Hepatitis B is a serious viral infection that can lead to significant liver damage, but alarmingly, over half of those infected are unaware of their status. In fact, a considerable percentage, between 50% and 70%, of individuals with acute hepatitis B experience no noticeable symptoms at all. This silent nature of the virus underscores the critical importance of diagnosis. Without proper testing, individuals unknowingly living with hepatitis B can transmit the virus to others, perpetuating its spread.
Chronic Hepatitis B Virus (HBV) infection poses a substantial threat, potentially leading to severe health complications and even death. However, the good news is that reliable and cost-effective screening tests are available to detect HBV infection long before serious liver disease develops. Early diagnosis through routine monitoring and treatment is crucial in managing chronic HBV infection, significantly reducing the risk of morbidity and mortality. Furthermore, proactive management of chronic infection through preventative measures plays a vital role in curbing further transmission.
For those seeking more in-depth information on the rationale behind updated testing recommendations, further reading is available on the CDC website.
Deciding When to Test or Screen for Hepatitis B
Understanding the distinction between screening and testing is important in the context of hepatitis B diagnosis.
Screening generally involves serological testing of individuals who are asymptomatic and not known to be at a heightened risk of HBV exposure. It’s a broad approach to identify potential cases in the general population.
Testing, on the other hand, is typically conducted on individuals who are exhibiting symptoms of hepatitis or those recognized as being at an increased risk of HBV exposure. This is a more targeted approach based on individual circumstances.
Recommendations for Hepatitis B Testing:
Adults:
The Centers for Disease Control and Prevention (CDC) recommends that all adults aged 18 years and older undergo hepatitis B screening at least once in their lifetime. This should be done using a triple panel test. To facilitate broader access to testing, it is recommended that HBV testing be provided to anyone who requests it, irrespective of whether they disclose any risk factors. Many individuals may hesitate to reveal stigmatizing risks, making this open access approach essential.
Infants:
For infants, the CDC recommends testing all babies born to mothers who are positive for Hepatitis B surface antigen (HBsAg). These infants should be tested for both HBsAg and antibody to hepatitis B surface antigen (anti-HBs) seromarkers.
Pregnant Women:
HBV screening is recommended for all pregnant women during each pregnancy, preferably during the first trimester. This recommendation stands regardless of their vaccination status or previous testing history. Pregnant women who have had appropriately timed triple panel screening and have not had new HBV exposures since then, only need HBsAg screening.
Individuals at Increased Risk of Hepatitis B
Regular testing is crucial for susceptible individuals who face ongoing risk of exposure, regardless of their age. These at-risk groups include:
- Individuals with a history of sexually transmitted infections (STIs) or multiple sexual partners.
- People with a history of past or current Hepatitis C Virus (HCV) infection.
- Individuals who are currently or formerly incarcerated in correctional facilities such as jails or prisons.
- Infants born to mothers who are HBsAg-positive.
- People born in regions with a Hepatitis B prevalence of 2% or higher.
- US-born individuals who were not vaccinated at birth and whose parents were born in regions with an HBsAg prevalence of 8% or higher.
- People who inject drugs (PWID) or have a history of injection drug use.
- Individuals with Human Immunodeficiency Virus (HIV) infection.
- Men who have sex with men (MSM).
- Household contacts, or former household contacts, of individuals with known HBV infection.
- People who have shared needles or had sexual contact with individuals known to have HBV infection.
- Individuals undergoing maintenance dialysis, including in-center hemodialysis, home hemodialysis, and peritoneal dialysis.
- People with elevated liver enzymes.
It’s important to note that susceptible individuals are those who have never been infected with HBV and have either not completed a full hepatitis B vaccine series or are known to be non-responders to the vaccine.
For further information, guidelines on managing hepatitis B exposures in healthcare settings are available: Guidelines for Responding to Hepatitis B Exposures in Health Care Settings.
Recommended Hepatitis B Tests: The Triple Panel
The CDC currently recommends the use of the triple panel test for comprehensive hepatitis B diagnosis. This panel includes testing for the following three serologic markers:
- Hepatitis B surface antigen (HBsAg): Indicates current HBV infection.
- Antibody to hepatitis B surface antigen (Anti-HBs): Indicates immunity to HBV, either from vaccination or past infection.
- Total antibody to hepatitis B core antigen (total anti-HBc): Indicates past or present HBV infection.
Any subsequent follow-up testing can be tailored based on the results obtained from the initial triple panel test.
It’s worth noting that previous guidelines recommended a single test for HBsAg.
Incorporating HBV screening and testing into clinic workflow.
Understanding Hepatitis B Test Results
Different combinations of serologic markers help identify various phases of HBV infection. These markers determine if a patient has acute or chronic HBV infection, has immunity due to prior infection or vaccination, or is still susceptible to infection. Key markers include:
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Hepatitis B surface antigen (HBsAg): This protein on the surface of HBV is detectable at high levels in serum during both acute and chronic HBV infection. Its presence signifies that the person is infectious. It’s important to note a possible exception: HBsAg can be transiently positive within 30 days after hepatitis B vaccination. The body typically produces antibodies to HBsAg as part of the immune response. HBsAg is the antigen used in the hepatitis B vaccine.
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Antibody to hepatitis B surface antigen (Anti-HBs): The presence of anti-HBs generally indicates recovery from and immunity to HBV infection. Anti-HBs also develops in individuals who have been successfully vaccinated against hepatitis B. While anti-HBs levels may decrease over time in vaccine responders, most individuals remain immune and will mount an immune response upon HBV exposure.
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Antibody to hepatitis B core antigen (Anti-HBc): Total anti-HBc appears at the onset of symptoms in acute hepatitis B and persists for life. It measures both Immunoglobulin M (IgM) and Immunoglobulin G (IgG). The presence of total anti-HBc indicates a previous or ongoing HBV infection at some point in time. Importantly, individuals who have immunity from vaccination will not develop anti-HBc.
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IgM antibody to hepatitis B core antigen (IgM anti-HBc): IgM anti-HBc positivity indicates a recent HBV infection, typically within the last 6 months, and signifies acute infection. This test is usually ordered when acute HBV infection is suspected.
* IgM anti-HBc might also be positive in individuals with chronic infection during severe flares or reactivation.
† Immunity is defined as anti-HBs concentration >10 mIU/mL after completing the vaccine series.
‡ Anti-HBs concentrations may decline over time in vaccine responders. Revaccination is generally not needed for those with a documented complete HepB vaccine series, except for specific populations like hemodialysis patients or healthcare personnel.
| Test Outcome | Interpretation | Action
