Hepatitis B is an inflammatory liver disease caused by the DNA-containing virus. About 58 million patients with an acute form of infection are registered in the world every year (Terrault et al., 2018). According to WHO experts, the total number of patients with hepatitis B and carriers exceeds 1 billion in different countries. More than 2 billion people are infected with hepatitis B in the world (Terrault et al., 2018). This paper aims to analyze the epidemiological determinants and risk factors associated with hepatitis B in the world, as well as the strategies to prevent its outbreak.
The earliest description of the hepatitis B epidemic was made in 1885. During a smallpox outbreak in Bremen, many of the shipyard workers who were injected other people’s lymph developed jaundice (Revill et al., 2019). Contaminated lymph was the source of an outbreak of hepatitis B, which spread all around the world. In 1966, American physician and geneticist Baruch Blumberg isolated the so-called “Australian antigen”, which turned out to be the surface antigen of the hepatitis B virus (Revill et al., 2019). The first successful hepatitis B vaccine was developed by Maurice Hinnelman.
Today, the hepatitis B virus can be found on all continents and in all countries. It continues to spread rapidly in both developed countries and those with low living standards. The hepatitis B rate is high in the WHO Western Pacific and African Region, with 6.2% and 6.1% of infected adults (Terrault et al., 2019). In the regions of the Eastern Mediterranean, Southeast Asia, and the WHO European Region, 3.3%, 2.0%, and 1.6% of the population are infected. In the WHO Region of the Americas, the rate is 0.7% (Terrault et al., 2018). Now a lot of attention is paid to the problems of prevention of this disease all over the world. A thorough study of the virus is underway to provide the most effective treatment.
The source of infection with hepatitis B is an infected person or a virus carrier. The virus is transmitted with any biological fluid in the body, but primarily with blood. The transmission of the virus occurs through broken skin and mucous membranes, during blood transfusions with infected blood, the use of drugs from infected blood, and poorly sterilized instrumentation. It is also possible that hepatitis B can be transmitted to the newborn from an infected mother during or after delivery (Revill et al., 2019). In the majority of cases, provided timely diagnosis and adequate treatment, patients with acute hepatitis B successfully recover and acquire lifelong immunity to re-infection. However, if the infected person has reduced immunity, the acute period of the disease passes unnoticed, the treatment is delayed and becomes chronic. In this case, the disease progresses slowly and can later turn into cirrhosis and hepatocellular carcinoma.
The main risk groups for hepatitis B are individuals who have unprotected sex with an infected person, people who inject drugs, and patients who receive frequent blood transfusions. Most often, children born to mothers who are carriers of the hepatitis B virus develop a chronic disease. There is a vaccine for the hepatitis B virus that reduces the risk of contraction by 95% (Revill et al., 2019). To prevent transmission, many countries now include hepatitis B inoculation in their immunization plans. The biggest declines in hepatitis B rates are in countries with high vaccination coverage.
In the case of the outbreak, anti-epidemic measures are carried out in the focus of infection, in hospitals, schools, and other institutions. They are aimed at limiting the spread of the pathogen in the environment and ensuring the localization and elimination of acute hepatitis B focus. The main volume of measures for the elimination of the outbreak includes activities carried out by specialists of health care facilities of bodies and institutions carrying out state sanitary and epidemiological supervision. When a patient with acute or chronic hepatitis B is detected, specialists must examine the focus of infection (Revill et al., 2019). The reporting protocol should include clinical, epidemiological, and laboratory data allowing to differentiate hepatitis B from the hepatitis of other etiology, and also estimate the duration of infection. The time and place of possible infection are determined, taking into account epidemiological surveillance of hepatitis B during the incubation period and data from an epidemiological history of possible contacts with patients or carriers.
The community should raise awareness among the population and health workers about the possibilities of preventing hepatitis B. The patients and the virus carriers should receive explanations under what conditions they can become dangerous to others, and what measures are necessary to prevent infections (Revill et al., 2019). Family members of patients with hepatitis B and virus carriers must know and strictly follow the rules of personal prevention and be sure to use individual personal hygiene items. People with hand injuries, dermatitis, maceration, and other lesions of the skin are advised to observe all basic precautions, such as gloves and fingertips.
It is important to reduce the transmission of hepatitis viruses, morbidity, and mortality from its complications, as well as ensure equitable access to comprehensive prevention and recommended testing and treatment services for all people. Thanks to advances in medicine, new horizons are opening up for understanding the problem and its further study. Unfortunately, a disease that has passed into a chronic stage is incurable, but now a lot of work is underway to study viral hepatitis B in detail and prevent its spread. Thus, patient education and ensuring an earlier diagnosis of this infection is a key public health challenge.
References
Revill, P. A., Chisari, F. V., Block, J. M., Dandri, M., Gehring, A. J., Guo, H.,… & Levrero, M. (2019). A global scientific strategy to cure hepatitis B. The Lancet Gastroenterology & Hepatology, 4(7), 545-558.
Terrault, N. A., Lok, A. S., McMahon, B. J., Chang, K. M., Hwang, J. P., Jonas, M. M.,… & Wong, J. B. (2018). Update on prevention, diagnosis, and treatment of chronic hepatitis B: AASLD 2018 hepatitis B guidance. Hepatology, 67(4), 1560-1599.