How did viruses appear? Who invented them and why do they take the lives of thousands of people around the world every year? Are there medicines against the most terrible viruses in the world and how to protect yourself from terrible diseases? We present to your attention the rating of the most dangerous viruses.

1. Human immunodeficiency virus

Human immunodeficiency virus (HIV) is the most dangerous human virus, the causative agent of HIV infection/AIDS, which is transmitted through direct contact of mucous membranes or blood with bodily fluid of the patient. During HIV infection, the same person develops new strains (varieties) of the virus, which are mutants, completely different in reproduction speed, capable of initiating and killing certain types of cells. Without medical intervention, the average life expectancy of a person infected with the immunodeficiency virus is 9–11 years. According to 2011 data, 60 million people have become infected with HIV throughout the world, of which 25 million have died, and 35 million continue to live with the virus.

2. Marburg virus

The most dangerous virus that a person can become infected with is the Marburg virus. It is named after the small, idyllic town on the Lahn River where the outbreak of the disease was first recorded and described. It is very similar to the Ebola virus: patients suffer from febrile convulsions and bleeding from mucous membranes, skin and organs. 80 percent of those infected die.

3. Ebola virus

The Ebola virus can appear as five different types, which were named after countries and regions in Africa: Zaire, Sudan, Tai Forest ebolavirus, Bundibugyo, Reston. The Ebola virus type Zaire is the most dangerous, as the mortality rate of people infected with it reaches 90 percent. It was the virus that infected people in Guinea, Sierra Leone and Liberia during the 2013 Ebola epidemic. Researchers believe that bats brought the virus to cities from Zaire.

4. Hanta virus

Hanta virus covers a wide range of viruses. It is named after the river where American soldiers were first infected with the virus during the Korean War in 1950. Symptoms of the virus include lung disease, fever and kidney failure.

5. Hantaviruses

Hantaviruses are a genus of viruses transmitted to humans through contact with rodents or their waste products. Hantaviruses cause various diseases belonging to such groups of diseases as “hemorrhagic fever with renal syndrome” (mortality on average 12%) and “hantavirus cardiopulmonary syndrome” (mortality up to 36%). The first major outbreak of disease caused by hantaviruses, known as Korean hemorrhagic fever, occurred during the Korean War (1950–1953). Then more than 3,000 American and Korean soldiers felt the effects of a then unknown virus that caused internal bleeding and impaired kidney function. Interestingly, it is this virus that is considered the probable cause of the epidemic in the 16th century that exterminated the Aztec people.

6. Lassa Virus

A nurse in Nigeria was the first person to become infected with the Lassa virus. The spread of the virus, which is carried by rodents, occurred endemically, i.e. very active, but in a specific region, in this case in West Africa. Even now, the virus is raging again in Nigeria. Researchers suspect that 15 percent of the rodents living there are carriers of this virus.

7. Rabies virus

The rabies virus is a dangerous virus that causes rabies in humans and warm-blooded animals, which causes specific damage to the central nervous system. This disease is transmitted through saliva from the bite of an infected animal. Accompanied by an increase in temperature to 37.2–37.3, poor sleep, patients become aggressive, violent, hallucinations, delirium, a feeling of fear appear, soon paralysis of the eye muscles, lower extremities, paralytic respiratory disorders and death occurs. The first signs of the disease appear late, when destructive processes have already occurred in the brain (swelling, hemorrhage, degradation of nerve cells), which makes treatment almost impossible. To date, only three cases of human recovery without vaccination have been recorded; all others ended in death.

8. Smallpox virus

Smallpox virus is a complex virus, the causative agent of a highly contagious disease of the same name that affects only humans. This is one of the oldest diseases, the symptoms of which are chills, pain in the sacrum and lower back, rapid increase in body temperature, dizziness, headache, vomiting. On the second day, a rash appears, which eventually turns into purulent blisters. In the 20th century, this virus claimed the lives of 300–500 million people. About US$298 million was spent on the smallpox campaign from 1967 to 1979 (equivalent to US$1.2 billion in 2010). Fortunately, the last known case of infection was reported on October 26, 1977 in the Somali city of Marka.

9. Rotavirus

Ninth on the list of the most dangerous human viruses is Rotavirus, a group of viruses that are the most common cause of acute diarrhea in infants and young children. Transmitted by the fecal-oral route. The disease is usually easy to treat, but kills more than 450,000 children under five worldwide each year, most of whom live in underdeveloped countries.

