One of the most effective methods of preventing the spread of STDs is preventive immunization.
Currently, lysed vaccines against hepatitis A and hepatitis B are being used. Vaccines against several STDs, including against HIV and herpes, are under development or in clinical trials. As the number of effective vaccines increases, immunization will become one of the most common methods of STD prevention.
There are 5 different viruses (AE), which are the causes of almost all viral hepatitis in humans. To make sure the diagnosis is correct, serological tests should be performed. For example, a health worker may assume that jaundice in a drug addict using intravenous drugs is due to hepatitis B, while injecting drug users who use intravenous drugs often have outbreaks of hepatitis A. The formulation of the correct diagnosis is the cornerstone in providing appropriate prevention measures. To ensure the authenticity of the registration of cases of viral hepatitis and adequate prophylaxis in persons who have had close household or sexual contacts with a patient with hepatitis, it is necessary to establish the etiology of viral hepatitis of each case by appropriate serological tests.
The cause of hepatitis A is the hepatitis A virus (HAV). HAV multiplies in the liver and is excreted from the body with feces. The highest concentration of the virus in the feces is found between two weeks before and during the first week of clinical signs of the disease. During this period, the virus is also detected in serum and saliva, but at a lower concentration than in feces. The most common method of transmission of HAV is fecal-oral: from person to person with close domestic or sexual contacts, or through contaminated food or water. Transmission of infection to sexual partners can occur with oral-anal contacts, which can be between heterosexual and same-sex partners. Because in the acute period of infection there is viremia, HAV can be transmitted through the blood, but of such cases there are only rare reports. Despite the fact that HAV is present in a small amount in the saliva of an infected person, saliva does not play a role in the transmission of infection.
Up to 20% of patients with acute hepatitis A require hospitalization and 0.1% develop progressive liver failure. The total mortality from acute hepatitis A is 0.3%, but it is higher (1.8%) in people older than 49 years. Infection caused by HAV is not associated with chronic liver disease.
In 1995, there were 31,582 people with hepatitis A in the United States. The most common transmission was through close personal or sexual contact with a person infected with hepatitis A, after taking care of a patient or at work, a recent overseas trip, homosexual contacts, injecting drug use, and was associated with food or waterborne outbreaks. Many people with hepatitis A do not identify any risk factors, perhaps the sources of their infection were other infected persons who did not have symptoms. The prevalence of hepatitis A among the population as a whole is 33% (CDC, unpublished data).
Outbreaks of hepatitis A among male homosexuals have been observed in cities, both in the US and abroad. The incidence of hepatitis A in male homosexuals is significantly higher than in heterosexual men (30% compared with 12% according to one study). A comparative study of a group of patients with control fupp, conducted in New York, showed that homosexual men with acute viral hepatitis had more unknown sexual partners, and were more likely to be involved in group sex than control groups; the relationship between the frequency of use of oral-anal contact (oral role) and digital-rectal contact (digital role) and the occurrence of this disease is shown.
Because hepatitis A is not accompanied by a chronic infection, the treatment is carried out, mainly, supportive. Hospitalization may be necessary for patients who are dehydrated due to nausea and vomiting, or with rapidly developing liver failure. Medications that can cause liver damage, or which are metabolized by the liver, should be used with caution.
General measures for the prevention of hepatitis A, such as personal hygiene, do not affect the transmission of the virus from person to person through sexual contact. In order to control hepatitis A outbreaks among heterosexual and bisexual men, in sanitary education, emphasis should be placed on how to transfer the CAA and the measures that can be taken to reduce the risk of transmitting STDs, including intestinal infections such as HAV. However, the most effective way to prevent hepatitis A is immunization.
There are two types of drugs available for the prevention of hepatitis A, immunoglobulin (IG) and a vaccine. IG is a solution containing antibodies derived from human plasma by precipitation, with the addition of ethanol, which also inactivates HSV and HIV. When administered intramuscularly before infection, or within two weeks after infection, the IG is able to prevent hepatitis A in more than 85% of cases. The use of IG is recommended in various situations of possible infection, including use in persons who were in close sexual or household contact with patients , having hepatitis A. The duration of the protective effect is relatively short (3-6 months) and depends on the dose.
