivirus antibodies. Seventeen samples were seropositive for bovine viral diarrhea virus (BVDV); only one animal had antibodies for Border disease virus. Microneutralization test titers ranged from 1:5 to 1:125. We found no significant difference in antibody prevalence among deer in habitats with high, intermediate and low density of cattle. There were significantly more seropositive individuals in roe deer compared to fallow deer. Significantly more seropositive individuals were found among juvenile animals than among adults. Antibody prevalence in free-ranging cervids was significantly higher compared with that of deer in enclosures. Antibody prevalence in summer was significantly higher than in winter.

SEROSURVEY FOR SELECTED INFECTIOUS DISEASE AGENTS IN FREE-RANGING BLACK AND WHITE RHINOCEROS IN AFRICA

Two hundred and eighty one serum samples collected from free-ranging black (Diceros bicornis) and white (Ceratotherium simum) rhinoceros, in the Republic of South Africa (RSA), Namibia, and Kenya from 1987–97, were examined for antibody to 16 different infectious agents. Positive antibody titers were detected against Akabane (59.8%), bluetongue (55%), African horse sickness (27.9%), epizootic haemorrhagic disease of deer (19.4%), parainfluenza type 3 (25.3%), bovine herpes virus 1 (3.1%), equine herpes virus 1 (8.8%) and bovine viral diarrhea (1.2%) viruses, and four serovars of Leptospira interrogans, (ranging 1.2 to 8.8%). No antibody was detected against Rift Valley fever virus, encephalomyocarditis virus, Brucella abortus, and Trypanosoma equiperdum. Interspecies differences were detected for African horse sickness, epizootic haemorrhagic disease of deer and parainfluenza type 3 viruses. There appeared to be some geographic variation in the prevalence of antibody for African horse sickness, bluetongue, epizootic haemorrhagic disease of deer, parainfluenza type 3, equine herpes virus 1 and Leptospira interrogans serovar bratislava.

CHARACTERIZATION OF A BOVINE VIRAL DIARRHEA VIRUS ISOLATED FROM ROE DEER IN GERMANY

The 5′ untranslated region (5′ UTR) of cytopathogenic pestiviruses isolated from two seronegative roe deer (Capreolus capreolus) in northern Germany was partially sequenced and compared with those of 28 other pestiviruses. Due to the occurrence within a narrow location and the complete identity of the sequenced fragments from both roe deer isolates (SH9 and SH11) they seem to belong to the same bovine virus diarrhea virus (BVDV) strain called SH9/11. This strain is highly homologous (up to 93% identity) to “classical” BVDV strains. However, SH9/11 has characteristic variations in its 5′ UTR distinct from all other pestiviruses analyzed in this study. Strain SH9/11 is more similar to BVDV group I than to group II, although it is clearly separated from all other cattle isolates tested. In monoclonal antibody (mAb)-typing studies, isolate SH9 reacted with one pestivirus-specific mAb (C16), with two BVDV specific mAbs (N2B12 and D5), and with one mAb (f48) raised against the E2 protein of classical swine fever virus out of a panel of 13 mAbs. The separate position of strain SH9/11 again was demonstrated by the unique reaction pattern of isolate SH9 when compared with other mAb f48-positive BVDV and BDV strains. All these results indicate that distinct BVDV strains might exist among freeranging roe deer in Germany.

Antibodies against equine herpesviruses and equine arteritis virus in Burchell's zebras (Equus burchelli ) from the Serengeti ecosystem.

A total of 51 sera from a migratory population of Burchells zebras (Equus burchelli) were collected in the Serengeti National Park (Tanzania) between 1999 and 2001 to assess levels of exposure to equine herpesvirus types 1, 2, 4, 9 (EHV-1, −2, −4, −9), EHV-1 zebra isolate T965, and equine arteritis virus (EAV). Using virus-specific neutralizing antibody tests, seroprevalence was high for EHV-9 (60% of 45), moderate for EAV (24% of 51), and lower for the EHV-1-related zebra isolate (17% of 41), EHV-1 (14% of 49), and EHV-4 (2% of 50). No evidence for exposure to EHV-2 was found (0% of 51). The high level of exposure to EHV-9 is interesting because evidence of infection with this virus has not been previously described in any wild equine population. Although the epidemiology of EHV-9 in Burchells zebras is presently unknown, our results suggest that in East Africa, this species may be a natural host of EHV-9, a neuropathogenic virus that was only recently isolated from captive Thomsons gazelles (Gazella thomsoni) in Japan. There is currently no evidence that EHV-9 induced mortality in Burchells zebras in the Serengeti, but because of the reported virulence of this virus for more susceptible species such as Thomsons gazelles, viral transmission from infected zebras to ungulates may result in mortality.

