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Epidemiology of hepatitis B in children
Medical expert of the article
Last reviewed: 06.07.2025
Hepatitis B is an anthroponosis: the only source of infection is humans. The main reservoir is "healthy" virus carriers; patients with acute and chronic forms of the disease are of lesser importance.
Currently, according to incomplete data, there are about 300 million virus carriers in the world.
The hepatitis B virus is transmitted exclusively parenterally: by transfusion of infected blood or its products (plasma, red blood cell mass, human albumin, protein, cryoprecipitate, antithrombin III, etc.), by using poorly sterilized syringes, needles, cutting instruments, as well as by scarification, tattoos, surgical interventions, dental treatment, endoscopic examination, duodenal intubation and other manipulations during which the integrity of the skin and mucous membranes is violated.
Natural transmission routes of HBV include transmission during sexual contact and vertical transmission from mother to child. The sexual transmission route should also be considered parenteral, since infection occurs through inoculation of the virus through microtraumas of the mucous membranes of the genitals.
Infection of children from mothers who are HBV carriers occurs primarily during childbirth as a result of contamination from blood-containing amniotic fluid through macerated skin and mucous membranes of the child. In rare cases, the child becomes infected immediately after birth through close contact with the infected mother. In these cases, the infection is transmitted through microtrauma, i.e. parenterally, and possibly during breastfeeding. The child most likely becomes infected not through milk but as a result of the mother's blood (from cracked nipples) getting on the macerated mucous membranes of the child's oral cavity.
The susceptibility of the population to the hepatitis B virus is apparently universal, and the outcome of a person's encounter with the virus is usually an asymptomatic infection. The frequency of atypical forms cannot be accurately calculated, but judging by the detection of seropositive individuals, for each case of manifest hepatitis B there are tens and even hundreds of subclinical forms.
As a result of hepatitis B, a stable lifelong immunity is formed. A repeated disease is unlikely.
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