Henipavirus is a genus of the Paramyxoviridae family, which consists of enveloped, negative-sense, single-stranded RNA viruses. This genus includes two major species that are known to cause severe disease in humans: Nipah virus and Hendra virus. These viruses are primarily hosted by fruit bats (Pteropus spp.), but they can also infect other animals such as pigs, horses, and cats, and can be transmitted to humans through close contact with infected animals or their secretions. Henipaviruses are classified as biosafety level 4 agents due to their high mortality rate and potential for causing severe epidemics. Infection with these viruses can lead to a range of clinical symptoms, including fever, respiratory distress, and encephalitis, which can be fatal in some cases.

Henipavirus infections are caused by two paramyxoviruses, Hendra virus and Nipah virus. These viruses can cause severe illness in both humans and animals, particularly horses and pigs.

The natural hosts for these viruses are fruit bats (Pteropus spp.), also known as flying foxes. Transmission to humans can occur through direct contact with infected animals or their bodily fluids, consumption of contaminated food or drink, or through exposure to an environment contaminated with the virus.

Infection with Hendra virus can cause respiratory and neurological symptoms in humans, with a high fatality rate. Nipah virus infection can cause respiratory illness, fever, headache, dizziness, and altered consciousness, which can progress to encephalitis and coma. The case fatality rate for Nipah virus infection is estimated to be around 40-75%.

There are no specific treatments or vaccines available for henipavirus infections, and prevention efforts focus on reducing exposure to the viruses through public health measures such as avoiding contact with infected animals and their bodily fluids, practicing good hygiene and food safety, and implementing appropriate infection control practices.

Hendra virus (HeV) is an enveloped, negative-sense, single-stranded RNA virus that belongs to the genus Henipavirus in the family Paramyxoviridae. It was initially identified in 1994 during an outbreak of a mysterious disease affecting horses and humans in Hendra, a suburb of Brisbane, Australia. The natural host of this virus is the fruit bat (Pteropus spp.), also known as flying foxes.

HeV infection can cause severe respiratory and neurological diseases in various mammals, including horses, humans, and other domestic animals. Horses are considered the primary source of human infections, as they get infected after direct or indirect contact with body fluids (e.g., urine, saliva, or nasal discharge) from infected fruit bats. Human cases usually occur through close contact with infected horses or their bodily fluids during veterinary care, slaughtering, or other activities.

The incubation period in humans ranges from 5 to 16 days, followed by the onset of nonspecific influenza-like symptoms such as fever, cough, sore throat, and muscle pain. In severe cases, HeV can cause pneumonia, encephalitis, or both, with a high fatality rate (approximately 57%). No specific treatment or vaccine is currently available for humans; however, ribavirin has shown some efficacy in treating HeV infections in vitro and in animal models. Preventive measures include avoiding contact with infected horses and implementing strict biosecurity practices when handling potentially infected animals.

Nipah virus (NiV) is a zoonotic virus (it is transmitted from animals to humans) that causes severe illness in both humans and animals. It was first identified during an outbreak of disease in pigs and people in Malaysia and Singapore in 1998-1999.

The natural host of the virus are fruit bats of the Pteropodidae Family, Pteropus genus. Transmission to humans may occur through direct contact with infected bats or consumption of date palm sap contaminated by excretions or secretions from infected bats. Human-to-human transmission is also possible through close contact with people's secretions and excretions.

Infection with NiV can lead to a range of clinical presentations, from asymptomatic infection to acute respiratory illness and severe encephalitis (inflammation of the brain). The case fatality rate is estimated to be about 40-75% in humans. There is no vaccine available for either humans or animals. Prevention strategies include avoiding consumption of raw date palm sap, wearing protective clothing while handling infected animals or their contaminated materials, and practicing good hygiene.

Ephrin-B3 is a type of protein that belongs to the ephrin family and is involved in cell signaling, particularly during the development and functioning of the nervous system. It is a transmembrane protein, which means it spans the membrane of the cell and has a domain outside the cell and a domain inside the cell.

