Hepatitis B vs. Hepatitis A
by Nadia Hoxworth
Hepatitis is inflammation of the liver. Viruses that target the liver are responsible for most cases of hepatitis. Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus (HAV). [5] Hepatitis A virus is the only member of the genus Hepatovirus within the family Picornaviridae [11]. HAV is a small non-enveloped single-stranded RNA virus. It is thermostable and acid-resistant. HAV replicates in hepatocytes and interferes with liver function, sparking an immune response that cause liver inflammation [2].
Hepatitis B is a liver infection caused by the hepatitis B virus (HBV) [6]. HBV is a small DNA virus that belongs to Hepadnaviridae family of viruses. HBV is enveloped virus composed of protein that is termed “surface antigen” or “HBsAg”. The outer shell surrounds an inner protein shell that if referred to as the core particle, which contains the viral DNA and enzymes used in viral replication [4].
Transmission of hepatitis A spread by exposure to fecal material, through household or sexual contact with an infected person or by consuming hepatitis A virus-contaminated food or water [10]. As the infectious dose is very low (10 to 100 virus particles), hands or surface that appear clean can still harbor infectious material, contributing to virus spread. Since the capsids of HAV have properties that promote survival for long periods under harsh conditions such as desiccation, freezing, and extremes in pH, those viruses are well adapted to survival in and on foods [1].Transmission of HBV happens predominantly by percutaneous or mucosal exposure to infected blood and various body fluids, including saliva, menstrual, vaginal, and seminal fluids, which have all been implicated as vehicles of human transmission. Sexual transmission of hepatitis B may occur, particularly in unvaccinated men who have sex with men and heterosexual person with multiple sex partners or contact with sex workers. Transmission of the virus may also result from accidental inoculation of minute amounts of blood or fluid during medical, surgical and dental procedures, or from razors and similar objects contaminated with infected blood; use of inadequately sterilized syringes and needles; intravenous and percutaneous drug abuse; tattooing; body piercing; and acupuncture [12].
Hepatitis is either acute or chronic. Acute hepatitis is characteristic of hepatitis A. Almost everyone who contacts hepatitis A (except in pregnancy) eventually recovers, although full recovery can take several month [3]. After infection, HAV illness spans four phases. The first phase is characterized by viral replication in the body without symptoms and lasts an average of 28-30 days. The second phase, known as prodromal or preicteric, is characterized by an onset of symptoms including anorexia, vomiting, fatigue, and jaundice and lasts an average of 5-7 days. The third phase is characterized by the onset of jaundice and an enlarged liver lasting up to28 days. During the final phase, symptoms resolve and liver enzymes returns to normal [1]. The hepatitis A vaccine can prevent infection with the virus. The hepatitis A vaccine is typically given in two doses — initial vaccination followed by a booster shot six months later.
Chronic hepatitis is a progressive disorder that can lead to sever medical problems. Hepatitis B can be both acute and chronic [7]. Acute hepatitis B is usually a self-limiting disease marked by acute inflammation and hepatocellular necrosis, with a case fatality rate of 0.5-1%. Chronic hepatitis B (CHB) infection encompasses a spectrum of disease, and is defined as persistent HBV infection (the presence of detectable hepatitis B surface antigen [HbsAg] in the blood or serum for longer than six month), with or without associated active viral replication and evidence of hepatocellular injury and inflammation [12]. Chronic hepatitis B has 5 phases: 1. Immune tolerant, 2.Immune active, 3. Inactive chronic hepatitis, 4. Immune escape, 5. Reactivation or acute-on-chronic hepatitis [12]. Signs and symptoms of hepatitis B, ranging from mild to severe, usually appear about one to four month after person been infected. Signs and symptoms of hepatitis B are the same as for hepatitis A [8]. If person been exposed to the hepatitis B virus, injection of hepatitis B immune globulin within 12 hours of coming in contact with the virus may help protect from developing hepatitis B. Acute hepatitis B is short lived and will go away on its own, nutrition and fluids are recommended. Chronic hepatitis B may require a treatment to reduce the risk of liver disease and prevent from passing it to others. Treatment include: Antiviral medications, Interferon alfa-2b (Intron A), Liver transplant.