Inactivated hepatitis A vaccines have been used in the US since 1995. These vaccines are safe, have high immunogenicity and efficacy, and appear to provide longer-lasting protection against hepatitis A, compared to IG. Studies on the study of immunogenicity show that the first dose of the vaccine creates immunity in 99% -100% of individuals; the second dose provides longer protection. Studies show that the preventive efficacy of inactivated hepatitis A vaccines reaches 94% -100%.
Vaccination before infection
Preventive vaccination is indicated for the following at-risk groups, who may be visitors to institutions where STDs are administered.
- Men who have sex with men. Sexually active men who have sex with men (both teenagers and adults) should be vaccinated.
- Drug addicts. Vaccination is recommended for drug addicts using injecting and non-injecting drugs if local epidemiological data indicate a current or current outbreak of illness among people at such a risk in behavior.
Vaccination after infection
Persons who have recently been infected by the CAA (ie, those who were in close sexual or household contact with persons who have hepatitis A) and who have not been vaccinated before, should be given one IV dose of IU (0.02 ml / kg) as soon as possible, but not later than 2 weeks after a suspicious contact. Persons who have been prescribed at least one dose of hepatitis A vaccine, at least 1 month prior to suspicious contact with a patient with hepatitis A, do not need an IG. IG should be given as soon as possible, but it is not effective when administered more than 2 weeks after infection.
Hepatitis B (HBV) is a common STD. Sexual transmission occurs in 30-60% of the 240,000 new cases of hepatitis B that are observed annually in the United States in the last 10 years. Among infected adults, a chronic infection develops in 1-6% of cases. These individuals can transmit the virus to others and belong to a group at risk of developing fatal complications of the disease. According to estimates, in the US, hepatitis B causes 6,000 deaths from liver cirrhosis and hepatocellular carcinoma annually.
The risk of perinatal transmission of hepatitis B to newborns from infected mothers is 10-85%, depending on the presence of antigen e of hepatitis B virus (HBV) in the mother. Infected newborns become carriers of viral hepatitis B and are at risk of developing chronic liver disease. Even in the absence of infection during the perinatal period, children of infected mothers remain prone to a high risk of infection by contact and household during the first 5 years of life.
There is no specific treatment against viral hepatitis B. Usually, detoxification and symptomatic treatment are carried out. Over the past four years, many antiviral drugs have been studied for the treatment of chronic hepatitis B. Alpha-2b interferon is effective in 40% of cases with chronic hepatitis B mainly in individuals who have contracted being adults. The effectiveness of antiretroviral drugs for hepatitis B (for example, lamivudine) has been demonstrated and studies in this area continue. The goal of antiretroviral therapy is to stop the replication of viral hepatitis B and the criterion for the effectiveness of treatment can be considered normalization of the results of liver tests, improvement of liver histological examination and obtaining negative results of serological response to HBsAg, instead of a previously determined positive reaction. Observations of patients treated with alpha interferon revealed that the remission of chronic hepatitis caused by the use of this drug has a long duration. The effectiveness of interferon treatment is associated with a low level of viral hepatitis B DNA before treatment, high levels of ALAT before treatment, short duration of infection, infection in adulthood, positive dynamics of histological examination and female sex.
Although the methods used to prevent other STDs must prevent infection and HBV, immunization against hepatitis B is the most effective method of preventing this infection. Epidemiology of HB in the USA shows that for immunization of wide layers of the population and effective prophylaxis of transmission of HBV and HBV-dependent chronic liver diseases it is necessary to divide the population into age groups, in each of which these activities will be carried out. Vaccination of people with a history of STDs is part of the overall strategy for the elimination of hepatitis B in the United States. This strategy also includes: prevention of prenatal infection through routine screening of all pregnant women; routine vaccination of all newborns; vaccination of older children at high risk of infection (eg residents of Alaska, Pacific Islands living in families of the first generation of immigrants from countries where HBV infection is at a high or moderate level of endemicity); vaccination of 11-12-year-old children who were not previously vaccinated against hepatitis B, and vaccination of adolescents and adults at high risk.
Vaccination before infection
With the introduction of routine vaccination against hepatitis B in neonates and the introduction of a broad-based vaccination program for adolescents, high-risk adult vaccination has become of primary importance for the prevention of hepatitis B in the United States. All persons attending STD clinics or those at high risk of hepatitis B infection (eg, persons with multiple sexual partners, sex partners of people with chronic HBV infection or drug addicts) should be offered vaccination against hepatitis B and should be warned that they are at high risk of contracting hepatitis B (as well as HIV infection), which means that it is necessary to take measures that reduce this risk (ie, be choosy in choosing their sexual partners, use condoms, avoid using nester ial needles and syringes for injection).
