Recently, the global authoritative medical journal “New England Medicine” (NEJM) recently published a communication article of a collaboration between Chinese and Singaporean scientists. of a new animal-derived henipavirus. The authors named it Langya henipavirus, LayV.
Professor Liu Wei, Professor Fang Liqun, Institute of Microbial Epidemiology, Academy of Military Medical Sciences, Chinese Academy of Military Sciences, Professor Wang Linfa, Duke-NUS School of Medicine and other scholars in this project A newly discovered, possibly animal-derived, henipa virus has been linked to some febrile cases, with symptoms including fever, fatigue, cough, anorexia, myalgia, and nausea, the study noted. This finding warrants further study to better understand relevant human diseases. “This virus is in the same genus as Nipah virus, and so far these cases have not been fatal or very serious. So it’s fair to say that (we) should be vigilant about this new virus, not Feeling panic. But we need to be careful because there are many more similar viruses in nature, and if a different virus jumps to humans, the situation may be different.” One of the above researchers, Professor Wang Linfa, NUS Faculty of Medicine Said to Surging News on August 8. So,what exactly is a zoonotic disease? What is Henipavirus? How does it spread? What are the symptoms of infection? Can it be passed from person to person or a mass epidemic? …I believe many people don’t know it, Let’s learn together!
01
What is a zoonotic disease?
According to the definition of WHO and the United Nations Food and Agriculture Organization, zoonotic diseases refer to diseases caused by common pathogens in humans and vertebrates, Diseases related to the disease, which can be transmitted between humans and livestock and poultry, seriously endangering public health security.
The zoonotic diseases are divided into two categories: zoonotic infectious diseases and zoonotic parasitic diseases according to their different pathogens. According to a July report by the United Nations, an estimated 2 million people worldwide die each year from neglected zoonotic diseases.
02
what is strong>LayV?
LayV belongs to the family Paramyxoviridae and the genus Henipavirus, and is an important emerging zoonotic disease One of the causes is that the fatality rate after human infection is between 40% and 75%, which is much higher than that of the new coronavirus. Henipavirus is currently known to infect humans with two viruses, Nipah virus (NiV)< /span> and Hendra virus (HeV), both cause serious diseases in animals and humans, and have been listed as the most dangerous fourth-level viruses in biosecurity.
Currently, there is no vaccine or post-exposure treatment that is effective for Henipa virus infection. However, some studies have pointed out: ①Routine cleaning and disinfection of pig farms with sodium hypochlorite or other detergents is expected to be effective in preventing infection; The fresh date palm juice collected should be boiled, and the fruit should be washed and peeled thoroughly before eating; ③Close physical contact with Nipah virus infected persons should be avoided; span>④ Wear gloves and protective equipment when caring for patients; ⑤ Wash hands as usual after taking care of or visiting patients; ⑥ When handling infected animals or their tissues, Gloves and protective clothing should be worn during slaughtering and culling.
03
Nipah virus (NiV)Things of
NiV is a The high-risk pathogens of bats have the characteristics of wide host distribution, cross-species transmission, human-to-human transmission, and high lethality. The WHO has listed them as key infectious diseases for prevention and control.
(1) Epidemiology
this As a potential biological and agricultural terrorism pathogen, virus has caused many epidemics in the past few years, and has become one of the emerging infectious diseases of high international concern in the past 20 years.
(2) Sources of infection and natural hostsFrost bats have been confirmed to be NiV The main natural host, but studies have found that pigs, cats, dogs, horses, goats, sheep, humans, etc. are also their natural hosts, and they are infectious after infection, of which pigs are the main source of infection, and other natural hosts include hounds and rodents, etc. In the past outbreaks, there have been many cases of human-to-human transmission, and patients and infected persons are also important sources of infection.(3) Transmission Mode
The mode of transmission of Nipah virus between animals and between animals and humans is not fully understood, summarize the existing research and evidence , the transmission methods are divided into the following three types:
①Unprotected contact with pig secretions or tissues of sick animals;
②Eating fruit or fruit products (such as raw date palm juice) contaminated with NiV-carrying bat secretions is the most likely route of infection;
③close Contact with human secretions and excretions leads to human-to-human transmission, mostly among family members and caregivers or medical staff.