10. Influenza virus

Influenza virus is a virus that causes an acute infectious disease of the respiratory tract in humans. Currently, there are more than 2 thousand of its variants, classified into three serotypes A, B, C. The group of viruses from serotype A, divided into strains (H1N1, H2N2, H3N2, etc.) is the most dangerous for humans and can lead to epidemics and pandemics. Every year, between 250 and 500 thousand people worldwide die from seasonal influenza epidemics (most of them children under 2 years of age and elderly people over 65 years of age).

Clarification and Disclaimer: Victor® does not employ medical professionals and this article should not be construed as medical advice. If you or someone you know has symptoms of hantavirus, contact your doctor immediately.

Hantavirus pulmonary syndrome (HPS), known to the general public as hantavirus, is a disease characterized by flu-like symptoms and difficulty breathing, in which patients often require the use of breathing machines. Symptoms of hantavirus pulmonary syndrome include headaches, fever, nausea, chills, muscle pain and digestive problems. The disease is mainly transmitted to humans from rodents through physical contact and airborne transmission.

Early detection can help with the patient's prognosis. There is currently no vaccine for HPS. The best ways to treat symptoms of hantavirus pulmonary syndrome include supportive care, mechanical ventilation, and (for the most severe cases) intensive care. HPS is fatal in about one in three cases.

The history of hantavirus

Hantavirus pulmonary syndrome was first identified in the spring of 1993, when residents of four states - Arizona, New Mexico, Utah, Colorado - developed symptoms that did not correspond to any of the known diseases. Cold symptoms in infected people quickly develop into an acute respiratory infection. The virus was soon identified as Sin Nombre virus (SNV), which was eventually traced back to deer mice (Peromyscus maniculatus). Among infected people, this virus turned out to be a trigger for a new disease - hantavirus. In the more than 20 years since it was first identified, more than 10 strains of hantavirus have been identified, each carried by a different species of rodent.

Where is the virus spread?

Over the past two decades, cases and outbreaks have been reported at various times in rural areas throughout the United States and Canada. The infection has been diagnosed in farms, forests, etc. The most common hantavirus known to trigger HPS is Sin Nombre Virus (SNV).

There are various other places where HPS has been diagnosed in some parts of North America. Typically, the disease most often manifests itself in Central and South America.

How is HPS spread?

Rodents are the only creatures known to spread HPS. Non-rodent pets cannot carry hantavirus, although there are cases where dogs or cats can spread the disease to people, such as when a cat catches an infected rodent and a person accidentally comes into contact with it.

HPS carriers, such as rats, spread the disease through their droppings and urine. Human infection usually occurs by inhaling air that has been saturated with saliva fumes, etc. Other ways of transmitting the virus from rodents to humans include:

• Bites. People can become infected with HPS through rodent bites, although this is one of the rarest forms of transmission.
• Touch. When a person touches an area or object, such as a stain on the floor or carpet, that has traces of rodent urine or saliva on it, and then touches their mouth, infection can occur.
• Infection through water.

None of the strains known to have emerged in North America can spread from person to person. It is also worth noting that the disease cannot be transmitted through blood transfusions from infected people. The disease is carried by deer mice, cottonmouth rats or white-footed hampers.

US HPS Statistics

As of 2016, the total number of reported cases of HPS in the United States is 690. The vast majority of these cases (659) were diagnosed when the disease was first identified by scientists in 1993, while the remaining 31 were identified retrospectively.

In more than one third of cases (36%), the disease was fatal. Infected people ranged in age from 5 to 84 years, and nearly two-thirds of those infected were men. Thus, the following statistics were compiled:

People suffering from HPS came from different races. 19% of reported HPS cases are Hispanic (ethnicity is considered separate from race). Infections are known to have occurred in cities, suburbs and rural areas (about three-quarters of all cases were recorded here).

Hantavirus in other countries

Outside the United States and Canada, cases of infection have been reported in South America. The list included the following countries:

• Argentina;
• Bolivia;
• Brazil;
• Chile;
• Ecuador;
• Paraguay;
• Panama;
• Uruguay;
• Venezuela.

Outbreaks of HPS have been less frequent in Latin America, where the virus rarely persists for long periods of time. The exception was cases when disasters occurred that provoked the spread of hantavirus. Viruses with similarities to Sin Nombre virus have also been found in rodents in Central America and Mexico, but they have not been identified in humans.

People at risk

Anyone who encounters a rodent infected with one of the hantavirus strains runs the risk of contracting the disease. City residents can get sick if they live in an apartment building. No matter how healthy a person is, he is not immune from infection. After all, even if the dust contains hantavirus strains, the risk of infection is very high if these particles enter your lungs.

