Hepatitis - types A, B, C, D - symptoms and treatment

Hepatitis - types A, B, C, D - symptoms and treatment

Hepatitis - INFLAMMATION of the LIVER. There are numerous kinds and causes of hepatitis. Most hepatitis results from specific viruses that cause infections of the liver, ALCOHOL abuse, and hepatotoxic drugs. Hepatitis is the leading cause of LIVER FAILURE, and reason for LIVER TRANSPLANTATION, in the United States.

Infectious (viral) hepatitis

The viruses that cause viral hepatitis belong to several virus families: the picornavirus family, which causes hepatitis A; the hepacivirus family, which causes hepatitis B; and the flavirus family, which causes hepatitis C.

Though these viruses are among the smallest researchers have yet detected, they cause a wide range of illnesses from COLDS to viral MENINGITIS to POLIO. Researchers refer to those that specifically target the liver as hepatotropic and label them alphabetically in the sequence of their discovery. Each individual VIRUS has unique characteristics that cause a particular pattern of disease. Researchers classify viral hepatitis according to the viral variant responsible for the disease response.

Five viruses identified as hepatotropic (“liver loving”) cause 95 percent of the infectious hepatitis diagnosed in the United States: hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV). Hepatitis A and hepatitis E cause acute infection only and rarely cause permanent liver damage, though hepatitis A infection can cause serious illness and fatality. Hepatitis A accounts for more than 60 percent of hepatitis cases in the United States and hepatitis B for nearly 30 percent. Other identified hepatitis viruses (HFV and HGV) are rare in the United States. Hepatitis B and hepatitis C can be present without showing symptoms; about a third of people who have hepatitis B are carriers (the virus is present in their bodies and infects others, though does not cause illness in them). Though health agencies routinely test donated BLOOD, tissue, and organs for hepatitis (as well as numerous other infectious agents), people who receive donor substances face some risk of infection. Hepatitis C accounts for about 80 percent of such infections; new infections have become rare as a result of stringent donor substances screening. Hepatitis D can replicate only when hepatitis B is also present. It often causes “superinfection” - acute disease with chronic hepatitis B infection. Hepatitis E occurs in outbreaks related to water contamination, such as might follow widespread flooding, and tend to be more common among people who contract the virus during travel to developing countries where COMMUNITY SANITATION is inadequate.

Viral hepatitis begins with an acute illness that lasts from 2 to 10 months, though in most people the acute phase resolves in 4 to 6 months. Chronic forms of hepatitis often follow infection with HBV and HCV, resulting in recurring episodes of symptoms. The repeated inflammation is very harmful to the liver, causing scarring (fibrosis) that eventually becomes CIRRHOSIS (SCAR tissue replaces liver tissue). The damage tends to be progressive, culminating in liver failure in about 25 percent of people who have chronic hepatitis. About 10 percent of people who develop chronic hepatitis subsequently develop LIVER CANCER. People who have chronic forms of hepatitis may show no signs or symptoms of disease though are carriers who pass the virus to others with whom they have close contact (particularly sexual contact).

Hepatitis VirusMode of InfectionPreventive Measures
hepatitis A (HAV) fecal-oral
food-borne
person-to-person
occupational exposure
vaccination
frequent HAND WASHING and conscientious PERSONAL
HYGIENE
postexposure prophylaxis
hepatitis B (HBV) blood
sexual contact
shared needles among illicit injected DRUG users
perinatal (to infant at birth)
hemodialysis
occupational exposure
vaccination
safer sex practices
avoid sharing needles
barrier precautions to prevent occupational exposure
postexposure prophylaxis
hepatitis C (HCV) blood
sexual contact
shared needles among illicit injected drug users
perinatal (to infant at birth)
hemodialysis
occupational exposure
safer sex practices
avoid sharing needles
barrier precautions to prevent occupational exposure
postexposure prophylaxis
hepatitis D (HDV) blood
shared needles among illicit injected drug users
perinatal (to infant at birth)
hemodialysis
occupational exposure
HBV vaccination (HDV can infect people only already infected with HBV)
avoid sharing needles
barrier precautions to prevent occupational exposure
postexposure prophylaxis
hepatitis E (HEV) fecal-oral
water
boiling water when contamination is possible

Alcoholic hepatitis

Alcohol is highly toxic to the liver. Chronic alcohol abuse results in repeated inflammation of liver tissue, with resulting scarring (fibrosis) that ultimately limits the liver’s ability to function (cirrhosis). Liver damage that occurs is permanent and may lead to liver failure.

