Hepatitis is a general term for a condition that may be caused by a number of different agents, including viruses, bacteria, parasites, toxic drugs, toxins, or diseases of the immune system. Five viruses have been identified that specifically attack the liver and produce hepatitis A, B, C, D, and E. Infectious mononucleosis, certain toxic chemicals and insecticides may cause hepatitis.
Hepatitis can be acute (short-term) or chronic (long-term). All forms of hepatitis share similar symptoms, including dark urine, appetite loss, fatigue, bloating, jaundiced skin colouring, yellowing of the whites of the eyes, nausea and vomiting, and low-grade fever. Liver function tests include the measurement of specific enzymes that seep into blood if the liver is inflamed. The bilirubin test measures the amount of this pigment in the blood. A level above three mg/dl indicates a liver disorder, though this test does not indicate the cause of that disorder.
Hepatitis A is acquired by consuming materials (usually by drinking or eating foods) contaminated with faecal matter of an individual who already has the disease. It is usually communicated as the result of poor hygiene or through personal contact. The virus can survive at normal room temperature for hours on a hard surface like a toilet seat. The incubation period for hepatitis A lasts about two to six weeks, so the disease can spread widely before countermeasures are taken. Most patients recover within a few months. Complications are possible among the elderly, those with compromised immune systems, and those who already have liver problems, such as alcoholics.
Hepatitis Bis spread through infected body fluids like blood, semen, saliva, suppurating sores, or breast milk. It does not spread by simple physical contact, from droplets coughed or sneezed into the air, or by eating food prepared by someone who has the disease. The incubation period for hepatitis B lasts from one to six months, so it is usually impossible to tell how it was acquired. Once recovered, the infected person will be immune to any later reinfection with this particular virus, although he or she may contract one of the other hepatitis viruses. Someone infected with hepatitis B may fully recover and have no symptoms and yet remain a carrier capable of infecting others through sexual contact, shared hypodermic needles, and shared food or drinks. A pregnant woman can pass the virus to her unborn child so all babies should be vaccinated for hepatitis B at birth.
Hepatitis C. Many individuals who are infected with hepatitis C have no symptoms and never realize that they have the disease. Most people with hepatitis C become chronically infected. People with strong immune systems may recover spontaneously from hepatitis C without treatment. Those with chronic hepatitis C who are not treated or not cured by treatment may live normal lives, but they remain carriers of the disease and can infect others. Some people with chronic hepatitis C develop complications like cirrhosis, liver failure, or liver cancer.
Hepatitis D attacks individuals who have already had hepatitis B. The virus does not cause the disease by itself but worsens infections of hepatitis B; a person may get the two forms of hepatitis at the same time. It is transmitted through the same routes as hepatitis B, through bodily fluids from shared IV needles or unprotected sex. Hepatitis D is usually suspected when the condition of someone with hepatitis B suddenly becomes severely worse. It is diagnosed with tests that reveal hepatitis D antibodies in the blood.
Hepatitis E is almost nonexistent in developed countries; it is found mainly in sub-Saharan Africa and in Asia. It is similar to hepatitis A and spreads primarily through contaminated water supplies, with an incubation period that lasts from about two to six weeks. It is not transmitted by sexual contact, contaminated blood, IV needles, or other bodily fluids. Most people with hepatitis E recover from it on their own within a few months.
If an individual with hepatitis remains symptomatic for more than a few months, the condition is considered chronic. The person may experience few symptoms (chronic persistent hepatitis) or many symptoms; about half of patients with hepatitis B or C experience no symptoms at all. Symptoms of chronic active hepatitis include jaundice, nausea and vomiting, dark urine, and pain in the vicinity of the liver. About a third of all individuals with viral hepatitis will progress to the chronic active form. Additionally, a compromised autoimmune system may result in a condition where the immune system attacks and destroys liver cells as if they were foreign invaders.