Hendra virus: A member of the Nipah and Langya virus family

The Hendra virus (HeV) infection is a unique zoonosis that can spread from animals to humans. This disease carries severe, often fatal consequences and was first transmitted among horses in Australia. The Hendra virus is found in its natural environment among fruit bats, which are members of the Pteropodidae family. The urine and other bodily fluids of these animals carry the pathogen, which can be a source of human infection, especially when contact with horses occurs.

The Hendra virus was first isolated in the mid-1990s when an outbreak occurred near Brisbane. This disease affected 21 horses and several people, and since then, a limited number of cases have been observed. The transmission of the virus primarily occurs through direct contact with sick or deceased horses. Human-to-human transmission of the virus has not been documented to date, making it crucial to adhere to proper precautions to prevent the disease.

Characteristics of the Hendra Virus

The Hendra virus belongs to the Paramyxoviridae family and is a member of the Henipavirus genus. The virus is found in fruit bats, which are the natural carriers of the Hendra virus. These animals belong to the Pteropus genus, and their urine and other bodily fluids play a key role in the spread of the virus. The Hendra virus is related to the Nipah virus, which can also cause zoonosis.

The virus was isolated in 1994 during an outbreak, with samples taken from the suburbs of Brisbane showing its presence. Since then, the virus has affected more than 70 horses and seven people who became infected due to direct contact with infected animals. Most cases have occurred in the Australian states of Queensland and New South Wales, where fruit bats are prevalent.

Transmission and Risks of Infection

The transmission of the Hendra virus to humans can occur through contact with the bodily fluids, feces, or tissues of infected horses. Horses likely become infected with the virus found in bat urine. Those at greatest risk are people living in the fruit bat habitat who regularly come into contact with potentially infected horses, such as veterinarians, caregivers, or those involved with horses for recreational purposes.

Symptoms of Hendra virus infection typically appear after an incubation period of 9-16 days and can cause severe influenza-like respiratory illnesses. The mortality rate of the infection is high, estimated at around 57% based on previously documented cases. The presence of the virus can be detected from blood or throat samples, where diagnosis can be made through the identification of antibodies or direct isolation of the virus.

Symptoms, Diagnosis, and Treatment

Symptoms of Hendra virus infection encompass a wide range, with influenza-like symptoms such as fever, cough, and breathing difficulties occurring in the early stages of the disease. In more severe cases, the disease can lead to neurological complications, which can be fatal. Diagnosis is established through laboratory tests, where the presence of antibodies or direct detection of the virus is possible.

Currently, there is no specific treatment for Hendra virus infection, and patients receive intensive supportive care. In addition to symptomatic treatments, the possibility of using monoclonal antibodies is under investigation. The drug ribavirin has shown promise in laboratory settings, but its clinical efficacy has yet to be proven.

The Role of Prevention and Vaccination

The most important way to prevent Hendra virus infection is the early diagnosis and treatment of intermediate animal hosts, namely horses. Avoiding contact with infected or sick horses is essential to prevent outbreaks. For those working with horses, such as veterinarians and caregivers, it is crucial to follow appropriate precautions, including the use of protective equipment.

Currently, there is a vaccine available for the Hendra virus, which is only accessible for animals. The vaccine available commercially in Australia is an effective method to reduce the risk of horses becoming infected, thereby contributing to minimizing human exposure. Vaccination serves to protect not only horses but also humans, placing it at the forefront of efforts to reduce the risks posed by the Hendra virus.