Hepatitis B virus infection in Singapore.
Abstract
Although Singapore is in an endemic region for hepatitis B infection, the hepatitis B carriage rate of 5-6% is relatively low. The highest positivity rates for hepatitis B surface antigen (HBsAg) are found in the paediatric age group, with another peak in 40-49 year olds. Studies suggest that, although perinatal transmission is an important route of infection, most children acquire the virus through horizontal transmission between family members. Viral replication continues at a high rate in young carriers and tends to slow down with increasing age. Up to 50% of hepatitis B carriers in Singapore have chronic hepatitis, shown by raised serum ALT values and liver histology, and about 10% are infected with the precore mutant virus. About 20% of carriers have cirrhosis. Among patients with HCC, up to 75% are HBsAg positive, of whom 45% are still viraemic. Mass vaccination against hepatitis B was introduced into Singapore on a voluntary basis in 1983, with compulsory vaccination of babies born to HBeAg positive mothers since 1985. The number of cases of acute hepatitis B has fallen by 60% between 1989 and 1995 although the problems of the longterm complications of chronic hepatitis B still need to be tackled.
Full text
Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1008K), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Goh KT. Hepatitis B surveillance in Singapore. Ann Acad Med Singapore. 1980 Apr;9(2):136–141. [PubMed] [Google Scholar]
- Chan SH, Oon CJ. Epidemiology of HBV infection in Singapore. Asian Pac J Allergy Immunol. 1984 Jun;2(1):139–143. [PubMed] [Google Scholar]
- Coursaget P, Yvonnet B, Chotard J, Vincelot P, Sarr M, Diouf C, Chiron JP, Diop-Mar I. Age- and sex-related study of hepatitis B virus chronic carrier state in infants from an endemic area (Senegal). J Med Virol. 1987 May;22(1):1–5. [PubMed] [Google Scholar]
- Stevens CE, Beasley RP, Tsui J, Lee WC. Vertical transmission of hepatitis B antigen in Taiwan. N Engl J Med. 1975 Apr 10;292(15):771–774. [PubMed] [Google Scholar]
- Chan SH, Tan KL, Goh KT, Lim C, Tsakok M, Oon CJ, Ratnam SS. Maternal-child hepatitis B virus transmission in Singapore. Int J Epidemiol. 1985 Mar;14(1):173–177. [PubMed] [Google Scholar]
- Quak SH, Singh R, Oon CJ, Wong HB. The immune status of Singapore children to hepatitis B virus. Aust Paediatr J. 1983 Jun;19(2):100–103. [PubMed] [Google Scholar]
- Tan CC, Guan R, Yap I, Tay HH, Kang JY. Horizontal or vertical transmission of hepatitis B virus? A serological survey in family members of hepatitis B carriers in Singapore. Trans R Soc Trop Med Hyg. 1991 Sep-Oct;85(5):656–659. [PubMed] [Google Scholar]
- Yap I, Wee A, Guan R. Chronic hepatitis B infection in Singapore. Singapore Med J. 1991 Oct;32(5):352–355. [PubMed] [Google Scholar]
- Yap I, Guan R, Kang JY, Tay HH, Lee E, Choong L, Woo KT. Seroprevalence of antibodies to the hepatitis C virus in Singapore. Southeast Asian J Trop Med Public Health. 1991 Dec;22(4):581–585. [PubMed] [Google Scholar]
- Guan R, Yap I, Wong L, Tan LH, Oon CJ, Wee A. Evidence of viral replication in HBsAg positive patients with hepatocellular carcinoma: measurement of serum hepatitis B virus deoxyribonucleic acid (HBV-DNA). Ann Acad Med Singapore. 1989 Jan;18(1):8–11. [PubMed] [Google Scholar]
- Guan R, Oon CJ, Wild C, Motesano R. A preliminary survey on aflatoxin exposure in Singapore. Ann Acad Med Singapore. 1986 Apr;15(2):201–205. [PubMed] [Google Scholar]
- Lin Y, Shi CY, Li B, Soo BH, Mohammed-Ali S, Wee A, Oon CJ, Mack PO, Chan SH. Tumour suppressor p53 and Rb genes in human hepatocellular carcinoma. Ann Acad Med Singapore. 1996 Jan;25(1):22–30. [PubMed] [Google Scholar]
- Lok AS, Wu PC, Lai CL, Lau JY, Leung EK, Wong LS, Ma OC, Lauder IJ, Ng CP, Chung HT. A controlled trial of interferon with or without prednisone priming for chronic hepatitis B. Gastroenterology. 1992 Jun;102(6):2091–2097. [PubMed] [Google Scholar]
- Lai CL, Lok AS, Lin HJ, Wu PC, Yeoh EK, Yeung CY. Placebo-controlled trial of recombinant alpha 2-interferon in Chinese HBsAg-carrier children. Lancet. 1987 Oct 17;2(8564):877–880. [PubMed] [Google Scholar]
- Guan R, Ho KY, Yap I, Kang JY, Tan CC, Ng C, Smith R, Wee A. Treatment of hepatitis B surface antigen carriers in the early stage of the infection using recombinant alpha-interferon with steroid priming. Aliment Pharmacol Ther. 1995 Oct;9(5):535–540. [PubMed] [Google Scholar]
- Lee BW, Yap HK, Tan M, Guan R, Quak SH, Choong L, Murugasu B, Woo KT, Jordan SC. Cell-mediated immunity in patients on hemodialysis: relationship with hepatitis B carrier status. Am J Nephrol. 1991;11(2):98–101. [PubMed] [Google Scholar]
- Wong DK, Cheung AM, O'Rourke K, Naylor CD, Detsky AS, Heathcote J. Effect of alpha-interferon treatment in patients with hepatitis B e antigen-positive chronic hepatitis B. A meta-analysis. Ann Intern Med. 1993 Aug 15;119(4):312–323. [PubMed] [Google Scholar]
- Guan R, Yap I, Tay HH. Hepatitis B vaccination: half dose recombinant DNA hepatitis B vaccine (B-Hepavac II) is as immunogenic as the full recommended dose in healthy adults. J Gastroenterol Hepatol. 1991 Jul-Aug;6(4):374–376. [PubMed] [Google Scholar]
- Pol S, Driss F, Carnot F, Michel ML, Berthelot P, Brechot C. Efficacité d'une immunothérapie par vaccination contre le virus de l'hépatite B sur la multiplication virale B. C R Acad Sci III. 1993 Jul;316(7):688–691. [PubMed] [Google Scholar]
- Carman WF, Zanetti AR, Karayiannis P, Waters J, Manzillo G, Tanzi E, Zuckerman AJ, Thomas HC. Vaccine-induced escape mutant of hepatitis B virus. Lancet. 1990 Aug 11;336(8711):325–329. [PubMed] [Google Scholar]
- Harrison TJ, Hopes EA, Oon CJ, Zanetti AR, Zuckerman AJ. Independent emergence of a vaccine-induced escape mutant of hepatitis B virus. J Hepatol. 1991;13 (Suppl 4):S105–S107. [PubMed] [Google Scholar]