What are ARVIs and how are they dangerous?

The abbreviation ARVI stands for "acute respiratory viral infections". The word "respiratory" means that they primarily affect the respiratory tract.

There are many viruses that cause ARVI. These include influenza pathogens. But usually they are singled out in a special category.Common Colds: Protect Yourself and Others / CDC, insofar as flu is characterized by more severe symptoms and an increased risk of complications compared to "cold" infections. The latter, as a rule, are less dangerous. However, sometimes they also pose a serious threat to health.

We will consider the most common types of ARVI. Their symptoms suggest what kind of virus you have contracted and what it might lead to.

What are ARVI

Rhinovirus infection

The most commonCommon Colds: Protect Yourself and Others / CDC among ARVI. According to some reportsStephen B. Greenberg, Respiratory Consequences of Rhinovirus Infection / JAMA Internal Medicine, rhinoviruses are the cause of one in two colds in the world.

How to recognize

The root "rino" in the name of this category viruses risesRhinoviruses / ScienceDirect to the Latin word for nose. This is due to the fact that rhinovirus infections often make themselves felt precisely by problems with the nose: a severe runny nose, itching in the nostrils, sneezing, a feeling of nasal congestion.

This selectivity is not accidental. Scientists have establishedEllen F. Foxman, James A. Storer, Megan E. Fitzgerald, Bethany R. Wasik, Lin Hou, Hongyu Zhao, Paul E. Turner, Anna Marie Pyle, and Akiko Iwasaki. Temperature-dependent innate defense against the common cold virus limits viral replication at warm temperature in mouse airway cells / PNASthat rhinoviruses reproduce best when the temperature of a frozen nose is around 33–35 ° C. So if you get hypothermic and then find yourself runny nose or other of the above signs, with a high probability it is a rhinovirus infection.

Then pathogenic microbes can go lower - and then a sore throat will join the symptoms, as well as a mild temperature as the body's reaction to the inflammation that has arisen.

What is dangerous

Previously, doctors did not take rhinovirus ARVI seriouslySamantha E. Jacobs, Daryl M. Lamson, Kirsten St. George, and Thomas J. Walsh. Human Rhinoviruses / Clinical Microbiological Review., believing that such colds pass quickly and without consequences. However, over decades of observation, extensive clinical and epidemiological data have been collected.Ronald B. Turner. Rhinovirus: More than Just a Common Cold Virus / The Journal of Infectious Diseasessuggesting that these "nasal" problems dramatically increase the risk of bacterial infections:

• otitis media;
• sore throat;
• sinusitis;
• bronchitisBirgit Winther. Rhinovirus infections in the upper airway / Proceeding of the American Thoracic Society;
• pneumonia.

How this happens is not yet entirely clear. But, for example, the presence of rhinoviruses is known to help Streptococcus pneumoniae to adhere better to the epithelial cells of the respiratory tract. This type of microbes is the main pathogen community-acquired pneumoniaand can also cause meningitis and sepsis.

In addition, rhinovirus infection sometimes exacerbates existing asthma and chronic lung disease. This type of ARVI is especially dangerous for young children, the elderly and adults with weakened immunity.

But there is good news as well. According to some reportsKieran Dee, Daniel M. Goldfarb, Joanne Haney, Julien A. R. Amat, Vanessa Herder, Meredith Stewart, Agnieszka M. Szemiel, Marc Baguelin, Pablo R. Murcia. Human Rhinovirus Infection Blocks Severe Acute Respiratory Syndrome Coronavirus 2 Replication Within the Respiratory Epithelium: Implications for COVID-19 Epidemiology / The Journal of Infectious Diseases, infection with rhinovirus can slow down and sometimes even stop the multiplication of the SARS ‑ CoV ‑ 2 virus. This effect is observed if a person caught a cold before he met the coronavirus, or in the early stages of the disease. COVID-19.

Adenovirus infection

If rhinoviruses prefer to multiply in the nasal passages, moreover, they are frozen, then for adenoviruses, temperature does not play a role. They willingly occupy mucous membranes.Adenovirus Infection / Center for Health Protection. The Government of the Hong Kong respiratory tract, eyes, gastrointestinal tract.

Therefore, infection does not necessarily occur through the nose. Adenoviruses are easily transmitted by contactBrenda L. Tesini. Adenovirus Infections / MSD Manual way. For example, when you divide towel with an infected person. Or you scratch your eyes or nose with your fingers that just held onto an infected handrail on public transport. Also, adenoviral SARS can be contracted when swimming in a lake or poorly disinfected pool.

How to recognize

Today there are seven main types of human adenoviruses. Each of them causes a disease with its own characteristic signs.

In general, it is possible to assume an adenovirus infection by such symptoms.Adenovirus. Symptoms / CDC:

• Flu-like manifestations, in particular fever (temperature above 38 ° C) and general weakness.
• Sore throat.
• Sometimes sore chest pain - when the virus descends into the bronchi.
• Conjunctivitis against the background of a cold - if the virus infects the mucous membrane of the eyes.
• Abdominal pain, nausea, diarrhea, coupled with the same cold. This happens when a particular type of adenovirus attacks the intestinal mucosa.

What is dangerous

In healthy adults and children, adenoviral ARVI is usuallyCausative agents of acute respiratory infections / Federal Budgetary Institution of Health "Center for Hygienic Education of the Population" of Rospotrebnadzor proceeds without complications, and its symptoms disappear within a few days.

