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Hepatitis C: CDC Viral Hepatitis Serology Training

December 22, 2019

(electronic music) – [Voiceover] Hepatitis C liver disease, caused by the hepatitis C virus, referred to as HCV, can be acute or chronic. Although most persons, 70-85%, with newly acquired HCV
infection are asymptomatic, most, up to 85%, will go on
to have chronic infection. Those who clear the virus on their own are said to have resolved infection. Since antiviral treatment
is intended for persons with current HCV infection, it is important to distinguish
people with chronic infection from those whose infection has resolved. In recently acquired HCV infection, liver enzymes may be
elevated to 200IU/L or more. This is depicted here by the enzyme alanine
aminotransferase, ALT, shown in blue. Since most newly infected persons have no symptoms of hepatitis, they are often not
identified and diagnosed with acute hepatitis C. If symptoms do occur, as
depicted by the purple bar, it is usually six to seven
weeks after exposure, ranging from two to 26 weeks, and they persist during the time when enzyme levels are elevated. About 40% of persons infected will have detectable antibody to HCV, called anti-HCV and represented
by the solid pink line, in serum approximately
10-11 weeks after exposure, with the percent increasing
to 80% by 15 weeks, and virtually all infected persons will present the antibodies by six months following exposure. When following up someone
with a known exposure to HCV, this is important to keep in mind. Anti-HCV remains positive
generally for life. HCV ribonucleic acid, HCV
RNA, a marker for viremia, can be detected in the blood
with a nucleic acid test, also known as a NAT assay, as early as one to two
weeks after exposure. In patients with recently
acquired HCV infection who resolve their infection, liver enzyme levels return to normal and HCV RNA disappears as anti-HCV rises. Antibody tests alone, either rapid or
laboratory-conducted assays, cannot distinguish between
a recently acquired, chronic, or resolved infection. Chronic infection is characterized by the persistent presence
of HCV RNA, shown in yellow, and may be accompanied by
fluctuating ALT levels, shown in blue, indicating
continuing liver inflammation. ALT levels seen in patients
with chronic HCV infection are elevated, but tend to be lower than patients with recently
acquired HCV infection. In fact, ALTs can be intermittently normal in patients with chronic infection Here is the recommended testing sequence for identifying current HCV infection: If the HCV antibody, anti-HCV,
test result is nonreactive, there is no detectable antibody to HCV, and, unless there are
special circumstances, such as recently exposed,
immuno-compromised, or other special medical circumstances, the person can be
considered never infected and therefore susceptible. If anti-HCV is reactive, this indicates either
current HCV infection, past HCV infection that has resolved, or false positive test result. A reactive anti-HCV test result should be followed by a NAT for HCV RNA. If HCV RNA is detected, this indicates current HCV infection. If HCV RNA is not detected, this indicates either past HCV
infection that has resolved, or a false positive anti-HCV test result. As with a nonreactive
anti-HCV test result, a person with a negative HCV RNA test who has a known or
expected exposure to HCV within the prior six months, or with other medical issues
that may impact test results, should be followed up as
recommended elsewhere. (electronic music)
This segment is now complete.


  • Reply HealthCare 2World November 30, 2015 at 6:54 am

    that video was really helpful. I will make sure to spread this info to our local people.ย  Thank you for your hard work and appreciate your online efforts.

  • Reply Adhil Aramam December 9, 2015 at 3:11 pm

    nice presentation..keep it up

  • Reply Amer Mh December 20, 2016 at 3:42 pm

    A tip for you CDC, always use the green color for a symbol resembling a positive meaning and a red for anything resembling negativity!! ๐Ÿ™‚

  • Reply loolly March 29, 2018 at 10:45 pm

    What's the next step after PCR is negative ?

  • Reply Ahmed Khan March 17, 2019 at 4:27 pm

    What is the latest info in 2019 can u plz tell

  • Reply ali raza May 25, 2019 at 5:57 pm

    What menz 95.010

  • Reply mandeep kour July 7, 2019 at 5:38 am


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