Detection methods for HAV are: RT-PCR; ELISA; NASBA; RT-LAMP; [1]. Detections methods for HBV include serological markers of HBV infection (HbeAg); measuring aminotransferase levels to help determine liver inflammation; quantification of HBV DNA levels; and stage of liver fibrosis by non-invasive test (NITs); transient elastography or FibroTest; PCR [12].
To prevent transmission of HAV, adults and children must wash hands thoroughly, especially after using the toilet. People who acutely infected with HAV should avoid preparing food for others. Clean up spilled blood or body fluids with 10:1 bleach solution. Do not share razors, toothbrushes, or needles. Practice safe sex. Thoroughly wash any fruits and vegetables [12]. However, Advisory Committee for Immunization Practice (ACIP) of the Centers for Disease Control and Prevention (CDC) recommended routine immunization [9]. HAV vaccine is considered safe, effective and may last 14-25 years [3]. To prevent risk of hepatitis B, people should know the HBV status of any sexual partner, use new condom every time, stop using illicit drugs, be cautious about body piercing and tattooing. The hepatitis B vaccine is the best prevention, and typically given as three or four injections over six month [9].
Work Cited
1. Bozkurt, D’Souza, Michael Davidson. Thermal Inactivation of Foodborne Enteric Viruses and Their Viral Surrogates in Foods. Healthline. Journal of Food Protection, Vol. 78, No. 8, 2015. 1597-1617 pp. <http://www.healthline.com/health-blogs.>
2. Franco, Meleleo, Serino, Sorbara, Laura Zaratti. Hepatitis A: Epidemiology and Prevention in Developing Countries. World Journal of Hepatology. Web. 2012 <http://www.cbi.nlm.nih.gov/pm c/articles/PMC3321492/>
3. Franciscus A. HCSP Facts Sheet. Hepatitis A (HAV). Web. 2014.
<http://www.hcvadvocate.org>
4. Hepatitis B Foundation. Hepatitis B Virus. Web. 2014 <http://www. hepb.org/hepb/hepatitis_b_virus.htm>
5. Mayo Clinic Staff. Diseases and Conditions Hepatitis A. Web. 9Sep. 2014.
6. Mayo Clinic Staff. Diseases and Conditions Hepatitis B. Web. 9Sep. 2014.
7. Martini, F., Kathleen Welch. A & P Application Manual. Frederic H. Martini, Inc. 2012. 184p.
8. Mayo Clinic Stuff. Hepatitis B Symptoms, Prevention 29 Aug. 2014. Web.
<http://
9. Nelson K. The Changing Epidemiology of Hepatitis A Virus Infections in the United States. Journal of Infectious Diseases Advance Access. 29 Jan. 2015. Web. <http://www.jid.oxfordjournals.org>
10. The Center of Disease Control and Prevention. Foodborne Hepatitis A Outbreaks in the U.S. Are Well-Documented; Vaccine Provides Lifetime Protection. Web. 2014
<http://www.immunize.org/catg.d?p2104.pdf.item#P2104>
11. Watanabe, Isoda, Ohtake, Hirosawa, Morimoto, Aoki, Ohnishi, Takahashi, Sugano, Hiroaki Okamoto. Full Genome Analysis of Philippine Indigenous Subgenotype IA Hepatitis A Virus Strains from Japanese Patients with Imported Acute Hepatitis A. Healthline. Web. 2014. <http://www.helthline.com/health-blogs.>
12. World Health Organization. Guidelines For The Prevention, Care and Treatment of Persons with Chronic Hepatitis B Infection. WHO Press. Web. 2015. <http://www.who.int>