Vesicular exanthema of swine virus (VESV) is a virus which produces a disease in pigs that is clinically indistinguishable from the viruses causing foot-and-mouth disease (FMD) and swine vesicular disease (SVD). VESV affects only pigs and marine mammals. It is not transmissible to humans.
VESV is only a concern among Californian pig-farmers; otherwise, the disease is now, by and large, a historical curiosity. It was globally eradicated in swine in 1959. [3]
Viruses that are virtually identical to VESV are present in marine mammals and fish along the Pacific coast of the United States. These viruses are sometimes called San Miguel Sea Lion Virus. [3] It is therefore assumed that the source of VESV was waste seafood fed to pigs or as garbage finding its way to pigs from farmed mink that were fed seafood.
VESV was first diagnosed in pigs in Southern California in 1932. Because of its close similarity to FMD, all the pigs were destroyed. It kept reappearing in California from time to time, with the pigs being slaughtered each time. Then, in 1952, the virus escaped from California in a trainload of infected pork. Garbage-fed pig herds came down with the disease, and it spread from them to neighboring herds until herds in 43 states were affected. It was eventually stamped out in 1956 by a major slaughter policy combined with a ban on feeding uncooked garbage to pigs. It was declared an exotic disease in the United States in 1959.
The only cases outside the United States were in slaughter pigs on ships from the U.S. bound for Hawaii in 1947 and in pigs fed uncooked pork scraps from an American military base in Iceland in 1955.
The source of the virus remained a mystery until 1972, when an essentially similar virus, the San Miguel sea lion virus (SMSV) was isolated from San Miguel Island sea lions. When inoculated experimentally into pigs, it caused typical signs of VESV.
Once established within a herd, transmission from pig to pig is by direct contact. Initiation of new outbreaks starts by feeding infected uncooked pork scraps.
Symptoms are very similar to FMD and include:
Mortality is low, but there may be some deaths in suckling piglets. Growing pigs may become debilitated.
Diagnosis requires laboratory tests. Serological methods such as complement fixation, serum neutralization and PCR are available. [3]
Virions consist of a capsid. Virus capsid is not enveloped, round with icosahedral symmetry. The isometric capsid has a diameter of 35–39 nm. Capsids appear round to hexagonal in outline. The capsid surface structure reveals a regular pattern with distinctive features. The capsomer arrangement is clearly visible. Capsid with 32 cup-shaped depressions.
Under in vitro conditions, virions are inactivated in acid environment of pH 3–5.
The genome is not segmented and contains a single molecule of linear positive-sense, single-stranded RNA. Minor species of non-genomic nucleic acid are also found in virions. The complete genome is 7900 nucleotides long. The 5'-end of the genome has a viral protein genome-linked (VPg). The 3'-terminus has a poly (A) tract. The genome encodes viral structural proteins. Lipids are not reported.
By itself, the genomic nucleic acid is infectious.
No vaccines are available. The cooked garbage policy in the United States should prevent its reappearance. Pigs should not be fed waste seafood. [3]
Parvoviruses are a family of animal viruses that constitute the family Parvoviridae. They have linear, single-stranded DNA (ssDNA) genomes that typically contain two genes encoding for a replication initiator protein, called NS1, and the protein the viral capsid is made of. The coding portion of the genome is flanked by telomeres at each end that form into hairpin loops that are important during replication. Parvovirus virions are small compared to most viruses, at 23–28 nanometers in diameter, and contain the genome enclosed in an icosahedral capsid that has a rugged surface.
Tombusviridae is a family of single-stranded positive sense RNA plant viruses. There are three subfamilies, 17 genera, and 95 species in this family. The name is derived from Tomato bushy stunt virus (TBSV).
Aphthovirus is a viral genus of the family Picornaviridae. Aphthoviruses infect split-hooved animals, and include the causative agent of foot-and-mouth disease, Foot-and-mouth disease virus (FMDV). There are seven FMDV serotypes: A, O, C, SAT 1, SAT 2, SAT 3 and Asia 1, and four non-FMDV serotypes belonging to three additional species Bovine rhinitis A virus (BRAV), Bovine rhinitis B virus (BRBV) and Equine rhinitis A virus (ERAV).
Sheeppox is a highly contagious disease of sheep caused by a poxvirus different from the benign orf. This virus is in the family Poxviridae and genus Capripoxvirus. Sheeppox virus (SPV) is the most severe of all the animal pox diseases and can result in some of the most significant economic consequences due to poor wool and leather quality.
Varicellovirus (var′i-sel′ō-vi′rŭs) is a genus of viruses belonging to subfamily Alphaherpesvirinae, a member of family Herpesviridae. Humans and other mammals serve as natural hosts. There are 19 species in this genus. Diseases associated with this genus include: HHV-3—chickenpox (varicella) and shingles; BoHV-1—infectious bovine rhinotracheitis/infectious pustular vulvovaginitis (IPV); and SuHV-1 —Aujesky's disease.
