Infection by Hepatitis B Virus (HBV) has been one of health concerns for a long time. The virus leads to both acute and chronic hepatitis. In 2004, Hepatitis B infection was estimated to affect more than 350 million people in various parts of the world. The virus is said to be spreading in all continents including Asia, Africa, America and Europe (Lok 2002, p. 1685). In the last twenty years there has been great improvement on research on Hepatitis B. The researches have led to a vaccine for preventing acquiring Hepatitis B, better treatment and better management methods to prevent transmission. Despite of this, there are still many challenges on research of HBV, management methods and adoption of effective approaches for treating chronic hepatitis. Hepatitis B continues to contribute to numbers of illnesses and mortality in the world. The review aims at pointing out various important aspects of Hepatitis B.
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Hepatitis B refers to inflammation in the liver while Hepatitis B virus is the important cause of Hepatitis. Acute and chronic Hepatitis B is a major health concern and is capable of leading to complications to the liver. HBV is a DNA virus that belongs to the family of Hepadnaviridae. It produces HVB from two regions. There exist eight genotypes of the virus while a number of the virus is able to mutate (Liaw & Chu 2009, P.153). Virus mutation has very several implications including decreased affinity of HBdAg to antibodies and HBsAg (Hepatitis B antigen). Such mutations are evident in infants from HBAAG-positive mothers. Some for the children develop Hepatitis even though they had been vaccinated. Chorionic Hepatitis results from prevalence of HBsAg, HBdAg and hepatitis virus DNA after initial infection with acute Hepatitis. Progress of hepatitis is children are usually silent with most symptoms showing up at adolescence and adulthood.
Hepatitis B virus is transmitted via body fluid. It is mainly transmitted through blood contact although it is also transmitted through other body fluids such as saliva and semen. Because of presence of Hepatitis B virus in body fluids, sexual intercourse becomes one of the major ways through which the virus is transmitted. Among the groups that are more venerable to hepatitis B include individuals with multiple sexual partners, individual engaging in unprotected sex, health workers working with hepatitis B patients (Teo & Lok 2007, par 5). Symptoms for Acute hepatitis show up shortly after an individual is infested with hepatitis B virus. Symptoms for chronic hepatitis B however last longer that six month and may not be able to get away completely (Rehermann, Ferrari, Pasquinelli & Chisari 1996, p. 1113).
Hepatitis B infection can either be symptomatic, asymptomatic or, in rare occasions, enteric. In children that receive the virus from their mothers before birth, there are generally no observable symptoms. Only about 5 and 15% of those prenatally infested hepatitis b develop into illness. Symptoms are more evident in older children and adults. Symptoms are evident in about 33 and 50% of those infested with the virus. Symptoms of hepatitis B are close to those of flu. Many individuals with hepatitis b mistake the disease with flu. Some of the symptoms included loss of appetite, fatigue, itching, nausea, jaundice and abnormal stool and urine. Unique symptom of the infection is itching at the liver (Lavanchy 2004, p. 81-82).
Basic presentation of hepatitis B is testing positive in a blood screening for hepatitis B. An adolescent with hepatitis B would test positive for hepatitis virus but fail to show any symptoms such as nausea, abdominal pain or weight loss (Rollins 2007, p.281). According to report by annual surveillance, a child with hepatitis virus may remain asymptomatic for years. Because of this unique nature of hepatitis, sure way of identifying the virus is through routine blood test and evaluation of risk factors. Because of participating in unsafe sexual activities and sharing of gadgets used in drug use, adolescents are at a higher rate of contracting hepatitis b. Apart from adolescent, the other groups that are more venerable to hepatitis B include infants. Infant can acquire the virus from mothers with more that 90% presence of HBeAg-seropositive.
Screening for presence of hepatitis B surface antigen is the basis for laboratory diagnosis. Diagnosis is also carried out using various serologic assays that are highly sensitive, high level of specificity and reproductively. Essays such as ELISA are used to detect presence of HBV marker (Murray, Baron, Jorgensen, Landry, M & Pfaller 2007, P.67). Apart from the above approaches, nucleic acid testing for HBV-DNA is also used. Nucleic acid testing helps in quantifying viral load in the body and measure success of corrective therapies.
