What are ARVIs and how are they dangerous?

2024 Author: Malcolm Clapton | [email protected]. Last modified: 2023-12-17 03:44

The colds just seem to be the same.

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 they are usually allocated to a special category, since the flu is characterized by more severe symptoms and an increased risk of complications, compared to "colds" 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 common among ARVI. According to some reports, rhinoviruses are the cause of every second common cold in the world.

How to recognize

The root "rhino" in the name of this category of viruses goes back 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 found that rhinoviruses reproduce best at temperatures typical of a frozen nose, around 33–35 ° C. So, if you get hypothermic, and then find you have a runny nose or other of the above symptoms, it is most likely 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 seriously, believing that such colds pass quickly and without consequences. However, over the decades of observation, extensive clinical and epidemiological data have been collected, suggesting that such "nasal" problems dramatically increase the risk of developing bacterial infections:

• otitis media;
• sore throat;
• sinusitis;
• bronchitis;
• 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 causative agent of community-acquired pneumonia, and 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 immune systems.

But there is good news as well. According to some reports, 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 COVID-19 disease.

Adenovirus infection

If rhinoviruses prefer to multiply in the nasal passages, moreover, they are frozen, then for adenoviruses, temperature does not matter. They willingly occupy the mucous membranes of the respiratory tract, eyes, gastrointestinal tract.

Therefore, infection does not necessarily occur through the nose. Adenoviruses are easily transmitted by contact. For example, when you share a 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, adenovirus infection can be assumed by the following symptoms:

• 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 if a particular type of adenovirus attacks the intestinal mucosa.

What is dangerous

In healthy adults and children, adenoviral ARVI usually proceeds without complications, and its symptoms disappear within a few days.

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

Parainfluenza

Parainfluenza viruses were discovered in the 1950s. And at first, doctors considered them a 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-" means "something that is nearby").

These infections are not as widespread as rhinoviral 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

Parainfluenza symptoms 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 be 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 type of virus.

• Parainfluenza virus type 1 is the most common cause of croup. 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 pandemic, and its predecessor SARS ‑ CoV ‑ 1, the causative agent of SARS, are not all 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 manifest themselves with similar symptoms:

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

Some features associated with the serotype may then 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. The delta strain does not exhibit such a manifestation - 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 the following symptoms against the background of a cold:

• 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 that are able to manifest themselves even weeks and months after recovery.

Respiratory syncytial viral infection

This type of ARVI is especially common among young children. Experts from the US Centers for Disease Control and Prevention (CDC) claim that almost all babies are familiar with viruses in this category even before their second birthday.

How to recognize

Respiratory syncytial viral infection most often makes itself felt by the symptoms of a common mild cold:

• runny nose;
• decreased appetite;
• coughing;
• sneezing;
• wheezing in the chest;
• an increase 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 can 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 recommend reducing activity, resting, and drinking more fluids. Details about the treatment can be found here.