Vet Microbiol

. 2021 Sep 20;262:109240.

 doi: 10.1016/j.vetmic.2021.109240. Online ahead of print.

Disinfection and conditions associated with thermo-assisted drying and decontamination inconsistently produce negative PRRSV rRT-PCR results on metal surfaces

Rita Anne Neat 1, Zhang Jianqiang 2, Hai Hoang 3, Lauren McKeen 4, Christine L Mowrer 5, Derald J Holtkamp 6

Affiliations 

Affiliations

• 1Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: ritaneat@iastate.edu.
• 2Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: jqzhang@iastate.edu.
• 3Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: hai.hoangthanh@hcmuaf.edu.vn.
• 4Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: lamckeen@iastate.edu.
• 5Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: clmowrer@iastate.edu.
• 6Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: holtkamp@iastate.edu.

• PMID: 34600200
 
• DOI: 10.1016/j.vetmic.2021.109240

Abstract

Because contaminated livestock trailers are a significant risk for transmitting viruses between herds, various methods of washing, disinfecting, and thermo-assisted drying and decontamination (TADD) have been evaluated for their effectiveness in inactivating porcine reproductive and respiratory syndrome virus (PRRSV) on contaminated surfaces. Information on when to expect negative qRT-PCR results after adequate trailer sanitation is lacking. The objective of this study was to evaluate whether there are conditions associated with washing-disinfectant-TADD procedures that will consistently produce a negative qRT-PCR result for the purpose of monitoring compliance with trailer sanitation and decontamination protocols for PRRSV on metal surfaces. 144 diamond plate aluminum coupons were spiked with PRRSV or phosphate-buffered saline (PBS) and treated with a designated disinfectant protocol. Disinfectants evaluated included multiple accelerated® hydrogen peroxide (AHP) disinfectants and a quaternary ammonium and glutaraldehyde combination disinfectant. Disinfectant was applied for 5 or 60 minutes of contact time at either 20 °C or -10 °C in a matrix of feces or PBS. All coupons were heated until the surface temperature of the coupon reached 71 °C and then held for 10 minutes to simulate TADD under field conditions. Post-treatment swabs for all treatment groups, except negative control groups, were positive by PRRSV qRT-PCR. Under the conditions evaluated in this study, consistently negative qRT-PCR results after treatments were not found. Therefore, for the purpose of monitoring compliance with trailer sanitation and decontamination protocols for PRRSV, alternatives to qRT-PCR should be explored.

Keywords: PCR; PRRSV; Swine; biosecurity.

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