title: Experimental infection of house sparrows (Passer domesticus) with West Nile virus strains of lineages 1 and 2.
abstract: West Nile virus (WNV) is a zoonotic pathogen which is maintained in an enzootic cycle between mosquitoes and birds; humans, equines, other mammals and some bird species are dead-end hosts. Lineage 1 WNV strains have predominated in Europe since the 1960s. However, in 2004 lineage 2 strains emerged in Hungary and Russia, respectively, spreading since then to a number of neighbouring countries (e.g., Austria, Greece, Italy, Serbia and Romania). Wild bird mortality is a hallmark of North American WNV outbreaks, a feature uncommon in Europe. This study aimed to compare the course of infection of lineage 1 (NY99) and lineage 2 (Austria/2008) WNV strains in the house sparrow, a bird species common in Europe and North America. House sparrows were inoculated with either NY99 or Austria/2008 WNV strains, or sham-inoculated, and clinical and analytic parameters (viraemia, viral load, antibodies) were examined until 14 days after inoculation. Although all inoculated sparrows became infected, no mortality or clinical signs were observed due to the infection. However, the magnitude and duration of viraemia were higher for NY99 - than for Austria/2008 - infected birds. The house sparrow proved to be a competent host for both strains, although the competence index calculated for NY99 was higher than for Austria/2008. Viral load in tissues and swabs was also higher in NY99-inoculated sparrows. In conclusion, the house sparrow is a convenient avian model for studying host competence of WNV strains. The observed differences between NY99 and Austria/2008 strains might have important epidemiological consequences for disease incidence and dispersal capacity.
authors.affiliation: Centro de Investigación en Sanidad Animal (CISA)-INIA, Ctra. Algete-El Casar s/n, 28130 Valdeolmos, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Del Amo
authors.affiliation: Centro de Investigación en Sanidad Animal (CISA)-INIA, Ctra. Algete-El Casar s/n, 28130 Valdeolmos, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Llorente
authors.affiliation: Centro de Investigación en Sanidad Animal (CISA)-INIA, Ctra. Algete-El Casar s/n, 28130 Valdeolmos, Spain.
authors.forename: Elisa
authors.initials: E
authors.lastname: Pérez-Ramirez
authors.affiliation: Estación Biológica de Doñana-CSIC, Seville, Spain.
authors.forename: Ramón C
authors.initials: RC
authors.lastname: Soriguer
authors.affiliation: Estación Biológica de Doñana-CSIC, Seville, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Figuerola
authors.affiliation: Institute of Virology, Viral Zoonoses, Emerging and Vector-Borne Infections Group, University of Veterinary Medicine, Vienna, Austria; Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman.
authors.forename: Norbert
authors.initials: N
authors.lastname: Nowotny
authors.affiliation: Centro de Investigación en Sanidad Animal (CISA)-INIA, Ctra. Algete-El Casar s/n, 28130 Valdeolmos, Spain. Electronic address: majimenez@inia.es.
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Jiménez-Clavero
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000821:virology*; D046370:Sparrows; D014766:Viremia / Q000662:veterinary; D014901:West Nile Fever / Q000662:veterinary* / Q000821:virology; D014902:West Nile virus / Q000145:classification*
keywords: Experimental infection; Host competence; House sparrow; WNV lineage 1 and 2; West Nile virus