Prevalence of chronic viral hepatitis B, D among Mongol migrants in Sweden compared to a sex- and age-matched native Mongol cohort

Chronic hepatitis B/D is the most severe form of chronic viral hepatitis, yet public awareness of its burden remains low. This study examined the prevalence of viral hepatitis B and D among Mongol migrants in Sweden and facilitated linkage to care. We conducted a viral hepatitis screening event on January 28th -29th, 2023 at Karolinska University Hospital, Stockholm, for individuals of Mongol descent. Consenting participants underwent blood testing and liver stiffness measurements. The prevalence of viral hepatitis was compared with an age- and sex-matched general population cohort in Mongolia. We screened 850 adult Mongols (mean age (SD) 43.2 ± 8.6 years; 61.9% women). The prevalence of HBsAg+, anti-HDV+, and HDV-RNA + were 4.4%, 2.1%, and 1.3%, respectively. The corresponding prevalences in the matched native Mongol cohort were significantly higher at 9.8%, 5.1%, and 3.7%. Among HBsAg + individuals, 48.6% were anti-HDV+; 61.1% of anti-HDV + individuals had detectable HDV-RNA. Prior HBV infection was identified in 62.9% of participants, 8.7% had evidence of vaccination, and 22.8% were susceptible to HBV infection. Overall, 58 (6.8%) individuals with chronic viral hepatitis were linked to care. Among HBsAg + or anti-HBc + individuals, only 54.1% and 65.8% were aware of their current or past HBV infection, respectively. Anti-HCV + prevalence was 18.6%; 13.3% had detectable HCV-RNA, indicating chronic infection. Mongol migrants had lower prevalences of hepatitis B and D than the general population in Mongolia, but higher than in the Swedish general population. Increased screening efforts are needed to enhance awareness, improve diagnosis and linkage to care for populations at higher risk of chronic viral hepatitis in Sweden and Europe.