Bagaza virus is pathogenic and transmitted by direct contact in experimentally infected partridges, but is not infectious in house sparrows and adult mice.
Bagaza virus (BAGV) is a mosquito-borne flavivirus belonging to the Ntaya serocomplex. In 2010, a disease outbreak was reported in Cádiz (Southern Spain) affecting game birds (red-legged partridges and common pheasants). In this work, red-legged partridges were inoculated experimentally with infectious BAGV isolated from this outbreak in order to make a complete clinical and analytical assessment of the disease caused by the pathogen in this species. Viral load (by real-time RT-PCR) in blood, oral and cloacal swabs, and feathers, and neutralizing antibody titres (by VNT) were measured. In order to determine direct contact transmission, non-inoculated partridges were caged together with the inoculated ones. To assess infectiousness in other species, house sparrows and mice were also inoculated with the virus. All the inoculated partridges were clinically affected, and 30% of them died. All the infected individuals lost weight, with larger losses being recorded in females. Conversely, no mortality or disease symptoms were observed in the sparrows or mice. Remarkably, all the contact partridges acquired the infection by direct (non-vectored) transmission. This study confirms that the red-legged partridge is a susceptible host for BAGV infection, and that this pathogen is transmitted by direct contact. Long-lasting viral loads detected in calami of immature feathers demonstrate that feather sampling could be a useful strategy in active surveillance programs for early detection of BAGV.
Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CISA), Ctra Algete-El Casar s/n, Valdeolmos, Spain. dgracia@inia.es.
Francisco
F
Llorente
Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CISA), Ctra Algete-El Casar s/n, Valdeolmos, Spain. elisaperezramirez@gmail.com.
Elisa
E
Pérez-Ramírez
Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CISA), Ctra Algete-El Casar s/n, Valdeolmos, Spain. fpinero@inia.es.
Jovita
J
Fernández-Pinero
Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CISA), Ctra Algete-El Casar s/n, Valdeolmos, Spain. toroja@hotmail.com.
Maia
M
Elizalde
Estación Biológica de Doñana (EBD-CSIC), Avenida de Americo Vespucio s/n, Seville, Spain. jordi@ebd.csic.es.
Jordi
J
Figuerola
Estación Biológica de Doñana (EBD-CSIC), Avenida de Americo Vespucio s/n, Seville, Spain. soriguer@ebd.csic.es.
Ramón C
RC
Soriguer
Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CISA), Ctra Algete-El Casar s/n, Valdeolmos, Spain. majimenez@inia.es.
Miguel Ángel
MÁ
Jiménez-Clavero
D000818:Animals; D001715:Bird Diseases / Q000276:immunology / Q000635:transmission* / Q000821:virology; D005260:Female; D005416:Flavivirus / Q000502:physiology*; D018177:Flavivirus Infections / Q000276:immunology / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D046094:Galliformes; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012376:Rodent Diseases / Q000276:immunology / Q000635:transmission* / Q000821:virology; D000069078:Seroconversion; D046370:Sparrows; D014018:Tissue Distribution; D014766:Viremia / Q000662:veterinary; D017201:Virus Shedding