Epidemiology of HIV / AIDS
Last reviewed: 23.04.2024
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HIV infection is found on all continents and practically in all countries where a systematic search of patients is conducted. According to WHO, about 50 million people live with HIV. Every year more than 2 million people with HIV infection are identified.
The age structure of the diseased, and especially the infected, is not exactly established. According to generalized data, the share of children among the sick reaches 10% or more.
The reservoir and source of infection is only an infected person, a sick person or a virus carrier. The virus in the human body is in the blood and various organs. Especially often the virus is found in lymphocytes, which makes it possible to consider lymphocyte as the natural site of HIV infection. The virus is excreted mainly with sperm and menstrual blood. There is information about the presence of the virus in saliva, tears and human milk. However, the concentration of the virus in these biological fluids is low.
Infection of children occurs in the transplacental way and with transfusion of blood products. Intrauterine transmission of infection begins to be detected from 15 weeks of gestation, while HIV, unlike other retroviruses, is not transmitted to the offspring as an insertion into the genome, but penetrates into the fetus directly with the mother's blood. Infection of the child can occur during the passage of the birth canal. As a result, up to 36% of infants born to infected mothers become infected with HIV.
Theoretically, infection can occur with close contact through microtrauma, cuts, bites, if the virus-containing material (blood, saliva, semen) gets on the damaged skin or mucous membranes. HIV infection is possible with organ and tissue transplantation, as well as with artificial insemination. Transmission of HIV by airborne droplets, through saliva, bloodsucking insects has not been proven and is unlikely.
Susceptibility to HIV is not precisely established. There is reason to consider it extremely high or even universal.
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