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Objectives: To evaluate the effectiveness of disinfection protocols on porcine circovirus type 2 (PCV2) in 1:61 scale model livestock trailers and determine the infectivity of PCV2 DNA detected using a bioassay.
Materials and methods: Each model trailer was contaminated with intestinal content from a pig experimentally infected with PCV2, washed, and disinfected with one of four protocols. Between protocol steps, swabs were collected from six different areas of each trailer and tested for PCV2 DNA. Disinfection protocols were quaternary ammonium compound (DISF1), oxidizing agent containing potassium peroxomonosulfate (DISF2), combined glutaraldehyde and quaternary ammonium product (DISF3), and DISF2 followed by sodium hypochlorite compound (DISF4). Four PCV2-contaminated, nonwashed, nondisinfected trailers served as positive controls and an uncontaminated trailer as negative control. Two 6- to 10-week-old PCV2-naive pigs were placed in each cleaned and disinfected trailer for 2 hours. Blood samples collected weekly for 7 weeks were tested for anti-PCV2 IgG antibodies and PCV2 DNA.
Results: In all four disinfection protocols, the amount of PCV2 DNA was significantly smaller (P < .05) after the initial wash; however, only in DISF4 (P < .01) was the amount of PCV2 DNA reduced after the disinfection step. After disinfection, 1.5 to 5.3 log10 PCV2 genomic copies per mL were identified in the trailers. While animals exposed to positive control trailers became viremic and seroconverted, no seroconversion or viremia was detected in animals exposed to disinfected trailers.
Implications: Although detectable amounts of PCV2 may remain in transport vehicles after proper disinfection, risk of transmission appears minimal.
Materials and methods: Each model trailer was contaminated with intestinal content from a pig experimentally infected with PCV2, washed, and disinfected with one of four protocols. Between protocol steps, swabs were collected from six different areas of each trailer and tested for PCV2 DNA. Disinfection protocols were quaternary ammonium compound (DISF1), oxidizing agent containing potassium peroxomonosulfate (DISF2), combined glutaraldehyde and quaternary ammonium product (DISF3), and DISF2 followed by sodium hypochlorite compound (DISF4). Four PCV2-contaminated, nonwashed, nondisinfected trailers served as positive controls and an uncontaminated trailer as negative control. Two 6- to 10-week-old PCV2-naive pigs were placed in each cleaned and disinfected trailer for 2 hours. Blood samples collected weekly for 7 weeks were tested for anti-PCV2 IgG antibodies and PCV2 DNA.
Results: In all four disinfection protocols, the amount of PCV2 DNA was significantly smaller (P < .05) after the initial wash; however, only in DISF4 (P < .01) was the amount of PCV2 DNA reduced after the disinfection step. After disinfection, 1.5 to 5.3 log10 PCV2 genomic copies per mL were identified in the trailers. While animals exposed to positive control trailers became viremic and seroconverted, no seroconversion or viremia was detected in animals exposed to disinfected trailers.
Implications: Although detectable amounts of PCV2 may remain in transport vehicles after proper disinfection, risk of transmission appears minimal.
Patterson AR, Baker RB, Madson DM, et al. Disinfection protocols reduce the amount of porcine circovirus type 2 in contaminated 1:61 scale model livestock transport vehicles. J Swine Health Prod. 2011;19(3):156?164.
