Persistence of African swine fever virus on porous and non-porous fomites at environmental temperatures.

Background: African swine fever (ASF) is a lethal contagious disease affecting both domestic pigs and wild boars. Even though it is a non-zoonotic disease, ASF causes economic loss in swine industries across continents. ASF control and eradication are almost impossible since effective vaccines and direct antiviral treatment are not available. The persistence of ASFV on fomites plays an important role in the indirect transmission of ASFV to pigs encountering ASFV-contaminated fomites. ASFV persistence on porous and non-porous fomites (glass, metal, rubber, and cellulose paper) at different environmental temperatures was determined. The persistence of ASFV of fomites was determined by the rate of ASFV inactivation in terms of D or the time required to reduce ASFV per 1 log at each selected environmental temperature (T). D is used to compare the persistence of ASFV on the fomites.

Results: The mean D, D, and D, of dried infectious ASFV on glass, metal, rubber, and paper were in the ranges 1.42-2.42, 0.72-1.94, and 0.07-0.23 days, respectively. The multiple D were used to develop a D model to predict the D for some other environmental temperatures. The D models to predict the persistence of dried infectious ASFV on glass, metal, rubber, and paper are log D = (- T/21.51) + 1.34, log D = (- T/20.42) + 1.47, log D = (- T/14.91) + 2.03, and log D = (- T/10.91) + 2.84, respectively. A spreadsheet as a quick and handy tool predicting the persistence time of dried infectious ASFV on fomites at various environmental temperatures based on these D models is available for public to download.

Conclusion: Persistence of dried infectious ASFV on paper are significantly the longest at lower environmental temperatures whereas that of dried infectious ASFV on paper is significantly the shortest at higher environmental temperature.