Hepatitis B

Hepatitis B, while rare in western nations, is endemic in many countries in south asia.

It can cause acute infection or evolve into a chronic state where it can cause long term damage to the liver. Patients who have chronic Hepatits B infection are prone to liver cirrhosis and liver cancer.

Spread of Hepatitis B

The virus that causes Hepatitis B (HBV) is spread through the exchange of bodily fluids from person to person generally during sexual contact. It is very infectious. According to estimates, it is nearly 100 times more infectious than HIV. The infection is spread by:

  • Unprotected penetrative sex with someone who is infectious
  • Sharing contaminated needles or other drug-injecting apparatus
  • Using non-sterilised equipment for tattooing, acupuncture or body piercing
  • Mother to her baby, most commonly during delivery. Immunisation of the baby at birth prevents the transmission of hepatitis B.
  • Blood transfusion if the blood is not checked for HBV

Natural History of Hepatitis B infection

While some people with active Hepatitis B infection have no symptoms, others have symptoms of malaise, jaundice etc, similar to infection with Hepatitis A.

If hepatitis B infection is acquired as a baby, e.g. mother to baby transmission, individuals often remain chronic carriers of HBV. However, most adults infected with the hepatitis B virus fully recover and develop life-long immunity. About 2% to 10% of individuals infected as adults will become chronic carriers, which means they will be infectious to others and can develop chronic liver damage. Infected children, especially newborn babies, are much more likely to become chronic carriers. If a person lives with hepatitis B infection for a number of years then they may develop liver cirrhosis and liver cancer.

Nothwithstanding, chronic HBV infection does not usually present with symptoms and hence treatment is not necessary for most chronic carriers. However, they need to be monitored long term for development of cirrhosis and/or liver tumours.

Testing for Hepatitis B

Acute Hepatitis B infection is diagnosed by detecting the presence of Hepatitis B Surface Antigen (HBsAg) in the blood.

Hepatitis B immunisation

In asia, the rate of HBV infection is high and hence immunisation is recommended for the general population at large.

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    Hi Dr Tan

    My Hepatitis B screening result are:
    HBs Atigen : Reactive
    Anti-HBs : Non-Reactive

    what could be the interpretation of results. As doctor told me that he dont know the virus is active of non active.
    Please advise your expert opinion for above mentioned results.


    • Your results would indicate that you are a hepatitis B carrier. To know whether there is viral activity or not, we would have to run a hepatitis B viral load and possibly some other blood tests. If you are concerned, please visit us for a proper consultation and testing.

  2. Hephziba

    Hi doctor,I have a question.can a baby who is barely a month old contact hbv by kissing or licking the sweat of an infected person

  3. Hi,

    After a potential exposure to hepatitis b. What test do you suggest to rule out infection (surface antigen or core antibody)? How long after exposure is the test be conclusive?


  4. Hi Drs,

    Would a 6 and 12 week hbsag test be conclusive after possible xposure?

  5. Hi Doctor,

    I did the followingHep B tests on 39 days and the result came negative.


    2. Hepatitis B Surface Antigen (HBsAg) (ELISA)

    Can I consider the above tests conclusive at 39 days? Should I perform more tests?

  6. Dr I done my hep b surface antigen test at 12 th week it came out negative ,,,is it conclusive???

  7. Dear Dr Tan

    i would like to ask,last week i check with general doctor and said that i got Hepatitis B and give me several medicine to prevent liver cancer, i would like to ask that is still need to check with lab for maintain liver status or how?

    Thanks before

    • This is too general a question to answer. I do not know if you were diagnosed with acute Hepatitis B or chronic Hepatitis B or if you are a carrier. Depending on which one it is we usually do several lab tests to determine the severity of the infection and decide if you need anti-viral therapy or not. Also, there should be active follow up. In other words, your doctor should give you a date to see him again to monitor the liver. I have also never heard of any medicines to “prevent liver cancer”. I think this must have been some miscommuincation. We do not have enough information to comment on this. You should go back to your doctor to clear any doubts you have. Or see a specialist.

