Hepatitis is a condition pertaining to the liver. Its name literally means liver inflammation from the Greek words hêpar (liver) and –itis (inflammation). It is caused by several agents but worldwide, the most common medium for its distribution are viruses. There are five types of viruses namely Hepatitis: A, B, C, D, and E; these viruses are unrelated to each other except that they target the liver and cuase inflammation. Among all five Hepatitis B (HepB) is the most transmitted.
HepB is caused by the hepatitis b virus (HBV) which belongs to the family hepadnaviridae which have single stranded DNA (Previsani and Lavanchy). The virus targets our liver cells (hepatocytes). What makes this virus so dangerous is that it is a “silent killer- no symptoms and blood tests are usually normal” which makes diagnosis often come too late for effective treatment (Stanford School of Medicine). This condition is special to me since, I myself am undergoing chronic hepatitis B. I’ve had this infection since I was 14 and I’ve been through many tests, treatments, and medications. My liver was so damaged that I needed a transplant. For now I am going through medications and tests to ensure I lower the risk of reinfection after the transplant. The effect of the drugs and the infection itself has drastically affected my lifestyle. As a victim, I’ve been going through a lot of emotional stress, insomnia, and many more. Also other than the antiviral drugs, I also take other medicine and IVs in order to ensure my body is properly functioning.
Epidemiology
All age groups are affected by HepB. In the United States alone ages from 25 to 44 are the most commonly affected (London and Romito). The virus is transmitted through fluids which is mostly by blood to blood contact, unprotected sex, unsterile needles and lastly by vertical transmission (mother to baby) (Hepatitis B Foundation).
HepB has a worldwide distribution. As of 2014 it affects 350-400 million people. The epidemiology conducted by the World Health Organization divides its geographical distribution into six areas: Americas, Europe, Eastern Mediterranean, Africa, South East Asia, and lastly in the Western Pacific. Its prevalence varies between 1-20% among these regions. Specifically, low prevalence (0.1-2%) areas include United States, Canada, Western Europe, Australia, and New Zealand. Intermediate prevalence (3-5%) areas are Eastern and Northern Europe, Japan, the Mediterranean basin, the Middle East, Latin and South America, and Central Asia. The virus transmission route for both of these groups are mainly due to sexual transmissions and skin transmissions. Lastly high prevalence areas (above 8%) China, Southeast Asia, Indonesia, sub-Saharan Africa, Pacific Islands, parts of the Middle East, and the Amazon Basin. Unlike the other two group’s mode of transmission, this one is mostly due to vertical transmission (Pyrsopoulos, “Epidemiology”). A study done by Hwang and Cheung (1) estimates that 30% of cirrhosis and 53% of liver is caused by the virus and 15-40% chronic patients end up with end stage liver failure.
Pathophysiology
Doto (“pathophysiology”) writes that inside the liver, the virus attaches to the hepatocyte. The virus’ antigen structure has 3 main parts. The surface is called HepB surface antigen (HBsAg) followed by the HepB (HBeAg) early antigen and at the core is the HepB core antigen (HBcAg). These antigens are what binds to the receptors in the hepatocytes. When the membranes of the virus and cell fuse, it’s partially double stranded DNA enters the host cell’s nucleus. Once inside, the DNA is then turned into covalently closed circular DNA (now double stranded). This in turn creates four mRNAs to make new copies of itself. Ultimately the new partially double stranded DNA is released and packaged creating new viruses that the infected cell will release. When immune system begins to notice the infection a cellular immune response is initiated. Cytotoxic t-lymphocytes and natural killer cells travel to the infected hepatocyte and trigger inflammation as well as under the microscope liver cells appear to look like having a “ground glass”. The virus is not the cause for hepatocyte death but the immune response is responsible for liver damage (BMJ Best practice).
Pyrsopoulos (“Epidemiology”) describes five stages in its viral life cycle. The first stage immune tolerance which spans from 2-4 weeks among adults-no symptoms occur. Second stage immune clearance, inflammation and a structural change of the hepatocyte occurs. For acute patients this occurs around 3-4 weeks but for patients with chronic infection it may last 10 years or more. At the third stage (inactive chronic infection), the antibodies (anti-HBe) are present which now allows the host to target infected hepatocytes and HBV resulting in low viral replications rates which is no longer measurable. The fourth stage chronic disease, a variant of the virus (HBeAg-negative) may emerge directly from stage two or after stage three. Lastly, stage 5 or the recovery stage occurs. Antibodies to the different antigens are now being produced and the virus is no longer detectable.
Signs and Symptoms
Symptoms usually appear after one to four months after infection. These are abdominal pain, dark urine, fever, joint pain, loss of appetite, nausea and vomiting, weakness and fatigue, and lastly jaundice (MayoClinic, “Signs and Symptoms”).
Different Types
Initially all individuals infected with HepB have an acute infection. Acute HepB occurs when the body is able to sufficiently ward off the virus which is why the infection only lasts from several weeks to six months. However, if the body’s immune system cannot remove the virus allowing it to persist after six months then it becomes a chronic infection. Infants are most susceptible for chronic HepB infection (Bacon et.al, 7).
