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

Background & Aims Chronic hepatitis B/D is the most severe chronic hepatitis, yet public awareness of its burden remains low. This study examines the prevalence of viral hepatitis B/D among Mongol migrants in Sweden with possible linkage to care. Methods A screening event for viral hepatitis was conducted on the 28th − 29th January 2023 at Karolinska University Hospital, Stockholm for individuals of Mongol descent. Consented participants underwent blood tests and liver stiffness measurements. The prevalence of viral hepatitis was compared to an age, sex-matched general population cohort in Mongolia with blood samples. Results In total, 850 adult Mongols, aged mean (SD) 43·2 ± 8·6 years and 61·9% women were screened. The prevalence of HBsAg+, anti-HDV+, and HDV-RNA + were 4.4%, 2.1%, and 1.3%, respectively. The corresponding figures were 9.8%, 5.1%, and 3.7% in the matched cohort in Mongolia. Persons with anti-HDV + constituted 48.6% of HBsAg+ (18/37), and 61.1% among anti-HDV + were HDV-RNA+ (11/18). Prior HBV infection was seen in 65.8%, 8.7% were vaccinated, and 21.6% were susceptible to HBV infection. In total, 58 (6.8%) persons with chronic viral hepatitis were linked to care. Of HBsAg + or anti-HBc+, 54.1% and 65.8% were aware of current or past HBV infection, respectively. Conclusion Mongol migrants had lower prevalence of hepatitis B, and D compared to Mongolia, but higher than the Swedish general population. More screening efforts are needed to reinforce the awareness, diagnosis, and improve linkage to care of populations at higher risk of chronic viral hepatitis in Sweden and Europe.