Preventing early childhood transmission of hepatitis B in remote Aboriginal communities in northern Australia

Abstract

Background Chronic hepatitis B is a public health concern in Aboriginal communities in the Northern Territory of Australia with prevalence almost four times the non-Aboriginal population. Infection is suspected to mainly occur in early life, however, the mode of transmission and vaccine effectiveness is not known in this population. WHO has set a target for hepatitis B elimination by 2030; elimination in this disproportionately affected population in Australia will require understanding of the modes of transmission and vaccine effectiveness. Methods We conducted the study at four very remote Aboriginal communities. We approached mothers who had chronic hepatitis B and had given birth between 1988 and 2013 for consent. We obtained hepatitis B serology, immunisation and birth details from the medical record. If both mother and child had hepatitis B viral DNA detected, we performed viral whole genome sequencing. Results We approached 45 women for consent, of whom 23 agreed to participate. We included 20 mothers and 38 of their children. Of the 20 included mothers, 5 (25%) had children who were hepatitis B immune by exposure and 3 (15%) had children with evidence of chronic hepatitis B infection at the time of assessment. Hepatitis B immunoglobulin (HBIg) had been given at birth in 29/38 (76.3, 95% CI 59.8–88.6) children, and 26 children (68.4, 95% CI 51.3–82.5) were fully vaccinated. Of the 3 children who had chronic hepatitis B, all had received HBIg at birth and two were fully vaccinated. Of the 5 who were immune by exposure, 4 had received HBIg at birth and one was fully vaccinated. Whole genome sequencing revealed one episode of definite mother to child transmission. There was also one definite case of horizontal transmission. Conclusions Chronic hepatitis B in this context is a sensitive issue, with a high proportion of women refusing consent. Although uncommon, there is ongoing transmission of hepatitis B to Aboriginal children in remote northern Australia despite vaccination, and this is likely occurring by both vertical and horizontal routes. Prevention will require ongoing investment to overcome the many barriers experienced by this population in accessing care.

Health workers’ perspectives of hepatitis B-related stigma among Aboriginal and Torres Strait Islander people in New South Wales, Australia

“…Aboriginal and Torres Strait Islander people represent 3.2% of the Australian population [ 19 ], yet estimates suggest that 7% of the population of people living with chronic HBV are Aboriginal and Torres Strait Islander people [ 15 , 20 ]. Rates of HBV overall are declining in Australia due to universal vaccination [ 21 ], but despite this HBV notifications were more than one and a half times higher among Aboriginal and Torres Strait Islander compared to non-Aboriginal or Torres Strait Islander people in Australia in 2020 [ 20 ], and some researchers suggest that transmissions may be occurring both vertically and horizontally among Aboriginal and Torres Strait Islander children [ 22 ].…”

An evaluation and refinement of the “Hep B Story” app, tailored to meet the community’s cultural needs

“…Despite the consensus that it was inappropriate for men to engage in the subject of women's business, there was agreement that the information relating to hepatitis B transmission was important. This was especially relevant in the NT context, where the primary mode of hepatitis B transmission is in early childhood, including mother-tochild [32]. The app's original design intentionally featured a dedicated section on women's business, requiring deliberate selection to access the information, ensuring men would not accidentally encounter it.…”

“Putting the power back into community”: A mixed methods evaluation of a chronic hepatitis B training course for the Aboriginal health workforce of Australia’s Northern Territory

“…In high CHB prevalence areas, such as the NT, the main route of HBV transmission is perinatal exposure at birth or in early childhood [ 15 ]. Given the life-long nature of CHB, there needs to be a shift away from specialist care and into a primary health care (PHC) model [ 16 ].…”