There have been many advances in the area of protection of susceptible pigs from PCV2. Even with the recent availability of PCV2 vaccines, the disease remains an economic threat to the swine industry worldwide. In addition to interventions such as vaccines, meticulous animal husbandry and hygiene practices play a proven role in disease prevention. However, little research on the effectiveness of commercially available disinfectants against PCV2 has been reported. With this in mind, this update will review some of the available research.
Martin, et al., conducted a trial evaluating the sensitivity of PCV2 to nine commonly used disinfectants. They also aimed at determining the concentrations at which these disinfectants would be effective against the virus. To conduct this experiment Martin, et al., chose nine disinfectants commonly used in the animal industry to test. PCV2 virus stock was combined with each one of the nine disinfectants at the concentration recommended by each of the disinfectant’s manufacturers. The virus remained in contact with the disinfectant for 30 minutes at 20 degrees Celsius. After this time, the reaction was stopped and the ability of the virus to infect was tested by measuring the virus’ infectivity on a specific laboratory cell tissue line derived from porcine kidney (PK15) cells. The researchers further tested the minimal concentration at which the disinfectants were effective against PVC2. They found that neither phenol, nor iodine-based disinfectants were capable of destroying the PCV2 virus. However, sodium hydroxide proved to be effective at one-fourth the recommended concentration. Sodium hypochlorite also was effective at one-half the recommended concentration. However, Martin, et al., stress the need to test these disinfectants in the field.
Royer, et al., conducted a similar set of experiments using the disinfectants ethanol, Weladol®, 1-Stroke Environ®, Tek-Trol®, Roccal® D Plus, Fulsan®, Clorox® bleach, Virkon® S, DC&R®, sodium hydroxide and Nolvasan®. The disinfectants were prepared at twice the manufacturers’ recommended concentration and combined with the virus at a 1:1 ratio. The disinfectant/virus mixture sat at room temperature for 10 minutes after which time the reaction was stopped and the infectivity of the treated virus was tested by inoculating it into a laboratory porcine kidney cell line (PK15). Royer, et al., found that Virkon S was the most effective disinfectant, followed by sodium hydroxide, Roccal D Plus, Clorox bleach, 1-Stroke Environ, Fulsan, Tek-Trol, Ethanol, Weladol, DC&R and Nolvasan. Like Martin, et al., Royer, et al., stress the need for testing to be done in a field setting.
A review of viral inactivation agents and mechanisms of inactivation is presented in Dr. Jill Bieker’s Ph.D. thesis, Chemical Inactivation of Viruses. Data presented in the thesis showed that a new disinfectant foam, DF-200, developed by Sandia National Laboratories (at the request of the Department of Defense) was highly effective against bovine enterovirus, bovine coronavirus, various group A influenza viruses and the foot and mouth disease (FMD) virus. A major advantage of this disinfectant foam is that it is less caustic than other disinfectants that were tested. DF-200 is now marketed under the trade name EasyDECON? and is expected to be highly effective against PCV2. However, to date, no studies proving the effectiveness of DF-200 on PCV2 inactivation have been published.
This and other PCVAD briefs are available online from http://www.pork.org. Visit the For Producers tab and click on Swine Health. Dick Hesse of Kansas State University collaborates with the Pork Checkoff to offer monthly updates on the state of PCVAD in the U.S. and global swine industry.
[e-Letter wishes to thank Angela DeMirjyn, NPB Manager, Science Communications, for providing us with this update from Dr. Hesse.]