(4) Susceptible CrowdsCrowds are generally susceptible, especially workers who have direct contact with NiV-infected pigs, such as veterinarians, breeders, sewage handlers and Slaughterhouse workers, etc.(5) Clinical featuresAccording to the WHO report, NiV-infected patients span>The incubation period (the time interval from infection to onset of symptoms) is 4~14 days, However, there have been reports of incubation periods as long as 45 days. span>The clinical symptoms of human infection vary widely, including asymptomatic (subclinical) infection, mild or severe acute respiratory infection, fatal encephalitis, cerebral edema and even death. The initial symptoms of infection are similar to those of influenza, with symptoms such as fever, headache, myalgia, sore throat, and vomiting. Later, patients may experience dizziness, lethargy, confusion, and neurological symptoms of acute encephalitis Systemic signs and symptoms. Atypical pneumonia and severe respiratory complications, including acute respiratory distress, may also occur in some individuals.Severe cases will develop encephalitis and epilepsy, and then fall into a coma within 24 to 48 hours. Severely ill patients may develop complications such as sepsis, gastrointestinal bleeding, and renal damage, as well as pulmonary embolism and atrial fibrillation, but they are rare. According to statistics, the fatality rate is estimated to be 40%-75%. Most patients die 3-14 days after the onset of the disease. The main cause of death is encephalitis, and 1/3 of the patients die in drowsiness.
(6) Prevention and Treatment
Currently, there is no Specific vaccines and drugs for this virus infection, preventive measures are mainly to control the source of infection, cut off the transmission route and protect susceptible populations.
The clinical treatment of infected patients is mainly based on life support and symptomatic treatment, and intensive supportive care is adopted to treat severe respiratory and nervous system complications.
04
Can the new virus be passed from person to person?
Previous reports have shown that human-to-human transmission of Henipa virus can occur, but the researchers pointed out that no cases and LayV haplotypes were found to have significant spatial or temporal clustering .
The original text mentioned that “Follow-up follow-up of 9 patients and their 15 close contact family members showed that the patients had close contacts with LayV transmission has not occurred between humans, but the human-to-human transmission status of LayV cannot be determined due to the small sample size.”
In other words, it has not yet been determined whether LayV can be transmitted from person to person.
And according to the chart, we can see the findings of 26 infected people The time spans from 2019 to 2021, suggesting that the population may be sporadic rather than large-scale concentrated outbreaks.
In addition, statistics show that human infection The mortality rate of Nipah virus is 40%-75%. The mortality rate may also be related to the local medical and health level and treatment level. Fortunately, its infectiousness is not very high, otherwise the harm will far exceed the new crown.
In general, henipaviruses are highly pathogenic to humans and have a high fatality rate, but in Human-to-human communication is limited.
According to past experience, after human infection with Hendra virus, which belongs to Henipa virus, mild cases can show mild symptoms. Influenza-like illness can cause fatal respiratory or neurological diseases in severe cases; and Nipah virus in the genus Henipavirus is listed by the World Health Organization as one of the ten potentially high-risk infectious diseases that need attention in 2018.
Infection with Nipah virus can attack the human lungs and brain, causing symptoms such as fever, headache, drowsiness, coma, and confusion. Causes respiratory syndrome and fatal encephalitis.
There is currently no targeted vaccine or effective treatment for Henipa virus. The only treatment is Controlled therapy to manage complications. In response to this, the World Health Organization said that in the event of a suspected case, isolation should be implemented as soon as possible, infection control measures should be implemented, and public health authorities should be notified immediately.
Wang Xinyu, deputy chief physician of the Department of Infectious Diseases, Huashan Hospital Affiliated to Fudan University, believes that the transmission route, transmission ability and pathogenicity of the new virus Further in-depth research is needed on scientific issues such as these.
In the article, the researchers also pointed out that LayV, as a newly discovered henipa virus that may come from animals, is closely related to humans. febrile illness, this finding warrants further study to better understand the associated human disease.
One of the researchers, Professor Wang Linfa, National University of Singapore School of Medicine”So far, these cases are not fatal or very serious. So it can be said that (we) should be vigilant about this new virus, not panic. But we need to be careful because there are more in nature,” said the interviewer. Similar viruses, if a different virus jumps to humans, the situation may be different.”
Dr. For virologists and epidemiologists, each newly discovered pathogen deserves attention, the reminder says. Once the virus of the parasitic animal host is adapted to humans, it may spread from person to person, and even cause a global pandemic like the new coronavirus. Monkeypox is a clear example.
In the early days, some scholars believed that “human-to-human transmission” of monkeypox would not occur, but now community transmission has occurred. So far, there have been nearly 3,000 confirmed cases of monkeypox in the UK, which fully shows that we cannot take any pathogen lightly.
Source: Public Health Physicians
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