Viral infection is the invasion of the virus into the human body. In the case of upper respiratory tract infections1, the virus that attacks the organism penetrates the tissues of the mucous membranes and utilizes them to propagate and destroy the cells, thus exposing the deeper layers (especially the nasopharynx). These usually protected spots are irritated and lead to, among other, feeling pain. In addition, the ciliary apparatus is damaged, which function is to protect the mucus.
These changes trigger the body’s defense mechanisms and they are responsible for the first symptoms of infection such as pain, fever or nasal discharge. Further development of the virus in the body leads to the development of infection, becomes more and more burdensome. In addition, the virus continues to multiply and poses a threat to further individuals.
Viruses causing upper respiratory infections are transmitted by droplets, therefore:
- Viral entry into the body is extremely easy.
- It is difficult to protect it effectively.
- Any sneeze or coughing spasms release tiny water droplets containing viruses.
- Droplets of virus particles are inhaled by subsequent persons.
- The body defends itself against viruses – physiological defense mechanisms.
- Lowered immunity (e.g. in case of overcooling or overheating of the body) makes the defense mechanisms not work and not remove the virus, facilitating infection.
2 Diagnosis of acute inflammations of the upper respiratory tracts (gdo) – selection of materials and interpretation problems related to the presence of physiological flora and carrier; text of the lecture presented on the XXVII Convention of the Polish Society of Microbiologists in Lublin on 5-8 of September 2012, Elżbieta Mazur http://www.pm.microbiology.pl/web/archiwum/vol5132012213.pdf