Hepatitis A, B, and C are believed to be viral infections of the liver that sometimes, only sometimes, manifest themselves in liver disease, most seriously as cirrhosis and liver cancer.
Hepatitis A, B, and C are believed to be viral infections of the liver that sometimes, only sometimes, manifest themselves in liver disease, most seriously as cirrhosis and liver cancer. Cases are classified as “chronic” if a virus can be detected in the absence of symptoms and as “acute” if liver disease is present.
Viruses are not the only causes of hepatitis and it is not clear that, when a virus is detected, it is the cause of disease. Hepatitis can also be caused by excessive consumption of alcohol, steroids, and some pharmaceuticals. Sometimes hepatitis is an auto-immune reaction. When a hepatitis virus is detected and symptoms are present, a diagnosis of hepatitis is given even if other risk factors are present.
Signs of hepatitis are dark urine, clay-coloured stools, jaundice (characterized by a yellowing of the skin), fluid accumulation in the abdomen, breast development in males, and a number of nonspecific symptoms such as nausea, diarrhea, and fever. Liver function tests are also available, such as by Alanine Transaminase, high levels of which indicate liver damage. Most people who test positive for one of the hepatitis viruses show none of these symptoms. Doctors will often warn these patients that they are at grave risk of liver disease in the future. But are they?
Hepatitis A is usually self-limiting and will resolve itself after one or two months. For hepatitis C, it is not clear that people who test positive are at greater risk of liver disease once cofactors such as drug and alcohol abuse are adjusted for. Two studies published in 2000, one in Annals of Internal Medicine and the other in Hepatology, found that over an extended period, (45 years in one study), people who were hepatitis-C-positive were not at greater risk of liver disease.
The main route of transmission for hepatitis A is believed to be oral, often from fecal contamination. Foods, such as lettuce, strawberries, or oysters are often blamed. The hepatitis B and C viruses are believed to be transmitted through blood, usually by dirty needles or through the transfusion of infected blood. In a significant fraction of cases of viral hepatitis cases there is no evidence for any known mode of transmission.
Although it is generally assumed that hepatitis A, B, and C are viral infections, they do not always behave that way. A 1997 paper in the European Journal of Clinical Chemistry noted a number of inconsistencies in the viral theory of hepatitis C: the detection of viral DNA in people who were hepatitis-C-negative and the lack of evidence to show that hepatitis-C RNA is associated with virus particles.
Both a 1978 and a 1987 study showed a significant percentage of people without risk factors developed hepatitis, according to lab measurements. The same studies showed some people who became hepatitis-B-positive after a hepatitis-B-negative blood transfusion.
A 1999 paper in the showed that both hepatitis B and C were more commonly found in needle-exchange-program users compared to non-needle users and those likely to use dirty needles on the street, calling into question either the accuracy of tests or the route of infection.
Vaccines are heavily promoted as a way to reduce the risk of hepatitis A and B infections. It is often noted that, in the United States, hepatitis A cases fell rapidly after 1995 when the first vaccine was licensed. The most dramatic decrease, however, was from 1971 to 1982, with minor peaks in 1989 and 1995. Similarly, cases of hepatitis B dropped from about the time the first vaccine was licensed in 1982. Hepatitis-B vaccines are not claimed to be fully effective, leading to a search for drug therapies.
The first pill for hepatitis B was Lamivudine, a Canadian AIDS drug also known as 3TC or Epivir, which was approved in 1998. As with all AIDS drugs this has fearsome, sometimes fatal, side-effects. Ironically, antiviral drugs are often associated with liver damage. Doctors may well blame the side-effects on the virus, resulting in drugs being continued when they are in fact worsening the disease. About half the people diagnosed with HIV also test positive for hepatitis B or C. They are most at risk for exacerbation of their symptoms due to the use of liver-toxic, anti-HIV, protease inhibitor drugs; liver mortality in HIV patients has doubled since these drugs became available in 1996.
Another antiviral drug, Ribavirin, is sometimes also recommended for hepatitis C. The dangers of treatment were acknowledged by a 2003 Harvard cost-effectiveness study, which concluded that patients without symptoms were better off not taking any therapy for hepatitis C.
Being diagnosed with hepatitis A, B, or C based on tests, and not illness, should not be cause for panic. Definitely remove any known liver-risk factors, such as the use of steroids and illegal or prescription drugs, which can cause liver injury. But taking toxic drugs based on a fear of future illness is a dangerous gamble. Natural products with beneficial effects on the liver may slow the onset of disease and, if no disease was actually going to occur, they are less likely to cause harm than patent medicines. Doctors may predict dire consequences, but the scientific literature shows that these viruses are usually quite benign.