Zoonotic Agents

Semi-Quantitative Assessment of the Risks of Bi-Directional Transmission of Influenza Between Pigs and Workers on an Indoor Hog Grower Unit

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Abstract

Influenza A viruses (IAV) are distributed worldwide and infect humans and animals. Domestic pigs (Sus domesticus) help maintain IAV transmission globally (H1N1, H3N2, and H1N2 subtypes within the United States). In 2009 a novel subtype of H1N1 IAV (H1N1pdm09) emerged from swine populations and adapted to human-to-human transmission leading to a pandemic which was estimated to infect 15-45% of the world’s population (1 – 3 billion individuals). Influenza viruses cause considerable economic burden to the pork industry due to their associated impact on growth rates and treatment costs, despite causing relatively mild disease in pigs. Influenza transmission between workers and pigs is known to occur but its relative contribution to the epidemiology of influenza in both species is poorly understood considering the potential public health and economic consequences of pandemic influenza. The purpose of our study was to assess the risks of interspecies transmission (pig-to-human or human-to-pig) of influenza within an indoor hog grower unit in the United States and to prioritize data gaps. We evaluated influenza transmission risk across two pathways common to the typical US Midwest Farm: 1. What is the likelihood that during a single production cycle on a single US indoor hog grower farm, at least one hog becomes infected with influenza virus (either H1N1pdm09, H1N1, H3N2, H3N2v, or H1N2) and that at least one worker becomes infected as a result and that the worker develops symptoms? 2. What is the likelihood that, during a single production cycle on a single US indoor hog grower farm, at least one worker becomes infected with influenza virus (either H1N1pdm09, H1N1, H3N2, H3N2v, or H1N2) and that at least one pig becomes infected as a result and at least one pig develops symptoms?

How to Cite:

Kontowicz, E., (2023) “Semi-Quantitative Assessment of the Risks of Bi-Directional Transmission of Influenza Between Pigs and Workers on an Indoor Hog Grower Unit”, SafePork 14(1).