Hepatitis

The keyword stem -hepat refers to the liver. The keyword stem -itis refers to inflammation. This means hepatitis(composed of both keyword stems) is an inflammation of the liver. There are five types of hepatitis: A, B, C, D and E. Types A, C and E are composed of RNA nucleic  acids and type B is made from DNA nucleic acids. B, C and E types can lead to liver cancer. Major causes of hepatitis are alcohol and drugs.

Hepatitis A or HAV is the most common cause of acute viral hepatitis and is more pronounced in children and young adults. In some countries where hygiene is poor, 75% of adults have been exposed. Transmission occurs primarily via the fecal-oral contact or consumption of feces infected with HAV.  The consumption of contaminated raw shellfish is a cause. Sporadic causes are also common as a result of person-to-person contact. It is believed that 20% of hepatitis A infections are spread through sexual contact. For example, oral-anal contact can expose one to HAV. Those at increased risk are men who have sex with other men and people who have mouth to anus contact.

Hepatitis B or HBV is very commonly spread via sexual intercourse and contaminated blood or blood products. Transmission also occurs via drug users that share needles.This is because HBV’s major transmission route is via the blood. Statistics show that 2 out of 3 infections from HBV in the United States are from sexual exposure. Body fluids containing the virus are semen, vaginal fluids and blood.  HBV is the 2nd most common cause of acute viral hepatitis. It is much less widespread than HAV. Patients in renal dialysis and oncology (cancer)  units along with hospital personnel in contact with blood are at increased transmission rates. Infectivity is far less than that of HAV. Transmission from insect bites is unclear. HBV infection has occurred sporadically without a known source.

Exposure to hepatitis C (HCV) during sexual contact is possible but not common. Sexual transmission of HCV is inefficient. You are at increased risk of contracting HCV if you have multiple sexual partners, have an existing STD/STI, have rouch sex, or have HIV. Like HBV, HCV is transmitted via blood. Hepatitis C is the most common chronic bloodborne infection in the United States. An estimated 3.2 million persons are chronically infected. Those at risk are people in contact with possible contaminated blood and drug users that share needles. The newly infected will be either asymptomatic (without symptoms) or have a mild clinical illness. Chronic infection develops in 70%-85% of HCV infected persons and 60%-70% of the chronically infected will develop evidence of liver disease. Many of the infected are unaware of their situation because they are not clinically ill. These people are at risk for other HCV-related chronic diseases for decades after infection.

Hepatitis D or HDV is a delta agent. It is a defective RNA virus that can only replicate in the presence of HBV. This means you must have hepatitis B before you can get hepatitis D.  You can have hepatitis B without hepatitis D but not the other way around. It occurs as a co-infection with acute hepatitis B or as a superinfection in chronic hepatitis B people. You can contract HDV via sexual contact. Drug users are at high risk but unlike HBV has not widely spread to the homosexual community. HDV varies geographically, and endemic (prevalent) in several countries.

Hepatitis E or HEV spreads like hepatitis A virus. Both are spread from infected persons to someone uninfected using the fecal-oral route. Both HEV and HAV can contaminate water or food supplies, causing community outbreaks. Hepatitis E is not common in the U.S. and there is no evidence that is spreads from sexual contact. HEV also doesn’t spread easily from activities such as shaking hands. Also like HAV, HEV does not cause chronic hepatitis or cirrhosis and there is no carrier state. See here for signs and symptoms of hepatitis. 

 

References:

1. Justin L. Kaplan MD, Robert S. Porter MD, eds. 2011. Merck Manual Of Diagnosis and Therapy, The – 19th Ed. Whitehouse Station, NJ. Merck Sharp & Dohme Corp., A Subsidiary of Merck & Co., Inc. ISBN-10: 0-911910-19-0, ISBN-13: 978-0-911910-19-3. ISSN: 0076-6526. STAT!Ref Online Electronic Medical Library. http://online.statref.com/document.aspx?fxid=21&docid=183. 8/5/2012 7:20:26 PM CDT (UTC -05:00).

2. About.com. Hepatitis. What you should know about the spread of hepatitis from sex. Available at: http://hepatitis.about.com/od/prevention/a/HepatitisSex.htm. Accessed 2012 Aug 5th

3. Centers for Disease Control and Prevention. Sexually Transmitted Diseases (STDs). Hepatitis C. Available at: http://www.cdc.gov/std/treatment/2010/hepc.htm. Accessed 2012 Aug 5th