Matched case-control study of the influence of inland waters surrounding poultry farms on avian influenza outbreaks in Japan

Abstract

To successfully control highly pathogenic avian influenza (HPAI), understanding the risk factors related to the incursion of the virus into poultry farms is essential. In this study, we focused on the presence of inland waters surrounding poultry farms as a potential risk factor of incursion of the virus. To evaluate the influence of inland waters surrounding poultry farms on HPAI outbreaks in Japan, a simple matched case-control study was conducted. The results of the conditional regression analyses indicated that the number of farms with neighbouring inland waters was significantly high among the affected farms during the 2016–2017 outbreak period. These results provide good grounds for strengthening biosecurity management at farms located near inland waters.

Association of wild bird densities around poultry farms with the risk of highly pathogenic avian influenza virus subtype H5N8 outbreaks in the Netherlands, 2016

“…Yellow triangle and circles indicate locations in an area with AOD >1.5 (dark grey). The bird census schemes used to determine bird densities are visualized in the same map in Figure S1 * * * * * and HPAI outbreaks (Bouwstra et al, 2017;Gilbert & Pfeiffer, 2012;Gonzales, Stegeman, Koch, de Wit, & Elbers, 2013;Mulatti et al, 2018;Napp, Majó, Sánchez-Gónzalez, & Vergara-Alert, 2018;Shimizu, Hayama, Yamamoto, Murai, & Tsutsui, 2018;Si, de Boer, & Gong, 2013;Ward, Maftei, Apostu, & Suru, 2008, 2009. Evidence from these studies suggests that wild bird density around farms could serve as a measure of exposure to HPAIV and, consequently, may be used to identify farms at high risk of virus introduction.…”

Spatial Variation in Risk for Highly Pathogenic Avian Influenza Subtype H5N6 Viral Infections in South Korea: Poultry Population-Based Case–Control Study

“…If waterfowl harbor the HPAI virus, bodies of water might be a source of infection for other carriers such as resident birds, or rodents spreading the virus onto nearby farms. The presence of adjacent inland waters was considered to be a major determinant in the prevalence of HPAI in poultry [ 52 ]. When IAVs are kept in water under cold conditions, a near-neutral pH, and a low-to-moderate specific conductance, the viruses can survive and can stay infectious for months after adsorption [ 53 ].…”

Interpolation of Point Prevalence Rate of the Highly Pathogenic Avian Influenza Subtype H5N8 Second Phase Epidemic in South Korea

“…According to Kwon et al [ 15 ], a higher density of domestic ducks might lead to a higher number of avian influenza outbreaks. Moreover, districts in Jeollabuk-do province, being nearer to the Yellow Sea, might be comparatively more at risk, as water bodies can be hazardous for avian influenza spread [ 62 , 63 , 64 ].…”