  8. I received a unprotected oral sex from CSW 6 months ago
    ( I am a male)
    Till today i dont really have any obvious symptoms
    1) can i get Hepatitis B infection via oral sex?

  9. Salutation Dr Tan, I just did an unprotected sex. I did test for HBV on the 9 week,can i consider this test to be conclusive?

  10. Wisdom Seeker

    HI DOCTOR,i wish to go for the HBV Immunization, can this immunization with effect my HIV window period? i been tested negative HIV with the 4 generation ag/ab combo test at 7week post exposure. I did a HBV testing for both AG (non reactive) & AB(non reactive)at 9week post exposure. Is it conclusive?Do i need to go for another test?? Please & thank you 🙂

    • If you are worried about HCV then why did you test for HBV? Sounds confusing to me.

  11. Hello Doctor,

    I received my negative Hep B Core Ab igm result after 33 days post exposure. Is this result considered conclusive?


  12. Hi doc how fast does the hepatitis b antigens appear beforee i can get tested? Is one month conclusive?

  13. doctor,

    i received a cunnilingus from a hepatitis be infected person. he licked my clitoris 8 times and he brushed his teeth with bleeding an hour before but no blood was there when he performed cunnilingus at me. am i at risk to get infected by hepatitis b?


    • I have not heard of anyone becoming infected with Hep B via cunnilingus. I would say you are not at risk. However, Hep B is a rather contagious virus and you certainly still should get checked. Also, get this opportunity to get yourself vaccinated against Hep B, Hep A and HPV.

      • you are right doctor.. i got tested and received all negative results for hbsag and anti hbsag.. what about kiss? can wet kiss contracted hepatitis b?

        thanks a lot

        • can wet kiss with exchange of saliva contract hepatitis b?


        • No, you cannot get hepatitis B from kissing.

          • Hello Doctor..
            I kissed a male then had a qualitative hbsag test with reference value of 0.05 IU/ml…. my result is 0.06 IU/ml for quantitative HBsag test.. what does it mean? i had it tested a week after i kissed this guy… i also had anti hbs and anti hbs as both non-reactive.. please let me know doctor.. really scared.. thanks in advance

          • First of all, you cannot get hepatitis B from kissing. Whatever you are testing for is irrelevant to the kissing event. I think you should consult your doctor who did the test for you. I am not able to comment on your hbsag quantitative test results.

          • hello doctor..

            what i meant was i had a quantitative hbsag test with reference value of 0.05 IU/ml and my result is 0.06 IU/ml..thanks

          • i am sorry reference value for quantitative hbsag test is : <0.05IU/ml notice the "<" or less than

          • Please consult your doctor who did the test for you.

          • Dr , I am pretty sure that the kissing is the only exposure to hepatitis b, maybe kissing can contract hepatitis b?

          • the only exposure to hepatitis b for me as i cannot recall any other occurrence…. is my test bad? thx

          • Kissing cannot transmit Hepatitis B. I think you should consult your doctor regarding your test results. Based on what you have written, it looks like it is borderline. You may want to repeat it.

          • does my test result show acute infection , early incubation??


          • Doctor…. is my test result showing acute stage of hepatitis incubation period? i really appreciate your opinion i dont know what to do…

          • melinda

            got my test today. hbsag qualitative non reactive.. i guess it means im free from hep b.. thanks Doctor

  14. Is there window period for HbsAg test?

    • The incubation period (when a person starts showing symptoms) for Hepatitis B ranges from 1 to 6 months. HBsAg test will start showing positive several weeks before onset of symptoms. It is recommended to get tested at least 1 month from exposure.

  15. Hi Doc
    May I ask is it possible to contract HIV or Hep B by fingering a woman and sucking or licking a woman’s breast when you have ulcer in your mouth. I do not think that the woman is lactating but even she did would it be possible?

