Monday 16 February 2015

What is hepatitis B? |


Definition

Hepatitis B is a liver disease caused by the hepatitis B virus (HBV). Most
hepatitis B infections clear up within one to two months without treatment. When
the infection lasts more than six months, it can develop into chronic hepatitis B,
which can lead to chronic inflammation of the liver, cirrhosis (scarring of the liver), liver cancer, liver failure, or death.













Causes

HBV is spread through contact with the body fluids of an infected person. These fluids include blood, semen, vaginal fluids, and saliva. A woman with hepatitis can pass the virus to the fetus during birth. HBV is not spread through food or water.




Risk Factors

The following factors may increase one’s risk of getting hepatitis B: having
sex with someone infected with hepatitis B or who is a carrier of
hepatitis B; injecting illicit drugs, especially with shared needles; having more
than one sexual partner; being a man who has sex with men; and living in the same
home with someone who is infected with hepatitis B.


Another risk factor is employment as someone who has contact with human body fluids. These workers include first aid or emergency workers, funeral directors, medical personnel, rescue workers, firefighters, police personnel, dentists, and dental assistants.


Other risk factors are having a sexually transmitted disease when
having contact with hepatitis B; traveling to areas of the world where hepatitis B
is common, such as China, southeast Asia, and sub-Saharan Africa; receiving a
blood transfusion before 1992 (the year a more reliable test to screen blood was
developed); receiving multiple transfusions of blood or blood products, as do
hemophiliacs (a risk that has been greatly reduced with modern blood screening
techniques); working or being a patient in a hospital or long-term care facility;
working or being incarcerated in a jail or prison; being bitten so that the skin
is broken by someone whose saliva contains the virus; and receiving hemodialysis
treatment.




Symptoms

Symptoms may appear about 25 to 180 days after one is exposed to the virus. The most common symptoms are yellowing skin and eyes (jaundice), fatigue that lasts for weeks or even months, abdominal pain in the area of the liver (upper right side of the abdomen), loss of appetite, nausea, vomiting, joint pain, low-grade fever, dark urine and light-colored stool, widespread itching, and rash.




Screening and Diagnosis

A doctor will ask about symptoms and medical history and will perform a
physical exam. Hepatitis B is diagnosed with blood tests. These blood tests are
also used to monitor the virus’s effect on the liver. For chronic cases, the
patient may need a liver biopsy (the removal of a sample
of liver tissue for testing).




Treatment and Therapy

If the patient has an uncomplicated case, he or she can expect to recover completely. Persons with chronic hepatitis B may be treated with medication to help reduce the activity of the virus and also to prevent liver failure. These medications include interferon alfa-2b (Intron A) injection, lamivudine (Epivir-HBV) oral medication, adefovir (Hepsera) oral medication, and entecavir (Baraclude) oral medication.


Persons who have chronic hepatitis B should avoid further injury to the liver by avoiding alcohol and certain medications, dietary supplements, and herbs. One should discuss these supplements and herbs with a doctor before taking.


One can prevent spreading the infection to others by notifying one’s own doctors, dentists, and sexual partner or partners; by avoiding donating blood or organs for transplant; and by discussing one’s hepatitis B status with a doctor during pregnancy or before becoming pregnant to ensure the baby receives treatment.




Prevention and Outcomes

Hepatitis B can be prevented with a vaccination. It consists of three injections that are given over a period of six months. Protection is not complete without all three injections. The Centers for Disease Control and Prevention (CDC) recommend that all infants receive the vaccine within their first year (the first dose at birth, the second at one to two months, and the third between six and fifteen months), and those who were not vaccinated as infants may be vaccinated up to the age of eighteen. Above the age of eighteen, the vaccine is recommended only for those at increased risk of contracting the disease.


In addition, to prevent the transmission of hepatitis B, one should use condoms during sexual intercourse or should abstain from sex, limit the number of sexual partners, avoid injecting drugs and avoid sharing needles or syringes, and avoid sharing personal items that might have blood on them (such as razors, toothbrushes, manicuring tools, and pierced earrings). Persons who get a tattoo or a body piercing should ensure that the artist or piercer properly sterilizes the equipment. Infection can occur if the tools have another person’s blood on them.


Health care and public safety workers should get vaccinated against hepatitis B; should always follow routine barrier precautions and safely handle needles and other sharp instruments; should wear gloves when touching or cleaning up body fluids on bandages, tampons or sanitary pads, and linens; and should cover open cuts or wounds.


Pregnant women should have a blood test for hepatitis B. Infants born to women with hepatitis B should be treated within twelve hours of birth.




Bibliography


Boyer, Thomas D., Teresa L. Wright, and Michael P. Manns, eds. Zakim and Boyer’s Hepatology: A Textbook of Liver Disease. 6th ed. Philadelphia: Saunders, 2011.



Feldman, Mark, Lawrence S. Friedman, and Lawrence J. Brandt, eds. Sleisenger and Fordtran’s Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. 9th ed. 2 vols. Philadelphia: Saunders, 2010. Print.



Frank, Steven A. Immunology and Evolution of Infectious Disease. Princeton: Princeton UP, 2002. Print.



"Hepatitis B." World Health Organization. WHO, July 2015. Web. 30 Dec. 2015.



Lehrer, Jenifer K. "Hepatitis B." MedlinePlus. Natl. Lib of Health, 20 Nov. 2014. Web. 30 Dec. 2015.



Palmer, Melissa. Dr. Melissa Palmer’s Guide to Hepatitis and Liver Disease. Rev. ed. Garden City Park: Avery, 2004. Print.



Pan American Health Organization. World Health Organization. Control of Diphtheria, Pertussis, Tetanus, “Haemophilus influenzae” Type B, and Hepatitis B Field Guide. Washington, DC: Author, 2005. Print.



"Viral Hepatitis—Hepatitis B Information." Centers for Disease Control and Prevention. Dept. of Health and Human Services, 31 May 2015. Web. 30 Dec. 2015.

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