People who are at greatest risk of exposure to hantavirus are those who live, work, or are in confined areas where rodents live. Even if HPS carriers are active at night and people are active during the day, the likelihood of getting sick remains extremely high. Working in outbuildings that contain infected rodents can also be dangerous. For this reason, caution is advised when entering garages, storage rooms and sheds after an extended winter break. Also, be careful not to inhale dust when opening tool drawers and cabinets that haven't been accessed for months.

Seasonal and harvesting work must also be carried out with care. When cleaning, you risk getting sick if rodents have been in the area. In particular, in the spring months, infections are easier to catch because immunity is reduced. Use personal protective equipment. Those most vulnerable to infection are those who work in the service sector, such as janitors and utility workers. In basements and attics, as well as when emptying garbage cans, you should also be as careful as possible.

Hantavirus can also affect campers, adventurers and hikers, where you can also come into contact with infected rodents. Remember that the countryside is a natural habitat for rodents. Many people diagnosed with HPS do not even know that they have come into contact with infected areas until symptoms become obvious. Therefore, it is important to avoid areas with rodents that carry hontavirus (deer mice, cotton rats, or white-footed hamsters).

How to protect your home from rodents and hantavirus

To keep rodents far enough away from your property, it is important that there are no rodent entry points on the property. You should also eliminate anything that might attract them: garbage, waste, various foods, etc. You should seal up any openings in the roof, gaps around chimneys or vents that could allow rodents to get into the room. Mice can slip through cracks and cracks as small as a dime.

To protect against rodent infestation, use Victor® Ultra PestChaser® for your home. This ultrasonic device connects to the network and repels pests with ultrasonic waves. They are silent to human ears, but unbearable to animals.

Food storage

Never leave food out in the open, including in your home, because it can serve as bait that rodents are more likely to find and then try to enter your home. We recommend following our recommendations:

1. Store food in glass jars or plastic/metal containers and make sure the lids are tightly sealed.
2. Don't fill sinks with dirty dishes. Wash dirty plates, cups and utensils as soon as possible.
3. After barbecue and backyard parties, remove any leftover food, clean out grates, and throw away any paper plates or plastic utensils.
4. Always keep pet food tightly sealed. Never leave cat or dog food in a bowl overnight.
5. Place bird feeders a safe distance from your home. Cover them with special protective devices to prevent rodents from entering.
6. Place trash only in tightly closed bags and containers. If there are gaps in the container, get rid of it. You should keep trash containers sealed inside and outside at all times. Containers must be cleaned regularly.
7. Compost bins should be located as far from the house as possible, preferably at least 100 feet.
8. Livestock feed should also be stored in tightly sealed metal or plastic containers.

Cleaning

If you find signs of the presence of rodents in residential or other premises, immediately take the necessary measures. Put on work clothes, a mask, gloves and prepare a cleaning solution (10% bleach and 90% water). Wearing rubber gloves, wipe away marks with paper towels. For best results, repeat cleaning in areas affected by stains, rodent droppings, and urine. Place paper towels in ziploc bags and throw them in a tightly sealed trash container. Before removing gloves, clean them in a bleach and water solution. Place your work clothes in the washing machine and wash your hands with soap and water several times, then shower.

Remove anything unnecessary from your garden or home area that could serve as a nest for rodents, such as fallen leaves, hay, etc. Anything stored in the backyard (firewood, trash cans, etc.) should be marked at a high point: at least 12 inches above the ground. Firewood should be stored at least 100 feet from the home.

Regularly trim tree branches near your home, because... they often serve as a kind of bridge for rodents, from which they can get directly to the roof. Lawns and lawns should be mowed weekly during the warmer months, and shrubs and shrubs around your yard, garage, house and fences should also be trimmed.

Mice and rats can slip through small openings. Consequently, in any house there are such “entrances” for them. It is necessary to seal all the cracks from the outside inside the house. Holes may appear in places that are not visible, for example:

• behind, below and inside kitchen cabinets, trays, refrigerators;
• in baseboards;
• on the ceiling and floor around the masonry fireplace;
• in and around the door leaf;
• around pipe openings;
• near floor, wall and laundry vents;
• along the eaves, gables and rafters on roofs;
• around entry holes for power lines and telephone, television and internet cables.

Check all these areas for holes or gaps and seal them as necessary. For small holes, use steel wool. For large holes, use a flat screen or sheet metal to seal the hole.

Repel Rodents with Ultrasonic Traps from Victor®

If rodents have settled on your property or nearby, take advantage of our suggestions. Of all the products on the market today, the best rodent repellent is the Victor® Ultra PestChaser®, which is plug-in.