Hepatotoxic hepatitis

The most common hepatotoxins resulting in hepatitis are acetaminophen (Tylenol) and NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) such as ibuprofen (Motrin). Other hepatotoxins include cleaning solutions, industrial pollutants, and carbon tetrachloride. Hepatotoxic hepatitis can result in rapid liver failure or lead to chronic hepatitis.

Symptoms and Diagnostic Path

The general symptoms of hepatitis are the same regardless of the cause and occur in four distinct stages:

  1. Infective asymptomatic, in which the virus has invaded the liver and is replicating. During this stage the person is most highly infective.
  2. Prodromal, in which infection has not yet manifested symptoms but the person begins to feel generalized malaise, loss of APPETITE, and aversions to certain foods (and often to cigarette smoke).
  3. Active disease response, with characteristic symptoms that include JAUNDICE, dark urine, pale stools, FEVER, fatigue, and abdominal tenderness.
  4. Recovery, during which the person continues to feel fatigue and malaise but liver functions are returning to normal, or liver failure, indicating the disease process has overwhelmed the liver.

Viral hepatitis remains infectious for as long as the virus is active in the body. With chronic forms of viral hepatitis, symptoms recur periodically. Alcoholic hepatitis and hepatotoxic hepatitis remain in active disease state until the causative substance clears the body.

Treatment Options and Outlook

Treatment for hepatitis is largely supportive, consisting of fluid consumption, adequate nutrition, and rest. The course of acute disease may be mild and flulike or life-threatening, depending on numerous variables such as the cause and the individual’s personal health status. People who have IMMUNE SYSTEM impairments, such as those who have HIV/AIDS, are very young, or are very old are at greatest risk for severe disease. ANTIVIRAL MEDICATIONS such as adefovir, ribavirin, interferon, amantadine, and lamivudine sometimes limit the course of active disease in chronic hepatitis (HBV and HDV). Liver damage due to hepatotoxic hepatitis may so overwhelming as to require immediate liver transplantation.

Chronic hepatitis remains a significant lifelong threat to health. Those who have chronic infectious hepatitis can pass the disease to others.Regardless of cause, chronic hepatitis limits the liver’s ability to function. Physiologic stress, such as alcohol consumption or taking certain medications, can seriously strain the liver’s capacity. People who have chronic hepatitis may experience frequent bouts of fatigue. Many people are able to enjoy relatively normal lifestyles, though must remain mindful of situations and substances that could challenge the liver.

Risk Factors and Preventive Measures

The primary risk factor for infectious hepatitis is exposure to others who have hepatitis infections. For hepatitis A, this includes consuming foods handled in an unsafe manner by a person who already has hepatitis A infection or handling contaminated fecal waste (such as diapers). Those at risk for blood-borne hepatitis infections (HBV, HCV, HDV) include

  • people who have unprotected sex with multiple partners (hepatitis B is especially common among men who have sex with men)
  • people who inject illicit drugs and share needles, paraphernalia, and drugs
  • people who undergo long-term hemodialysis to treat renal (kidney) failure
  • infants born to infected mothers
  • people who received organ transplants before 1992 or blood transfusions before 1987 (before stringent screening practices became available)
  • people who work in health care and public safety

The most effective measures for protecting against infectious hepatitis are diligent PERSONAL HYGIENE (especially HAND WASHING) and vaccination. Vaccines are available to prevent infection with hepatitis A and hepatitis B. The hepatitis B VACCINE also protects against hepatitis D, which requires the hepatitis B virus to replicate. Hepatitis A and hepatitis E infection confer lifelong immunity. Measures to reduce the risk for noninfectious hepatitis center on eliminating or limiting exposure to hepatotoxic substances including alcohol. The herb MILK THISTLE (silymarin) helps to protect the liver from damage and to recover from damage that occurs. Many health experts recommend that people who have hepatitis or have exposure to hepatotoxins take milk thistle.

See also FOOD SAFETY; HEPATITIS PREVENTION; LIVER CANCER; LIVER DISEASE OF ALCOHOLISM; SHORT BOWEL SYNDROME.

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