Equid alphaherpesvirus 4 | |
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Virus classification | |
(unranked): | Virus |
Realm: | Duplodnaviria |
Kingdom: | Heunggongvirae |
Phylum: | Peploviricota |
Class: | Herviviricetes |
Order: | Herpesvirales |
Family: | Herpesviridae |
Genus: | Varicellovirus |
Species: | Equid alphaherpesvirus 4 |
Synonyms | |
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Equid alphaherpesvirus 4, formerly Equine herpesvirus 4 (EHV-4) is a virus of the family Herpesviridae that cause rhinopneumonitis in horses. It is the most important viral cause of respiratory infection in foals. [2] Like other herpes viruses, EHV-4 causes a lifelong latent infection in affected animals. These horses are usually the source for new infection for foals over two months old, weanlings, and yearlings. Symptoms include fever, loss of appetite, and discharge from the nose. Most infected animals recover in one to three weeks, [3] but death can occur in environments with overcrowding and other stress factors. There are several vaccines available (ATCvet codes: QI05AA03 ( WHO ) inactivated, QI05AD01 ( WHO ) live, plus various combinations).
EHV-4 is an upper respiratory disease restricted to the infection of the respiratory tract epithelium and its associated lymph nodes. [4] EHV 4 and its close relative EHV 1 are clinically and pathologically indistinguishable and are the primary pathogens that cause respiratory tract disease in young horses from weanling to 2 years of age. [5] Incubation period of Equine Herpiesvirus is 2–10 days. Symptoms include fever (38.9–41.7 °C), loss of appetite, and a nasal discharge giving it the nickname "snots". Without antibiotic treatment, the damage to the respiratory mucosal barrier predisposes infected horses to secondary infections and the involvement of the lower airways (ex. bronchiolitis or pneumonia); Increasing the duration, severity and the mortality of the disease. [4] EHV-4 rarely causes abortion in infected pregnant mares unlike its EHV-1 counterpart. [5] Although there is no specific treatment for the disease once a horse is infected, vaccination against EHV-1 and EHV-4 is recommended as part of preventative herd health for those at high risk of infection. Multiple vaccines are available (Duvaxyn EHV1,4, EquiGuard, EquiVac EHV-1/4, etc.), most in an inactivated virus form. [4]
The Equine Herpesvirus occupies the horse in such a way that allows post infection viral persistency over the lifetime of an animal. These carrier horses may comprise up to half of a given horse population. Therefore, management practices are recommended for controlling and managing EHV include isolating incoming horses for 3–4 weeks before co-mingling with resident horses and pregnant mares, reducing stress to prevent the reappearance of a latent virus and if there is an appearance of EHV affected horses should be isolated, and disinfection of the contaminated premise should commence. [5] (The EHV has a large genome (150 kb) which is enclosed in a relatively fragile capsule. This limits their survival in the external environment and makes them highly susceptible to common disinfectants.) After an outbreak no horse should leave the premise for three weeks after the final clinical case recovers. Effective prevention measures, quick diagnosis, therapeutic intervention and the ability to control the spread in the case of an outbreak all allow for the management of EHV.
Canid alphaherpesvirus 1 (CaHV-1), formerly Canine herpesvirus (CHV), is a virus of the family Herpesviridae which most importantly causes a fatal hemorrhagic disease in puppies less than two to three weeks old. It is known to exist in the United States, Canada, Australia, Japan, England and Germany. CHV was first recognized in the mid-1960s from a fatal disease in puppies.
Herpesviridae is a large family of DNA viruses that cause infections and certain diseases in animals, including humans. The members of this family are also known as herpesviruses. The family name is derived from the Greek word ἕρπειν, referring to spreading cutaneous lesions, usually involving blisters, seen in flares of herpes simplex 1, herpes simplex 2 and herpes zoster (shingles). In 1971, the International Committee on the Taxonomy of Viruses (ICTV) established Herpesvirus as a genus with 23 viruses among four groups. As of 2020, 115 species are recognized, all but one of which are in one of the three subfamilies. Herpesviruses can cause both latent and lytic infections.
