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

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.

Automated summary

Wild aquatic birds are natural reservoirs of low-pathogenicity avian influenza viruses (LPAIVs). Gull-origin LPAIVs predominantly cause respiratory infections in laughing gulls, while mallard-origin LPAIVs are primarily transmitted through water contamination in mallards. Further studies are needed to confirm these transmission patterns for LPAIVs in different bird species.