Hepatitis C
From Medical-Wiki
Hepatitis C (HCV) has evolved into one of the world’s greatest infectious problems, affecting as many as 170 million people worldwide. It is an RNA virus that is transmitted through blood products, IV drug use and shared needles, shared razors, tattooing, high risk sexual practices, transplants, and some medical procedures such as colonoscopy, contamination of surgical instruments, and acupuncture (although the incidence of hepatitis C in health care workers is no greater than that in the normal population.).
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Blood transfusion risk of hepatitis C
With the use of polymerase chain reaction (PCR) identification, the incidence of blood contamination has dropped to 1 in 230,000 transfusions. Newer techniques have also decreased the lag time for identification to 1 to 2 weeks.
Morbidity with hepatitis C
Hepatitis C affects hepatocytes and possibly B lymphocytes. It has been estimated that in patients with chronic hepatitis C, as many as 50% of hepatocytes may be affected.
“HCV infections account for approximately 30,000 new infections and 8000-10,000 deaths each year in the United States, as reported by Alter et al in 1999. Of new infections, 60% occur in persons who use intravenous drugs; less than 20% are acquired through sexual exposure; and 10% are due to other causes, including occupational or perinatal exposure and hemodialysis. The overall prevalence of anti-HCV antibodies in the United States is 1.8% of the population. Approximately 74% of individuals are positive for HCV RNA; this rate indicates that an estimated 4 million persons are infected with HCV and 2.7 million persons in the United States have chronic infection. Three fourths of these individuals are infected with HCV genotype 1.” [1]
Diagnosis of hepatitis C
Clinical presentation
Clinical presentations of hepatitis C are rarely obvious. If there are any symptoms at all, they begin roughly 1 to 2 months after a person is infected. Pruritus, fatigue, and malaise are the most common symptoms. Chronic hepatitis C will often impair quality of life—primarily because of fatigue. Fatigue does not, however, appear to be related to the degree of liver damage. Other symptoms that patients may experience are similar to those of rheumatoid arthritis, fibromyalgia, or carpal tunnel syndrome. Sexual dysfunction in men may also be a problem.
It has been estimated that 55% to 85% of HVC infected patients go on to develop chronic hepatitis C. Of these, 5% to 20% will go on to develop cirrhosis over a period of 20 to 30 years. The risk of cirrhosis goes up with the total time of infection. 4% of chronic hepatitis patients will develop hepatocellular carcinoma (HCC).
Chronic hepatitis is also associated with an increased incidence of cryoglobulinemia, porphyria cutanea tarda, hypothyroidism, rheumatoid arthritis, and non-Hodgkins lymphoma. [2]
Laboratory findings
The ELISA or EIA test (enzyme-linked immunosorbent assay) is the first-line means of identifying the virus. This test may show a false negative pattern for from 1 week to a full year after disease contraction.
The recombinant immunoblot assay (RIBA) may used to confirm HCV infection, but in general it is of little clinical use.
HCV RNA assays are tests that use a polymerase chain reaction (PCR) to detect the viral RNA.
HCV RNA assays can also estimate viral load. There is one FDA approved quantitative test –Versant HCV RNA, based on branched DNA technology and has a dynamic range of 615-7,700,000 IU/mL.
An initial evaluation for HCV should include a CBC count with differential; liver function tests, including an ALT level determination; thyroid studies including a TSH; an anti-HCV antibody EIA; genotyping should be performed as an aid for guiding treatment; a quantitative HCV RNA assay (Reverse transcriptase PCR is more sensitive than bDNA testing); screening for co-infection with HIV or hepatitis B virus (HBV); and assessment for alcohol abuse, drug abuse, and/or depression. [3]
Treatment of hepatitis C
At present, the optimal regimen for treatment of hepatitis C appears to be a 24 or 48 week course of the combination of pegylated alpha interferon and ribavirin. Peginterferon is alpha interferon that has been modified by the addition of a large inert molecule of polyethylene glycol. This prolongs its half-life, allowing it to be given weekly and providing constant levels of interferon.
Ribavirin is an oral antiviral agent that by itself is ineffective against HVC. However, its addition to interferon increases the response by a factor of 2 to 3. [4]
Keywords: HEPATITIS C, hepatitis C virus, HCV, HCV infection, non-A non-B hepatitis, NANB hepatitis, chronic liver disease, hepatocellular carcinoma, hepatoma, HCC, cirrhosis, interferon, IFN, IFN therapy, interferon therapy, pegylated interferon therapy, PEG-IFN, pegylated interferon, hepatitis C viremia, hepatitis viremia