Dependoparvovirus is a genus in the subfamily Parvovirinae of the virus family Parvoviridae; they are Group II viruses according to the Baltimore classification. Some dependoparvoviruses are also known as adeno-associated viruses because they cannot replicate productively in their host cell without the cell being coinfected by a helper virus such as an adenovirus, a herpesvirus, or a vaccinia virus.
Kobuvirus is a genus of viruses in the order Picornavirales, in the family Picornaviridae. Humans and cattle serve as natural hosts. There are six species in this genus. Diseases associated with this genus include: gastroenteritis. The genus was named because of the virus particles' lumpy appearance by electron microscopy; "kobu" means "knob" in Japanese.
Tectiviridae is a family of viruses with 10 species in five genera. Bacteria serve as natural hosts. Tectiviruses have no head-tail structure, but are capable of producing tail-like tubes of ~ 60×10 nm upon adsorption or after chloroform treatment. The name is derived from Latin tectus.
Fijivirus is a genus of double-stranded RNA viruses in the family Reoviridae and subfamily Spinareovirinae. Plants serve as natural hosts. Diseases associated with this genus include: galls (tumours) in infected plants and Fiji disease, with severe stunting, deformation and death. The group name derives from Fiji island the place where the first virus was isolated. There are nine species in this genus.
Swine vesicular disease (SVD) is an acute, contagious viral disease of swine caused by swine vesicular disease virus, an Enterovirus. It is characterized by fever and vesicles with subsequent ulcers in the mouth and on the snout, feet, and teats. The pathogen is relatively resistant to heat, and can persist for a long time in salted, dried, and smoked meat products. Swine vesicular disease does not cause economically important disease, but is important due to its similarity to foot-and-mouth disease.
Ascoviridae is a family of double strand DNA viruses that infect primarily invertebrates, mainly noctuids and spodoptera species; it contains two genera, Ascovirus, which contains three species, and Toursvirus with a single species Diadromus pulchellus toursvirus.
Foot-and-mouth disease (FMD) or hoof-and-mouth disease (HMD) is an infectious and sometimes fatal viral disease that affects cloven-hoofed animals, including domestic and wild bovids. The virus causes a high fever lasting two to six days, followed by blisters inside the mouth and near the hoof that may rupture and cause lameness.
Endornaviridae is a family of viruses. Plants, fungi, and oomycetes serve as natural hosts. There are 31 species in this family, assigned to 2 genera. Members of Alphaendornavirus infect plants, fungi and the oomycete Phytophthora sp., members of Betaendornavirus infect ascomycete fungi.
Vesivirus is a genus of viruses, in the family Caliciviridae. Swine, sea mammals, and felines serve as natural hosts. There are two species in this genus. Diseases associated with this genus include: respiratory disease, Feline calicivirus (FCV); conjunctivitis, and respiratory disease.
Lagovirus is a genus of viruses, in the family Caliciviridae. Lagomorphs serve as natural hosts. There are two species in this genus. Diseases associated with this genus include: necrotizing hepatitis leading to fatal hemorrhages.
Mason-Pfizer monkey virus (M-PMV), formerly Simian retrovirus (SRV), is a species of retroviruses that usually infect and cause a fatal immune deficiency in Asian macaques. The ssRNA virus appears sporadically in mammary carcinoma of captive macaques at breeding facilities which expected as the natural host, but the prevalence of this virus in feral macaques remains unknown. M-PMV was transmitted naturally by virus-containing body fluids, via biting, scratching, grooming, and fighting. Cross contaminated instruments or equipment (fomite) can also spread this virus among animals.
Mastadenovirus is a genus of viruses in the family Adenoviridae. Humans and other mammals serve as natural hosts. There are 51 species in this genus. The genus as a whole includes many very common causes of human infection, estimated to be responsible for 2 to 5% of all respiratory infections, as well as gastrointestinal and eye infections. Symptoms are usually mild.
Suipoxvirus is a genus of viruses in the family Poxviridae and subfamily Chordopoxvirinae. Swine serve as natural hosts. There is only one species in this genus: Swinepox virus. Diseases associated with this genus include asymptomatic skin disease.
Varidnaviria is a realm of viruses that includes all DNA viruses that encode major capsid proteins that contain a vertical jelly roll fold. The major capsid proteins (MCP) form into pseudohexameric subunits of the viral capsid, which stores the viral deoxyribonucleic acid (DNA), and are perpendicular, or vertical, to the surface of the capsid. Apart from this, viruses in the realm also share many other characteristics, such as minor capsid proteins (mCP) with the vertical jelly roll fold, an ATPase that packages viral DNA into the capsid, and a DNA polymerase that replicates the viral genome.
Adnaviria is a realm of viruses that includes archaeal viruses that have a filamentous virion and a linear, double-stranded DNA genome. The genome exists in A-form (A-DNA) and encodes a dimeric major capsid protein (MCP) that contains the SIRV2 fold, a type of alpha-helix bundle containing four helices. The virion consists of the genome encased in capsid proteins to form a helical nucleoprotein complex. For some viruses, this helix is surrounded by a lipid membrane called an envelope. Some contain an additional protein layer between the nucleoprotein helix and the envelope. Complete virions are long and thin and may be flexible or a stiff like a rod.