Ephrin-B3 interacts with Eph receptors on neighboring cells to initiate bidirectional signaling, which means that both the cells that express ephrin-B3 and the cells that express the Eph receptor are affected by this interaction. This signaling is important for various processes such as axon guidance, cell migration, and tissue boundaries formation during development. In addition, ephrin-B3 has been implicated in the regulation of synaptic plasticity and vascular remodeling in adults.

Mutations in the gene that encodes ephrin-B3 have been associated with certain neurological disorders, such as intellectual disability and epilepsy.

Chiroptera is the scientific order that includes all bat species. Bats are the only mammals capable of sustained flight, and they are distributed worldwide with the exception of extremely cold environments. They vary greatly in size, from the bumblebee bat, which weighs less than a penny, to the giant golden-crowned flying fox, which has a wingspan of up to 6 feet.

Bats play a crucial role in many ecosystems as pollinators and seed dispersers for plants, and they also help control insect populations. Some bat species are nocturnal and use echolocation to navigate and find food, while others are diurnal and rely on their vision. Their diet mainly consists of insects, fruits, nectar, and pollen, although a few species feed on blood or small vertebrates.

Unfortunately, many bat populations face significant threats due to habitat loss, disease, and wind turbine collisions, leading to declining numbers and increased conservation efforts.

Ephrin-B2 is a type of protein that belongs to the ephrin family and is primarily involved in the development and function of the nervous system. It is a membrane-bound ligand for Eph receptor tyrosine kinases, and their interactions play crucial roles in cell-cell communication during embryogenesis and adult tissue homeostasis.

Ephrin-B2 is specifically a glycosylphosphatidylinositol (GPI)-anchored protein that is expressed on the cell membrane of various cell types, including endothelial cells, neurons, and some immune cells. Its interactions with Eph receptors, which are transmembrane proteins, lead to bidirectional signaling across the contacting cell membranes. This process regulates various aspects of cell behavior, such as adhesion, migration, repulsion, and proliferation.

In the context of the cardiovascular system, ephrin-B2 is essential for the development and maintenance of blood vessels. It is involved in the formation of arterial-venous boundaries, vascular branching, and remodeling. Mutations or dysregulation of ephrin-B2 have been implicated in various diseases, including cancer, where it can contribute to tumor angiogenesis and metastasis.

Paramyxovirinae is a subfamily of viruses in the family Paramyxoviridae, order Mononegavirales. These viruses are enveloped, negative-sense, single-stranded RNA viruses that cause various diseases in animals and humans. The subfamily includes several important human pathogens such as:

1. Respiratory syncytial virus (RSV): A major cause of respiratory tract infections in infants, young children, and older adults.
2. Human metapneumovirus (HMPV): Another common cause of respiratory illness, particularly in children.
3. Parainfluenza viruses (PIVs): Responsible for upper and lower respiratory tract infections, including croup, bronchitis, and pneumonia.
4. Mumps virus: Causes the infectious disease mumps, characterized by swelling of the salivary glands.
5. Measles virus: A highly contagious virus that causes measles, a serious respiratory illness with characteristic rash.
6. Hendra virus and Nipah virus: Zoonotic viruses that can cause severe respiratory and neurological diseases in humans and animals.

These viruses share common structural and genetic features, such as an enveloped virion with a helical nucleocapsid, and a genome consisting of non-segmented, negative-sense single-stranded RNA. They also utilize similar replication strategies and have related gene arrangements.

Rubulavirus infections refer to a group of viral illnesses caused by members of the Rubulavirus genus, which is part of the Paramyxoviridae family. The most well-known rubulavirus is the mumps virus, which causes mumps, a contagious disease characterized by swelling of the salivary glands, fever, and pain while chewing or swallowing. Other rubulaviruses include parainfluenza viruses 1 and 3, which can cause respiratory illnesses such as bronchitis and pneumonia. Rubulavirus infections are typically spread through respiratory droplets or direct contact with infected individuals. Vaccination is available for some rubulavirus infections, such as mumps.