Detection of Low Pathogenic Avian Influenza Virus Subtype H10N7 in Poultry and Environmental Water Samples During a Clinical Outbreak in Commercial Free-Range Layers, Netherlands 2017

Abstract

Wild birds are the natural reservoir of the avian influenza virus (AIV) and may transmit AIV to poultry via direct contact or indirectly through the environment. In the Netherlands, a clinically suspected free-range layer flock was reported to the veterinary authorities by the farmer. Increased mortality, a decreased feed intake, and a drop in egg production were observed. Subsequently, an infection with low pathogenic avian influenza virus was detected. This study describes the diagnostic procedures used for detection and subtyping of the virus. In addition to routine diagnostics, the potential of two different environmental diagnostic methods was investigated for detecting AIV in surface water. AIV was first detected using rRT-PCR and isolated from tracheal and cloacal swabs collected from the hens. The virus was subtyped as H10N7. Antibodies against the virus were detected in 28 of the 31 sera tested. An intravenous pathogenicity index (IVPI) experiment was performed, but no clinical signs (IVPI = 0) were observed. Post-mortem examination and histology confirmed the AIV infection. Multiple water samples were collected longitudinally from the free-range area and waterway near the farm. Both environmental diagnostic methods allowed the detection of the H10N7 virus, demonstrating the potential of these methods in detection of AIV. The described methods could be a useful additional procedure for AIV surveillance in water-rich areas with large concentrations of wild birds or in areas around poultry farms. In addition, these methods could be used as a tool to test if the environment or free-range area is virus-free again, at the end of an AIV epidemic.

Zoonotic Mutation of Highly Pathogenic Avian Influenza H5N1 Virus Identified in the Brain of Multiple Wild Carnivore Species

“…Another study showed that cats were also highly susceptible to HPAI H5N1 (A/Vietnam/1194/2004) infection after eating virus-infected chicks and demonstrated systemic disease including brain lesions already 7 days after experimental infection [ 28 ]. These findings lead us to the hypothesis that the red foxes, polecats, badger, and otter were infected by eating carcasses; however, ingesting water contaminated with infected bird feces could also be a route of infection [ 29 , 30 ].…”

Comparative pathogenicity and environmental transmission of recent highly pathogenic avian influenza H5 viruses

“…The suspension was filtered, after the final filtering step (0.2 µM filter, Nalgene) a sample of 5 ml was incubated with 1% of penicillin and gentamycin and incubated at room temperature for 1 h. RNA was isolated using MagNA Pure as described above. For sampling of the water, a 1- l sample was collected and filtered directly as described previously [ 29 ]. Briefly, the water was filtered using a hydrophilic mixed cellulose esters membrane (MF-Millipore™ Membrane Filter, Merck).…”

“…RNA was isolated using MagNA Pure as described above. For sampling of the water, a 1 liter sample was collected and filtered directly as described previously 29 . Briefly, the water was filtered using a hydrophilic mixed cellulose esters membrane (MF-Millipore™ Membrane Filter, Merck).…”

Seroprevalence of Avian Influenza Viruses in Asymptomatic Backyard Poultry Birds in District Multan, Pakistan

“…This might provide a clue for minimal chances of viral spread from apparently healthy rural poultry birds through oral route. The association between migratory birds, backyard poultry and the current status on avian influenza has been investigated in many countries like in Europe and UK (Hansen et al, 2018), in China (Wang et al, 2018) and in Netherlands (Germeraad et al, 2020).…”