Marburg virus disease is a severe illness of humans and non-human primates caused by either of the two Marburgviruses: Marburg virus (MARV) and Ravn virus (RAVV). MVD is a viral hemorrhagic fever (VHF), and the clinical symptoms are indistinguishable from Ebola virus disease (EVD).
Ticks are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by feeding on the blood of mammals, birds, and sometimes reptiles and amphibians. The timing of the origin of ticks is uncertain, though the oldest known tick fossils are from the Cretaceous period, around 100 million years old. Ticks are widely distributed around the world, especially in warm, humid climates.
Arbovirus is an informal name for any virus that is transmitted by arthropod vectors. The term arbovirus is a portmanteau word. Tibovirus is sometimes used to more specifically describe viruses transmitted by ticks, a superorder within the arthropods. Arboviruses can affect both animals and plants. In humans, symptoms of arbovirus infection generally occur 3–15 days after exposure to the virus and last three or four days. The most common clinical features of infection are fever, headache, and malaise, but encephalitis and viral hemorrhagic fever may also occur.
Tick-borne diseases, which afflict humans and other animals, are caused by infectious agents transmitted by tick bites. They are caused by infection with a variety of pathogens, including rickettsia and other types of bacteria, viruses, and protozoa. The economic impact of tick-borne diseases is considered to be substantial in humans, and tick-borne diseases are estimated to affect ~80 % of cattle worldwide.
Bunyavirales is an order of segmented negative-strand RNA viruses with mainly tripartite genomes. Member viruses infect arthropods, plants, protozoans, and vertebrates. It is the only order in the class Ellioviricetes. The name Bunyavirales derives from Bunyamwera, where the original type species Bunyamwera orthobunyavirus was first discovered. Ellioviricetes is named in honor of late virologist Richard M. Elliott for his early work on bunyaviruses.
Viral hemorrhagic fevers (VHFs) are a diverse group of animal and human illnesses in which fever and hemorrhage are caused by a viral infection. VHFs may be caused by five distinct families of RNA viruses: the families Filoviridae, Flaviviridae, Rhabdoviridae, and several member families of the Bunyavirales order such as Arenaviridae, and Hantaviridae. All types of VHF are characterized by fever and bleeding disorders and all can progress to high fever, shock and death in many cases. Some of the VHF agents cause relatively mild illnesses, such as the Scandinavian nephropathia epidemica, while others, such as Ebola virus, can cause severe, life-threatening disease.
Kyasanur forest disease (KFD) is a tick-borne viral haemorrhagic fever endemic to South-western part of India. The disease is caused by a virus belonging to the family Flaviviridae. KFDV is transmitted to humans through the bite of infected hard ticks which act as a reservoir of KFDV.
Crimean–Congo hemorrhagic fever (CCHF) is a viral disease. Symptoms of CCHF may include fever, muscle pains, headache, vomiting, diarrhea, and bleeding into the skin. Onset of symptoms is less than two weeks following exposure. Complications may include liver failure. In those who survive, recovery generally occurs around two weeks after onset.
Thogotovirus is a genus of enveloped RNA viruses, one of seven genera in the virus family Orthomyxoviridae. Their single-stranded, negative-sense RNA genome has six or seven segments. Thogotoviruses are distinguished from most other orthomyxoviruses by being arboviruses – viruses that are transmitted by arthropods, in this case usually ticks. Thogotoviruses can replicate in both tick cells and vertebrate cells; one subtype has also been isolated from mosquitoes. A consequence of being transmitted by blood-sucking vectors is that the virus must spread systemically in the vertebrate host – unlike influenza viruses, which are transmitted by respiratory droplets and are usually confined to the respiratory system.
Alkhurma virus (ALKV) is a zoonotic virus of the Flaviviridae virus family. ALKV causes Alkhurma hemorrhagic fever and is mainly based in Saudi Arabia.
Omsk hemorrhagic fever is a viral hemorrhagic fever caused by a Flavivirus.
Orthonairovirus is a genus of viruses in the family Nairoviridae of the order Bunyavirales that include viruses with circular, negative-sense single stranded RNA. It got its name from the Nairobi sheep disease that affects the gastrointestinal tracts of sheep and goats. The vast majority, and perhaps all viruses in this genus are tick-borne viruses that can have human or other vertebrate hosts.
Hyalomma is a genus of hard-bodied ticks common in Asia, Europe, and North Africa. They are also found in Southern Africa. The name is derived from Greek: hyalos (ὕαλος) crystal, glass; and omma (oμμα) eye.
Kemerovo tickborne viral fever is an aparalytic febrile illness accompanied by meningism following tick-bite. The causative agent is a zoonotic Orbivirus first described in 1963 in western Siberia by Mikhail Chumakov and coworkers. The virus has some 23 serotypes, and can occur in coinfections with other Orbiviruses and tick-transmitted encephalitis viruses, complicating the course of illness. Rodents and birds are the primary vertebrate hosts of the virus; Ixodes persulcatus ticks are a vector of the virus. Kemerovo and related viruses may be translocated distances in the environment by migratory birds.
Ticks of domestic animals directly cause poor health and loss of production to their hosts. Ticks also transmit numerous kinds of viruses, bacteria, and protozoa between domestic animals. These microbes cause diseases which can be severely debilitating or fatal to domestic animals, and may also affect humans. Ticks are especially important to domestic animals in tropical and subtropical countries, where the warm climate enables many species to flourish. Also, the large populations of wild animals in warm countries provide a reservoir of ticks and infective microbes that spread to domestic animals. Farmers of livestock animals use many methods to control ticks, and related treatments are used to reduce infestation of companion animals.
Tete orthobunyavirus is a bunyavirus found originally in Tete Province, Mozambique. It is a disease of animals and humans. Two forms, Bahig and Matruh viruses, were isolated from bird ticks including Hyalomma marginatum, but elsewhere mosquitoes and biting midges have been implicated as vectors.
In 1954 the Hazara orthonairovirus, one of the 34 tick-borne viruses of the genus Orthonairovirus, was discovered in Pakistan in the Ixodes tick native to that region. Today this virus is studied in mice in an attempt to develop treatments for the highly pathogenic Crimean-Congo Hemorrhagic Fever virus.
Batai orthobunyavirus (BATV) is a RNA virus belonging to order Bunyavirales, genus Orthobunyavirus.
Hyalomma dromedarii is a species of hard-bodied ticks belonging to the family Ixodidae.
Tibovirus Is term is often used to describe viruses that are transmitted by tick vectors. The word tibovirus is an acronym. This falls within the superorder arthropod thus tibovirus is classified under Arthropod Borne virus (Arborvirus). For a person to acquire infection the tick must bite and feed for a sufficient period of time. The tiboviruses that affect humans are limited to within 3 families: Flaviviridae, Reoviridae, and Bunyaviridae.
