Betaarterivirus suid 1

Porcine reproductive and respiratory syndrome virus (PRRSV), is a virus that causes a disease of pigs, called porcine reproductive and respiratory syndrome (PRRS), also known as blue-ear pig disease (in Chinese, zhū láněr bìng 豬藍耳病). This economically important, panzootic disease causes reproductive failure in breeding stock and respiratory tract illness in young pigs.

History

PRRS earlier known as "mystery swine disease" and "blue ear disease" during 1987–1988 in the United States and Canada caused first undiagnosed outbreaks, characterized by reproductive losses combined with respiratory signs. In 1990-1991, a similar disease was reported in several European countries such as Germany, The Netherlands, Belgium, Denmark, France, the United Kingdom, and Spain. The emergence of PRRS in Japan, Taiwan and mainland China was reported in 1987, 1991 and 1996, respectively.

According to the WOAH, the disease is now present throughout the world, especially in countries with major pig production. Australia, New Zealand, Norway, Sweden and Switzerland are PRRS free.

A better picture of PRRSV's genetic diversity suggested that the virus was present in the field before the "original" outbreaks. The lack of recorded data concerning the prevalence prior to the epidemic was due to unawareness of PRRS.

A hypothesis has been proposed that PRRSV derived of closely related murine lactate dehydrogenase-elevating virus. Phylogeographic analysis of PRRSV epidemiology suggested that the virus diversified into unique subpopulations in Russia and Belarus, approximately 110–140 years ago.