Endemic caseous lymphadenitis in a wild Caprinae population.

Between 2010 and 2013, an outbreak of caseous lymphadenitis (CLA) occurred in a captive stock of Iberian ibexes (Capra pyrenaica, Schinz 1838) maintained for conservation purposes in the National Game Reserve 'Ports de Tortosa i Beseit' (PTB), northeastern Spain. The aim of this study was to assess the CLA status in the free-ranging donor population of ibexes. An ELISA test to detect antibodies to CLA was performed in 360 hunter-harvested ibexes between 2007 and 2013. A spatial analysis and recursive partitioning approaches with regression tree models were used to explore CLA-associated risk factors. Nineteen per cent of ibexes had antibodies to CLA. Significant differences in seroprevalence were observed among game management areas but no clear trends of CLA occurrence were observed over the study period. Ibexes from areas of higher population density and living close to aggregation points displayed a higher probability of testing positive to CLA. These results suggest that CLA is endemic in the Iberian ibex population inhabiting PTB and density-dependent risk factors. To the best of our knowledge, this is the first record of CLA maintenance in a free-ranging wild Caprinae population.

Post-Natal Persistent Infection With Classical Swine Fever Virus in Wild Boar: A Strategy for Viral Maintenance?

In this study, fifteen wild boar piglets were intranasally inoculated <10 h after birth with the moderately virulent classical swine fever virus (CSFV) strain Catalonia 01. At 5 days post-inoculation, seven other animals within 48 h of birth were put in contact with them. Viral replication and innate and specific immune responses were evaluated. Of the inoculated animals, 46.67% remained post-natally persistently infected and were apparently healthy with neither humoral nor cellular immunological responses specific to CSFV and with high viral loads in their blood, organs and body secretions. Moreover, the present data extend the time period to 48 h after birth when a moderately virulent CSFV strain could lead to post-natal persistent infection given the generation of persistently infected wild boars in the contact group (33.33%). The innate immune response to the virus, as measured by type I IFN-α in serum, was mostly not impaired in the persistently infected wild boars. Interestingly, a decrease and lack of IFN-γ-producing cells against CSFV and PHA was observed. In endemic countries where wild swine species are increasing and low and moderate virulence CSFV strains are prevalent, the possible generation of this form of disease cannot be ruled out.

The European hare (Lepus europaeus) as a potential wild reservoir for ruminant pestiviruses.

Ruminant pestiviruses cause important economic losses in livestock and the epidemiological role of free-ranging sympatric wildlife is of special interest for the implementation of pestivirus eradication plans. Moreover, the emergence of high mortality outbreaks of pestivirus in Pyrenean chamois (Rupicapra pyrenaica pyrenaica) since 2001 in the border between Spain and France has increased the value of knowing the hosts that role pestivirus infection. In the present study, pestivirus infection was assessed in 94 sera from wild hunted European hares (Lepus europaeus) collected in two different areas: Pyrenees (alpine and subalpine ecosystems) versus Non Pyrenees (non alpine and subalpine ecosystems). The presence of antibodies against Border Disease Virus (BDV) and Bovine Viral Diarrhea Virus (BVDV) was evaluated by means of the Virus Neutralization Test and the presence of viral RNA in sera samples was assessed by Reverse transcription-polymerase chain reaction (RT-PCR). A total of 34 out of 94 (36.2%; CI95 0.26-0.46) sera presented neutralizing antibodies against ruminant pestiviruses, and significant differences between BDV4 and BVDV1 titres were found in 7 hares. In the Pyrenean area not statistically significant seroprevalence was observed when comparing with the Non Pyrenean area. RT-PCR analysis of sera samples resulted all negative. The results of the present study indicate that the European hare is susceptible to pestivirus infection and that could be involved in the epidemiology of ruminant pestiviruses. To the authors' knowledge, this is the third wild non-artiodactyl with reported antibodies against ruminant pestivirus after the rabbit and Bennet's wallaby.

Pestivirus in alpine wild ruminants and sympatric livestock from the Cantabrian Mountains, Spain.

Bovine viral diarrhoea virus (BVDV) and Border disease virus (BDV) were investigated at the wildlife-livestock interface in the distribution area of chamois in the Cantabrian Mountains, North-Western Spain. From 2010 to 2014, sera from sympatric wild (n=167) and domestic (n=272) ruminants were analysed for pestivirus antibodies by cELISA, virus neutralisation test (VNT) and for the presence of pestiviral RNA using a reverse transcription (RT)-PCR. Results showed a higher seroprevalence in cattle (59.4 per cent, 13/13 of herds) than in domestic small ruminants (5.9 per cent sheep, 2/8 of flocks; 0 per cent goats of 4 flocks) and wildlife (10.8 per cent in red deer, 0 per cent in roe deer and 0 per cent in Cantabrian chamois). High VNT titres were detected in two cattle herds, suggesting the circulation of BVDV-1 and BVDV-2 strains. BVDV-1 RNA was detected in one cattle calf by RT-PCR and sequencing. Conversely to other similar grazing systems, sheep flocks did not play a relevant role in the pestivirus epidemiology in this region. Pestivirus infections in wild ruminants were sporadic and most probably dependent on a domestic source.