Porcine Reproductive and Respiratory Syndrome Virus
Encyclopedia
Porcine reproductive and respiratory syndrome virus (PRRSV), also known as blue-ear pig disease (in Chinese
, zhū láněr bìng 豬藍耳病), is a virus
that causes a disease
of pig
s, called porcine reproductive and respiratory syndrome (PRRS). This economically important, pandemic
disease causes reproductive failure in breeding stock and respiratory tract illness in young pigs. Initially referred to as "mystery swine disease" and "mystery reproductive syndrome," it was first reported in 1987 in North America
(2) and Central Europe
(3). The disease costs the United States swine industry around $600 million annually.
. It contains a single-stranded, positive-sense, RNA genome
with a size of approximately 15 kilobases. The genome contains nine open reading frame
s (Meulenburg et al., 1992, Lee and Yoo, 2005).
PRRSV is a member of the genus Arterivirus
, family Arteriviridae, order Nidovirales
. There are three other members of the genus Arterivirus; they are: equine arteritis virus
(EAV), simian hemorrhagic fever virus
(SHFV), and lactate dehydrogenase elevating virus
(LDV) (4-5).
.
Chinese language
The Chinese language is a language or language family consisting of varieties which are mutually intelligible to varying degrees. Originally the indigenous languages spoken by the Han Chinese in China, it forms one of the branches of Sino-Tibetan family of languages...
, zhū láněr bìng 豬藍耳病), is a virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
that causes a disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
of pig
Pig
A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...
s, called porcine reproductive and respiratory syndrome (PRRS). This economically important, pandemic
Pandemic
A pandemic is an epidemic of infectious disease that is spreading through human populations across a large region; for instance multiple continents, or even worldwide. A widespread endemic disease that is stable in terms of how many people are getting sick from it is not a pandemic...
disease causes reproductive failure in breeding stock and respiratory tract illness in young pigs. Initially referred to as "mystery swine disease" and "mystery reproductive syndrome," it was first reported in 1987 in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
(2) and Central Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
(3). The disease costs the United States swine industry around $600 million annually.
Classification
PRRSV is a small, enveloped RNA virusRNA virus
An RNA virus is a virus that has RNA as its genetic material. This nucleic acid is usually single-stranded RNA but may be double-stranded RNA...
. It contains a single-stranded, positive-sense, RNA genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
with a size of approximately 15 kilobases. The genome contains nine open reading frame
Open reading frame
In molecular genetics, an open reading frame is a DNA sequence that does not contain a stop codon in a given reading frame.Normally, inserts which interrupt the reading frame of a subsequent region after the start codon cause frameshift mutation of the sequence and dislocate the sequences for stop...
s (Meulenburg et al., 1992, Lee and Yoo, 2005).
PRRSV is a member of the genus Arterivirus
Arterivirus
Arterivirus is a genus of virus, with type species equine arteritis virus. In 1996, the family Arteriviridae was included within the order Nidovirales. Arteriviruses are small, enveloped, animal viruses with an icosahedral core containing a positive-sense RNA genome...
, family Arteriviridae, order Nidovirales
Nidovirales
The Nidovirales are an order of viruses with animal hosts. It includes the families Coronaviridae, Arterivirus and Roniviridae.-Virology:...
. There are three other members of the genus Arterivirus; they are: equine arteritis virus
Equine viral arteritis
Equine viral arteritis is a disease of horses caused by an RNA virus of the genus Arterivirus. The virus which causes EVA was first isolated from horses in Ohio in 1953 but the disease has afflicted equine animals worldwide for centuries. It has been more common in some breeds of horses in the...
(EAV), simian hemorrhagic fever virus
Simian hemorrhagic fever virus
Simian hemorrhagic fever virus or simian haemorrhagic fever virus or SHFV is a highly pathogenic virus in monkeys. It is a positive-stranded RNA virus classified in the family Arteriviridae.- Hosts :...
(SHFV), and lactate dehydrogenase elevating virus
Lactate dehydrogenase elevating virus
Lactate dehydrogenase elevating virus, or LDV for short, belongs to part of the arteriviridae family and the nidovirales order. Also included in the nidovirales order are the coronaviridae. The arteriviridae infect macrophages in animals and cause a variety of diseases...
(LDV) (4-5).
Strains
There are two prototype strains of PRRSV. The North American strain is VR-2332 and the European strain is the Lelystad Virus (LV). The European and North American PRRSV strains cause similar clinical symptoms, but they represent two distinct viral genotypes whose genomes diverge by approximately 40% (6), thus creating a veil of mystery about the origin of this virus. The genetic variation among the viruses isolated from different places (7-8) increases the difficulty of developing vaccines against it. Similarly, there is difficulty in maintaining diagnostic PCR detection assays due to the high mutation rate of this virus, see Risk of Missed PRRS PCR DetectionRisk of Missed PRRS PCR Detection
Porcine reproductive and respiratory syndrome virus is an RNA virus that causes reproductive and respiratory disease in swine. PRRS was first recognized in midwestern United States in the late 1980's. Pork producers and veterinarians use vaccination, test-and-removal, and other farm-management...
.
External links
- Porcine Reproductive and Respiratory Syndrome Virus Database
- New York Times article on the 2007 epidemic
- Animal viruses
- PRRS Research Award for PRRS Eradication
- PADRAP Production Animal Disease Risk Assessment Program PRRS Risk Survey
- Animal viruses
- The latest new features on this swine disease, created by Scott A. Dee
- PRRS, from ThePigSite disease guide