Week 3: Etiology/Pathophysiology of Hepatitis B

When looking at the etiology and Pathophysiology of a disease, it is good to know what you are looking for so we will begin with the definitions for Etiology and Pathophysiology.

According to the American Heritage Stedman’s Medical Dictionary:

Etiology:

1. The science and study of the causes or origins of disease.
2. The cause or origin of a disease or disorder as determined by medical diagnosis.

Pathophysiology:

1.     The functional changes associated with or resulting from disease or injury.

2.     The study of such changes. Also called physiopathology .

With this in mind, The Centers for Disease Control and Prevention (CDC) states that Hepatitis B is liver inflammation caused by the hepatitis B virus or HBV. HBV infection can be either acute or chronic (Kahn, A., 2012). Hepatitis B virus is a deoxyribonucleic acid (DNA) virus (Lewis, et al., 2014). HBV is highly contagious. It spreads through contact with infected blood, saliva, and other bodily fluids. Symptoms may not occur for a few days, or longer, after contracting the virus. However, you are still contagious, even without symptoms (Kahn, 2012).

Acute hepatitis B causes symptoms to appear quickly in adults. Children rarely develop acute HBV. Any infections are far more likely to be chronic (Kahn, 2012). Inflammation can interrupt bile flow (cholestasis). After resolution of an acute infection, liver cells can regenerate and, if no complications occur, resume their normal appearance and function (Lewis, 2014).

Acute Hepatitis B Virus Infection with Recovery Typical Serologic Course Symptoms HBeAg anti-HBe Total anti-HBcTitre HBsAg IgM anti-HBc anti-HBs 0 4 8 12 16 ... 100 (www.slideshare.net).

Chronic hepatitis B develops slowly. Symptoms may not be noticeable unless complications develop. According to the CDC, up to 1.4 million people in the United States have chronic hepatitis B (CDC) (Kahn, 2012). A chronic viral hepatitis infection causes chronic inflammation and can cause fibrosis that (over decades) can progress to cirrhosis (Lewis, 2014).

The Centers for Disease Control and Prevention state that 2,000 to 4,000 people die each year from complications caused by hepatitis B (CDC) (Kahn, 2012).

Chronic Hepatitis B Virus Progression (pixgood.com)

Incubation period and mode of transmission:

45-180 days (average 56-96)

Percutaneous (parenteral) or permucosal exposure to blood or blood products

Sexual contact

Perinatal transmission (from mother to baby at time of birth)

 

Sources of infection:

Contaminated needles, syringes, and blood products.

Sexual activity with infected partners.

Asymptomatic carriers.

Tattoos or body piercing with contaminated needles

Infectivity:

Before and after symptoms appear.

Infectious for 4-6 mo.

Carriers continue to be infectious for life. (Lewis, 2014).

References:

Lewis, Sharon L., Dirksen, Shannon R., Heitkemper, Margaret M., Bucher, Linda. (2014). Medical-Surgical Nursing, Assessment and Management of Clinical Problems, 9 ed., (p. 1006-1015). Elsevier Mosby, St Louis, Missouri. ISBN: 978-0-323-08678-3.

etiology. (n.d.). The American Heritage® Stedman's Medical Dictionary. Retrieved May 27, 2015, from Dictionary.com website: http://dictionary.reference.com/browse/etiology

pathophysiology. (n.d.). The American Heritage® Stedman's Medical Dictionary. Retrieved May 27, 2015, from Dictionary.com website: http://dictionary.reference.com/browse/pathophysiology

Kahn, April. (2012). Hepatitis B Overview. Retrieved May 27, 2015, from http://www.healthline.com/health/hepatitis-b#Overview1

Acute HBV Image. Retrieved May 30, 2015, from https://www.google.com/search?q=acute+Hepatitis+b+graphs&biw=1280&bih=626&tbm=isch&tbs=simg:CAQSEgnnjJZ9JQJ0KyHap1Yi7AYCaQ

Chronic HBV Progression Image. Retrieved May 30, 2015, from https://www.google.com/search?q=chronic+Hepatitis+b+graphs&biw=1280&bih=626&tbm=isch&tbs=simg:CAQSEgmDUnzzWjJ5aiHzfDK3shhsmA