A study funded by the Swine Health Information Center Wean-to-Harvest Biosecurity Research Program, in partnership with the Foundation for Food & Agriculture Research and Pork Checkoff, evaluated the effectiveness of a waterless trailer decontamination method using modified vaporous hydrogen peroxide (mVHP) in combination with an industrial vacuum system. The study, conducted by Dr. Erin Kettelkamp, Swine Vet Center, evaluated the effects of the vacuum plus mVHP on PEDV detection and inactivation using varying disinfectant contact times. Results showed that mVHP treatment paired with a vacuum system reduced the relative PEDV viral load via PCR detection on contaminated trailers while no difference was detected between contact times. Further research is needed to assess the impact of this technology on virus inactivation and its potential application and scalability in the field.
Find the industry summary for project #24-003 here.
Effective biosecurity protocols for swine transport are critical to controlling endemic pathogens like PEDV and preparing for foreign animal diseases such as African swine fever. The combination of an industrial vacuum and mVHP treatment presents a promising alternative to traditional trailer sanitation methods. Unlike current wash and thermo-assisted drying and decontamination procedures, this system is portable, waterless, and scalable, significantly reducing labor, infrastructure, and water usage associated with existing practices. This technology may be particularly valuable during disease outbreaks, when the rapid and thorough biocontainment of contaminated swine transport vehicles is critical.
Current trailer disinfection methods involving power washing, chemical disinfectants, and TADD are labor-intensive, water-dependent, and impractical for rapid or mobile deployment during disease outbreaks. The study of mVHP, which has been used successfully in military and biosafety level 4 laboratory settings due to its effectiveness in neutralizing biological agents across diverse materials without equipment degradation, shows promise. Hydrogen peroxide-based aerosol disinfectants have previously been shown to inactivate swine pathogens in work done by Dr. Kettelkamp. However, broader adoption of hydrogen peroxide-based disinfectants in swine production requires further research and optimization for field conditions. Effective field implementation of mVHP disinfection requires prior removal of organic material, such as using a portable industrial vacuum system described herein.
For this pilot study, two scenarios were evaluated: 1) mock-swine trailer under in-vitro conditions (i.e., chamber) and 2) mock-swine trailer under field-simulated conditions (i.e., shroud). For the second scenario, a miniature insulated trailer shroud was designed to mimic conditions for potential field application. A miniature aluminum trailer model was contaminated with PEDV fecal inoculum in both scenarios. An industrial-grade vacuum was used to remove organic material, followed by applying mVHP treatment across different contact times.
PEDV inoculum (USA/NC49469/2013; 10⁴ TCID₅₀/mL) was mixed with feces and shavings to prepare the contamination material. Aluminum trailer models (1:16 scale) were contaminated with PEDV fecal inoculum and treated with mVHP for 30, 60, or 120 minutes. Four replicates per treatment duration were performed, with positive controls held at ambient temperature.
Pre-marked trailer surfaces were sampled before and after treatment to confirm PEDV contamination and to assess differences in PEDV RNA detection via quantitative PCR. Bioassays were conducted via oral inoculation with post-treatment environmental samples, utilizing liquid that was recovered from the trailer after treatment. Pigs were observed for clinical signs and evidence of PEDV infection to determine if the virus had been inactivated with each treatment. The main effects of disinfectant treatment and contact time, as well as their interaction, were assessed.
Overall, study results demonstrated that application of mVHP following vacuum removal of bulk material reduced detectable levels of PEDV RNA as measured by PCR from contaminated trailer surfaces compared to untreated controls. No differences in PEDV detection levels via PCR Ct values were observed across different contact times. Further, similar numerical results were observed between the chamber and shroud scenarios.
The antiviral efficacy of mVHP treatment against PEDV could not be determined, as all environmental trailer samples failed to produce PEDV infection under in-vivo conditions, including the positive controls. All pigs remained clinically healthy during the bioassays and tested negative for PEDV infection. Limitations in virus viability and bioassay sensitivity warrant refinement in inoculum preparation and validation to ensure accurate assessment of disinfection efficacy for virus inactivation.
In this pilot study, mVHP treatment of contaminated trailers showed a reduction of detectable PEDV genetic material via PCR. The impact of mVHP treatment on PEDV infectivity was inconclusive; therefore, additional research is needed to validate virus inactivation capabilities and to improve the standardization of contamination methods to optimize bioassay procedures. With continued development, this approach could play an important role in improving transport biosecurity and disease outbreak response readiness for the swine industry.
Foundation for Food & Agriculture Research
The Foundation for Food & Agriculture Research (FFAR) builds public-private partnerships to fund bold research addressing big food and agriculture challenges. FFAR was established in the 2014 Farm Bill to increase public agriculture research investments, fill knowledge gaps and complement the U.S. Department Agriculture’s research agenda. FFAR’s model matches federal funding from Congress with private funding, delivering a powerful return on taxpayer investment. Through collaboration and partnerships, FFAR advances actionable science benefiting farmers, consumers and the environment.
Swine Health Information Center
The Swine Health Information Center, launched in 2015 with Pork Checkoff funding, protects and enhances the health of the US swine herd by minimizing the impact of emerging disease threats through preparedness, coordinated communications, global disease monitoring, analysis of swine health data, and targeted research investments. As a conduit of information and research, SHIC encourages sharing of its publications and research. Forward, reprint, and quote SHIC material freely. For more information, visit http://www.swinehealth.org or contact Dr. Megan Niederwerder at [email protected] or Dr. Lisa Becton at [email protected].