When it comes to repellents and traps for rats, mice and other rodents, Victor® offers a full range of products for indoor and outdoor use, including apartments, outbuildings and other applications.

(HPS), also known as hantavirus cardiopulmonary syndrome (HPS), while others have not been associated with known human disease. HPS (HCPS) is "a rare respiratory disease associated with inhalation of aerosolized rodent excrement (urine and feces) contaminated with Hantavirus particles."

Human hantavirus infections have been almost entirely associated with human contact with rodent feces; in 2005 and 2019, person-to-person transmission of Andes virus was reported in South America.

Hantavirus pulmonary syndrome

Deer mouse

Hantavirus pulmonary syndrome (HPS) is found in North, Central and South America. This is an often fatal lung disease. In the United States, the causative agent is the Nombre Sin virus carried by deer mice. Prodromal symptoms include flu-like symptoms such as fever, cough, muscle pain, headache, and lethargy. It is characterized by the sudden onset of shortness of breath with rapidly developing pulmonary edema, which is often fatal, despite mechanical ventilation and powerful diuretics, with a mortality rate of 36 percent.

Hantavirus pulmonary syndrome was first discovered during a 1993 outbreak in the Four Corners region of the southwestern United States. He was discovered by Dr. Bruce Tempest. It was originally called "Four Corners Disease" but the name was changed to "Sin Nombre Virus" after complaints from Native Americans that the name "Four Corners" stigmatized the region. It has since been defined throughout the United States. Pest control in and around the home remains the primary prevention strategy.

virology

Orthohantavirus
Transmission electron microscope from Sin Nombre orthohantavirus
classification Virus
(Unrated):	Virus
Type:	Negarnaviricota
Training class:	Ellioviricetes
Order:	Bunyavirales
Family:	Hantaviridae
Genus:	Orthohantavirus
Type species
Hantaan orthohantavirus
view
Synonyms
Hantavirus

classification

Hantaviruses are Bunyaviruses. Bunyaviridae the order is divided into five families: Orthobunyavirus , Nairovirus , phleboviruses , Tospovirus And Hantavirus. Like all members of this order, hantaviruses have a genome containing three negative-sense, single-stranded RNA segments, and are therefore classified as negative-sense RNA viruses. Members of others bunyaviruses familiies of the order are usually arthropod-borne viruses, but hantaviruses are believed to be transmitted to humans primarily by inhalation of aerosolized rodent feces or rodent bites.

genome

Like other members of the bunyavirus family, Hantaviruses are surrounded by viruses with a gene that consists of three single-stranded, negative-sense RNA segments, designated S (small), M (medium), and L (large). RNA S encodes the nucleocapsid (N) protein. M RNA encodes a polyprotein that is cotranslationally cleaved to form the shell glycoproteins Gn (formerly G1) and Cc (formerly G2).

L RNA encodes the L protein, which functions as viral transcriptases/replicatases. In virions, genomic RNAs from hantaviruses are believed to complex with the N protein to form helical nucleocapsids, the RNA components of which circularize due to sequence complementarity between the 5" and 3" terminal sequences of the genomic segments.

As in other bunyaviruses, each of the three segments has a consensus 3"-terminal nucleotide sequence (AUCAUCAUC), which is in addition to the 5" terminal sequence and different from those of the other four genera in the family. These sequences appear to form Panhandle structures that appear likely to play an important role in facilitated replication and encapsidation by binding to the viral nucleocapsid (N) protein. The large segment is 6530-6550 nucleotides (nt) in length, the medium is 3613-3707 nucleotides in length and the small segment is 1696-2083 nucleotides in length.

No non-structural proteins are known, unlike other genera of this family. The 5" and 3" of each segment are short non-coding sequences: the non-coding segment in all sequences at the 5" end is 37-51 nt. The 3" non-coding regions are different: L segment 38-43 nt; M segment 168-229 nt; and S segment 370-730 nt. The 3" end of the S segment is retained between genera suggesting a functional role.

Virions

Hantavirus virions are about 120-160 nanometers (nm) in diameter. The lipid bilayer of the viral envelope is about five nm and is embedded with viral surface proteins to which sugar residues are attached. These glycoproteins, known as Gn and Gc, are encoded by the M segment of the viral genome. They tend to bind (heterodimerize) with each other and have both an inner tail and an outer region that extends approximately six nm beyond the envelope surface.

Inside the envelope are nucleocapsids. It consists of multiple copies of the nucleocapsid N protein that interact with three segments of the viral genome to form helical structures. Virally encoded RNA polymerases are also found in the interior. By weight, the virion is more than 50% protein, 20-30% lipids and 2-7% carbohydrates. The density of virions is 1.18 grams per cubic centimeter. These functions are common to all members of the bunyaviruses.