Treatment and its goals
The National Health Service from England (“Treating Hepatitis B) states that if the doctor sorts out the infection as acute, then there is nothing to worry about. Generally, there is no specific treatment for acute infections. Only rest, proper nutrition, and plenty of fluids are recommended to help boost the body in fighting the infection. Painkillers may be prescribed plus regular blood tests and physical checkups are recommended. However if chronic HepB is diagnosed then medication is required. If liver seems to still work properly, then peginterferon alfa-2a is initially prescribed but if the liver seems to show signs of failure antiviral medication which are tenofovir and entecavir (a rare but severe side effect called lactic acidosis may occur) are prescribed, and lastly liver transplant. The primary goal of chronic HepB medication is to constantly suppress viral replications which would the patient’s condition as well as decreasing the risk of cirrhosis, liver failure and liver cancer (Block et.al).
Prognosis
Acute infections only last from several weeks to six months. It generally goes away without treatment and there is complete recovery for most adults. For those infections that progress to chronic HepB, infection lasts from six months to years. It is more common for infants. Effects of this long term infection will result into liver cirrhosis leading to liver failure, impaired function due to fibrosis, and lastly liver cancer. A rare condition may also occur in chronic patients called fulminant HepB where the immune system attacks the liver (Mandal).
Prevention
As the saying goes “Prevention is always better than a cure” should be followed religiously. The most effective way for preventing HepB is by vaccination. Other measures for preventing HepB infection is by knowing the HBV status of your sexual partner, using protection during sex, do not share needles during drug abuse or better yet stop drug abuse, caution when getting tattooed or body piercings (MayoClinic, “Prevention”).
Conclusion
While advances in medical science allow for effective treatments upon reaching chronic stages this should not be taken for granted. As mentioned in the paper earlier, HepB is a silent killer. Before proper treatment is administered, it would have been already too late. Other than a decline in physical health it also places a lot of emotional strain to the victim which may cause a slower recovery speed as well as complications that arise from chronic HepB infections especially cancer are only manageable at best with current medical milestones. It is important to practice preventive measures especially during sex and travelling both of which are common practices. In the global big picture of things, awareness is key in order to fight the disease.
Works Cited
Bacon, Bruce, Theo Heller, Luby Garza-Abijaoude, and Thelma Theil. NIH: National Institute of Diabetes and Digestive and Kidney Disorders. National Institute of Health, 1 Dec. 2012. Web. 26 Nov. 2014. <http://www.niddk.nih.gov/health-information/health-topics/liver-disease/hepatitis-b/Documents/hepb_508.pdf>.
Block, Timothy M., Robert Gish, Haitao Guo, Anand Mehta, Andrea Cuconati, W. Thomas London, and Ju-Tao Guo. "Chronic Hepatitis B: What Should Be the Goal for New Therapies?" Antiviral Research 98.1 (2013): 27-34. PubMed. National Institute of Health. Web. 26 Nov. 2014.
"BMJ Best Practice." BMJ Best Practice. BMJ Publishing Group. Web. 26 Nov. 2014. <http://bestpractice.bmj.com/best-practice/monograph/127/basics/pathophysiology.html>.
Doto, Jessica. Rn.com. AMN Healthcare, Inc., 3 June 2013. Web. 26 Nov. 2014. <http://www.rn.com/getpdf.php/2024.pdf?Main_Session=06f6db442de70fe5ef38f8f7f306a8b1>.
"FAQ about Hepatitis B - Education - Asian Liver Center - Stanford University School of Medicine - Unite against Hepatitis B & Liver Cancer!" Stanford School of Medicine. Stanford University. Web. 26 Nov. 2014. <http://liver.stanford.edu/education/whatishepb.html>.
"Hepatitis B." Mayo Clinic. Mayo Foundation for Medical Education and Research, 29 Aug. 2014. Web. 26 Nov. 2014. <http://www.mayoclinic.org/diseases-conditions/hepatitis-b/basics/symptoms/con-20022210>.
Hwang, Elizabeth W., and Ramsey Cheung. "Global Epidemiology of Hepatitis B Virus (HBV) Infection." American Chinese Journal of Medicine and Science 4.1 (2011): 7. NAJMS. The North American Journal of Medical Sciences. Web. 26 Nov. 2014. <http://najms.net/wp-content/uploads/v04i01p007.pdf>.
London, W. Thomas, and Kathleen Romito. "Who Is Affected by Hepatitis B." WebMD. WebMD, 29 Oct. 2012. Web. 26 Nov. 2014. <http://www.webmd.com/hepatitis/who-is-affected-by-hepatitis-b>.
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3627746/pdf/nihms-440683.pdf>.
Mandal, Ananya. "Hepatitis B Prognosis." News-Medical.net. AZo Network, 12 Aug. 2014. Web. 26 Nov. 2014. <http://www.news-medical.net/health/Hepatitis-B-Prognosis.aspx>.
Previsani, Nicoletta, and Daniel Lavanchy. "Hepatitis B." WHO. World Health Organization. 2002. Web. 26 Nov. 2014. <http://www.who.int/csr/disease/hepatitis/whocdscsrlyo 20022/en/index1.html>.
