Viruses are infectious agents that can only multiply in living cells, using the host’s structures and mechanisms. They can cause humans from very mild symptoms to severe illness that leads to the loss of life.

“A virus is a pathogen that can only be seen under a microscope. It consists of a protein coat (capsid) inside which is its genetic material (DNA or RNA). It breaks through the natural barriers and control of our immune system, gets inside human cells and uses the cell’s structures to multiply and cause infection,” explains Mr. Theofilos Sachinidis Director Pathologist, Head of Department of International Patients at Metropolitan Hospital.

Then it refers to the types of infections caused by viruses, their symptoms, prevention, diagnosis and treatment:

What groups of viruses are there?

Viruses are divided into different groups depending on the organs they target, the way they spread or the symptoms they cause:

– Viral respiratory infections
– Viral gastroenteritis
– Viral hemorrhagic fevers
-Viral sexually transmitted diseases (STDs)
– Viral rash diseases
-Viral infections of the Central Nervous System (CNS)
-Congenital viral diseases

How do they infect people?

Viruses are transmitted through contact with other people (coughing, sneezing, close contact), through surfaces or objects previously touched by a sick person, through sexual contact, through the bite of an insect infected with the virus, or finally, through contaminated food or water.

What are the usual symptoms they cause?

Symptoms caused by viruses depend on the affected area of ​​the body. “When the upper respiratory tract is affected, we usually present with a runny nose, pharyngalgia and cough (e.g. the common cold virus), while in the lower respiratory tract we present a high fever, headache, muscle aches and malaise (e.g. flu, COVID-19). In gastrointestinal infections, we present nausea, vomiting and diarrheal stools.
Viruses can cause serious illness and even death, especially in people belonging to vulnerable groups: pregnant women, extreme age groups (under 5 years and over 65), kidney patients, heart patients, patients with chronic respiratory diseases, cancer patients and immunocompromised “, emphasizes the expert.

How is the laboratory diagnosis made?

There are now several methods for the laboratory diagnosis of viral infections: Culture, electron microscopy, agglutinin reactions, sediment reactions, Coombs test, complement binding, indirect hemagglutination, immunofluorescence, ELISA, PCR). The rapid antigen detection of the virus (rapid test) and the molecular technique for detecting the genetic material of the virus (PCR) have now become well-known due to infection by COVID-19.

Viral respiratory infections

In the period we are going through, viral respiratory infections (upper and lower) are on the rise. Every day we are bombarded with news of new cases of COVID-19, influenza, RSV or Coxsackie.

How are respiratory infections prevented?

“The basic prevention of viruses is vaccination. We follow the recommendations of the national vaccination committee (either for childhood vaccination, or for vaccination against influenza, COVID-19 and shingles for adults). Other ways of prevention are the use of a mask in closed spaces or places of sharing, the frequent use of antiseptic on the hands, good ventilation of the spaces and, of course, a healthy diet and systematic exercise” points out Mr. Sachinidis.

How are respiratory infections treated?

“Treatment of viruses is mainly symptomatic. Antibiotics do not help, because the virus penetrates into human cells and does not have its own mechanisms of reproduction. We use antipyretics, painkillers, decongestants, drink lots of fluids and fruit juices and try to rest to give our body time to deal with the invading virus. For specific viruses (flu, SARS-CoV-2, HIV, hepatitis B and C) there are special antiviral drugs that prevent their multiplication and spread in the human body. The attending physician will guide us as to whether and when it is necessary to receive antiviral treatment,” he adds.

When do we contact the attending physician?

If we present symptoms of a viral infection, we should contact the attending physician if the fever remains above 38.5o C for more than 3 days, we present chest pain, shortness of breath or hemoptysis and finally if our environment detects confusion. If of course we belong to the vulnerable groups, we must contact our doctor immediately.

How long do respiratory viruses last?

“Respiratory infections last from a few days to 2 weeks. It is important to stay at home on all fever days and for 24 hours of rest (without taking antipyretics) to reduce the chance of transmission. The same instructions apply to children.

Viruses are infectious agents that attract our attention especially during the winter months. Should we be afraid? No. We must get vaccinated, eat right, exercise, stop smoking and follow the instructions of our doctors. And if we experience a virus more severely, there are now enough drugs in our quiver to deal with it” concludes Mr. Sahinidis.