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Last updated: January 2017
Hepatitis B screening as part of an STI screen aims to identify acute or chronic infection and to identify individuals requiring vaccination.
Asymptomatic infection is common.
Active infection is indicated by the presence of hepatitis B surface antigen (HBsAg) in serum.
Acute hepatitis B is diagnosed in patients who are positive for HBsAg and have evidence of disturbed liver function, symptoms (e.g. lethargy, nausea, fever, anorexia for a few days and then jaundice, pale stools and dark urine) and a risk history suggesting recent infection. Incubation period is 45-180 days. Repeatedly positive HBsAg over a 6-month period, in the absence of acute symptoms or risk history to suggest recent infection, indicates a chronic hepatitis B infection that can be life long.
Increases in AST, ALT – Acute/Chronic Infection.
Hep B sAg – Current hep B infection.
Hep B sAb – Immunity to hep B infection.
Hep B cAb – Previous exposure.
Hep B eAg – Associated with high infectivity.
Hep B eAb – Associated with lower infectivity.
HBV DNA – Viral replication.
In a primary care setting, the following initial tests are suggested for individuals with UNKNOWN status – Hep B sAg, Hep B sAb and Hep B cAb. All 3 tests will determine infection status and need for vaccination (Refer to Australian STI Guidelines for Primary Care)
For clients seen at Clinic 275, if a history of Hep B vaccination is reliable i.e. written dated record of each dose of a complete series, there is NO need to check Hep B sAb.
If there is uncertain or no history of Hep B vaccination, check to see if patient was born in Australia and schooled in Australia since 1985. If so, likely to have been vaccinated and nil further testing required except for the very first visit ever to the clinic where a Hep B sAg is ordered.
If uncertain or no history of Hep B vaccination and patient was not born in Australia or schooled in Australia, check to see if they are at high risk of Hepatitis B exposure. If so, check Hep B cAb and Hep B sAb. (However, if there is concern of a new infection, Hep B sAg should also be done)
Individuals at high risk of hepatitis B exposure include:
Hep B sAg –ve and Hep B sAb +ve = Immune, no need to test further for hepatitis B.
Hep B cAb - ve and Hep B sAb +ve = Immune, no need to vaccinate, usually indicative of vaccination.
Hep B cAb – ve and Hep B sAb – ve = No previous exposure and No immunity. Susceptible to Hepatitis B = Offer vaccination.
Hep B cAb +ve and Hep B sAb-ve = Order Hep B sAg. If Hep B sAg -ve = Seek consultant advice. If Hep B sAg + = work up (clinical assessment, Hep B eAg, Hep eAb, LFT, INR, CBP, alpha-feto protein, liver ultrasound) and refer to appropriate specialist for further testing including Hep B DNA.
All Hep BsAg +ve patients should be tested for Hep D Ab as well.
Individuals with active disease, for example Hep B sAg positive and abnormal liver function tests should be referred to an appropriate specialist. Even if LFTs are normal, referral to an appropriate specialist is recommended unless liver fibrosis could be excluded
Adelaide Sexual Health Centre offers vaccination to all non-immune clients, free of charge.
Vaccines used in Clinic 275 – Engerix (20 micro grams per 1 ml) and Recombivax H-B Vax2 (10 micrograms per 1 ml).
Vaccination doses are given at 0, 1 and 6 months. The minimum interval between the 1st and 2nd dose is 1 month, between 2nd and 3rd dose is 2 months and between the 1st and 3rd dose is 3 months for shortened 3 dose schedules to attain comparable antibody levels.
(For accelerated schedules and indications, refer to Australian Immunisation Handbook)
Switching between brands of vaccines is NOT recommended.
Vaccination of persons already immune to hepatitis B infection is not harmful with no increase in adverse events.
Booster doses of the vaccine are not currently recommended for immunocompetant persons. However, booster doses may be considered for immunocompromised patients (e.g. HIV infection or renal failure) – consult appropriate specialist for advice.
A modified dosing regimen is required for HIV infection as there may be an impaired response to Hep B vaccination. (40 mcg Engerix B at 0, 1, 2 and 6 months).
Post vaccination serological testing for immunity is not necessary after routine vaccination in adolescents and adults. Periodic testing to determine Ab levels after routine vaccination in immunocompetent persons is not necessary.
However, post vaccination testing (for Hep B sAb 1-2 months after 3rd vaccine dose) may be considered in HIV infected or other immunocompromised persons to determine need for revaccination, for subsequent clinical management depending on knowledge of immune status e.g. health care workers at high risk of percutaneous mucosal exposure to body or sexual and needle sharing partners of Hep B sAg positive persons to determine need for revaccination.
In these patients if Hep B sAb < 10 IU/ml after a primary vaccine series, they should be given a single booster dose i.e. 4th dose of vaccine. Hep B sAb is tested again after 8 weeks. If still no response, exclude Hep B infection i.e. test Hep B sAg. If +ve = appropriate specialist review. If –ve, a further 2 doses of the vaccine at monthly intervals are given. Retesting for Hep B sAb should be done at 4 weeks after the last dose. If patient remains non- responsive after a primary course of vaccination and subsequent additional IMI doses >/= 5 doses in total = persistent non- responders. These patients remain susceptible to hepatitis B infection and precautions should be advised to prevent hepatitis B infection. If exposed, will require Hep B Immunoglobulin (0.06 ml/Kg).
Cases eligible for hepatitis B post-exposure prophylaxis should be referred to appropriate specialist. Following sexual exposure to hepatitis B, 400 IU of Hep B Immunoglobulin by IMI injection, as a single dose, is given within 72 hours of last sexual contact (100 IU if body weigh < 30 kg). ). 0.5 ml or 1 ml of vaccine IMI is also given depending on age, within 14 days and two more doses at one and 6 months after the first dose.
The following points should be discussed:
Contact tracing/Partner notification is required.
For acute hepatitis B infections, contact tracing includes up to 6 months prior to onset of acute symptoms. Patients are infectious for 2 weeks before onset of symptoms and until they become Hep B sAg negative. Test sexual, household contacts, family members and offer vaccination if susceptible.
A person with positive HBsAg should be retested in 6 months. A positive test on follow-up at 6 months indicates chronic hepatitis B infection. If the patient has abnormal liver function tests, refer to an appropriate specialist.
Prior infection and clearance indicates lifelong immunity to reinfection but patients with resolved acute infection may experience a hepatitis B flare up if immunocompromised (e.g. if receiving chemotherapy).
For further information on the diagnosis and management of hepatitis B contact Adelaide Sexual Health Centre5.
These guidelines are based on review of current literature, current national and international guidelines and recommendations, and expert opinion.
They are written primarily for use by Adelaide Sexual Health Centre staff and some flexibility is required in applying them to certain private practice situations.