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Hepatitis B: CDC Viral Hepatitis Serology Training

December 31, 2019


(midi music) – [Voiceover] Liver disease
caused by the hepatitis B virus, referred to as HBV, can be either acute or chronic. The first serologic marker
to appear in someone infected following exposure to HBV, is hepatitis B surface antigen, referred to as HBsAg. HBsAg, shown by the red hatched line, can be detected on average, one month after exposure to the virus, but can range from as early as one week to nine weeks after exposure, and may precede the onset of symptoms by one to two months. Symptoms, when present, occur on average twelve weeks after exposure to HBV, with a range of nine to 21 weeks. This period is noted by the green bar. When the serologic test
for HBsAg is positive, HBV DNA can usually be detected
in the patient’s blood. The duration of detection of HBsAg, and hence HBV DNA, is variable. About 50% of patients will test negative for HBsAg and HBV DNA by seven weeks after symptoms of acute
illness have appeared. All patients who recover
from an acute infection will be HBsAg and HBV DNA negative by 15 weeks after the
appearance of symptoms. Hepatitis B e-antigen,
referred to as HBeAg, is usually detectable in
patients with acute disease, and is noted by the green bar. The presence of HBeAg in serum generally correlates with
higher titers of virus and greater infectivity, while the presence of antibody
to hepatitis B e-Antigen, referred to as anti-HBe, shown by the yellow bar, denotes lower levels of virus
and thus, less infectivity. A diagnosis of acute hepatitis B can be made on the basis of
detection of IgM class antibody to hepatitis B core antigen, IgM anti-HBc. This serologic marker is depicted
by the pink hatched line. IgM anti-HBc is usually detectable at the onset of symptoms, and becomes undetectable
within six to nine months. Total antibody, IgM and IgG, to hepatitis B core antigen, referred to as total anti-HBc, and illustrated by the
purple hatched line, persists indefinitely as a
marker of past infection. Antibody to hepatitis B surface antigen, referred to as anti-HBs, is depicted by the orange hatched line. Anti-HBs becomes detectable
during convalescence and after the disappearance of HBsAg, and generally indicates recovery and immunity from reinfection. There is a period of time, often called the window period, which occurs after the
disappearance of HBsAg and before the appearance of anti-HBs. During this window period, when using routine tests for
diagnosis of acute hepatitis, IgM anti-HBc and total anti-HBc, may be the only serologic markers present. There is also a period of
time soon after exposure when these routine tests will find only the hepatitis marker HBsAg, present. A person with chronic
hepatitis B virus infection, will have both hepatitis
B surface antigen, HBsAg shown in red, and total antibody to
hepatitis B core antigen, total anti-HBc shown in blue, persistently detectable
by serologic testing throughout the duration of chronicity. HBV DNA will usually be
detectable in serum as well, using a nucleic acid test, or NAT. Hepatitis B e-antigen, HBeAg shown in green, generally indicates
higher levels of HBV DNA, and thus greater infectivity. Presence of antibody to
hepatitis B e-antigen, anti-HBe shown in purple, conveys just the opposite scenario. Chronic HBV infection is diagnosed when a patient has a positive
serologic test result for either HBsAg or HBeAg or HBV DNA on at least two separate samples, six months apart. Or when a patient has a positive test for any one of these on a single sample, and has a negative test for IgM anti-HBc. Successful vaccination
against HBV infection results in production of anti-HBs, with sero-protection
defined as an anti-HBs level of 10 milli-International
Units per milliliter or more one to two months after completion of the vaccination series. HBsAg may be transiently positive for two to three weeks after vaccination, but this is clinically insignificant. A serologic test result
of anti-HBs positive alone indicates immunity following vaccination with at least three doses
of hepatitis B vaccine. Without repeated exposure to HBV, antibody levels will
naturally decline over time. But immunity is likely maintained even if levels decline below 10 mIU/mL. This table summarizes the interpretation of serologic test results
for HBV infection. Negative results for
hepatitis B surface antigen, HBsAg, total antibody to
hepatitis B core antigen, total anti-HBc, immunoglobulin M, IgM, anti-HBc, and antibody to hepatitis
B surface antigen, anti-HBs, should be interpreted as never infected, and therefore susceptible. Positive HBsAg, with the other 3 tests being negative, indicates early acute infection, but could also indicate
receipt of the vaccine within several weeks. This is a transient effect. Positive HBsAg, total anti-HBc, and IgM anti-HBc, with negative anti-HBs
indicates acute infection. As acute infection resolves, HBsAg will disappear, and before anti-HBs appears, both HBsAg and anti-HBs will be negative, while total anti-HBc and IgM anti-HBc will be positive. Negative HBsAg and IgM anti-HBc, with positive total anti-HBc and anti-HBs, indicates past infection with recovery and immunity to new infection. Positive HBsAg and total anti-HBc, with IgM anti-HBc and anti-HBs negative indicates chronic infection. Total anti-HBc positive alone, with the other 3 negative, has several possible interpretations, including a false positive result and therefore susceptible. Past infection resolved. Low-level chronic infection, and unlikely to be infectious except under unusual circumstances involving direct percutaneous exposure to large quantities of blood, such as blood transfusion, or passive transfer of anti-HBc to an infant from an infected mother. Anti-HBs alone should be detected following vaccination, as described previously, or may be detected for 3-6 months following receipt of
Hepatitis B Immune Globulin, H-BIG, also commonly referred to as H-Big. This segment is now complete. (midi music)

8 Comments

  • Reply Nouha Gharbi August 3, 2016 at 12:21 pm

    There's a contradiction here, at 5:08 it says when u have an anti Hbc total(IgM and IgG) and IgM antiHbc it's considered to be a chronic infection, obviously the total HBC has IgM in it so how can it be negative? 1st or did u mean just the IgG and not total Hbc?

  • Reply Y Huế lớp N September 18, 2016 at 2:57 pm

    this video makes HBV easier, why don't you make a new video about treatment HBV, i'am looking forward to seeing new useful video from you

  • Reply designerdroge November 29, 2017 at 10:19 am

    I don't get the IgM anti HBc thing. What is the difference of the total anti-HBc IgM and the single IgM. Shouldn't IgM be low after 32 weeks and only IgG is detectable?

  • Reply Mariam Mahrous October 14, 2018 at 11:24 pm

    Excellent video

  • Reply Bhoj raj Timilsina April 14, 2019 at 2:50 pm

    Why it is imposiiable to cure…. what will be the chance of cure in future

  • Reply SINGH Brothers April 18, 2019 at 1:00 pm

    Sir i have hepatitis b. Doctor told me that the reading is 1.how much time will it take to cure?? Whether i will be completely cured or not. Reply plz

  • Reply dita ita October 23, 2019 at 6:41 am

    How to check HbcAg with rapid rest method?

  • Reply Sonu Kumar Agrahari November 10, 2019 at 12:00 am

    Hii

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