Recovery and chemical disinfection of foot-and-mouth disease and African swine fever viruses from porous concrete surfaces.

AIMS: Develop an effective laboratory method to consistently recover viral loads from porous concrete coupons sufficient for disinfectant efficacy testing. Investigate the role of concrete matrix pH on the recovery of foot-and-mouth disease virus (FMDV) and African Swine Fever virus (ASFV) from porous concrete. Compare parameters off FMDV and ASFV inactivation on porous and nonporous surfaces in quantitative carrier tests of a liquid chemical disinfectant. METHODS AND RESULTS: Concrete test coupons were fabricated from commercial and industrial sources and carbonated by exposure to 5% CO(2) in a humidified incubator, lowering the matrix pH. Neither dried FMDV nor ASFV were recovered from high-pH concrete control coupons. Recovery of infectious virus from lower pH carbonated concrete was similar to stainless steel coupon controls. Exposure to the liquid disinfectant Virkon™ S inactivated FMDV and ASFV on porous concrete. CONCLUSIONS: Concrete matrix pH had a greater impact than surface porosity on the ability to recover viable virus from unsealed concrete. SIGNIFICANCE AND IMPACT OF THE STUDY: Concrete is commonly found in environments where virus decontamination is required. This study demonstrates a reproducible method to recover sufficient viral loads from porous concrete coupons to facilitate quantitative carrier testing. This method provides a basis for evidence-based validation testing of chemical disinfectants to inactivate pH-sensitive viruses on unsealed concrete.