UNCORRECTED PROOF TRSTMH 427 1—5 Transactions of the Royal Society of Tropical Medicine and Hygiene (2006) xxx, xxx—xxx 3 available at www.sciencedirect.com journal homepage: www.elsevierhealth.com/journals/trst Trend in incidence of hepatitis B virus infection during a decade of universal childhood hepatitis B vaccination in Saudi Arabia 4 5 6 Tariq A. Madani * 7 Ministry of Health, Riyadh, and Department of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia 8 Received 19 May 2005; received in revised form 21 October 2005; accepted 4 December 2005 9 KEYWORDS Hepatitis B virus; Hepatitis B surface antigen; Hepatitis B vaccine; Saudi Arabia Summary Since 1990, the national strategy to eliminate hepatitis B virus (HBV) infection in Saudi Arabia has included universal administration of HBV vaccine to all infants. From 1990 to 1995 this vaccine was also routinely administered to children at school entry. The prevalence of hepatitis B surface antigen (HBsAg) among children before this programme was reported to be 6.7%. The objective of this study was to describe the trend in incidence of HBV infection over a decade of surveillance following the introduction of this programme. From January 1990 to December 1999 a total of 30 784 cases of HBV infection (positive for HBsAg) were reported. The total number of HBV infections among children <15 years of age was 4180 cases, with a prevalence of 0.05%. The total number of HBV infections among adults was 26 604 cases, with a prevalence of 0.22%. The prevalence varied by region, ranging from 0.03% to 0.72% with a mean prevalence of 0.15%. There was a clear decline in incidence among children whereas the incidence in adults slightly rose, perhaps owing to population growth estimated to be 3.3% annually. This study showed that the universal childhood HBV vaccination programme had an enormous positive impact on HBsAg seroprevalence among children in Saudi Arabia. © 2006 Published by Elsevier Ltd on behalf of Royal Society of Tropical Medicine and Hygiene. 1. Introduction 10 Hepatitis B virus (HBV) infection is a major public health 11 problem worldwide. The WHO estimated that two billion 12 people (one-third of the world’s population) have serological 13 evidence of either current (positive for HBV surface antigen 14 * Present address: Department of Medicine, King Abdulaziz University Hospital, P.O. Box 80215, Jeddah 21589, Saudi Arabia. Tel.: +966 2 640 8243; fax: +966 2 640 8315. E-mail address: taamadani@yahoo.com. (HBsAg)) or past (positive for antibody to surface antigen 15 (anti-HBs) or antibody to core antigen (anti-HBc) and nega- 16 tive for HBsAg) infection with HBV. Of these, an estimated 17 350 million subjects have chronic HBV infection (positive for 18 HBsAg with or without the envelope antigen (HBeAg)). At 19 least one million chronically infected persons die annually 20 of HBV-related complications, namely cirrhosis and hepato- 21 cellular carcinoma (Lavanchy, 2004). 22 Serosurvey studies in Saudi Arabia before 1990 showed 23 that the prevalence of HBsAg positivity among Saudi Ara- 24 bian children up to 12 years of age was on average 6.7% 25 (Al-Faleh et al., 1992). Among adults, the prevalence of 26 1 0035-9203/$ — see front matter © 2006 Published by Elsevier Ltd on behalf of Royal Society of Tropical Medicine and Hygiene. 2 doi:10.1016/j.trstmh.2005.12.003