The hepatitis A and E viruses first enter the gut and begin reproducing. They
spread to the liver and multiply in liver cells. Hepatitis A and E
thrive in unsanitary conditions. There is a vaccine for hepatitis A.
Hepatitis A resolves itself, but can be fatal in children, the elderly,
or the chronically ill. Hepatitis E poses a danger to pregnant women in
the third world. If someone has hepatitis C and they get hepatitis A it
can prove fatal.
Hepatitis B, C, D, and G enter the bloodstream; when they pass through the
liver, they enter liver cells and begin to reproduce. The body attacks
the infected cells, which causes the liver to become inflamed. In
hepatitis B infection, the liver usually repairs itself, leaving
antibodies to the surface antigen, which shows that the infection
occurred, but that the body defeated it. However, recent studies show
that hepatitis B may resurface many years later in individuals who have
supposedly cleared the virus, much like the “post-polio syndrome.” Up to
90% of those infected with hepatitis B will clear the virus. There is a
vaccine
When someone catches the hepatitis C virus, their body produces antibodies to
try to destroy it. More often than not, the antibodies fail to identify
the hepatitis C virus properly. The infection then remains
long-term. Most infected people don’t know they have the virus. This is
because for some people there will be no symptoms and for others,
symptoms may take an average 13 years to develop. Some people may have
hepatitis C for 20 years or more before finding out. There is no vaccine
for hepatitis C.
The way that hepatitis affects people is different for different people. Some
are not affected by the condition, but others are affected very badly.
It currently seems that if 100 people catch hepatitis C:
15-20 people will get rid of it within 2-6 months (much like we get rid
of a flu virus)
60 people will have a long-term infection that may cause no problems or
may cause levels of liver damage ranging from mild to serious.
20-25 people will have a long-term infection that leads to serious
liver damage after 20 years. Of these people (i.e., those with
serious damage after 20 years):
10-will remain stable and the other 15 will progress to liver failure
or liver cancer after another 5 years According to an article in
Gut 2000;47:131-136, the 5 year rate for progression to
hepatocellular cancer is 13.4% and the 5 year rate for progression
to death is 15.3%.
Hepatitis C infection doesn’t always make people sick. When someone does get
sick, symptoms take a long time to develop (approximately 13 years).
Symptoms often stay at a certain level and don’t always get worse. They can
come and go with no real pattern.
Some people with chronic infection don’t have any noticeable liver damage or
symptoms. These people remain well, but THEY ARE INFECTIOUS AND SHOULD
TAKE CARE TO REDUCE ANY RISK OF TRANSMITTING THE VIRUS TO OTHERS.
Data on the clinical course of HCV is limited because the onset of infection
often goes unrecognized, and the early course of the disease is indolent
and protracted in many individuals.
Prospective cohort studies are few, typically small, include relatively few
subjects whose date of infection can be well documented, (e.g., blood
transfusion recipients and victims of accidental needle sticks), and have
relatively short follow-up. The natural history of the disease appears to
differ according to geography, alcohol use, virus characteristics, (e.g.,
genotype, viral load), co-infection with other viruses, and other
unexplained factors. - National Institutes of Health Statement on
Hepatitis C 1997.
