What is hepatitis A?

Definition

Hepatitis A is an infection of the liver that is caused by the hepatitis A virus. The infection was formerly called infectious hepatitis.

Causes

The hepatitis A virus is usually found in the stool (feces) of people who have the infection. It is spread by putting something in one’s mouth that has been infected with the hepatitis A virus; by drinking water contaminated by raw sewage; by eating hepatitis-contaminated food, especially if it has not been properly cooked; by eating raw or partially cooked shellfish contaminated by raw sewage; and by having sexual contact (particularly anal sex) with a person who is infected with the hepatitis A virus.

Risk Factors

Risk factors for hepatitis A include close contact with an infected person (although the virus is generally not spread by casual contact); using household items that were used by an infected person but were not properly cleaned; having sex with multiple partners; having sex with a partner who has hepatitis A; traveling to or spending long periods of time in a country where hepatitis A is common or where sanitation is poor; injecting drugs, especially if sharing needles; changing diapers or toilet training young children; being in day-care centers or other similar facilities; and receiving plasma products (as do people with hemophilia).

Symptoms

Hepatitis A does not always cause symptoms. Adults are more likely to have them than children. Symptoms include tiredness, loss of appetite, fever, nausea, abdominal pain or discomfort, jaundice (yellowing of the eyes and skin), darker colored urine, light or chalky colored stools, rash, itching, and muscle pain.

Screening and Diagnosis

A doctor will ask about symptoms and medical history and will perform a
physical exam. Tests may include a blood test to look for hepatitis A
antibodies (proteins that the body has made to fight the
hepatitis A virus), liver function studies, and, in severe cases, a
liver
biopsy (removing a sample of liver tissue to be
examined).

Treatment and Therapy

There are no specific treatments. The goals of hepatitis A treatments are to keep the patient as comfortable as possible, to prevent the infection from being passed to others, and to prevent more liver damage by helping the patient avoid substances such as medications and alcohol that might stress the liver while it is healing.

The disease will usually go away without treatment within two to five weeks.
About 15 percent of people who are infected by hepatitis A will have relapsing
symptoms. This can happen for up to nine months. In almost all cases, once a
person recovers, there are no lasting effects and the person will be immune to the
virus. In rare cases, the infection is severe, necessitating a liver
transplant.

Prevention and Outcomes

Prevention includes proper sanitary habits, such as washing one’s hands with soap and water (important after using the toilet or changing a diaper); washing one’s hands with soap and water before eating or preparing food; avoiding using household utensils that a person with hepatitis A may touch; ensuring that all household utensils are carefully cleaned; avoiding sexual contact with a person with hepatitis A; avoiding the use of injectable drugs and especially avoiding sharing needles. If one travels to a high-risk region, he or she should take the following precautions: drink bottled water, avoid ice chips, wash fruits well before eating, and eat well-cooked food.

Another preventive measure is to have an immunoglobulin (Ig) injection, which contains antibodies that provides temporary protection from hepatitis A. The Ig injection can last about one to three months and must be given before exposure to the virus or within two weeks after exposure.

Getting a hepatitis A vaccine is another measure. This vaccine is
made from inactive hepatitis A virus and is highly effective in preventing
infection. It provides full protection four weeks after the first injection. A
second injection provides protection lasting up to twenty years. The vaccine is
also used after exposure. If given within two weeks, it can prevent infection.

The hepatitis A vaccine is recommended for all children who are twelve months of age, children ages twelve months or older living in high-risk areas, people traveling to areas where hepatitis A is prevalent, people who have anal sex, drug users, people with chronic liver disease, people with blood-clotting disorders such as hemophilia, children who live in areas where hepatitis A is prevalent, and people who will have close contact with an adopted child from a medium- or high-risk area. One should consult a doctor before getting the vaccine.

Bibliography

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

Lehrer, Jenifer K. "Hepatitis A." MedlinePlus. Natl. Lib. of Medicine, 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.

Ronco, Claudio, and Rinaldo Bellomo, eds. Critical Care Nephrology. 2nd ed. Philadelphia: Saunders, 2009. Print.

Thomas, Howard C., et al. Viral Hepatitis. 4th ed. Malden: Wiley, 2013. Print.

“An Updated Recommendation from the Advisory Committee on Immunization Practices (ACIP) for Use of Hepatitis A Vaccine in Close Contact of Newly Arriving International Adoptees.” Morbidity and Mortality Weekly Report 58 (2009): 1006. Print.

"Viral Hepatitis—Hepatitis A Information." Centers for Disease Control and Prevention. Dept. of Health and Human Services, 27 Aug. 2015. Web. 30 Dec. 2015.