The study of the genetic diversity of HBV among international migrants was completed at the Saint-Petersburg Pasteur Institute. The study shows that routine screening for hepatitis B surface antigen (HBsAg) underestimates the true scale of the problem: the proportion of individuals with negative HBsAg but detectable HBV DNA in their blood (occult hepatitis B infection) was comparable to overt (HBsAg-positive) cases. Moreover, the majority of these cases lack any serological markers for HBV, making them invisible to current screening protocols.
Molecular analysis revealed a wide range of imported genotypes — from the dominant genotype D in the region to the rare B4 and C2 genotypes imported from Southeast Asia. A substantial proportion of the samples contained mutations in epitopes responsible for virus recognition by the immune system, as well as markers of resistance to certain nucleos(t)ide analogues. These data indicate the circulation of clinically significant variants capable of escaping immune surveillance and standard therapy.
The authors emphasize that the lack of screening for hepatitis B and C within the mandatory medical examination for migrants creates an undetected transmission and requires a policy review. The introduction of molecular diagnostic methods into this system will enable early detection of occult forms of the disease and enhance epidemiological safety.
The article “Genetic Diversity, Occult Hepatitis B, and Mutational Signatures in Migrants from Regions with Varying HBV Endemicity: Importation of Diverse Viral Variants into St. Petersburg, Russia” was published in the International Journal of Molecular Sciences. Authors: Elena N. Serikova, Yulia V. Ostankova, Alexandr N. Shchemelev, Nadezhda A. Pechnikova, Edward S. Ramsay и Areg A. Totolian.