Infectious Dose of African Swine Fever Virus When Consumed Naturally in Liquid or Feed

Abstract

African swine fever virus (ASFV) is a contagious, rapidly spreading, transboundary animal disease and a major threat to pork production globally. Although plant-based feed has been identified as a potential route for virus introduction onto swine farms, little is known about the risks for ASFV transmission in feed. We aimed to determine the minimum and median infectious doses of the Georgia 2007 strain of ASFV through oral exposure during natural drinking and feeding behaviors. The minimum infectious dose of ASFV in liquid was 10 ⁰ 50% tissue culture infectious dose (TCID ₅₀), compared with 10 ⁴ TCID ₅₀ in feed. The median infectious dose was 10 ^1.0 TCID ₅₀ for liquid and 10 ^6.8 TCID ₅₀ for feed. Our findings demonstrate that ASFV Georgia 2007 can easily be transmitted orally, although higher doses are required for infection in plant-based feed. These data provide important information that can be incorporated into risk models for ASFV transmission.