Disinfection of transboundary animal disease viruses on surfaces in pork packing plants

Authors: Krug, Peter; DAVIS, TALINA - Oak Ridge Institute For Science And Education (ORISE); O'BRIEN, CATHERINE - Oak Ridge Institute For Science And Education (ORISE); Larocco, Michael; Rodriguez, Luis

Submitted to: Veterinary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/23/2017
Publication Date: 6/1/2018
Citation: Krug, P.W., Davis, T., O'Brien, C.C., LaRocco, M.A., Rodriguez, L.L. 2018. Disinfection of transboundary animal disease viruses on surfaces in pork packing plants. Veterinary Microbiology. 219:219-225.

Interpretive Summary: Transboundary animal disease (TAD) viruses such as foot-and-mouth disease virus (FMDV), African swine fever virus (ASFV) and classical swine fever (CSFV) are highly contagious and cause severe morbidity and mortality in livestock. If an TAD virus-infected animal were to be processed by a meat packing plant, equipment, personnel and the final meat product could all be vectors to spread the disease to other animals, thereby worsening the outbreak situation. Since meat packing plant disinfection is intended towards antibacterial objectives, it is not known if the products used by the industry will successfully inactivate TAD viruses. We modeled the contamination of a pork packing plant by drying TAD viruses in swine products such as blood and feces on relevant surfaces such as stainless steel and concrete. These virus-contaminated targets were disinfected with non-commercial chemicals as well as food service-grade disinfectants used by the packing industry. We found that the industry disinfectants were mostly efficacious against all three TAD viruses tested when dried in saline. The disinfectant efficacy of all tested disinfectants was greatly inhibited when viruses were dried in swine blood and meat juices. These results reiterate the importance of the disinfectant manufacturer’s recommended pre-clean step to remove visible debris before disinfection. Assuming this pre-cleaning step is performed, our results show that the tested food-industry disinfectants will largely inactivate TAD viruses in a packing plant environment.

Technical Abstract: In the event of an intentional or accidental incursion of a transboundary animal disease (TAD) virus into the US, a major concern to the meat production industry would be the potential contamination of packing plants by processing infected animals. TAD agents such as foot and mouth disease virus (FMDV), African swine fever virus (ASFV) and classical swine fever virus (CSFV) are found in swine products such as blood and feces and are present in the tissues of infected animals. To model the disinfection of TAD viruses in a pork-packing environment, a previously developed disinfection assay was used to test two biocides currently used by industry sanitarians, against TAD viruses dried on industry relevant surfaces in saline or swine products. With one virus exception, both tested commercial disinfectants were effective against the TAD viruses dried on steel, plastic, and sealed concrete surfaces in the absence of the swine products. The activity of the tested disinfectants was greatly inhibited by the presence of blood and meat juices in the dried samples. The acidic disinfectants were able to inactivate the viruses in swine feces whereas the fecal material generally inhibited sodium hypochlorite-based disinfectants. These results highlight the importance of manufacturer-recommended pre-cleaning steps to remove gross soil before surface disinfection. Taken together, these data support the use of acid- and surfactant-containing commercial products for packing plant disinfection during a TAD virus outbreak event.