But in infants (under the age of one year), the elderly and people with weakened immunity, this kind of cold can lead to pneumonia, infections Bladder and even lesions of the brain and spinal cord, such as meningoencephalitis.

Parainfluenza

Parainfluenza viruses were discovered in the 1950s. And at first the doctors consideredKelly J. Henrickson. Parainfluenza Viruses / Clinical Microbiology Review their kind of influenza pathogens. But quite quickly differences in structure were discovered, and then four types of new microorganisms were combined under the name "parainfluenza" (the Greek prefix "para-" meansPara- / Big Explanatory Dictionary "Something that is nearby").

These infections are not as widespread as rhinovirus and adenoviral infections. However, due to the severity of the symptoms, they are considered one of the most expensive in terms of economic impact. Such a disease can incapacitate a working person for at least a few days.

How to recognize

SymptomsParainfluenza / CDC parainfluenza are similar to real flu:

• heat;
• runny nose;
• cough;
• sore throat;
• decreased appetite;
• irritability;
• sometimes ear pain.

What is dangerous

Parainfluenza is a common infection, and almost everyone encounters it in childhood. But as a result, immunity is developed, so in most healthy adults, repeated infections can pass.Parainfluenza Virus Infections / MSD Manual very easy or even without symptoms.

But in young children or in people with a weakened immune system, parainfluenza ARVI can develop into serious complications. Which - depends on the typeParainfluenza - what is it? / Federal Budgetary Institution of Healthcare "Center for Hygienic Education of the Population" of Rospotrebnadzor virus.

• Parainfluenza virus type 1 is the most common cause of groats. This is the name of a condition in which a sharp edema of the larynx and trachea occurs, which makes it more difficult for air to enter the lungs. For young children, croup is especially dangerous, since their airways already have a narrow lumen, which means they can be completely blocked.
• Parainfluenza virus type 2 can also cause croup symptoms, but in a less severe form.
• Parainfluenza virus type 3 is fraught with the development of pneumonia, bronchitis and bronchiolitis Bronchiolitis is an inflammation of the lower branches of the bronchi. .
• Parainfluenza virus type 4 occurs much less frequently than the previous ones, but it can also cause severe diseases of the bronchi and lungs.

Coronavirus infection

The famous coronavirus SARS ‑ CoV ‑ 2, which has become a pandemic, and its predecessor SARS ‑ CoV ‑ 1, the causative agent of SARS, are far from allCoronavirus Types / CDC representatives of coronavirus infections in humans. There is also MERS-CoV - this pathogen triggers the Middle East respiratory syndrome, no less dangerous than COVID-19.

However, four more common coronaviruses are relatively harmless: they cause the common cold. Most healthy adults and children tolerate this infection easily, and sometimes even asymptomatic.

How to recognize

Distinguishing the “safe” variant from the SARS ‑ CoV ‑ 2 is almost impossible. All types of coronaviruses at the initial stage of the disease showCommon Human Coronaviruses / CDC themselves alike signs:

• an increase in temperature;
• cough;
• distinct weakness;
• pain in the head and muscles.

Then some features associated with the serotype may be highlighted. Serotypes are variations within a group of viruses or bacteria. virus. For example, in the original case of COVID-19, loss of smell was a characteristic and common symptom. Delta strain such a manifestation is not typical - unlike a runny nose, sore throat and headache, which are difficult to relieve with over-the-counter analgesics.

What is dangerous

Like other acute respiratory viral infections, coronavirus complications are dangerous. In particular, acute respiratory distress syndrome is the name for breathing problems that occur when the virus infects a significant part of the lungs. Call an ambulance immediately if you have these symptoms against the background of a cold.Coronavirus. Symptoms / CDC:

• difficulty breathing;
• tightness or chest pain;
• confused consciousness;
• pronounced pallor, gray or bluish tinge of the skin and nails.

These signs indicate oxygen deprivation and require urgent medical attention.

In addition, other complications are possible with coronavirus infections. Including those who are able to express themselves even weeks and months later after recovery.

Respiratory syncytial viral infection

This type of ARVI is especially common among young children. US Centers for Disease Control and Prevention (CDC) experts sayRespiratory Syncytial Virus Infection (RSV). Symptoms and Care / CDCthat almost all babies get acquainted with viruses of this category even before their second birthday.

How to recognize

Respiratory syncytial viral infection most often makes itself felt with symptomsRespiratory Syncytial Virus Infection (RSV). Symptoms and Care / CDC common mild cold:

• runny nose;
• decreased appetite;
• coughing;
• sneezing;
• wheezing in the chest;
• rise in temperature.

Infected infants often have only irritability, loss of appetite, and somewhat shortness of breath.

Symptoms of the disease do not appear immediately, but gradually. And they also gradually disappear - usually after a week or two.

What is dangerous

Healthy adults and children over 1 year old, as a rule, tolerate such ARVI easily. But when it comes to infants or people with weakened immune systems, a respiratory syncytial viral infection canRespiratory Syncytial Virus Infection (RSV). Symptoms and Care / CDC develop into bronchiolitis and pneumonia.

This is the most common cause of bronchiolitis and pneumonia in children under one year of age.

People in the most vulnerable categories may require hospitalization to treat breathing problems and dehydration caused by high fever.

How to treat ARVI

There is no specific treatment for colds. Scientists are still only working on the creation of antiviral agents and vaccines.

Therefore, the main therapy for ARVI, regardless of its type, is considered symptomatic. To speed up recovery, doctors recommendCommon colds / NHS reduce activity, rest, and drink more fluids. Details about the treatment can be found here.