Bovine alphaherpesvirus 1 (BoHV-1) is a virus of the family Herpesviridae and the subfamily Alphaherpesvirinae, known to cause several diseases worldwide in cattle, including rhinotracheitis, vaginitis, balanoposthitis, abortion, conjunctivitis, and enteritis. BoHV-1 is also a contributing factor in shipping fever, also known as bovine respiratory disease (BRD). It is spread horizontally through sexual contact, artificial insemination, and aerosol transmission and it may also be transmitted vertically across the placenta. BoHV-1 can cause both clinical and subclinical infections, depending on the virulence of the strain. Although these symptoms are mainly non-life-threatening it is an economically important disease as infection may cause a drop in production and affect trade restrictions. Like other herpesviruses, BoHV-1 causes a lifelong latent infection and sporadic shedding of the virus. The sciatic nerve and trigeminal nerve are the sites of latency. A reactivated latent carrier is normally the source of infection in a herd. The clinical signs displayed are dependent on the virulence of the strain. There is a vaccine available which reduces the severity and incidence of disease. Some countries in Europe have successfully eradicated the disease by applying a strict culling policy.
Bovine alphaherpesvirus 2 (BoHV2) is a virus of the family Herpesviridae that causes two diseases in cattle, bovine mammillitis and pseudo-lumpy skin disease. BoHV2 is similar in structure to human herpes simplex virus.
Aujeszky's disease, usually called pseudorabies in the United States, is a viral disease in swine that has been endemic in most parts of the world. It is caused by Suid herpesvirus 1 (SuHV-1). Aujeszky's disease is considered to be the most economically important viral disease of swine in areas where classical swine fever has been eradicated. Other mammals, such as cattle, sheep, goats, cats, dogs, and raccoons, are also susceptible. The disease is usually fatal in these animal species.
Equid alphaherpesvirus 3, formerly Equine herpesvirus 3 (EHV-3), is a virus of the family Herpesviridae that affects horses.
Equid alphaherpesvirus 1, formerly Equine herpesvirus 1 (EHV-1), is a virus of the family Herpesviridae that causes abortion, respiratory disease and occasionally neonatal mortality in horses. Initial spread of EHV-1 by a newly introduced horse through direct and indirect contact can lead to abortion and perinatal infection in up to 70 percent of a previously unexposed herd. Abortion usually occurs in the last four months of gestation, two to four weeks after infection of the mare. Perinatal infection can lead to pneumonia and death. Encephalitis can occur in affected animals, leading to ataxia, paralysis, and death. There is a vaccine available, however its efficacy is questionable. The virus varies in severity from sub-clinical to very severe. Most horses have been infected with EHV-1, but the virus can become latent and persist without ever causing signs of infection. In 2006, an outbreak of EHV-1 among stables in Florida resulted in the institution of quarantine measures. The outbreak was determined to have originated in horses imported from Europe via New York, before being shipped to Florida.
Equid gammaherpesvirus 2, formerly Equine herpesvirus 2 (EHV-2), is a virus of the family Herpesviridae, originally known as equine cytomegalovirus due to its slow replication in tissue culture. However, complete sequencing of the EHV-2 genome has demonstrated that it is a member of the subfamily Gammaherpesvirinae, in the genus Percavirus. It has an uncertain role in respiratory disease in horses, but EHV-2 has been isolated from cases exhibiting symptoms such as coughing, conjunctivitis, and swollen submaxillary and parotid lymph nodes.
Feline viral rhinotracheitis (FVR) is an upper respiratory or pulmonary infection of cats caused by Felid alphaherpesvirus 1 (FeHV-1), of the family Herpesviridae. It is also commonly referred to as feline influenza, feline coryza, and feline pneumonia but, as these terms describe other very distinct collections of respiratory symptoms, they are misnomers for the condition. Viral respiratory diseases in cats can be serious, especially in catteries and kennels. Causing one-half of the respiratory diseases in cats, FVR is the most important of these diseases and is found worldwide. The other important cause of feline respiratory disease is feline calicivirus.
Gallid alphaherpesvirus 1 (GaHV-1) is a species of virus in the order Herpesvirales, family Herpesviridae, subfamily Alphaherpesvirinae, and genus Iltovirus. Originally recognised in chickens in the United States in 1926, this virus causes avian infectious laryngotracheitis, a potentially fatal, economically deleterious disease, widely recognised as one of the most contagious diseases in the poultry industry. The virus and its associated disease also occur in pheasants.
