The Arctic fox, also known as the white fox, polar fox, or snow fox, is a small fox that belongs to the family of Canidae, native to the Arctic regions of the Northern Hemisphere and common throughout the Arctic tundra biome. It is well adapted to living in cold environments, and is best known for its thick, warm fur that is also used as camouflage. It has a large and very fluffy tail. In the wild, most individuals do not live past their first year but some exceptional ones survive up to 11 years. Its body length ranges from 46 to 68 cm, with a generally rounded body shape to minimize the escape of body heat.
An RNA virus is a virus—other than a retrovirus—that has ribonucleic acid (RNA) as its genetic material. The nucleic acid is usually single-stranded RNA (ssRNA) but it may be double-stranded (dsRNA). Notable human diseases caused by RNA viruses include the common cold, influenza, SARS, MERS, COVID-19, Dengue Virus, hepatitis C, hepatitis E, West Nile fever, Ebola virus disease, rabies, polio, mumps, and measles.
Rhabdoviridae is a family of negative-strand RNA viruses in the order Mononegavirales. Vertebrates, invertebrates, plants, fungi and protozoans serve as natural hosts. Diseases associated with member viruses include rabies encephalitis caused by the rabies virus, and flu-like symptoms in humans caused by vesiculoviruses. The name is derived from Ancient Greek rhabdos, meaning rod, referring to the shape of the viral particles. The family has 40 genera, most assigned to three subfamilies.
Lyssavirus is a genus of RNA viruses in the family Rhabdoviridae, order Mononegavirales. Mammals, including humans, can serve as natural hosts. The genus Lyssavirus includes the rabies virus traditionally associated with the disease of the same name.
Rabies virus, scientific name Rabies lyssavirus, is a neurotropic virus that causes rabies in animals, including humans. Rabies transmission can occur through the saliva of animals and less commonly through contact with human saliva. Rabies lyssavirus, like many rhabdoviruses, has an extremely wide host range. In the wild it has been found infecting many mammalian species, while in the laboratory it has been found that birds can be infected, as well as cell cultures from mammals, birds, reptiles and insects. Rabies is reported in more than 150 countries and on all continents except Antarctica. The main burden of disease is reported in Asia and Africa, but some cases have been reported also in Europe in the past 10 years, especially in returning travellers.
Menangle pararubulavirus, also called Menangle virus, is a virus that infects pigs, humans and bats.
Australian bat lyssavirus (ABLV), originally named Pteropid lyssavirus (PLV), is a enzootic virus closely related to the rabies virus. It was first identified in a 5-month-old juvenile black flying fox collected near Ballina in northern New South Wales, Australia, in January 1995 during a national surveillance program for the recently identified Hendra virus. ABLV is the seventh member of the genus Lyssavirus and the only Lyssavirus member present in Australia. ABLV has been categorized to the Phylogroup I of the Lyssaviruses.
Mokola lyssavirus, commonly called Mokola virus (MOKV), is an RNA virus related to rabies virus that has been sporadically isolated from mammals across sub-Saharan Africa. The majority of isolates have come from domestic cats exhibiting symptoms characteristically associated to rabies virus infection.
Betaarterivirus suid 1, commonly 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. This economically important, panzootic disease causes reproductive failure in breeding stock and respiratory tract illness in young pigs.
Influenza A virus subtype H9N2 (A/H9N2) is a subtype of the species Influenza A virus . Since 1998 a total of 86 cases of human infection with H9N2 viruses have been reported.
Duvenhage lyssavirus (DUVV) is a member of the genus Lyssavirus, which also contains the rabies virus. The virus was discovered in 1970, when a South African farmer died of a rabies-like encephalitic illness, after being bitten by a bat. In 2006, Duvenhage virus killed a second person, when a man was scratched by a bat in North West Province, South Africa, 80 km from the 1970 infection. He developed a rabies-like illness 27 days after the bat encounter, and died 14 days after the onset of illness. A 34-year-old woman who died in Amsterdam on December 8, 2007, was the third recorded fatality. She had been scratched on the nose by a small bat while travelling through Kenya in October 2007, and was admitted to hospital four weeks later with rabies-like symptoms.
