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HEPATITIS B INFECTION:  WHAT THE PRIMARY CARE DOCTORS SHOULD KNOW

The decision to treat CHB is based on a combination of clinical, laboratory and histological factors. The primary goal of treatment for CHB is to eliminate or permanent suppress HBV. This will decrease pathogenicity and infectivity.⁷ Currently interferon-alpha (IFN-α), lamivudine and adefovir have been licensed globally for the treatment of CHB. IFN-α, an immunomodulator, works by affecting viral replication. Studies had shown that the response rate to IFN- α is approximately 33% after 4-6 month course of treatment.^9,10 Treatment for longer than 12 months may improve the rate of HBeAg seroconversion. Re-treatment of relapsed CHB patients with this drug has a response rate which varies from 20-40%.⁹  In one randomised trial it was shown that In chronic hepatitis B, treatment with interferon- α2b (5 million units per day for 16 weeks) was effective in inducing a sustained loss of viral replication and achieving remission, assessed both biochemically and histologically, in over a third of patients.¹⁰  Lamivudine is a nucleoside analogue which inhibits the viral reverse transcriptase.¹¹  The advantages of Lamivudine include high degree of tolerability and also safe even in patients with decompensated cirrhosis. It can also be used as first line therapy or following IFN-α failure.¹²  Adefovir is a synthetic acyclic adenine nucleotide analogue and it is also a potent inhibitor of hepatitis B reverse transcriptase. Studies had shown that there were significant improvements in histological, virologic and biochemical markers after 48 weeks of treatment.^13,14 The main advantage is the low incidence of drug resistance and its ability to suppress lamivudine-resistant mutants.^13,14

CONCLUSION
Hepatitis B virus infection is a global public health problem. The prevalence of hepatitis B infection is higher in Asia. The rate of HBsAg carriage in the general population ranges from 2-20%. The WHO has recommended that by the end of 21st century hepatitis B vaccination should be incorporated into routine childhood immunisation programmes for all nations. Vaccination against hepatitis B remains the most important aspect of preventive care. Most importantly hepatitis B vaccination can protect individual from fulminant hepatitis, liver cirrhosis and hepatocellular carcinoma. Primary care physicians must be familiar with the pathology, epidemiological and clinical presentations of this disease and be able to refer patients for appropriate treatment at the tertiary centre.

REFERENCES

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Address for correspondence: Dr. Loh Keng Yin, IMU Clinical school, Jalan Rasah, 70300 Seremban, Negeri Sembilan Darul Khusus. Tel: 06-7677798, Fax: 06-7677709, Email: kengyin_loh@imu.edu.my

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