Spatio-temporal trends and risk factors affecting West Nile virus and related flavivirus exposure in Spanish wild ruminants.
BACKGROUND
During the last decade, the spread of many flaviviruses (Genus Flavivirus) has been reported, representing an emerging threat for both animal and human health. To further study utility of wild ruminant samples in West Nile virus (WNV) surveillance, we assessed spatio-temporal trends and factors associated with WNV and cross-reacting flaviviruses exposure, particularly Usutu virus (USUV) and Meaban virus (MBV), in wild ruminants in Spain. Serum samples from 4693 wild ruminants, including 3073 free-living red deer (Cervus elaphus), 201 fallow deer (Dama dama), 125 mouflon (Ovis aries musimon), 32 roe deer (Capreolus capreolus) and 1262 farmed red deer collected in 2003-2014, were screened for WNV and antigenically-related flavivirus antibodies using a blocking ELISA (bELISA). Positive samples were tested for neutralizing antibodies against WNV, USUV and MBV by virus micro-neutralization tests.


RESULTS
Mean flavivirus seroprevalence according to bELISA was 3.4 ± 0.5 % in red deer, 1.0 ± 1.4 % in fallow deer, 2.4 ± 2.7 % in mouflon and 0 % in roe deer. A multivariate logistic regression model revealed as main risk factors for seropositivity in red deer; year (2011), the specific south-coastal bioregion (bioregion 5) and presence of wetlands. Red deer had neutralizing antibodies against WNV, USUV and MBV.


CONCLUSIONS
The results indicate endemic circulation of WNV, USUV and MBV in Spanish red deer, even in areas without known flavivirus outbreaks. WNV antibodies detected in a free-living red deer yearling sampled in 2010, confirmed circulation this year. Co-circulation of WNV and USUV was detected in bioregions 3 and 5, and of WNV and MBV in bioregion 3. Sampling of hunted and farmed wild ruminants, specifically of red deer yearlings, could be a complementary way to national surveillance programs to monitor the activity of emerging flaviviruses.
Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Córdoba-Agrifood Excellence International Campus (ceiA3), Rabanales, 14071, Córdoba, Spain.
Ignacio
I
García-Bocanegra
Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Córdoba-Agrifood Excellence International Campus (ceiA3), Rabanales, 14071, Córdoba, Spain.
Jorge
J
Paniagua
Instituto de Investigación en Recursos Cinegéticos IREC, (CSIC-UCLM-JCCM), Ciudad Real, Spain.
Ana V
AV
Gutiérrez-Guzmán
ANSES, Laboratoire de Santé Animale de Maisons-Alfort, UMR 1161 Virologie, INRA, ANSES, ENVA, Maisons-Alfort, F-94703, France.
Sylvie
S
Lecollinet
Sabiotec, Camino de Moledores s.n., Ed. Polivalente UCLM, 13005, Ciudad Real, Spain.
Mariana
M
Boadella
Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Córdoba-Agrifood Excellence International Campus (ceiA3), Rabanales, 14071, Córdoba, Spain.
Antonio
A
Arenas-Montes
Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Córdoba-Agrifood Excellence International Campus (ceiA3), Rabanales, 14071, Córdoba, Spain.
David
D
Cano-Terriza
ANSES, Laboratoire de Santé Animale de Maisons-Alfort, UMR 1161 Virologie, INRA, ANSES, ENVA, Maisons-Alfort, F-94703, France.
Steeve
S
Lowenski
Instituto de Investigación en Recursos Cinegéticos IREC, (CSIC-UCLM-JCCM), Ciudad Real, Spain.
Christian
C
Gortázar
Instituto de Investigación en Recursos Cinegéticos IREC, (CSIC-UCLM-JCCM), Ciudad Real, Spain. ursula.hofle@uclm.es.
Ursula
http://orcid.org/0000-0002-6868-079X
U
Höfle
D000818:Animals; D000835:Animals, Wild; D003670:Deer / Q000821:virology*; D005416:Flavivirus / Q000302:isolation & purification; D018177:Flavivirus Infections / Q000453:epidemiology / Q000662:veterinary*; D012307:Risk Factors; D012418:Ruminants; D016036:Seroepidemiologic Studies; D013030:Spain / Q000453:epidemiology; D014901:West Nile Fever / Q000662:veterinary*; D014902:West Nile virus / Q000302:isolation & purification
Meaban virus; Red deer Cervus elaphus; Risk factors; Spain; Usutu virus; West Nile virus; Wild ruminants