Submitted to: Pan American Congress on Veterinary Science Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 1, 2000
Publication Date: N/A
Technical Abstract: The first case of a new disease of swine was recognized in the USA in 1987, presenting primarily as reproductive failure in pregnant gilts and sows and respiratory tract illness in young pigs. It soon spread throughout North America; in 1990 it appeared for the first time in Europe. Today this disease, known as porcine reproductive and respiratory syndrome (PRRS), is present in most countries where swine are raised commercially. It has become one of the most economically important infectious diseases ever faced by the swine industry. The cause of PRRS, presumed to be a virus early on, was identified with certainty in 1991 when Dutch scientists isolated PRRS virus (PRRSV) in porcine alveolar macrophages. Soon thereafter American scientists isolated a different strain of PRRSV in an established line of monkey kidney cells (MA-104). Numerous previous attempts to isolate and propagate PRRSV using other cell types had been unsuccessful. The ability to isolate and propagate PRRSV in vitro made it possible to perform a large number of subsequent studies on the nature of the virus and the disease. Despite all of these studies PRRS still remains a mystery disease in many respects, and there is still no highly reliable strategy for its prevention and control. This report reviews some of what is presently known about PRRS and PRRSV, and what is still unknown in an effort to provide a guideline for future research. As we learn more about the virus and the disease we will develop progressively better methods for their control and perhaps eradication. This information is based on PRRSV and PRRS appearing in North America. Strains of the virus, prevalence, and severity of the disease may differ elsewhere in the world.