Exposure to West Nile virus and tick-borne encephalitis virus in dogs in Spain

Abstract

In the past decade, the spread of emerging zoonotic flaviviruses (genus Flavivirus, family Flaviviridae) has been reported in many regions worldwide, representing a threat to both human and animal health. A serosurvey was carried out to assess exposure and risk factors associated with antigenically related flaviviruses, particularly West Nile virus (WNV), Usutu virus (USUV) and tick-borne encephalitis virus (TBEV), in dogs in Spain. Flavivirus antibodies were detected in 39 of 815 dogs (4.8%; 95% CI: 3.3-6.3) by bELISA. Significantly higher seropositivity was observed in hunting dogs compared to pet dogs. Virus neutralization tests confirmed WNV-specific and TBEV-specific antibodies in 11 and 14 bELISA-positive dogs, respectively. This is the first serosurvey of WNV and TBEV in dogs in Spain and the first report of TBEV circulation in this country. The seropositivity obtained indicates widespread, but not homogeneous, distribution of WNV and TBEV in dogs in Spain. In 2013 and 2015, WNV-seropositive dogs were detected in those areas of Andalusia where the highest number of WNV outbreaks were reported in both horses and humans. Antibodies against TBEV have been found in dogs sampled in two different periods and regions in Spain. Serosurveillance in dogs could be a complementary way of monitoring the activity of emerging flaviviruses in Spain.

Exposure of Wild Ungulates to the Usutu and Tick-Borne Encephalitis Viruses in France in 2009–2014: Evidence of Undetected Flavivirus Circulation a Decade Ago

“…Among the seropositive animals by cELISA, the confirmatory rate by MNT and MIA was higher and the mean % S/N of cELISA was lower for wild boar, suggesting higher antibody titrer in wild boar. Similar differences in the seroprevalence of flavivirus infections (as regards WNV) were found between wild boar and cervids (roe deer and red deer) in Spain [28,31,35]. These results may suggest lower antibody response in roe deer to infections by flaviviruses of the Japanese encephalitis antigenic complex.…”

“…TBEV/LIV seropositivity in Hautes-Pyrénées could originate from an infection with LIV or LI-like virus, since these viruses have been reported in sheep, goats and Cantabrian chamois (Rupicapra pyrenaica parva) in close geographical areas in Spain: In the Basque and Asturias regions [23,25,63]. The presence of a virus from the TBEV-serocomplex was found at a broader scale in Spain by serology, with antibodies neutralizing TBEV reported in southern Spain and on the island of Mallorca [28,29]. The positive serum in the Yvelines might also reveal the western limit of distribution of TBEV in France.…”

“…In these countries, except for Great Britain (LIV), data on the natural transmission cycle are not available. Recently, TBEV serocomplex neutralizing antibodies were detected in dogs in the south of Spain [28] and in horses on the island of Mallorca (off the eastern coast of Spain) [29]. Based on our current knowledge of the TBEV epidemiological cycle, it is more likely that the virus involved is LIV or a LI-like virus.…”

Ecology of West Nile Virus in the Danube Delta, Romania: Phylogeography, Xenosurveillance and Mosquito Host-Feeding Patterns

“…This study supports previous studies, which identified horses and dogs as suitable sentinel species for WNV [53,54]. WNV seroprevalence in dogs (6.3%) and horses (3.1%) was similar to conventional sampling of the species in different areas with WNV activity [67][68][69]. Nevertheless, the seroprevalence in horses was markedly lower than in southeastern Romania (15.1%) [70].…”

Specific detection and differentiation of tick‐borne encephalitis and West Nile virus induced IgG antibodies in humans and horses

“…Several IgG tests for equine and human TBEV and WNV infections are available, but the observed cross‐reacting antibodies often lead to false‐positive results (Beck et al, ; Cleton et al, ; Sanchini et al, ; Ziegler et al, ). This is of concern especially in areas of co‐circulation of two or more flaviviruses (García‐Bocanegra et al, ). Whereas TBEV is known since decades to be endemic in many parts of Europe, WNV has emerged more recently (Bakonyi et al, ; Barzon, ) and its activity has dramatically increased during the last decade, with large outbreaks in humans and horses reported each year (Bakonyi et al, ).…”