Chronic hepatitis B prevalence among Aboriginal and Torres Strait Islander Australians since universal vaccination: a systematic review and meta-analysis

Abstract

BackgroundIn Australia, higher rates of chronic hepatitis B (HBsAg) have been reported among Aboriginal and Torres Strait Islander (Indigenous) compared with non-Indigenous people. In 2000, the Australian government implemented a universal infant/adolescent hepatitis B vaccination program. We undertook a systematic review and meta-analysis to assess the disparity of HBsAg prevalence between Indigenous and non-Indigenous people, particularly since 2000.MethodsWe searched Medline, Embase and public health bulletins up to March 2011. We used meta-analysis methods to estimate HBsAg prevalence by Indigenous status and time period (before and since 2000).ResultsThere were 15 HBsAg prevalence estimates (from 12 studies) among Indigenous and non-Indigenous people; adults and pregnant women (n = 9), adolescents (n = 3), prisoners (n = 2), and infants (n = 1). Of these, only one subgroup (adults/pregnant women) involved studies before and since 2000 and formed the basis of the meta-analysis. Before 2000, the pooled HBsAg prevalence estimate was 6.47% (95% CI: 4.56-8.39); 16.72% (95%CI: 7.38-26.06) among Indigenous and 0.36% (95%CI:-0.14-0.86) in non-Indigenous adults/pregnant women. Since 2000, the pooled HBsAg prevalence was 2.25% (95% CI: 1.26-3.23); 3.96% (95%CI: 3.15-4.77) among Indigenous and 0.90% (95% CI: 0.53-1.28) in non-Indigenous adults/pregnant women.ConclusionsThe disparity of HBsAg prevalence between Indigenous and non-Indigenous people has decreased over time; particularly since the HBV vaccination program in 2000. However HBsAg prevalence remains four times higher among Indigenous compared with non-Indigenous people. The findings highlight the need for opportunistic HBV screening of Indigenous people to identify people who would benefit from vaccination or treatment.

Hepatitis B Virus Epidemiology

“…This was first documented among Aboriginal and Torres Strait Islander people in Australia, leading to HBsAg initially being named the "Australia antigen" (Blumberg et al 1965). However, many other First Peoples-including Maori, Indigenous Taiwanese, Indigenous peoples of the Amazon, Native North Americans, and Inuit peoples of the circumpolar regions-have subsequently been noted to have a higher prevalence of CHB (Mahoney 1999;Harpaz et al 2000;Robinson et al 2005;Viana et al 2005;Weinbaum et al 2008;Graham et al 2013). Other specific ethnic groups have been shown to have a higher prevalence of CHB in countries, such as India (Batham et al 2007) and China (Liang et al 2009).…”

Hepatitis B immunization for indigenous adults, Australia

“…Expert opinion was based on a review of published HBsAg seroprevalence data 8 , 9 , 24 – 28 and published 17 and unpublished hepatitis B vaccination coverage estimates, and was informed by previous experience implementing immunization programmes targeting indigenous Australians. While hepatitis B vaccination coverage in indigenous Australian infants has been consistently high (in the vicinity of 95%) after universal immunization was introduced in the year 2000, 23 , 29 , 30 coverage for adolescents was estimated to have been moderate and for adults was estimated to have been poor.…”

“…A funded universal infant hepatitis B immunization programme was introduced nationally in May 2000 7 . The seroprevalence of hepatitis B virus surface antigen (HBsAg) in indigenous Australian adults was estimated to be 17% in a meta-analysis of studies conducted before 2000, thus meeting the WHO definition for high endemicity 8 . Since then, HBsAg seroprevalence in indigenous Australians is estimated to have declined to 3.7% of the 548 366 population nationally in 2011 9 .…”

“…Indigenous Australians also have a higher prevalence of comorbidities such as type 2 diabetes mellitus and alcohol-related liver disease 10 which are associated with poorer prognosis and more rapid progression of chronic hepatitis B 8 , 9 , 11 , 12 . The incidence of liver cancer is up to 10 times higher compared with non-indigenous Australians 8 , 9 .…”

“…The incidence of liver cancer is up to 10 times higher compared with non-indigenous Australians 8 , 9 . In the light of this increased risk, indigenous Australians have been identified as a priority group for hepatitis B testing and immunization 13 – 15 .…”