Serological Evidence of Hepatitis E Virus Circulation Among Reindeer and Reindeer Herders.

Various deer species are infected with hepatitis E virus (HEV) and may be a source of zoonotic infection for humans. So far, HEV has not been isolated from reindeer and the role of this domesticated deer species in HEV transmission is unknown. We tested serum samples from 191 reindeer (Rangifer tarandus) and 86 adult reindeer herders from the circumpolar regions of Yakutia (Russian Federation) for anti-HEV and HEV RNA. Anti-HEV IgG prevalence was 12.0% (95% confidence interval [95% CI]: 8.1-17.5) in reindeer and 4.7% (95% CI: 1.5-11.7) in reindeer herders. The latter was similar to the positivity rate observed in adult residents of the city of Yakutsk, the capital of Yakutia, who do not have routine contact with reindeer (3.7% [19/519, 95% CI: 2.3-5.7]). No samples positive for HEV RNA were identified. The study provides evidence of HEV circulation in reindeer. Nevertheless, the low seroprevalence in reindeer herders indicate a low risk of zoonotic HEV infection.

Coverage with Timely Administered Vaccination against Hepatitis B Virus and Its Influence on the Prevalence of HBV Infection in the Regions of Different Endemicity.

Universal hepatitis B vaccination of newborns was implemented in Russia starting from 1998. From 1998 to 2019, the incidence of acute hepatitis B reduced from 43.8 to 0.57 cases per 100,000 population. Here, we assessed the timely coverage of newborns with the birth dose (HepB-BD), second dose (HepB-2nd), and three vaccine doses (HepB3) in two remote regions of Russia with low (Belgorod Oblast) and high (Yakutia) levels of hepatitis B virus (HBV) endemicity. Vaccination data were obtained from the medical records of 1000 children in Yakutia and 2182 children in Belgorod Oblast. Sera of healthy volunteers from Belgorod Oblast (n = 1754) and Yakutia (n = 1072) across all age groups were tested for serological markers of HBV to assess the infection prevalence and herd immunity. Average HepB-BD coverage was 99.2% in Yakutia and 89.4% in Belgorod Oblast (p < 0.0001) and in both regions varied significantly, from 66% to 100%, between medical centers. The principal reason for the absence of HepB-BD was parent refusal, which accounted for 63.5% of cases of non-vaccination (83/123). While timely HepB-2nd coverage was only 55.4%-64.7%: HepB3 coverage by the age of one year exceeded 90% in both study regions. HBV surface antigen (HBsAg) prevalence in the 1998-2019 birth cohort was 0.2% (95% CI: 0.01-1.3%) in Belgorod Oblast and 3.2% (95% CI: 1.9-5.2%) in Yakutia. The proportion of persons testing negative for both antibodies to HBsAg (anti-HBs) and antibodies to HBV core antigen (anti-HBc) in the 1998-2019 birth cohort was 26.2% (125/481) in Belgorod Oblast and 32.3% (162/501) in Yakutia. We also assessed the knowledge of and attitude towards vaccination among 782 students and teachers of both medical and non-medical specialties from Belgorod State University. Only 60% of medical students knew that hepatitis B is a vaccine-preventable disease. Both medical and nonmedical students, 37.8% and 31.3%, respectively, expressed concerns about safety and actual necessity of vaccination. These data indicate the need to introduce a vaccine delivery audit system, improve medical education with respect to vaccination strategies and policies, and reinforce public knowledge on the benefits of vaccination.