Epidemiological study of hepatitis B virus infection in Manitoba, Canada, 1992-2003.
In comparison with other Canadian provinces and most Western countries, the province of Manitoba maintains a different vaccination policy for hepatitis B. This policy provides selective antenatal screening for hepatitis B in women and an inoculation program for hepatitis B vaccination for fourth-grade pupils. There has been increasing concern for this policy with regard to its influence on secular trends of acute hepatitis B incidence in Manitoba. This created a need to summarise the epidemiological characteristics of hepatitis B virus (HBV) infection in Manitoba and to allocate finances and human resources for future prevention programs. The Cadham Provincial Laboratory in Winnipeg, a Canadian Public Health Laboratory, is responsible for testing all specimens for diagnosis of various common infectious diseases in Manitoba. During the period from 1 January 1992 to 31 December 2003, a total of 285,946 clinical specimens were submitted to this laboratory, which confirmed 310 cases of acute HBV and 7,556 cases of chronic HBV infection. A total of 18,168 individuals were identified as having vaccine-induced immune status. The incidence rate of acute HBV infection has significantly decreased from 6.52/100,000 person-years in 1996 to 0.86/100,000 person-years in 2003. Annual prevalence rates of chronic HBV infection in Manitoba increased slightly from 42.96 cases/100,000 population in 1992 to 71.47 cases/100,000 population in 2003. Incidence rates were generally higher in men than in women at all age groups, with values of 2.65 and 1.65 per 100,000 population, respectively (chi-square=15.768, p value <0.001). The highest incidence rate for both males and females was observed in the age group 30-34 years. The North Eastman and Winnipeg Regional Health Authorities showed significantly higher incidence rates of acute hepatitis B compared with the other nine Regional Health Authorities. Selective hepatitis B vaccination programs for children in Manitoba had achieved the greatest success in the prevention of vertical and horizontal transmission. There is an urgent need to develop cost-effective harm-reduction strategies for hepatitis B prevention among adults (aged 30-34) and groups at risk in Manitoba.
Hong
Z
Z
Blood-Borne Pathogens Section, Blood Safety Surveillance and Health Care Acquired Infection Division, Centre for Infectious Disease Prevention and Control, Public Health Agency of Canada, Ottawa, K1A 0L2, Canada. zhiyong_hong@phac-aspc.gc.ca
Smart
G
G
Zaniewski
G
G
Wu
H
H
Wu
J
J
Goedhuis
N
N
Giulivi
A
A
Kaita
K
K
Dawood
M
M
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology*; D017325:Hepatitis B Vaccines; D006801:Humans; D015994:Incidence; D007223:Infant; D016015:Logistic Models; D008297:Male; D008350:Manitoba / Q000453:epidemiology; D015995:Prevalence; D012737:Sex Factors
D017325:Hepatitis B Vaccines