How to prevent hepatitis B in children?

Prevention of hepatitis B in children is primarily a thorough examination of all categories of donors with mandatory blood testing for HBsAg at each delivery using highly sensitive methods of its identification (ELISA, RIA), as well as the determination of ALT activity.

Do not tolerate the donation of people who have suffered in the past viral hepatitis, patients with chronic liver disease, as well as individuals who received blood transfusions and its components during the last 6 months. It is forbidden to use blood and its components for transfusion from donors not examined on HB, Ag.

To increase the safety of blood products, it is recommended to examine donors not only for HBsAg, but also for anti-HBs. Elimination of donors from individuals who have anti-HBs, considered as hidden carriers of HBsAg, virtually eliminates the possibility of posttransfusion hepatitis B.

To prevent infection of newborns, all pregnant women are twice examined on HBsAg by highly sensitive methods: when taking a pregnant woman on the register (8 weeks of pregnancy) and when taking a maternity leave (32 weeks). In case of HBsAg detection, the issue of pregnancy bearing should be decided strictly individually. It is important to take into account that the risk of intrauterine infection of the fetus is especially large in the presence of HBeAg in a woman and is negligible in its absence, even if HBsAg is detected in a high concentration. The risk of infection of the child is significantly reduced, and with delivery by cesarean section.

The interruption of transmission routes is achieved by the use of disposable syringes, needles, scarifiers, probes, catheters, blood transfusion systems, other medical equipment and equipment used in manipulations associated with disruption of the integrity of the skin and mucous membranes.

All medical instruments and re-use equipment must undergo thorough pre-sterilization cleaning and sterilization after each use.

For the prevention of posttransfusion hepatitis, strict adherence to indications for hemotherapy is very important. Transfusion of canned blood and its components (erythrocyte mass, plasma, antithrombin III, VII factor concentrates) is done only for vital indications and is noted in the medical history. It is necessary to go as far as possible to transfusion of blood substitutes or, in extreme cases, to transfuse its components (albumin, specially washed red blood cells, protein, plasma). This is due to the fact that the pasteurization of plasma (60 "C, 10 h), although it does not guarantee the complete inactivation of HBV, still reduces the risk of infection, even less the risk of infection with transfusion of albumin and protein, and the risk of infection with transfusion of immunoglobulins is negligible.

In the high-risk departments of hepatitis B infection (hemodialysis centers, intensive care units, intensive care units, burn centers, oncological hospitals, hematology departments, etc.), hepatitis B prevention is achieved through strict adherence to antiepidemic measures: use of disposable instruments, fixation of each apparatus beyond a fixed group of patients, thorough purification from the blood of complex medical devices, maximum dissociation of patients, restriction of parenteral meshatelstv and others. In all these cases, HBsAg identification is carried out by highly sensitive methods, and at least 1 time per month.

To prevent occupational infections, all employees must work with blood in rubber gloves and strictly observe the rules of personal hygiene.

To prevent the spread of infection in families of patients with hepatitis and carriers, HBV conducts current disinfection, strictly personalize personal hygiene items (toothbrushes, towels, bed linens, loofahs, combs, shaving accessories, etc.). All members of the family are explained under what conditions the infection can occur. For family members of patients with chronic hepatitis B and carriers of HBsAg, medical supervision is established.

Specific prophylaxis of hepatitis B is achieved through passive and active immunization of children with a high risk of infection.

Immunoglobulin with a high antibody content for HBsAg (passive hemagglutination 1: 100,000-1: 200,000) is used for passive immunization. Such an immunoglobulin is obtained from the plasma of donors, in the blood of which anti-HBs are detected in a high titer.

[1], [2], [3], [4], [5], [6], [7], [8], [9]

Indications for immunoglobulin prophylaxis of hepatitis B in children

• Children born to mothers who carry HBsAg or who have contracted acute hepatitis B in recent months of pregnancy (immunoglobulin is administered immediately after birth, and then again at 1.3 and 6 months).
• After entering the body of a virus-containing material (blood or its components are swept from the patient or carrier of HBV, accidental cuts, injections with alleged contamination with virus-containing material). In these cases, the immunoglobulin is administered in the first hours after the alleged infection and after 1 month.
• With a long-lasting threat of infection (children entering hemodialysis centers, patients with hemoblastoses, etc.) - re-enter at different intervals (after 1-3 months or every 4-6 months). The effectiveness of passive immunization depends primarily on the timing of the introduction of immunoglobulin. When administered immediately after infection, the prophylactic effect reaches 90%, in the time to 2 days - 50-70%, and when administered after 5 days immunoglobulin prophylaxis is practically ineffective.

