Filoviridae family consists of viruses generally known as Filoviruses. Filoviruses have a ss(-)RNA genome. They are enveloped viruses because they have envelope. Viruses in this family are pleomorphic in nature, and thus have varying shapes. They actually appear in very long and thread-like structure. The length of Filoviruses can be above 10,000 nm in size due to the variability of the pathogen. Filoviruses measure about 80 nm in diameter. But the normal length of Filoviruses is between 800-1000 nm.
The Filoviridae family is comprised of only two genera of viruses viz: Marburgvirus and Ebolavirus, both of which cause haemorrhagic fevers in humans. The viruses in each of these genera can generally be called Marburg virus and Ebola virus for those that cause Marburg virus infection and Ebola virus infection respectively. They are usually named according to the geographic region where they cause a disease outbreak. Marburg virus is the causative agent of Marburg disease, a type of haemorrhagic fever generally known as Marburg haemorrhagic fever (MHF). Marburg virus is only a single-type virus i.e., it is the only virus in the genus Marburgvirus. MHF has an incubation period of 5-10 days; and the disease only occurs in Africa.
Maculopapular rash, nausea, vomiting, chest pain, diarrhea, abdominal pain and massive haemorrhagic and multiple organ dysfunction or failure are some of the clinical symptoms of the disease. Marburg virus infects humans and other primates; and human-to-human transmission of the disease is possible. Ebola virus is the causative agent of Ebola disease, a severe haemorrhagic fever that occurs in parts of Africa and the Philippines. There are four subtypes of Ebola virus that have been recognized to infect humans. These four serotypes include Zaire ebolavirus (ZEBOV), Sudan ebolavirus (SEBOV), Cote d’Ivoire ebolavirus (CIEBOV), and Reston ebolavirus (which occurs only in the Philippines). ZEBOV, SEBOV and CIEBOV infect humans while CIEBOV infect monkeys in the Philippines.
The incubation period of Ebola disease is 2-21 days. The disease is characterized clinically by high fever, joint pains, muscle aches, sore throat, diarrhea, headache and vomiting. A maculopapular rash which appears all over the body and severe internal and external bleeding is also associated with ebolavirus infection. Filoviruses (i.e., viruses in the Filoviridae family) are primate-borne viruses that are usually transmitted to humans who come in contact with excreta or body secretions of the animals or primates that serve as natural host for these viruses. Filoviruses are of biosafety and biosecurity concern because of the bioterrorism threat they pose. Viruses in the Filoviridae family are classified as biosafety level 4 (BSL-4) pathogens because of their high biosecurity and/or disease outbreak risk.
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