What Is Henipavirus?
At the beginning of August 2022, a group of researchers presented a paper in The New England Journal of Medicine regarding the discovery of a new henipavirus which they named Langya henipavirus (LayV).
The study reported a total of 35 cases of people in China who didn’t have contact with each other. Media from all over the world have reported this research, and, because of this, we felt it important to bring you their findings and tell you exactly what a henipavirus is and other information you should know.
What is a henipavirus?
Henipaviruses are negative-stranded RNA viruses belonging to the Paramyxoviridae family. Infections such as mumps and measles are caused by viruses in this family. As experts point out, the first viruses of this genus were discovered in the mid-to-late 1990s. Specifically, the Hendra virus (HeV) and the Nipah virus (NiV) were identified during that time.
So far, the two mentioned above as well as the Langya virus are the only ones in the family that can infect humans. Certainly, many more have been identified, such as the Cedar virus (CedPV). Hendra virus (HeV) and Nipah virus (NiV) have caused serious outbreaks in animals and humans, so much, so that they’re associated with a high mortality rate.
According to recent research, bats appear to be the natural reservoirs of henipaviruses. Despite this, and although it’s only a hypothesis, the new Langya virus seems to find its reservoir in shrews. Specialists warn that henipavirus infection causes severe systemic neurological and respiratory disease. In many of these cases, the prognosis is fatal.
The first virus of the genus was reported in 1994 in an outbreak of a respiratory disease in horses and humans in the suburb of Hendra, Australia (hence its name, Hendra virus).
Thirteen horses and their trainer died from the infection, and a further seven horses and one groom developed a non-fatal infection. Then, in 1999, an outbreak of encephalitis was reported among pig farmers in Peninsular Malaysia and Singapore.
The Malaysian outbreak infected at least 265 people of whom 105 died. It was first isolated from Sungai Nipah in Port Dickson, Negeri Sembilan, Malaysia (hence its name, Nipah virus). Since its discovery, outbreaks have been reported almost every year in Asia, especially in countries like Bangladesh and India.
How are henipaviruses transmitted?
Currently, experts believe that the natural reservoir of henipaviruses are bats, specifically, fruit-eating bats. The virus passes from these to other animals, and finally from the latter to humans. Horses display a predisposition to natural infection, although the viruses are also known to infect pigs, cats, dogs, cows, and goats under these conditions.
In the laboratory, guinea pigs, hamsters, ferrets, and various species of non-human primates (such as the squirrel monkey and the African green monkey) have been infected. All this to evaluate the mechanisms of the virus in the body, as well as to develop possible vaccines and treatments. Human-to-human transmission is possible, although very close and prolonged contact is required.
In fact, the Nipah virus is the only one that has shown such a transmission. Despite this, and as research indicates, the consumption of contaminated food and contact with infected animals is the preferred route of transmission of this virus. The same is true of the newly discovered Langya virus.
What do we know about the Langya virus?
The Langya virus was identified in eastern China through a series of cases, 35 in total, reported from 2018 to August 2022. It manifests symptoms similar to other viruses of the genus, although these are milder. In fact, up to the time of writing these lines, not a single death associated with the infection has been reported.
Similarly, the virus doesn’t spread easily from person to person. There’s no substantial evidence to confirm that the above is possible.
The 35 cases reported so far had no contact with each other, and their friends and relatives didn’t develop the infection despite close and permanent contact with them. Even so, it isn’t completely ruled out that the Langya virus can do the same because the sample of infected people is very small.
The infection is characterized by symptoms such as a fever, cough, and fatigue. From an analysis of the pharyngeal secretions of the first patient identified with the disease, the virus could be isolated. It was then given the name of the Langya city, located in Shandong, where the patient came from.
Most of those infected so far are farmers, who reported being in contact with different animals before the manifestation of symptoms.
As we already mentioned, only about thirty cases have been reported over four years. No infected patients have died, and symptoms range from mild to moderate in intensity. There’s no reason to believe that the virus will cause an epidemic or a pandemic, although the authorities are being vigilant.
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