With intramuscular injection of immunoglobulin, the peak concentration of anti-HBs. In the blood comes in 2-5 days. To obtain a faster protective effect, it is possible to administer immunoglobulin intravenously.

The immunoglobulin release period ranges from 2 to 6 months. A reliable protective effect is noted only in the first month after the administration, therefore, in order to obtain a prolonged effect, it is necessary to re-introduce the immunoglobulin. In addition, the use of immunoglobulin is effective only at a low infectious dose of HBV. In the case of massive infection (blood transfusion, plasma, etc.), immunoglobulin prophylaxis is ineffective.

Despite the shortcomings, the introduction of a specific immunoglobulin can take a worthy place in the prevention of hepatitis B. According to the literature, the timely introduction of a specific immunoglobulin can prevent infection with hepatitis B in 70-90% of vaccinated.

Vaccination against hepatitis B in children

To actively prevent hepatitis B, genetically engineered vaccines are used.

In our country, several recombinant vaccines against hepatitis B (manufactured by CJSC "Kombiotech", etc.) have been created. In addition, several foreign preparations have been registered and approved for use (Engerix B, HB-VAXII, euvax B, Shenkwak-B, eberbiovac AB, regevac B, etc.).

Active immunization against hepatitis B is subject to:

• all newborns in the first 24 hours of life, including children born to healthy mothers and children at risk, who include newborns born to mothers, carriers of HBsAg, patients with hepatitis B virus or who have had viral hepatitis B in the third trimester of pregnancy who do not have the results of the survey on hepatitis B markers, as well as those related to the groups at risk: drug addicts, in families in which there is a carrier of HBsAg or a patient with acute viral hepatitis B and chronic viral hepatitis;
• Newborns in areas endemic for hepatitis B, with a HBsAg carrier level of more than 5%;
• patients who often undergo various parenteral manipulations (chronic renal insufficiency, diabetes mellitus, blood diseases, presumed surgery using an artificial circulation device, etc.);
• persons who are in close contact with HBsAg-carriers (in families, closed children's groups);
• medical staff of hepatitis departments, hemodialysis centers, blood service departments, surgeons, dentists, pathologists;
• persons who have been accidentally injured by instruments contaminated with blood from patients with hepatitis B or carriers of HBsAg.

Vaccination against hepatitis B is carried out three times in accordance with the scheme 0, 1, 6 months, healthy children - 0, 3, 6 months. Other schemes are acceptable: 0.1, 3 months or 0.1.12 months. Revaccination is carried out every 5 years.

Active immunization is restricted to individuals whose blood does not reveal HBV markers (HB, Ag, anti-HBc, anti-HBs). If one of the hepatitis B markers is present, there is no vaccination.

The effectiveness of vaccination against hepatitis B is very high. Numerous studies show that when a vaccine is administered in a 0.1.6 month schedule, 95% of people develop protective immunity, which provides reliable protection against HBV infection for 5 years or more.

There are no contraindications to vaccination against hepatitis B. The vaccine is safe, areactogenic. With the help of vaccination, it is possible to reduce the incidence of hepatitis B by 10-30 times.

To prevent vertical transmission of HBV, the first phase of vaccination is performed immediately after birth (no later than 24 hours), then vaccinated at 1, 2 and 12 months. For this purpose, combined passive-active immunization of newborns from mothers, patients with hepatitis B, or carrier viruses can be used. Specific immunoglobulin is administered immediately after birth, and vaccination is given in the first 2 days. Vaccination is carried out in the 0.1, 2 month mode with a booster at 12 months. Such passively-active immunization reduces the risk of infection of the child in mothers with HBeAg from 90 to 5%.

The widespread introduction of vaccination against hepatitis B will reduce the incidence of not only acute but also chronic hepatitis B, as well as cirrhosis and primary liver cancer.