Voir page 1327 le resume en francais. En la pagina 1328 figura un resumen en espanol.
Hepatitis B (NB) is of major public health importance, infecting more than one person in every three of the world's population at some time during life and causing 2 million deaths annually (1, 2). Some infections clear up and are followed by long-term immunity (identified by the presence of HB core antibody (HBcAb) without the presence of HB surface antigen (HBsAg) in serum). Chronic infections, however, which do not clear up (identified by the presence of HBsAg in serum for more than six months), lead to the largest burden of disease and death (3). Public health officials need to know the prevalence of chronic infection and immunity in the population and the characteristics of those who are infected (risk groups) in order to plan public health programmes, particularly vaccination programmes (4). In the Eastern Mediterranean Region prevalence of chronic infection varies from 1.5% in Kuwait (5) to 1.8% in East Jerusalem and the West Bank (6) and 28% in Saudi Arabia (7).
There were no accurate estimates of the prevalence of disease markers or the risk groups in which they occurred in the population of Al Ain Medical District, United Arab Emirates. However, it was known that most children aged under 11 years were immune because of universal childhood immunization programmes in which 92% received all three doses (8). A formal study to gather this information would have been costly and time-consuming. It was therefore decided to identify existing databases that could be used to generate data on the prevalence of HBsAg and HBcAb and to determine whether sufficiently accurate information could be obtained from them for planning public health programmes, particularly immunization programmes (by identifying disease burden and risk groups and by aiding cost calculations).
Five databases were identified which contained recent information on the prevalence of the HBsAg marker; one of them also contained information on the prevalence of the HBcAb marker (Box 1). It was assumed that persons found to be HBsAg+ were chronic carriers as all the databases were created by screening of apparently healthy individuals. Approval for the study was obtained from the Research Ethics Committee of the Faculty of Medicine and Health Sciences, United Arab Emirates University. Information was abstracted from each database on nationality (United Arab Emirates or non-United Arab Emirates), age, sex (where available) and the presence of HB markers for each individual tested, and was analysed separately for each database by means of the SPSS software. The statistical significance of differences between two or more categorical variables was determined by means of the [chi square] test, in which P< 0.05 was considered significant.
Box 1. Summary of databases containing recent information on the prevalence of HBsAg marker
* Two hospital laboratory databases created during routine antenatal screening between October 1997 and October 1998 (the Tawam and Al Ain antenatal databases)
-- one at Tawam Hospital, created by means of the HBsAg Axsym MEIA Kit (Abbott) for HBsAg and the Core Axsym MEIA Kit (Abbott) for HBcAb;
-- one at Al Ain Hospital, created by means of the Auszyme Monoclonal Diagnostic Kit (Abbott) for HBsAg.
* Database created during screening of students applying for higher education between July and October 1998, by means of the Auszyme Monoclonal Diagnostic Kit (Abbott) for HBsAg (higher education database).
* Database created during screening by the Preventive Medicine Department of individuals seeking immunization between May and July 1997, by means of the Auszyme Monoclonal Diagnostic Kit (Abbott) for HBsAg (preventive medicine database).
* Database created during screening of males applying for the government marriage gift in 1997 (the marriage gift is a government grant available to male United Arab Emirate citizens marrying for the first time who agree to undergo screening), by means of the Auszyme Monoclonal Diagnostic Kit (Abbott) for HBsAg (marriage gift database). …