Salt inactivation of classical swine fever virus and African swine fever virus in porcine intestines confirms the existing in vitro casings model

• Published in: Veterinary microbiology Vol. 238; p. 108424
• Main Authors: Jelsma, Tinka, Wijnker, Joris J., Smid, Bregtje, Verheij, Eline, van der Poel, Wim H.M., Wisselink, Henk J.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.11.2019; Elsevier BV
• Subjects: 3D collagen matrix model; African swine fever; African swine fever virus; animal experimentation; Animal research; Animals; Asfarviridae; Classical swine fever; Classical Swine Fever - virology; Classical swine fever virus; Classical Swine Fever Virus - drug effects; Collagen; containers; D-values; Food Microbiology - methods; in vivo studies; Intestine; intestines; Intestines - virology; Mimicry; Salts - pharmacology; sausages; storage time; Swine; temperature; Virus inactivation; Virus Inactivation - drug effects; Viruses; 3D collagen matrix model; African swine fever; Classical swine fever; Intestine; Virus inactivation; D-values
• ISSN: 0378-1135; 1873-2542; 1873-2542
• DOI: 10.1016/j.vetmic.2019.108424

•High viral loads of ASFV and CSFV were detected in porcine intestines.•Standard casing salt treatment of ASFV infected intestines was effective above 4 °C.•Standard casing salt treatment of CSFV infected intestines was effective above 20 °C.•P-salt showed faster virus reduction compared to NaCl treatment for both ASFV and CSFV.•Dintestine values were comparable with D-values of in vitro 3D collagen matrix model. Natural casings, to be used as sausage containers, are being traded worldwide and may be contaminated with contagious viruses. Standard processing of such natural casings is by salt treatment with a duration of 30 days before shipment. Since information is lacking about the efficacy of these virus inactivation procedures, an in vitro 3D collagen matrix model, mimicking natural casings, was developed previously to determine the efficacy of salt to inactivate specific viruses. To validate this model, a comparison in vivo experiment was performed using intestines of pigs experimentally infected with African swine fever virus (ASFV) and classical swine fever virus (CSFV). Decimal reduction (D) values, were determined at 4 °C, 12 °C, 20 °C and 25 °C. The standard salt processing procedure showed an efficient inactivation of ASFV and CSFV over time in a temperature dependent way. Dintestine values of both viruses, treated with the standard salt treatment, were in line with the Dcollagen values. It was concluded that these results underline the suitability of the 3D collagen matrix model to determine virus inactivation and to replace animal experiments. Furthermore, an increase in storage time for standard salt processed casings derived from CSFV endemic regions is highly recommended for an efficient inactivation of CSFV.