  16. Dear Doctors,

    I had protected oral and vaginal sex with a sex workers about 6 weeks ago. Around 3-4 weeks back i noticed my lymph nodes behind the neck and ear has swollen. Other than that i feel healthy. I’m quite paranoid and scared. I’m planning to go for a hiv test tomorrow but will it be too early in case the test is negative? Please advise. Thanks!

    • It’s not too early to have a HIV test. You have passed the window period.
      You should get yourself tested for other STDs as well.

  17. Dear Dr. Tan,

    I performed a cunnilingus to a CSW 4 weeks ago. I am suffering of anxiety about this event. In particular, I am very worried about Hepatitis B and HIV.

    Many thanks

    • Hi Rolando,

      Cunnilingus carries very negligible risk for transmitting both HIV and Hep B. If you’d like, I’d advise testing for HIV with a 4th generation test and doing an antibody screen for Hep B to alleviate your worries.

  18. Hello Dr.Tan!
    I am a man 41 years old and I was diagnoses with chronic hepatitis b 3 months ago. I did the dna test but I am not sure what it means, I havent gone to the doctor yet but I am very anxious. Its written 8,6×10 in power 4. Please hel me interprete this result, is it high?
    Thank u very much, Arti.

  19. scared to death

    dear dr tan,
    can i ask that hepetatis b take how long to be detected normally?is 3 months negative after exposure accurate?

    • Hi scared to death,

      If you suspect you have a Hepatitis B infection then you should see your doctor. Diagnosis of Hepatitis B is not as straightforward as just doing one test. The doctor will have to check you liver function and do tests known as viral markers.


      Dr Tan

  20. Dear Dr Tan,
    I did blood test Hep B surface antigen(HBsAg) NOT DETECTED,AND HEP B surface Antibody (HBsAb) 179 IU/L,i had vacination for Hep B since i was young..3 times injections….i forgot to ask my Dr who did this test for me, can i ask you? If i have unproted sex with a men and he is hep B positive,is it possible the virus will trasmit to me?or the virus will transmit to the baby only?please reply….thanks

    • Hi miao,

      The test shows that you are protected against Hepatitis B. So even if you contract Hepatitis B, be it via sexual or non-sexual transmission, your body will be able to fight off the virus and you will not suffer from a Hepatitis B infection.


      Dr Tan

  21. Hi Dr Tan

    My Hepatitis B screening result are:
    HBsAg : Non-Reactive
    Anti-HBs : Non-Reactive
    Hepatitis A Virus: Non-Reactive

    I’m planning to get the vaccination for Hepatitis A & B.
    However The Count of Polymorphs,Lymphocytes & Eosinophils is a bit unnormal* based on the result of the full blood screenings as shown below:-

    Polymorphs :44%* [50-70]
    Lymphocytes:47%* [20-40]
    Monocytes :5% [<6 ]
    Eosinophils:4%* [<4 ]
    Basophils :0% [<1 ]

    Total WBC :6,500 /cmm [4,000-11,000]
    ESR (Westergen):37* mm/hr [Female 1-20]
    Platelet count:437,000* /cmm [150,000 -400,000]
    Platelet :Midly increased*

    P/S *unnormal

    My questions are:
    (1) Can I get the vaccination for Hepatitis A & B at this period while the count of Polymorphs,Lymphocytes & Eosinophils is a bit unnormal?

    (2)What is the cause of this unnormal? I had blisters 2 months ago and flu 2 days ago before the blood screening. Besides that I still have that swollen lymph node behind the right ear since 2 months ago.

    (3)Varicella Zoster (Herpes Zoster) lgG Ab: Detected
    Can this prove that my 100 blisters that popped out 2 months ago was 100% Adult chicken pox?

    Thanks Doctor 😀

    • Hi Ringo,

      I suggest you ask the doctor who did these tests for you to explain the results in detail and to advise you on when to get vaccinated. This is because he has seen and examined you. Blood test results should always be interpreted with reference to a clinical examination. Your doctor can also help you understand and interpret the Varicella Zoster IgG Ab results.


      Dr Tan


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