Rabies is a viral disease that causes encephalitis in humans and other mammals. It was historically referred to as hydrophobia due to the symptom of panic when presented with liquids to drink. Early symptoms can include fever and abnormal sensations at the site of exposure. These symptoms are followed by one or more of the following symptoms: nausea, vomiting, violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, confusion, and loss of consciousness. Once symptoms appear, the result is virtually always death, regardless of treatment. The time period between contracting the disease and the start of symptoms is usually one to three months but can vary from less than one week to more than one year. The time depends on the distance the virus must travel along peripheral nerves to reach the central nervous system.
Almost all human deaths caused by rabies occur in Asia and Africa. There are an estimated 59,000 human deaths annually from rabies worldwide.
Pseudotyping is the process of producing viruses or viral vectors in combination with foreign viral envelope proteins. The result is a pseudotyped virus particle, also called a pseudovirus. With this method, the foreign viral envelope proteins can be used to alter host tropism or increase or decrease the stability of the virus particles. Pseudotyped particles do not carry the genetic material to produce additional viral envelope proteins, so the phenotypic changes cannot be passed on to progeny viral particles. In some cases, the inability to produce viral envelope proteins renders the pseudovirus replication incompetent. In this way, the properties of dangerous viruses can be studied in a lower risk setting.
Viral phylodynamics is defined as the study of how epidemiological, immunological, and evolutionary processes act and potentially interact to shape viral phylogenies. Since the coining of the term in 2004, research on viral phylodynamics has focused on transmission dynamics in an effort to shed light on how these dynamics impact viral genetic variation. Transmission dynamics can be considered at the level of cells within an infected host, individual hosts within a population, or entire populations of hosts.
Cryptic rabies refers to infection from unrecognized exposure to rabies virus. It is often phylogenetically traced to bats. It is most often seen in the southern United States. Silver-haired bats and tricolored bats are the two most common bat species associated with this form of infection, though both species are known to have less contact with humans than other bat species such as the big brown bat. That species is common throughout the United States and often roosts in buildings and homes where human contact is more likely.
Cross-species transmission (CST), also called interspecies transmission, host jump, or spillover, is the transmission of an infectious pathogen, such as a virus, between hosts belonging to different species. Once introduced into an individual of a new host species, the pathogen may cause disease for the new host and/or acquire the ability to infect other individuals of the same species, allowing it to spread through the new host population. The phenomenon is most commonly studied in virology, but cross-species transmission may also occur with bacterial pathogens or other types of microorganisms.
The bat virome is the group of viruses associated with bats. Bats host a diverse array of viruses, including all seven types described by the Baltimore classification system: (I) double-stranded DNA viruses; (II) single-stranded DNA viruses; (III) double-stranded RNA viruses; (IV) positive-sense single-stranded RNA viruses; (V) negative-sense single-stranded RNA viruses; (VI) positive-sense single-stranded RNA viruses that replicate through a DNA intermediate; and (VII) double-stranded DNA viruses that replicate through a single-stranded RNA intermediate. The greatest share of bat-associated viruses identified as of 2020 are of type IV, in the family Coronaviridae.
Negative-strand RNA viruses are a group of related viruses that have negative-sense, single-stranded genomes made of ribonucleic acid (RNA). They have genomes that act as complementary strands from which messenger RNA (mRNA) is synthesized by the viral enzyme RNA-dependent RNA polymerase (RdRp). During replication of the viral genome, RdRp synthesizes a positive-sense antigenome that it uses as a template to create genomic negative-sense RNA. Negative-strand RNA viruses also share a number of other characteristics: most contain a viral envelope that surrounds the capsid, which encases the viral genome, −ssRNA virus genomes are usually linear, and it is common for their genome to be segmented.
West Caucasian bat lyssavirus (WCBL) is a member of genus Lyssavirus, family Rhabdoviridae and order Mononegavirales. This virus was first isolated from Miniopterus schreibersii, in the western Caucasus Mountains of southeastern Europe in 2002. WCBL is the most divergent form of Lyssavirus, and is found in Miniopterus bats (insectivorous), Rousettus aegyptiacus, and Eidolon helvum. The latter two are both fruit bats. The virus is fragile as it can be inactivated by UV light and chemicals, such as ether, chloroform, and bleach. WCBL has not been known to infect humans thus far.
