Porcine Reproductive and Respiratory Syndrome (PRRS): A Persistent Challenge in Swine Production

Abstract

The porcine reproductive and respiratory syndrome is the most economically consequential disease facing the swine industry today.

It is caused by the PRRSV a small, enveloped, RNA virus within the Arteviridae family. PRRSV targets monocytes and macrophages, heavily affecting the respiratory and reproductive system of the pigs. The virus spread through aerosols, direct contact, contaminated semen, oral ingestion, and can cross the placental barrier and spread through vertical transmission. The virus causes mild respiratory disease in adult pigs and often causes reproductive failure like stillbirths and mummified fetuses in sows.

It was initially detected in a few isolated cases in the late 1980s, but after two outbreaks one in Germany and the other in the US the virus spread across the world. These outbreaks gave rise to two separate variants which have become endemic to most pork producing countries today. The European variant which is called Type 1 and is mostly found in Europe, and the North American variant which is called Type 2 and is mostly found in North America, South America, and Asia.

There's currently no cure, only vaccines with limited effect, and limited treatments. Currently most treatments consist of symptomatic treatment and broad-spectrum antibiotics to prevent secondary infections. The most effective method for preventing PRRS outbreaks is by controlling its spread. Currently stringent biosecurity measures, closed herd systems, strategic vaccination programs, and regional collaboration for disease monitoring and control have proven effective.