ARS | Publication request: Chemical disinfection of high-consequence transboundary animal disease viruses on nonporous surfaces

Submitted to: Biologicals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 27, 2011
Publication Date: July 1, 2011
Citation: Krug, P.W., Lee, L.J., Eslami, A.C., Larson, C.R., Rodriguez, L.L. 2011. Chemical disinfection of high-consequence transboundary animal disease viruses on nonporous surfaces. Biologicals. 39(4):231-235.

Interpretive Summary: Border disease viruses such as foot-and-mouth disease (FMDV), classical swine fever, and African swine fever (ASFV)are highly contagious and cause severe morbidity and mortality in livestock. Accidental or intentional introduction of these viruses into non-endemic countries can result in the culling of a large proportion of resident animals, causing enormous economic losses. Proper disinfection during an outbreak can help prevent virus spread and will shorten the time for contaminated agriculture facilities to return to food production. While there are many commercial disinfectants registered by the US Environmental Protection Agency (EPA)for virus disinfection, there is little published data describing the efficacy of ordinary chemicals against dried forms of the viruses. We were tasked by the EPA to develop a model for nonporous surface disinfection to test various chemicals to inactivate virus. We found that FMDV and ASFV were susceptible to sodium hypochlorite and citric acid resulting in complete disinfection, but dried CSFV (Classical Swine Fever Virus) was not completely disinfected by 2% citric acid. 4% Sodium carbonate is commonly used for surface disinfection of vehicles and aircraft leaving FMDV-endemic areas, however, we were unable to completely disinfect FMDV with sodium carbonate in our assay. We conclude that disinfectants formulated with a minimum of 1000 ppm sodium hypochlorite be used for ASFV and CSFV (Classical Swine Fever Virus) disinfection, and a minimum of 1% citric acid be used for FMDV disinfection. These findings will help animal welfare agencies determine what disinfectants to use in response to border disease outbreaks.

Technical Abstract: Disinfection is a critical part of the response to animal disease virus outbreaks by inactivating fomites to help control infection. To model high-consequence animal disease virus fomite inactivation, we used a disinfection assay to determine the effectiveness of selected chemicals against Foot and Mouth Disease virus (FMDV), African Swine Fever virus (ASFV), and Classical Swine Fever virus (CSFV) dried on steel and plastic surfaces. We observed a 2 to 3 log reduction of virus infectivity by drying alone. FMDV and ASFV were susceptible to sodium hypochlorite and citric acid resulting in complete disinfection. Sodium carbonate, while able to reduce FMDV infectivity by greater than 4 logs, was unable to completely inactivate the dried virus. 2% citric acid did not completely disinfect dried CSFV, suggesting it may not be completely effective for disinfection in the field. Based on this data we suggest disinfectants be formulated with a minimum of 1000 ppm sodium hypochlorite for ASFV and CSFV disinfection, and a minimum of 1% citric acid for FMDV disinfection.