Henipavirus

Henipavirus

Hendra virus, a type of Henipavirus

Henipavirus is a genus of viruses in the family Paramyxoviridae, order Mononegavirales, containing five established species: Hendra virus, Nipah virus, Cedar virus, Mojang virus, and Ghanaian bat virus. These viruses are known for their zoonotic potential, meaning they can be transmitted from animals to humans, often with severe consequences.

Virology

Structure of a Henipavirus

Henipaviruses are enveloped viruses with a non-segmented, negative-sense RNA genome. The genome is approximately 18,000 nucleotides in length and encodes six structural proteins. The viral envelope is derived from the host cell membrane and contains two major glycoproteins: the attachment glycoprotein (G) and the fusion glycoprotein (F), which are essential for viral entry into host cells.

Genome

Genome organization of Henipavirus

The genome of Henipaviruses is organized into six genes, which encode the nucleocapsid protein (N), phosphoprotein (P), matrix protein (M), fusion protein (F), glycoprotein (G), and the large polymerase protein (L). The P gene also encodes additional proteins through RNA editing, including the V and W proteins, which are involved in evading the host immune response.

Transmission

Henipaviruses are primarily transmitted to humans through contact with infected animals or their secretions. Fruit bats of the family Pteropodidae are natural reservoirs for these viruses. Human infections have been associated with exposure to infected horses (Hendra virus) or pigs (Nipah virus), as well as direct contact with bat secretions.

Clinical Features

In humans, Henipavirus infections can cause severe respiratory illness and encephalitis. The incubation period varies, but symptoms typically begin with fever, headache, and myalgia, progressing to more severe neurological symptoms in some cases. The case fatality rate is high, particularly for Nipah virus infections.

Prevention and Control

Preventive measures focus on reducing the risk of transmission from animals to humans. This includes avoiding contact with sick animals, implementing biosecurity measures in animal husbandry, and educating at-risk populations. There is currently no specific antiviral treatment for Henipavirus infections, but supportive care and intensive medical management are critical.

Research and Development

Research on Henipavirus

Research is ongoing to develop vaccines and therapeutics for Henipavirus infections. The development of a vaccine for Hendra virus has been successful in horses, which helps prevent transmission to humans. Efforts are also underway to develop vaccines for Nipah virus and other Henipaviruses.

Related Pages

• Paramyxoviridae
• Zoonosis
• Viral encephalitis
• RNA virus