Human Immunodeficiency Virus

This is a retrovirus. It lacks a metabolic system, so it needs to survive in living (human immune) cells. There are 2 known human immunodeficiency viruses: HIV-1 and HIV-2. HIV-1 is more widespread worldwide. It mutates very quickly. There are 8 variants of HIV-1 identified. Viruses are detected in human blood, semen, vaginal secretions, breast milk, saliva, and urine. These viruses perish at 56 °C in 30 minutes, and at 100 °C instantly. When dried, the viruses in secretions die within 3-7 days. Viruses are quickly destroyed by disinfectants: sodium hypochlorite, 70% alcohol. They are resistant to ultraviolet radiation and delta rays. Ways of virus transmission: through sexual contact, direct contact with infected HIV blood and contaminated human biological fluids, from mother to child through the placenta, during childbirth, or through breast milk.

Human immunodeficiency virus (HIV) infection is a chronic infectious disease. During the disease, when the virus destroys the human immune system to a critical level, acquired immunodeficiency syndrome (AIDS) occurs, manifested by opportunistic infections. This syndrome is a sign of the late clinical stage of HIV infection. Several weeks or months after HIV infection, many infected individuals experience an acute illness similar to mononucleosis, which resolves on its own within 1-2 weeks. Until the onset of another clinical stage of the disease, infected individuals may not experience any disturbances or clinical signs of the disease for many months or years.

Antibodies to HIV develop in many infected individuals within 1-3 months. Sometimes this period lasts up to 6 months, very rarely longer than 6 months. Infection before the formation of HIV antibodies can be detected by examining HIV antigen p24 and PCR (this reaction detects the virus nucleic acid in human biological fluids).

Source | Glossary of Most Commonly Used Biomedical Terms and Concepts | Lithuanian University of Health Sciences | Academician Professor Antanas Praškevičius, Professor Laima Ivanovienė