[Virology today and tomorrow].

Virus infections are the most common human diseases, particularly acute respiratory infections (mostly in children and young adults). Virus infections of the upper respiratory tract in children are proved in 77.4%, viral bronchitis in 58.6%, viral pneumonia in 47.6% and febrile conditions with lymphadenopathy in 44.1% patients. Current studies show that virus infections can cause not only acute, but also persistent virus diseases. A certain number of viruses are able to incorporate their nucleic acid into the genome of the host-cell, leading to rearrangement of the cell genes and formation of malignant tumors. In women with cervical changes, by application of hybridization technique in situ, the most frequently identified virus genotypes are human papilloma viruses 16 and 18 (in 21.67%), genotypes 6 and 11 in 8.33% and genotypes 31, 33 and 35 in 3.33% examined women. Viral persistence can cause manifestations of latent or chronic infections, as well as prion-caused slow infections of the central nervous system. Defective particles play an important role in maintaining viral persistence. Viruses are important agents involved in various disorders of the immunological homeostasis of the organism. Recent knowledge described in SARS infected patients indicates that induction of the so-called TH2 cytokine profile can be responsible for death of infected patients.