Cardiovirus are a group of

viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almo ...

within order ''

Picornavirales ''Picornavirales'' is an order of viruses with vertebrate, invertebrate, protist and plant hosts. The name has a dual etymology. First, ''picorna-'' is an acronym for poliovirus, insensitivity to ether, coxsackievirus, orphan virus, rhinovirus, ...

'', family ''

Picornaviridae Picornaviruses are a group of related nonenveloped RNA viruses which infect vertebrates including fish, mammals, and birds. They are viruses that represent a large family of small, positive-sense, single-stranded RNA viruses with a 30 nm ...

''.

Vertebrates Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

serve as natural hosts for these viruses.

Taxonomy

The genus contains the following species: * ''Cardiovirus dhusarah'' (Cardiovirus F) * ''Cardiovirus ranori'' (Cardiovirus C) * ''Cardiovirus rudhira'' (Cardiovirus E) * ''Cardiovirus rueckerti'' (Cardiovirus A), Encephalomyocarditis virus * ''Cardiovirus saffoldi'' (Cardiovirus D), Saffold virus * ''Cardiovirus theileri'' (Cardiovirus B), which contains Theiler's murine encephalomyelitis virus

Structure

Cardioviruses are single-stranded RNA, non-enveloped viruses with icosahedral or spherical geometries, and a T=pseudo3 icosahedral capsid protein geometry. The diameter is around 30 nm. Genomes are linear and non-segmented, around 7.8 kb in length. The T=pseudo3 icosahedral capsid of Cadiovirus is made of 60 protomers, each of which contains 4 polypeptides: VP1, VP2, VP3, and VP4. Inside the capsid of the virus there is a single linear, positive single-stranded RNA. On both the 3' and 5' ends of the genome there are untranslated regions. These untranslated regions of genome are important for the DNA replication, with the untranslated region on the 5' side being the location of internal ribosomal entry site (IRES).

Life cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment of the virus to host receptors, which mediates endocytosis. Replication follows the positive stranded RNA virus replication model. Positive stranded rna virus transcription is the method of transcription. Translation takes place by −1 ribosomal frameshifting, viral initiation, and ribosomal skipping. The virus exits the host cell by lysis, and viroporins. Human and vertebrates serve as the natural host. Transmission routes are

zoonosis A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a virus, bacterium, parasite, fungi, or prion) that can jump from a non-human vertebrate to a human. When ...

and fomite. The 3’ end of the genome encodes a

polyA Polyadenylation is the addition of a poly(A) tail to an RNA transcript, typically a messenger RNA (mRNA). The poly(A) tail consists of multiple adenosine monophosphates; in other words, it is a stretch of RNA that has only adenine bases. In euka ...

tail while the 5’ end encodes a genome-linked protein. A unique feature of this genus is the presence of the L* protein, 18kDa, that is made out of frame from the polyprotein and is present in the DA subgroup of TMEV. In the case of Encephalomyocarditis virus, the virus can cause encephalitis and myocarditis, mostly in rodents, which are natural

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County * Host Island, in the Wilhelm Archipelago, Antarctica People * ...

s. The virus is transmitted from rodents to other animals. Severe epidemics have been seen in

swine Suina (also known as Suiformes) is a suborder of omnivorous, non-ruminant artiodactyl mammals that includes the domestic pig and peccaries. A member of this clade is known as a suine. Suina includes the family Suidae, termed suids, known in ...

and

elephant Elephants are the largest living land animals. Three living species are currently recognised: the African bush elephant ('' Loxodonta africana''), the African forest elephant (''L. cyclotis''), and the Asian elephant ('' Elephas maximus ...

Clinical

Human cardioviruses were first isolated in 1981. Seven additional isolates have since been described in North America, Europe and South Asia. They have been associated with gastroenteritis, influenza-like symptoms and non-

polio Poliomyelitis ( ), commonly shortened to polio, is an infectious disease caused by the poliovirus. Approximately 75% of cases are asymptomatic; mild symptoms which can occur include sore throat and fever; in a proportion of cases more severe ...

-associated

acute flaccid paralysis Flaccid paralysis is a neurological condition characterized by weakness or paralysis and reduced muscle tone without other obvious cause (e.g., trauma). This abnormal condition may be caused by disease or by trauma affecting the nerves associ ...

. The first infection of cardiovirus in humans was identified in 2007 in a stool sample of an infant that was experiencing fever of unknown origin. It was subsequently named the Saffold virus after the lead researcher, Morris Saffold Jones. Other pathogenic cardioviruses isolated from humans include the Syr-Darya valley fever virus and Vilyuisk human encephalomyelitis virus.Anonymous. (2014) Genetic characterization of the Syr-Darya valley fever virus (SDVFV) (Picornaviridae, Cardiovirus) isolated from the blood of the patients and ticks ''Hyalomma as. asiaticum'' (Hyalomminae), ''Dermacentor daghestanicus'' (Rhipicephalinae) (Ixodidae) and ''Ornithodoros coniceps'' (Argasidae) in Kazakhstan and Turkmenistan. Vopr Virusol 59(4):15–19 Diseases associated with cardioviruses include:

myocarditis Myocarditis is inflammation of the cardiac muscle. Myocarditis can progress to inflammatory cardiomyopathy when there is associated ventricular remodeling and cardiac dysfunction due to chronic inflammation. Symptoms can include shortness of bre ...

encephalitis Encephalitis is inflammation of the Human brain, brain. The severity can be variable with symptoms including reduction or alteration in consciousness, aphasia, headache, fever, confusion, a stiff neck, and vomiting. Complications may include se ...

multiple sclerosis Multiple sclerosis (MS) is an autoimmune disease resulting in damage to myelinthe insulating covers of nerve cellsin the brain and spinal cord. As a demyelinating disease, MS disrupts the nervous system's ability to Action potential, transmit ...

, and

type 1 diabetes Type 1 diabetes (T1D), formerly known as juvenile diabetes, is an autoimmune disease that occurs when the body's immune system destroys pancreatic cells (beta cells). In healthy persons, beta cells produce insulin. Insulin is a hormone require ...

References

External links