Life cycle

Entry into host cells is believed to occur through attachment to virions by cellular receptors and subsequent endocytosis. Nucleocapsids are introduced into the cytoplasm by pH-dependent synthesis of the virion with the endosomal membrane. Once released from the nucleocapsid into the cytoplasm, the complexes target the ER-Golgi intermediate compartments (ergic) through microtubule-linked movement leading to the formation of viral factories in the ERGIC.

These factories then facilitate the transcription and subsequent translation of viral proteins. Transcription of viral genes must be initiated by the association of the L protein with the three nucleocapsid species. In addition to transcriptase and replicase functions, the viral L protein is also thought to have endonuclease activity, which cleaves cellular messenger RNA (mRNA) to produce locked primers used to initiate transcription of viral mRNA. As a result of this cap snatching, hantavirus mRNA is capped and contains nontemplated 5" terminal extensions.

G1 (called Op) and G2 (Gc) glycoproteins form hetero-oligomers and are then transported from the endoplasmic reticulum to the Golgi complex, where glycosylation is completed. The L protein produces the nascent genome from replication using a positive sense RNA intermediate. Hantavirus virions are believed to assemble by combining nucleocapsids with glycoproteins embedded in Golgi membranes, and then budding into Golgi cisternae. Nascent virions are then transported in secretory vesicles to the plasma membrane and released by exocytosis.

pathogenesis

The pathogenesis of Hantavirus infections is unclear, and there is a lack of animal models to describe it (rats and mice do not appear to acquire severe disease). While the primary site of viral replication in the body is not known, in HFRS the main effect is in the blood vessels, while in HPS most symptoms are associated with the lungs. In HFRS, there is increased vascular permeability and decreased blood pressure due to endothelial dysfunction and the most dramatic damage is seen in the kidneys, whereas in HPS, the lungs, spleen and gallbladder are the most affected. Early symptoms of HPS tend to present similar to the flu (muscle aches, fever and fatigue) and usually appear approximately 2 to 3 weeks after infection. Later stages of the disease (about 4 to 10 days after the onset of symptoms) include difficulty breathing, shortness of breath and cough.

transmission

The species that cause hantavirus hemorrhagic fever have not been shown to be transmitted from person to person. Transmission by aerosolized rodent feces is the only known way the virus is transmitted to humans. Similar negative double-stranded RNA viruses, such as Marburg and Ebola hemorrhagic fevers, can be transmitted through contact with infected blood and other body fluids, and are known to spread to healthcare workers in African hospitals, although not easily transmitted in modern hospital settings with universal precautions. Transmission through fomites has not been demonstrated in hantavirus disease in either hemorrhagic or pulmonary forms.

evolution

Findings of significant correspondence between the phylogenies of hantaviruses and the phylogeny of their rodent reservoirs have led to the theory that rodents although infected with the virus are not damaged by this due to long-standing hantavirus rodent host coevolution, although findings in 2008 led to a new hypothesis regarding hantavirus evolution:

Various Hantaviruses have been found to infect several species of rodents, and cases of interspecies transmission (host switching) have been recorded. Additionally, substitution rates based on nucleotide sequence data indicate that the Hantavirus clade and rodent subfamily may not have diverged at the same time. Additionally, as of 2007, hantaviruses have been found in a large number of species of shrews and moths.

Given the controversy in coevolution theory, it was proposed in 2009 that the patterns seen in hantaviruses in relation to their reservoirs could be attributed to preferential host switching driven by geographic proximity and adaptation to specific host types. Another proposal from 2010 is that geographic clustering of Hantavirus sequences may be caused by an isolation mechanism, by distance. By comparing hantaviruses found in hosts of the orders Rodentia and shrews, it was proposed in 2011 that hantavirus evolutionary history represents a combination of both host switching and codivergence and that ancestral shrews or moles, rather than rodents, may have been the original original hosts of ancient hantaviruses.

Africa

In 2010, a novel hantavirus virus, Sangassou, was isolated in Africa, which causes hemorrhagic fever with renal syndrome.

Asia

In China, Hong Kong, the Korean Peninsula and Russia, hemorrhagic fever with renal syndrome is caused by Hantaan, Puumal and Seoul viruses.

Australia

In 2005, there were no human infections reported in Australia, although rodents were found to carry antibodies.

