Low-pathogenicity influenza viruses replicate differently in laughing gulls and mallards.

Miria F Criado,David E Stallknecht,Kira A Moresco,David E Swayne

doi:10.1111/irv.12878

Abstract

Wild aquatic birds are natural reservoirs of low‐pathogenicity avian influenza viruses (LPAIVs). Laughing gulls inoculated with four gull‐origin LPAIVs (H7N3, H6N4, H3N8, and H2N3) had a predominate respiratory infection. By contrast, mallards inoculated with two mallard‐origin LPAIVs (H5N6 and H4N8) became infected and had similar virus titers in oropharyngeal (OP) and cloacal (CL) swabs. The trend toward predominate OP shedding in gulls suggest a greater role of direct bird transmission in maintenance, whereas mallards shedding suggests importance of fecal‐oral transmission through water contamination. Additional infectivity and pathogenesis studies are needed to confirm this replication difference for LPAI viruses in gulls.

Highlights

IntroductionLow-pathogenicity avian influenza viruses (LPAIVs) have been identified in many bird species, but primarily from the orders Anseriformes (ducks, geese, and swans) and Charadriiformes (gulls, terns, and shorebirds).[1]
Low-pathogenicity avian influenza viruses (LPAIVs) have been identified in many bird species, but primarily from the orders Anseriformes and Charadriiformes.[1]
This knowledge is needed to identify mechanisms related to LPAIV maintenance, subtype diversity, and evaluate the risk factors that contribute to LPAIV spread to new geographic regions or hosts, which includes other wildlife species, poultry, domestic animals, and humans

Summary

Introduction

Low-pathogenicity avian influenza viruses (LPAIVs) have been identified in many bird species, but primarily from the orders Anseriformes (ducks, geese, and swans) and Charadriiformes (gulls, terns, and shorebirds).[1]. Our goals were to understand AIV infectivity and pathogenesis in gulls, through clinical assessment, viral shedding patterns, and seroconversion, to related findings to potential mechanisms of transmission and ecological maintenance. Such experimental studies with gulls have been previously conducted on H13 and H16 viruses but not on less prevalent LPAIV subtypes. We performed experiments using the laughing gulls (Leucophaeus atricilla) and mallards challenged with North American LPAIVs that were originally isolated from either gulls or mallards, respectively

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Conclusion