A case in the Chinese province of Yunnan, where a man who died on a bus was found to have a hantavirus after an autopsy, prompted scientists to think about a new threat. Russia has the second highest number of confirmed cases of hantavirus-related haemorrhagic fever, after China. For domestic epidemiologists, this pathogen is familiar and has long been studied, told Izvestia in the Federal Scientific Center for Research and Development of Immunobiological Preparations named after N. M. P. Chumakov RAS. Our country has created rapid tests and a vaccine to treat it. However, it has not yet undergone clinical trials.
Bus incident
A man who suddenly collapsed dead in a bus in the Chinese province of Yunnan excited the whole world. It was not the coronavirus that was found in his blood, as one might assume, but the hantavirus, a special pathogen that spreads only in some countries. It causes hemorrhagic fever with renal syndrome, which is a type of painful condition accompanied by high fever, internal bleeding, and kidney failure.
“The territory of China is endemic (specific) for hantaviruses,” the head of the scientific direction of the Federal Research Center for Research and Development of Immunobiological Preparations named after I. M. P. Chumakov RAS Evgeny Tkachenko. - Cases such as the one that happened to the man on the bus are known to Chinese doctors, they are well aware of the symptoms. Therefore, it was possible to quickly conduct the necessary test and identify the pathogen.
Sometimes, as experts say, in the absence of treatment in a hospital, an infected person can sharply develop DIC syndrome (disseminated intravascular coagulation or thrombus formation. - Izvestia), as well as multiple organ failure. The kidneys suffer the most from this. There may even be a rupture of one of them, as well as an ischemic heart attack, which may have become the cause of death in Yunnan province.
“The causative agent of the disease, hantavirus, belongs to the genus of human and animal viruses from the Hantaviridae family,” Nikolai Karpov, an employee of the Institute of Biology of Tyumen State University, told Izvestia.
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- The danger depends on the specific strain and the state of the immune system. It is believed that hantaviruses are not transmitted from person to person, the expert emphasized. \
In terms of the prevalence of these pathogens, it is China that occupies first place in the world, so they are vaccinated, and there are also rapid tests to detect this infection. The virus is transmitted primarily from rodents in three different subfamilies: mice, voles, and hamsters. However, there are cases of transmission from bats - by airborne dust.
“Mainly summer residents and villagers are infected by inhaling dust from dried excrement of certain species of forest small rodents, colloquially collectively called mice,” explained Sergey Netesov, Corresponding Member of the Russian Academy of Sciences, Head of the NSU Laboratory of Biotechnology and Virology. - With hospital treatment, as a rule, a person recovers.
Russian way
Our country is in second place in the world in fixing diseases caused by hantaviruses. In Russia, the Volga region, Bashkortostan and Sochi are among the most dangerous regions.
The situation was especially difficult in 2019, in winter, in the Saratov region. In the natural park "Kumysnaya Dolina" about 3 thousand people became infected. There were also deaths.
- Undoubtedly, fewer people are infected with hantavirus than with coronavirus, - noted Evgeny Tkachenko. - But the pandemic will pass, and the annual situation with hemorrhagic fever will remain. Therefore, it is so important to conduct clinical trials of our vaccine and have it in stock for the future. The Chinese drug is not suitable for us, since they have completely different viruses, the expert emphasized.
The consequences after the illness, according to Evgeny Tkachenko, can be extremely serious. Asthenic syndrome often develops, and this condition can last for a whole year. Sometimes, as the expert notes, men experience temporary impotence. This especially "hits" the young, because they are most susceptible to disease. Two thirds of patients with hemorrhagic fever due to the strain are male.
Also, according to the expert, there are still hantaviruses that are transmitted from person to person.
- In South America, there is one hantavirus, which has been observed to transmit from person to person, - said Evgeny Tkachenko. - There, this pathogen causes a serious illness with a high mortality rate, it reaches 50%. To date, several cases of infection of medical personnel have been described while caring for such patients.
Danila Konnov, head of the infectious diseases department of the H-Clinic RUDN University, also agrees with Evgeny Tkachenko. However, the expert believes that all these facts have no epidemiological significance.
- Although descriptions of isolated cases of transmission from person to person are periodically found in the literature, rodents still remain the main sources and reservoirs of infection. There are no drugs that have shown high efficiency in the treatment of hantavirus infections at the moment, although the administration of the antiviral drug ribavirin has shown some effectiveness, - the scientist noted.
A pandemic spread of hantavirus can occur only if mutations in the pathogen allow it to acquire new properties - to be transmitted from person to person. However, there are currently no data on such trends.
Russia already has a quick test for hantavirus infection, which gives an answer within an hour.
Authors: Anna Urmantseva, Maria Nedyuk