Europe

In Europe, three Hantaviruses - Puumala, Dobrava and Saaremaa viruses - are known to cause hemorrhagic fever with renal syndrome. Puumala usually causes a usually mild illness - nephropathia epidemica - which usually presents with fever, headache, gastrointestinal symptoms, impaired renal function and blurred vision. Dobrava infections while similar often also have hemorrhagic complications. There are a few reports of confirmed infections in Saaremaa, but these appear to be similar to those caused by Puumal and less pathogenic than Dobrava.

The Puumal virus is carried by its rodent host, the bank vole ( Clethrionomys glareolus) and is present throughout most of Europe except for the Mediterranean region. The Dobrava and Saaremaa viruses are respectively carried out using yellow neck mice ( Aroetis flavicollis) and field mouse ( Aroetis agrarius), reported mainly in eastern and central Europe.

In 2017 alone, the Robert Koch Institute (RKI) in Germany received 1,713 notifications of Hantavirus infections.

In June 1993, a newly discovered hantavirus was identified as the etiological agent responsible for an outbreak of severe respiratory disease in the southwestern United States.

Currently, this disease is called hantavirus pulmonary syndrome. Hundreds of cases caused by closely related hantaviruses have been reported. The disease is characterized by a febrile prodrome, followed by rapid development of non-cardiogenic lung disease and arterial hypotension or shock. More than 50% of patients with hantavirus pulmonary syndrome died.

Etiology

Hantaviruses are a genus belonging to the Bunyavirus family. Hantaviruses have a supercapsid and contain a minus-strand RNA consisting of three unique segments. Several pathogenic viruses have been isolated within the genus, including the Hantaan virus, which causes the most severe hemorrhagic fever with renal syndrome, found primarily in mainland Asia; Dubrava virus; Puumala virus, Seoul virus. Prospect Hill hantavirus is widespread and spread by gray voles, but no disease caused by this virus has been described in humans.

Cases of hantavirus pulmonary syndrome identified in 1993 were caused by the Sin Nombre virus isolated in New Mexico from a deer hamster. Many of the causative agents of hantavirus pulmonary syndrome known to date belong to the same genetic group of hantaviruses and are associated with rodents. The habitats of these rodents are limited to the American continent, so hantavirus pulmonary syndrome is considered a disease of the Western Hemisphere.

Epidemiology

Patients usually have a history of recent outdoor contact with deer hamsters or living in an area where many of these rodents live. Cluster cases of hantavirus pulmonary syndrome have been observed among workers who clean rodent-infested houses. Approximately 50% of cases occur between May and July. Almost all patients are people from 12 to 70 years old, 60% of them are aged 20-39 years. In children under 12 years of age, cases of the disease are rarely reported. 2/3 of the patients are men, which probably reflects their more active outdoor activities. It is unknown whether the almost complete absence of cases of the disease among young children is due to congenital immunity or lack of contact with the pathogen. During outbreaks in Argentina, human transmission was proven.

In their animal reservoirs, hantaviruses cause lifelong asymptomatic infection. Infected animals can shed the virus in saliva, urine, and feces for many weeks, but the duration of shedding and the period of maximum infectivity remain unknown. The presence of the virus in saliva, the sensitivity of these animals to parenteral infection with hantaviruses, and field observations of infected rodents indicate that bites are an important mechanism for the spread of the virus among rodents. Aerosols formed from saliva or secretions of rodents are involved in human infection. People who visited animal care facilities where rodents found shelter became infected after contact that lasted at least 5 minutes. It is possible that hantaviruses are spread through contaminated food and wounds to the skin or mucous membranes; transmission to humans occurred through rodent bites. Human-to-human transmission of hantavirus is extremely rare, but has been reported in Argentina.

Symptoms

Hantavirus pulmonary syndrome is divided into prodromal and cardiopulmonary stages. On average, 5.4 days pass from the onset of prodromal symptoms to hospitalization. The average length of time from the onset of symptoms to death is 8 days (median 7 days, range of fluctuations 2-16 days). During the prodromal period, the most common symptoms are fever and myalgia (100%), cough or shortness of breath (76%), and gastrointestinal disorders including vomiting, diarrhea and in the mid-abdomen (76%), (71%). The cardiopulmonary stage manifests itself with increasing cough and shortness of breath. Physical examination during this period most often reveals rapid breathing (100%), tachycardia (94%) and arterial hypotension (50%). In the most severe cases, acute pulmonary edema, hypoxia and shock quickly develop. In fatal cases, pulmonary edema was accompanied by severe hypotension, often leading to sinus bradycardia, electromechanical dissociation, ventricular tachycardia, or fibrillation. Arterial hypotension may worsen even with adequate treatment.

