Submitted to: Swine Disease Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 4, 2002
Publication Date: December 4, 2002
Technical Abstract: Porcine reproductive and respiratory syndrome (PRRS) is a disease of swine caused by the PRRS virus (PRRSV). This disease was first recognized in 1987 and since then PRRS has become the number one infectious disease concern of the US swine industry resulting in significant economic losses due to abortions in sows and respiratory disease in young pigs. Summarized in this paper are the results of PRRSV vaccine and virus transmission experiments. Vaccines have been developed to help control and prevent PRRS. Although the vaccines are safe and efficacious under experimental conditions, there is concern in the field about the safety and efficacy of these vaccines. A critical part of any PRRS control strategy involves stopping the spread or transmission of PRRSV from one swine herd to another. Typically, this occurs through direct contact between infected and susceptible pigs or from the use of PRRSV-contaminated semen collected from infected boars. Some PRRSV transmission appears to occur without direct contact and these cases of PRRSV transmission are referred to as indirect contact transmission, i.e., no direct contact between animals in the infected herd and the susceptible herd. In many of these indirect transmission cases there is no evidence that people or equipment transmitted the virus from one herd to another, e. g., through the use of contaminated equipment or boots. In these cases it is assumed that PRRSV was transmitted from the infected to susceptible herd by way of insects and birds carrying the virus or by way of the wind - an aerosol route of transmission. Application of this experimental data to the control and prevention of PRRS is discussed.