Viral Hepatitis
Introduction:
Acute viral hepatitis is a potentially serious infection of the liver. There are various different hepatitis viruses that cause this diffuse liver inflammation as is summarized in the table below. The link explains that there are a other factors that can also cause in flammation. Transmission of viral hepatitis is by the fecal-oral route. Blood and secretions (blood, saliva, sperm) can also be contagious.
Contaminated needles are a big problem wherever needles are shared. Many, if not most infections are unrecognized and subclinical, which means that nobody suspects the person to have had hepatitis. There may only be a fleeting tiredness.
| Viral hepatitis |
| Name of hepatitis |
Type of virus |
Comments: |
| Hepatitis A |
RNA picorna virus, single stranded |
does not lead to chronic hepatitis or cirrhosis |
| Hepatitis B |
infectious particle has a double stranded DNA virus core and an outer envelope |
significant portion goes on to chronic hepatitis, cirrhosis of the liver and liver cancer |
| Hepatitis C |
flavivirus-like RNA virus, single stranded |
if not treated aggressively, goes on to chronic hepatitis, liver cirrhosis and liver cancer later. Common among drug users sharing needles. Also common in prostitutes. |
| Hepatitis D |
defective RNA virus, needs hepatitis B virus to be present |
about 50 % of unusually severe hepatitis B cases are due to simultaneous hepatitis D; can lead to severe chronic hepatitis |
| Hepatitis E |
RNA virus |
this virus is transmitted through contaminated water; no chronic hepatitis known |
| Hepatitis G |
RNA virus, which is flavivirus-like |
may be responsible for some chronic hepatitis cases |
However, as 5% of hepatitis B patients, 100% of hepatitis C patients and a significant number of hepatitis D and G patients are going on to a chronic hepatitis state, these patients become a large, worldwide reservoir for new hepatitis cases.
Signs and symptoms:
Hepatitis can present like a mild flu-like illness, from which the patient recovers in a few days to 1 week, or it can present as an acute liver failure leading to a hepatic coma and death within a few days. Most cases present with a prodromal phase where a smoker has a violent distaste for cigarettes and where there is a profound dislike for food.
Nausea, vomiting, feeling sick, having joint pains all over are all part of the symptoms. With hepatitis B there are often itchy hives and other skin rashes that are a nuisance to the patient. About 3 to 10 days into hepatitis there is a darkening of the urine, which is followed by the development of jaundice. This is called the icteric phase (period where jaundice is obvious). The jaundice peaks over 1 to 2 weeks. Then the jaundice disappears over another 2 to 4 weeks, which is called the recovery phase. The physician will feel an enlarged liver that is tender to palpation.
Diagnostic tests:
Blood tests have to be done to do liver function tests with liver enzymes, but specific viral hepatitis markers have to be looked at as well.
IgM antibodies, if positive for hepatitis A, are typical as a marker. Hepatitis B is diagnosed by the hepatitis B surface antigen marker. The presence of hepatitis C is verified by anti hepatitis C antibody in the blood. The remaining hepatitis types (D, E and G) require input from special research laboratories and may have to be sent to such for further analysis. You may be curious to know what happened to "hepatitis F". The initial claim of a new type F hepatitis could not be verified by other researchers with more refined tests. So now "F" stands for "failed" and serves as an example in medical history of how not everything that appears to be something is necessarily something with the test of time.
In the acute phase of a viral hepatitis the transaminases are very high, in the range of 450 to 2000 IU/liter. Mostly the ALT is higher than the AST. There is no correlation between the severity of the disease and the height of the liver enzymes in the blood. White blood cell counts are usually low or normal, a blood smear reveals some atypical reactive lymphocytes.
In acute hepatitis liver biopsy is rarely required. However, with chronic hepatitis a biopsy is commonly done to identify why a person after 8 weeks into a hepatitis still has it. As hepatitis is an exceedingly complex area of medicine, it is wise to refer a patient with chronic hepatitis to a gastroenterologist or even to a hepatologist, who is even more specialized on liver diseases.
Treatment:
There is no specific treatment for viral hepatitis. In the past there was emphasis placed on isolation, but this has not prevented further spread of the disease. There should be awareness that stool and blood of an infected patient are infectious and these should be carefully handled. Needle stick injuries to personnel who treat hepatitis patients should be treated according to the known hepatitis type of the patient. If the patient has hepatitis A, standard immune globulin therapy would be used. If the patient has hepatitis B, then hepatitis B immune globulin would be given (this is more expensive). Newborns of hepatitis B positive mothers should be given hepatitis B immune globulin right away at birth along with hepatitis B vaccine. This will prevent 70% of chronic hepatitis B in these children! Hepatitis A and B vaccines should be given to travelers before going to endemic areas.
Chronic hepatitis develops in about 5 % of hepatitis B patients and 80% of hepatitis C patients. About 20% of patients with chronic hepatitis develop cirrhosis of the liver from the chronic inflammation, but it often takes several decades to develop. Here is a picture of a normal liver on the left versus an end stage cirrhotic liver on the right. A patient with this type of liver often is jaundiced as depicted here, has ascites in the abdomen and portal hypertension with periumbilical varicose veins as well as gynecomastia. Once cirrhosis has developed, the patients are at a higher risk to develop cancer of the liver later in life. In the past corticosteroids were thought to be useful, but now we know that they are not advisable in the treatment of chronic viral hepatitis as viral multiplication gets enhanced by corticosteroids. Interferon treatment can be used three times per week. This has led to remissions in about 1/3 of hepatitis B patients.
With respect to hepatitis C there is now new evidence that higher cure rates can be achieved than in the past when 50 % response rates in terms of suppression of inflammation in hepatitis C patients were considered "good". Several developments that occurred were instrumental in this improvement:
1) The response rate was found to be improved with the addition of ribavirin, an antiviral drug that is given twice per day.
2) It was found that there are at least 4 different genetic subtypes, called genotype 1, 2, 3 and 4, that can be analyzed with special genetic tests. The significance of this will be explained below.
3) The drug companies Roche and Schering were able to show that a process of "pegylation" leads to higher interferon levels in tissues and also to more sustained blood levels of interferon with higher cure rates of hepatitis C. Briefly, the interferon molecule is hooked up with an inert protein (polyethylene glycol protein). This allows the physician who specializes in this type of therapy for hep C patients to only administer the pegylated interferon once per week by injection and have much higher and sustained blood levels against the hepatitis C virus. After 24 weekly injections genotype 2 has a cure rate of 88% and genotype 3 a cure rate of 80%. Genotype 4 has a cure rate of 64% and genotype 1 only 56% (data from Ref.14, lecture by the hepatitis expert Dr. Frank Anderson). The medications from the two drug companies are: Unitron-PEG (Schering) and Pegasys (Roche).
A liver transplant is the last resort for hepatitis C patients. When liver function deteriorates and the patient would otherwise die, if left alone, the specialist can offer the hepatitis C patient a liver transplant. The longterm results are amazingly good despite a high reinfection rate. Liver function returns to normal after the transplant and the clinical course is much more stable for many years to come. Liver transplants are not successful for hepatitis B patients as autoimmune reactions will lead to early failure of the graft. All of the treatments mentioned above should be in the hands of a specialist for liver diseases or in the hands of an experienced gastroenterologist (Ref. 4, p. 377).
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