Diagnostics

Hantavirus pulmonary syndrome should be suspected in a previously healthy person who develops acute respiratory failure after a period of fever. Thrombocytopenia in combination with a febrile prodrome and contact with wild rodents in the spring or summer months is highly likely to indicate hantaviruses. To confirm the diagnosis, antibodies to class M hantaviruses are determined. Hantavirus antigen can be detected in tissues using immunohistochemical examination or amplification of the hantavirus nucleotide sequence using reverse transcription PCR. Assistance with diagnosis, epidemiological investigations and outbreak containment is available from the health department.

Treatment

It is necessary to ensure sufficient oxygenation, as well as maintain cardiovascular function. The pathophysiology of hantavirus pulmonary syndrome is similar to that of dengue fever shock. To treat symptomatic hypotension, vasopressor or inotropic agents should be used in combination with reasonable volumes of intravenous fluids to avoid aggravating pulmonary edema. Ribavirin, the early intravenous administration of which sometimes saves lives in hemorrhagic fever with renal syndrome, is useless in hantavirus pulmonary syndrome.

Forecast

Mortality is about 50%. Highly specific and sensitive prognostic factors for death are sharp deviations in hematocrit, leukocyte content, LDH and APTT.

Prevention

The only way to prevent hantavirus infection is to avoid contact with rodents. Control of rodents in and around your home is important. Since when working with blood, other biological fluids and tissues of sick people and animals, the formation of a virus-containing aerosol is possible, a second level of biological protection must be provided in the laboratory. Patients must be isolated.

The article was prepared and edited by: surgeon

• Hantaviruses are viruses transmitted to humans from the urine and droppings of rodents. Hantaviruses can cause pulmonary infection syndrome.
• Hantavirus pulmonary syndrome (HPS) is a respiratory disease that is a severe form of infection and can be fatal.
• Hantavirus pulmonary syndrome (HPS) is caused by inhalation of airborne particles of contaminated rodent urine, droppings, and nesting materials containing the virus. The form of hantavirus in the United States is not transmitted from person to person.
• The incubation period for hantavirus is two to three weeks before symptoms and signs appear.
• The main risk factor for developing hantavirus pulmonary syndrome is exposure to rodents that carry the virus. If you live, work, or travel in an area where rodent carriers are known to live, exposure is possible.
• People can easily mistake the signs and symptoms of hantavirus for the flu. Early symptoms include fatigue, fever, muscle aches, headaches, dizziness, chills, nausea, vomiting, diarrhea and abdominal pain.
• In the advanced stage, symptoms of HPS include cough and shortness of breath. Heart and pulmonary failure may occur.
• Blood tests are used to diagnose hantavirus pulmonary syndrome.
• There is no specific treatment for hantavirus pulmonary syndrome. Supportive treatment may include oxygen therapy, fluid replacement, and blood pressure medications
• Hantavirus pulmonary syndrome is fatal in 38% of cases, so early intervention is important.
• Prevention of hantavirus involves limiting contact with potentially infectious rodents in affected areas.

What is hantavirus pulmonary syndrome?

Hantavirus pulmonary syndrome (HPS, also called hantavirus cardiopulmonary syndrome or HCPS) is a respiratory disease that is a severe form of infection caused by hantaviruses and can be fatal. Hantaviruses are viruses transmitted to humans from the urine and droppings of rodents.

What's the story

An outbreak of an unexplained lung illness has occurred in the Four Corners region of the southwestern United States, including Arizona, New Mexico, Colorado and Utah. After much research and testing, experts linked pulmonary syndrome to a previously unknown type of hantavirus.

The last outbreak of the hantavirus form of the virus in Seoul occurred in 2017. Seventeen people developed infections in 11 states, including Colorado, Georgia, Illinois, Iowa, Minnesota, Missouri, Pennsylvania, South Carolina, Tennessee, Utah and Wisconsin.

The previous outbreak occurred in 2012, when 10 cases of hantavirus infection were confirmed among people who had recently visited Yosemite National Park. There were three deaths. Visitors came from California, Pennsylvania and West Virginia.

What causes hantavirus pulmonary syndrome?

Hantavirus pulmonary syndrome (HPS) is caused by inhalation of airborne particles of contaminated rodent urine, droppings, and nesting materials containing the virus.

Sin Nombre virus (SNV) and the southern (prototypic) form of Andean virus cause the most severe forms of hantavirus pulmonary syndrome. The Andes-Nort virus, Laguna Negra virus (LNV), and Choclo virus cause milder forms of HPS.

How does hantavirus spread?

