Epizootic of highly pathogenic H7N3 Avian Influenza in an ecologic reserve in Mexico

SummaryThis report includes a 2015 epizootic of highly pathogenic H7N3 avian influenza virus among captive and wild birds at “El Zapotal” ecologic reserve, located in the state of Chiapas, Mexico. Epidemiological control measures were implemented to prevent virus dissemination. The infection with the highly pathogenic H7N3 virus was detected predominantly among Plain Chachalaca (Ortalis vetula), with occasional detections in a White-fronted Parrot (Amazona albifrons) and a single Clay-colored Thrush (Turdus grayi). Here, we describe the characteristics of the outbreak environment, the surveillance strategy, the biosecurity measures, and the evaluation of the site, including external farms. These actions, timely implemented by the veterinary authorities, helped to contain the outbreak beyond the ecologic reserve. This contingency showed the importance of developing a more complete analysis of the existing risks and the challenges to implement minimal biosecurity measures in these facilities.

H7N3 Avian Influenza Virus Found in a South American Wild Duck Is Related to the Chilean 2002 Poultry Outbreak, Contains Genes from Equine and North American Wild Bird Lineages, and Is Adapted to Domestic Turkeys

ABSTRACT An H7N3 avian influenza virus (AIV) was isolated from a Cinnamon Teal (Anas cyanoptera) (A/CinnamonTeal/Bolivia/4537/01) during a survey of wild waterfowl in Bolivia in 2001. The NA and M genes had the greatest identity with North American wild bird isolates, the NS was most closely related to an equine virus, and the remaining genes were most closely related to isolates from an outbreak of H7N3 in commercial poultry in Chile in 2002. The HA protein cleavage site and the results of pathogenesis studies in chickens were consistent with a low-pathogenicity virus, and the infective dose was 105 times higher for chickens than turkeys.