WHAT TO EXPECT DURING HEPATITIS C DIAGNOSIS
Hepatitis C is an infection caused by the hepatitis C virus(HCV) that attacks the liver and leads to inflammation. The World Health Organization estimates about 71 million people globally having chronic hepatitis C infection with approximately 0.4 million dying from the infection due to cirrhosis and hepatocellular carcinoma. Infection due to HCV accounts for 20% of all cases of acute hepatitis.
Because most patients infected with HCV have chronic liver disease which can progress to cirrhosis. In fact, it is regarded as one of the most important causes of chronic liver disease and a common indication for liver transplantation.
Most patients with acute and chronic infections are asymptomatic. Although acute HCV infection is usually mild, chronic hepatitis develops in nearly 75% of patients. Surprisingly, blood panel reports of liver enzymes may be in the reference range. Biopsy of the liver will reveal chronic liver disease.
Risk of transmission of HCV is increased in the following cases
Health care worker exposed to a needle prick or infected blood via the mucosal surfaces
Previous history of injections or illicit drug usage
Multiple sexual partners
Use of uncleaned razors, blades at the barbershop
Presence of concomitant HIV
Past history of tattoo or piercing done in an unsterile environment
Previous history of blood transfusion
History of HCV in the family
It is difficult to identify the signs and symptoms of HCV infection because it is very subtle, but the ones which can be identified include
Yellow discoloration of skin and eyes
Swelling of legs
Spider-like vessels on the forehead
HEPATITIS C DIAGNOSIS
The recommendations for testing and follow up include-
HCV Antibody test
If the result turns out to be positive, a confirmatory test of HCV-RNA is compulsory. Even if the test turns out to be negative, HCV-RNA testing is conducted in all the following exceptions-
High degree of clinical suspicion
HCV exposure occurring in the past 6 months
If there is reinfection after previous spontaneous or treatment-related viral clearance there is need to obtain HCV-RNA test to find out the viral load
Always before initiating HCV antiviral therapy a quantitative HCV-RNA test is required to document the baseline viral load
If the antibody test is positive but RNA test is insignificant it reveals a past infection which has cleared from the body
Furthermore, the WHO recommends HCV-RNA quantitative and qualitative tests to confirm the cure from HCV by doing them at 12 and 24weeks following antiviral treatment completion. In areas with limited resources the WHO recommends usage of aminotransferase/Platelet ratio index or the fibrosis-4 score for evaluating hepatic fibrosis rather than invasive, costlier tests like biopsy, fibroscan.
Serological screening for HCV involves an enzyme immunoassay. These assays are 97% specific and though they cannot distinguish between acute and chronic hepatitis, they are used to find the prevalence of HCV in the community.
Other baseline studies which are done for diagnosing HCV include-
Complete blood count with differential leukocyte count
Liver function test
Thyroid function test
HCV genotyping for guiding treatment
Screening test for coinfection with HIV or Hepatitis B virus
Thrombocytopenia(low platelet counts) is documented in up to 10% of the patients. Low thyroxine levels are also found in 10% of the population.
Recombinant Immunoblot assay is another test to confirm the HCV infection. A positive immunoblot assay result followed by 2 or more instances of undetectable HCV RNA suggests that HCV infection has resolved.
HCV-RNA test includes both qualitative as well as quantitative assays. Qualitative assay means simply the presence or absence of the disease while the quantitative assay determines the viral load. RT-PCR(Reverse transcriptase-Polymerase chain reaction) is the method utilized in these tests for the amplification of viral nucleic acid for detection.
Liver Biopsy is the ultimate confirmation for diagnosis. But because of its invasive nature, it is only recommended in the following conditions
The diagnosis is uncertain
Other co-infections may be present