In the USA the virus may be infected deer mice ( Peromyscus maniculatus), cotton rats and rice rats in the southeast, and the white-breasted mouse in the northeast. Rodents shed hantavirus in their urine, feces and saliva. When fresh droppings or urine are mixed, small particles containing hantavirus are released into the air. Transmission of the virus to humans occurs when people inhale air contaminated with the virus.

Other possible ways the virus can spread among people include

• bites from an infected rodent (rare);
• touching something contaminated with rodent urine, droppings, or saliva, then touching your nose or mouth; and also
• eating food contaminated with contaminated rodent urine, droppings, or saliva.

What is the incubation period for Hantavirus pulmonary syndrome?

From the time the virus is first inhaled into the lungs, the incubation period for hantavirus is usually two to three weeks before symptoms appear (range is one to eight weeks).

Is hantavirus contagious?

Hantavirus is generally not contagious. Forms of hantavirus in the United States cannot be transmitted from person to person, but human-to-human transmission has occurred in rare cases in Chile and Argentina.

What are the risk factors for hantavirus pulmonary syndrome?

The main risk factor for developing hantavirus pulmonary syndrome is exposure to rodents that carry the virus. Even if you don't see rodents, if you live or work in an area where rodent carriers are known to live, infection is possible. Any activity that may expose a person to rodent droppings, urine, saliva, or nesting materials can put a person at risk of contracting hantavirus.

• House cleaning: Sweeping or vacuuming or other dust-generating activities can release infected particles into the air.
• Occupational Exposure: People in certain occupations, such as pest control, construction or utility workers, may be exposed to rodents.
• Camping/Hiking: Using Rodent Infested Shelters or Camps
• Opening/clearing unused buildings. Indoor structures such as sheds, cabins, sheds, garages and other storage areas can harbor rodents and old droppings.

What are the signs and symptoms hantavirus pulmonary syndrome?

Signs and symptoms of hantavirus can easily be mistaken for the flu, so it is important to tell your doctor if you live, work, or have recently traveled to areas with large numbers of rodents.

The early stage of hantavirus pulmonary syndrome lasts two to eight days, and signs and symptoms may include the following:

• Fatigue
• fever
• Muscle pain (especially in large muscle groups: hips, thighs, back and shoulders)
• Headaches
• Dizziness
• Chills
• Gastrointestinal disorders (nausea, vomiting, diarrhea and abdominal pain)

After the early stage, late symptoms of hantavirus pulmonary syndrome are related to fluid in the lungs and include

• cough,
• shortness of breath, and
• Heart and pulmonary failure may occur.

These symptoms can lead to organ failure and death in some patients.

Which tests do doctors use to diagnose hantavirus pulmonary syndrome?

Early symptoms of hantavirus pulmonary syndrome resemble the flu, and the illness can be difficult to diagnose.

Your doctor may order blood tests to look for abnormalities that may indicate HPS, such as low platelet counts, elevated blood levels of lactate dehydrogenase, and elevated levels of hepatocellular enzymes and serum lactate. The CDC has immunological tests it can use to detect viruses.

What are the options treatment hantavirus pulmonary syndrome?

There is no specific treatment for hantavirus pulmonary syndrome. It is important that the infection is diagnosed early so that patients can receive supportive care, including oxygen therapy, fluid replacement and blood pressure medications. Kidney dialysis may be required. Patients are usually admitted to the intensive care unit (ICU) for treatment. An antiviral drug called ribavirin is used to treat various strains of hantavirus, including hemorrhagic fever with renal syndrome (HFRS) caused by Hantaan virus (HTNV). The drug has not been shown to work against the strain prevalent in the United States. However, in some cases, doctors may try it.

What is the Prognosis for Hantavirus Pulmonary Syndrome?

The mortality rate from hantavirus pulmonary syndrome is relatively high. HPS is fatal in 38% of cases, so early recognition of the infection is important. The earlier the intervention, the better the prognosis, and those who survive usually recover quickly.

Can hantavirus pulmonary syndrome be prevented?

There is currently no vaccine that can prevent HPS. The Centers for Disease Control and Prevention (CDC) suggests limiting exposure to potentially infectious rodents in affected areas to help prevent hantavirus pulmonary syndrome.

• Minimize or eliminate exposure to rodents at home, work, or other places.
• Seal and seal any openings that could allow rodents to enter buildings.
• Open and ventilate buildings that are rarely used before entering.
• Eliminate potential rodent nesting sites by clearing brush and debris.
• If rodent nesting sites are found, soak the nests with 10% bleach before removing and wear latex gloves while cleaning.
• If there is a significant infestation in an area where hantavirus has already been reported, contact appropriate local, state, or federal health officials before beginning cleanup.