Serosurveillance of Schmallenberg virus in wild ruminants in Spain

Abstract

Schmallenberg disease (SBD) is an emerging vector-borne disease that affects domestic and wild ruminants. A long-term serosurvey was conducted to assess exposure to Schmallenberg virus (SBV) in all the wild ruminant species present in mainland Spain. Between 2010 and 2016, sera from 1,216 animals were tested for antibodies against SBV using a commercial blocking ELISA. The overall prevalence of antibodies was 27.1% (95%CI: 24.7-29.7). Statistically significant differences among species were observed, with significantly higher seropositivity found in fallow deer (Dama dama) (45.6%; 99/217), red deer (Cervus elaphus) (31.6%; 97/307) and mouflon (Ovis aries musimon) (28.0%; 33/118) compared to Barbary sheep (Ammotragus lervia) (22.2%; 8/36), Iberian wild goat (Capra pyrenaica) (19.9%; 49/246), roe deer (Capreolus capreolus) (17.5%; 34/194) and Southern chamois (Rupicapra pyrenaica) (10.2%; 10/98). Seropositive animals were detected in 81.4% (57/70; 95%CI: 70.8-88.8) of the sampled populations. SBV seroprevalence ranged from 18.8% (48/256) in bioregion (BR)2 (north-central, Mediterranean) to 32.3% (31/96) in BR1 (northeastern orAtlantic, Eurosiberian). Anti-SBV antibodies were not found before 2012, when the first outbreak of SBD was reported in Spain. In contrast, seropositivity was detected uninterruptedly during the period 2012-2016 and anti-SBV antibodies were found in yearling animals in each of these years. Our results provide evidence of widespread endemic circulation of SBV among wild ruminant populations in mainland Spain in recent years. Surveillance in these species could be a useful tool for monitoring SBV in Europe, particularly in areas where wild ruminants share habitats with livestock.

Survey of Culicoides ‐borne bluetongue and Schmallenberg viruses at the wildlife‐livestock interface in Doñana National Park (Spain)

“…The ability of wild ruminants to maintain an independent sylvatic cycle in the absence of susceptible livestock should be further investigated taking a long‐term surveillance approach (Barroso et al., 2021). Higher SBV seropositivity in fallow deer than in other wild ruminant species has also been observed in different epidemiological scenarios in several European countries, including Spain (García‐Bocanegra et al., 2017; Jiménez‐Ruiz et al., 2021; Malmsten et al., 2017; Southwell et al., 2020). The prevalence of SBV antibodies was lowest in wild boar (2.0%), which is consistent with the 2.8% (3/109) found in the same species in southern Spain and 1.0% detected in Poland (García‐Bocanegra et al., 2017; Kęsik‐Maliszewska et al., 2017), although higher seroprevalence (15.3%; 224/1462) has been detected in Germany (Mouchantat et al., 2015).…”

“…The sensitivity and specificity values provided by the manufacturer are 99.4% and 100% for BTV, and 99.5% and 99.0% for SBV. Both tests have previously been used in different wild ungulate species (e.g., Falconi et al., 2012; García‐Bocanegra et al., 2011; Jiménez‐Ruiz et al., 2016, 2021). Since all cattle had previously been vaccinated with both inactivated BTV‐1 and BTV‐4 (Ministerio de Agricultura, Pesca y Alimentación, 2021), and due to the limited role of wild boar in the epidemiology of BTV (OIE, 2021), these species were not tested for BTV antibodies.…”

“…Despite the control measures implemented, BTV and SBV are currently circulating in endemic and non-endemic regions in several European countries (Collins et al, 2019;Kundlacz et al, 2019). Wild ruminants are considered to be susceptible to both Culicoides-borne viruses, and their role in the maintenance of these shared pathogens has also been noted in Mediterranean ecosystems (García-Bocanegra et al, 2011Jiménez-Ruiz et al, 2021;Larska et al, 2014;Linden et al, 2012;Rossi et al, 2014). Given the similar transmission pathways of BTV and SBV, joint assessment of these viruses at multi-host domesticwild interfaces may give us a better understanding of their epidemiology, which is a key factor for driving more effective surveillance and control strategies in Europe (Yon et al, 2019).…”

Schmallenberg virus, cyclical reemergence in the core region: A seroepidemiologic study in wild cervids, Belgium, 2012–2017

“…The roe deer very low apparent seroprevalence to BTV‐8 is therefore caused by another mechanism, yet to be discovered. It has to be noted that in Spain (Jiménez‐Ruiz et al., 2020), the red deer population showed a statistically higher seroprevalence in comparison with roe deer, respectively, 31.6% versus 17.5%. Even if the difference is not comparable to what Linden and colleagues found for BTV‐8, it raises the question of the factors which impact the seroprevalence.…”

An approach to telmophagous Nematocera (Ceratopogonidae, Psychodidae, and Simuliidae) of Spain, with emphasis on its medical and veterinary importance

“…Although no further cases have been reported to date, SBV circulation has been detected regionally in catte. However, there is evidence of widespread endemic circulation among wild ruminants in mainland Spain in the recent years [32]. Interestingly, there have been no incidence reports of Culicoides bites on humans in Spain.…”