Detection of a Newly Described Pestivirus of Pyrenean Chamois (Rupicapra pyrenaica pyrenaica) in France

A pestivirus was detected and characterized in chamois (Rupicapra pyrenaica pyrenaica) originating from the French part of the Pyrenees. Phylogenetic analysis of the pestivirus was done on the basis of a fragment from the 5′ noncoding region including 22 published nucleotide sequences of different pestivirus strains. Our strain was grouped within the clade of border disease viruses (BDV). However, it had an intermediate position between clade BDV and classical swine fever viruses representing a basal position to BDV strains of domestic sheep. Our strain was grouped as a sister unit to a novel pestivirus (Chamois-1) recently described from chamois in Spain. Therefore, we postulate that this virus occurs in the entire population of Pyrenean chamois. On the basis of the phylogenetic grouping of this isolate, a postulated cross-species transmission of pestivirus from domestic sheep to chamois via shared pastures seems to be unlikely

EUROPEAN BROWN HARE SYNDROME IN FREE-RANGING HARES IN POLAND

A study of European brown hare syndrome (EBHS) was conducted in Poland (Czempin). From April 1993 until February 1994, 100 blood and 78 spleen samples of European brown hares (Lepus europaeus) were tested for prevalence of EBHS and rabbit hemorrhagic disease (RHDV) antibodies and EBHS virus antigen with two enzyme-linked immunosorbent assay (ELI-SA) test kits. Thirty-eight of 100 serum samples were positive for EBHS, and six (7.6%) of 78 of the spleen materials were-antigen positive for EBHS virus. Three (3%) of the sera were positive against RHDV, whereas two of these also were seropositive for EBHSV. European brown hare syndrome virus seropositive hares were most frequently found from April to September. Based on negative staining electron microscopy investigations of liver and spleen homogenates of all antigen-positive hares, we observed caliciviruses in only one animal. For histopathological investigations organ specimens were available from 98 hares. Histopathological findings corresponded with the clinical picture of chronic EBHS. A pathohistological picture consistent with EBHS was found in 22 (22%) of investigated hares and corresponded in 50% of the animals which reacted positively in the EBHSV antigen-ELISA and in 29% of the animals which reacted positively in the EBHSV antibody-ELISA. These results from western Poland are the first that caliciviruses are present in European brown hare population in Eastern Europe and may be one of the causes for increased mortality in the Polish hare population over the past 10 years.

SEROSURVEY FOR ANTIBODIES TO MALIGNANT CATARRHAL FEVER-ASSOCIATED VIRUSES IN FREE-LIVING AND CAPTIVE CERVIDS IN GERMANY

A total of 486 serum samples collected from several species of both free-living and captive cervids in Germany was examined for antibodies against malignant catarrhal fever (MCF)-associated viruses (MCFV) by a competitive-inhibition enzyme-linked immunosorbent assay (CI-ELISA). Eleven (2%) of these samples were positive for antibodies against MCFV. Among 157 serum samples collected from 16 different species of captive deer including four (7%) of 54 fallow deer and one (7%) of 14 sika deer (Cervus nippon) were seropositive. Among 329 samples from three species of free-ranging deer, including 253 roe deer (Capreolus capreolus), 22 red deer (Cervus elaphus) and 54 fallow deer (Cervus dama), only fallow deer were antibody-positive. Of the 25 fallow deer samples collected between 1990 and 1993, four (16%) were seropositive. Among 29 free-ranging fallow deer samples collected in the hunting period 1996–1997, antibodies to MCFV were detected in two (7%) of these sera. All of these fallow deer samples were collected from a circumscribed area in northern Germany. In the same area a high seroprevalence (72%) to MCFV was observed in domestic sheep (n = 50). Among 20 sheep samples (buffy coat) and 15 fallow deer samples (spleen or lymph nodes) examined for ovine herpesvirus 2 (OvHV-2) by PCR, all 20 sheep samples examined were OvHV-2 positive, but all of the 15 fallow deer samples, including seven seropositive deer, were OvHV-2 negative.

NEWCASTLE DISEASE VIRUS AND CHLAMYDIA PSITTACI IN FREE-LIVING RAPTORS FROM EASTERN GERMANY

Organ samples from free-living raptors from the federal states of Berlin and Brandenburg in eastern Germany were tested for Newcastle disease virus (NDV; n=331) and Chlamydia psittaci (n=39) by polymerase chain reaction (PCR). In 18 individuals NDV nucleic acids were detected. These samples originated from barn owls (Tyto alba; n=15, 28%), tawny owl (Strix aluco; n=1, 5%), common buzzard (Buteo buteo, n=1, 1%), and European kestrel (Falco tinnunculus; n=1, 4%). In 29 (74%) of 39 samples C. psittaci was detected. Chlamydia psittaci is common in free-living birds of prey in the investigated area.

Surveillance for Prion Disease in Cervids, Germany

An active survey on transmissible spongiform encephalopathies was performed from 2002 to 2005 on 4,255 roe deer, 1,445 red deer, and 1,604 fallow deer in Germany. All cervids tested negative. This survey has been the largest in European wildlife and provides no evidence of prion diseases in free-living German cervids.