The list of persons who need to be vaccinated against hepatitis B is as follows:
- Sexually active homosexual and bisexual men;
- Sexually active heterosexual men and women who have recently been diagnosed with another STD; Persons with more than one sexual partner in the last 6 months; visitors to STD clinics and prostitutes;
- Addicts, including injecting and non-injecting drug users;
- Medical workers;
- Recipients of certain blood donor preparations;
- Persons who have had close domestic or sexual contacts with hepatitis B patients;
- Arrivals from countries in which HBV infection is endemic;
- A certain contingent of persons committing foreign trips;
- Clients and staff of institutions for rehabilitation;
- Patients who are assigned hemodialysis.
Screening for antibodies or vaccination without screening
The prevalence of hepatitis B in sexually active homosexual men and drug users using intravenous drugs is high. The cost / effectiveness ratio of serologic screening in the members of this Fupp to prove the transferred infection before vaccination may be acceptable depending on the relative cost of laboratory tests and the vaccine. Given the current cost of the vaccine, testing before vaccination in adolescents is not beneficial, but for adult STD clinic users, it is recommended that pre-vaccination testing be carried out, given the prevalence of hepatitis B. However, given the fact that testing before vaccination may result in a waiver, The dose of the vaccine should be administered concomitantly with the testing. An additional dose of vaccine should be administered based on the results of the tests conducted. The preferred serological test before vaccination is the test for antibodies to the surface antigen (anti-HBs). With its help it is possible to identify persons with a chronic or chronic infection. Since the test for anti-HBs does not reveal persons immunized with the vaccine, it is necessary to make appropriate notes about vaccination in the history of the disease and to ensure that the vaccinated patient is not revaccinated.
Schedule of immunization
The vaccine against hepatitis B is highly immunogenic and stimulates the production of sufficient to protect the amount of antibodies after the administration of three doses, with different schedules of administration. According to the most common phafic, three doses of the vaccine are administered at 0.1-2 and 4-6 months. The intervals between the first and second doses of the vaccine should be at least 1 month, and between the first and third dose - at least 4 months. If the vaccination is interrupted after the first or second dose, then the missing dose should be administered at the nearest opportunity. Do not start vaccination again from the first dose if one dose has not been administered. The vaccine should be injected into the deltoid muscle (and not into the buttock).
Vaccination after exposure to infected viral hepatitis B face
Contact with a person who has acute hepatitis B
Sexual contact. Persons with acute infection can potentially infect sexual partners. Passive immunization with immunoglobulin against hepatitis B (IHGV) can prevent 75% of these infections. Vaccination against hepatitis B, if only one is used, is less effective in preventing infection than the combination of IHOW and vaccination. Persons who have had sex with persons with acute hepatitis B should receive IHPH and should receive a serial injection of the vaccine within 14 days of the last sexual intercourse. Testing the sexual partners for sensitivity to anti-HBs can be recommended if it does not delay treatment in the indicated 14 days.
Household contact. Household contact with persons with acute hepatitis B does not carry a high risk of infection, except in cases where blood contamination can occur (for example, through common toothbrushes or shaving accessories). However, vaccination of persons with household contacts with these patients is recommended, especially for children and adolescents. If the patient's HBsAg result remains positive after 6 months (that is, the infection has become chronic), all persons who have close household contact with him should be vaccinated.
Contact with a person who has chronic hepatitis B
Active immunization without the use of IHD is a highly effective method for the prevention of hepatitis B in people who have had household and sexual contacts with a patient with chronic hepatitis B. Serological reactions after vaccination are indicated for sexual partners of persons with chronic hepatitis and infants born to HBsAg-positive women.
Pregnancy is not a contraindication for the administration of IHDI or a vaccine.
HIV-infected patients develop chronic carrier of hepatitis B virus. Immune response in HIV-infected persons for vaccination is reduced. Therefore, HIV-infected individuals who are vaccinated should be examined for anti-HBs 1-2 months after the third dose of the vaccine. For those who do not have an immune response to the first vaccination, consideration should be given to revaccination with one (or more) dose of the vaccine. Patients who do not have a response to re-vaccination should be warned that they may remain sensitive to infection.
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