Page 246 - fourth year book

HEPATITIS C VIRUS

 Health care, emergency medical and public safety workers after a
needle stick injury or mucosal exposure to HCV-positive blood

 Current sexual partners of HCV-infected persons

B. Persons who are at risk should be tested for the presence of HCV

infection.
Blood tests are used to detect HCV infection are:

 The patients who suspected of having acute or chronic HCV infection
should first be tested for anti-HCV to check if patient has been
exposed to the hepatitis C virus. After exposure to HCV, it may take as
long as 26 weeks before antibodies can be detected using a standard
test (the ―window period‖).

Enzyme immunoassay (EIA) or enhanced chemiluminescence
immunoassay (CIA) are a blood tests that can detect HCV antibodies

and Recombinant immunoblot assay (RIBA) used to confirm the
results of EIA testing.
Under what circumstances is a false-positive anti-HCV test result

likely?

False-positive anti-HCV tests appear more often when persons at low risk
for HCV infection (e.g., blood donors) are tested. Therefore, it is
important to confirm a positive anti-HCV test with a supplemental test,

such as RIBA (recombinant immunoblot assay), as most false positive
anti-HCV tests are reported as negative on supplemental testing.

Under what circumstances might a false-negative anti-HCV test result
occur?

Persons with early HCV infection might not yet have developed
antibody levels high enough that the test can measure. In addition, some
persons might lack the (immune) response necessary for the test to work
well. In these persons, further testing such as PCR for HCV RNA may be
considered.

 Perform the HCV RNA testing (usually by a polymerase chain
reaction (PCR)), to check if the infection is active or not through

measure the amount of HCV RNA circulating in the blood. The
presence of detectable genetic viral material indicates that the virus is
actively replicating.

Qualitative tests used to detect presence or absence of virus (HCV
RNA PCR ) , while Quantitative tests used to detect amount (titer) of

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