Feline calicivirus (FCV) is a virus of the family Caliciviridae that causes disease in cats. It is one of the two important viral causes of respiratory infection in cats, the other being Felid alphaherpesvirus 1. FCV can be isolated from about 50% of cats with upper respiratory infections. Cheetahs are the other species of the family Felidae known to become infected naturally.
Duck plague is a worldwide disease caused by Anatid alphaherpesvirus 1 (AnHV-1) of the family Herpesviridae that causes acute disease with high mortality rates in flocks of ducks, geese, and swans. It is spread both vertically and horizontally—through contaminated water and direct contact. Migratory waterfowl are a major factor in the spread of this disease as they are often asymptomatic carriers of disease. The incubation period is three to seven days. Birds as young as one week old can be infected. DEV is not zoonotic.
Gammaherpesvirinae is a subfamily of viruses in the order Herpesvirales and in the family Herpesviridae. Viruses in Gammaherpesvirinae are distinguished by reproducing at a more variable rate than other subfamilies of Herpesviridae. Mammals serve as natural hosts. There are 43 species in this subfamily, divided among 7 genera with three species unassigned to a genus. Diseases associated with this subfamily include: HHV-4: infectious mononucleosis. HHV-8: Kaposi's sarcoma.
Bovine alphaherpesvirus 5 (BoHV-5) is a virus species of the genus Varicellovirus and subfamily Alphaherpesvirinae. It causes meningoencephalitis and respiratory disease in cattle and sheep. As with all herpes viruses latent infection can occur, with recrudescence at times of stressed and/or immunosuppression. Sites of latency include the CNS and mucosae of the nose and trachea. The disease has been documented in South America, the United States, Australia, Germany and Hungary. Caused by: BHV-5 – Bovine Encephalitis Virus – Bovine Encephalitis Herpesvirus
Equine viral arteritis (EVA) is a disease of horses caused by a virus of the species Alphaarterivirus equid, an RNA virus. It is the only species in the genus Alphaarterivirus, and that is the only genus in the Equarterivirinae subfamily. The virus which causes EVA was first isolated in 1953, but the disease has afflicted equine animals worldwide for centuries. It has been more common in some breeds of horses in the United States, but there is no breed "immunity". In the UK, it is a notifiable disease. There is no known human hazard.
The Herpesvirales is an order of dsDNA viruses with animal hosts, characterised by a common morphology consisting of an icosahedral capsid enclosed in a glycoprotein-containing lipid envelope. Common infections in humans caused by members of this order include cold sores, genital herpes, chickenpox, shingles, and glandular fever. Herpesvirales is the sole order in the class Herviviricetes, which is the sole class in the phylum Peploviricota.
Bovine gammaherpesvirus 4 (BoHV-4) is a member of the Herpesviridae family. It is part of the subfamily Gammaherpesvirinae and genus Rhadinovirus. Infection is normally sub-clinical but can cause reproductive disease in cattle such as endometritis, vulvovaginitis and mastitis. Transmission is both vertical and horizontal. It can also be indirectly spread by fomites. Distribution is worldwide and the virus infects a range of ruminants, including bison, buffalo, sheep and goats.
Equine alphaherpesvirus 9 (EHV-9) is a species of virus in the genus Varicellovirus, subfamily Alphaherpesvirinae, family Herpesviridae, and order Herpesvirales. It was first isolated from a case of epizootic encephalitis in a herd of Thomson's gazelle in 1993. Fatal encephalitis was reported from Thomson's gazelle, giraffe, and polar bear in natural infections. The virus was reported in an aborted Persian onager and a polar bear.
Equid gammaherpesvirus 5 (EHV-5), formerly Equine herpesvirus 5, is a species of virus in the genus Percavirus, subfamily Gammaherpesvirinae, family Herpesviridae, and order Herpesvirales. It is thought to be the cause of a chronic lung disease of adult horses; equine multinodular pulmonary fibrosis.
Caprine alphaherpesvirus 1 (CpHV-1) is a species of virus known to infect goats worldwide. It has been shown to produce systemic and respiratory symptoms in kids and to cause abortions in adult goats.