Vaccination and public awareness campaigns have significantly changed epidemiology of hepatitis B. The virus is mainly transmitted through exposure to blood or other body fluids that is infested with the virus. Main risk factors for hepatitis B include unsafe sexual activities, transfusion of unscreened blood, sharing of syringes, and exposure to the virus through working in any health care area or having tattoos (Liaw & Chu 2009, P.157).
The age at which an individual acquires hepatitis B has high influence on development of hepatitis B. Infants that are infested with the virus have about 90% chance of developing chronic hepatitis b. The rate of developing chronic hepatitis drops with increase in age. For example, children that are older than five years have been found to have 25% rate of developing chronic hepatitis after acute hepatitis (Suskind & Rosenthal 2004, P. 126). Epidemiology is also influenced by viral strain, genotype, ethnic background gender and other health factors.
Development of a vaccine for Hepatitis B Virus was a major boost to fight against hepatitis B (O’Mackie & Buxton 2009, p. 145). Among the groups that are of high risk of hepatitis B include the adolescent and infants from HBeSg-seropositive mothers. The main approach to fighting hepatitis has been through public awareness for behavior change and has been mainly directed towards the adolescents. Although this approach can lead to success, there is need for increased emphasis on preventing transmission to infants. This is because of the fact that infants are more vulnerable to hepatitis infection as well as other diseases. Public awareness and education is necessary in preventing transmission among youths while new vaccines schedule would help to reduce transmission to infants.
Increased knowledge on virology of HBV, natural trend of chronic infection and immunology has very significant role in eradicating hepatitis B. Although development hepatitis B vaccine has helped to reduce prevalence of hepatitis B, more effort is required in ensuring responsible behavior among the adolescent. Drug resistance to the vaccines has also been a setback to eradication of hepatitis B (Rehermann & Nascimbeni 2005, P. 217). Better knowledge on the routes and mode of transmission of Hepatitis B virus together with health education can be of positive contribution to prevention of hepatitis B infections.
Acute HBV infection has no specific and effective treatment. Chronic HBV infection, however, has some drugs such as lamivudine and adefovir dipivoxil that are used in its treatment. Other treatment approach include liver transplant for patients whose livers are greatly affected.
Hepatitis B is a major health challenge in the world, especially in developing countries. Sexual transmission of Hepatitis B Virus makes the virus easily communicable. Clinical presentation of hepatitis B is one of the challenges to its eradication. Presence of the virus is asymptomatic in many cases making it challenge to take corrective measures. To identify the virus in human body, there is need for frequent blood screening. Vaccination and public awareness and education are necessary in preventing transmission.
Lavanchy, D., 2004. Hepatitis B Viral Epidemiology, Disease Burden, Treatment, and Current and Emerging Prevention and Control Measures. Journal of Viral Hepatitis, Vol. 11. No. 2.
Liaw, Y. & Chu, C., 2009, Hepatitis B virus infection. The Lancet, Vol. 373 No 9663, 582-593.
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Lok, A., 2002, Chronic Hepatitis B. The New England Journal of Medicine, Vol. 346, No. 22, 1682-83.
Murray, P., Baron, E., Jorgensen, J., Landry, M. & Pfaller, M., 2007, Manual of clinical microbiology. Washington, D.C.: ASM Press.
O’Mackie, C. & Buxton, J., 2009. Hepatitis B, immunization strategies. Canadian Medical Association Journal, Vol.180, No. 2, pp. 196-203.
Rehermann, B. & Nascimbeni, M., 2005. Immunology of Hepatitis B Virus and Hepatitis C Virus Infection. Nature Reviews, Vol.5, pp. 14-18. Web.
Rehermann, B., Ferrari, C., Pasquinelli, C. & Chisari, F., 1996. The hepatitis B virus persists for decades after patient’s recovery from acute viral hepatitis despite of active maintenance of a cytotoxic t-lymphocyte response. Nature Medicine, Vol. 2, pp.1104-08.
Rollins, J., 2007. Investigational vaccine could offer protection for infants against haemophilus influenzae type B and meningococcal disease. Pediatric Nursing, Vol. 33, No. 3, pp. 279-281.
Suskind, D. & Rosenthal, P., 2004. Chronic viral hepatitis. Adolescent Medicine Clinics, Vol. 15, No. 1, pp.145-159.
Teo, K. & Lok, A., 2007. Epidemiology, transmission and prevention of hepatitis B virus infection. Web.