Rotavirus severe disease in children is now vaccine-preventable and the roll-out of vaccination programs globally is expected to make a significant impact in the reduction of morbidity and mortality in children <5. years of age. Rotavirus is also a pathogen of other mammals and birds, and its segmented RNA genome can lead to the emergence of new or unusual strains in human population via interspecies transmission and reassortment events. Despite the efficacy and impact of rotavirus vaccine in preventing severe diarrhea, the correlates of protection remain largely unknown. Therefore, rotavirus strain surveillance before, during and after the introduction of immunization programs remains a crucial for monitoring rotavirus vaccine efficacy and impact. In this context, molecular characterization of 1323 Bulgarian rotavirus strains collected between June 2010 and May 2013 was performed. A total of 17 strains of interest were analyzed by partial sequence analysis. Twelve strains were characterized as G3P and G6P of potential animal origin. Phylogenetic analysis and comparisons with the same specificity strains detected sporadically between 2006 and 2010 revealed the constant circulation of these unusual human strains in Bulgaria, although in low prevalence, and their increased potential for person-to-person spread.
Bibliographical noteFunding Information:
The study was funded by European Rotavirus Surveillance Network – EuroRotaNet project and partially by NCIPD (for RV screening of the stool samples). We thank Maria Georgieva (NRLDV, NCIPD), all staff of Specialized Hospital for Active Treatment of Infectious and Parasitic Diseases (Sofia) and University Hospital “St. George” (Plovdiv), and all the colleagues who contributed to the Bulgarian Rotavirus Surveillance Project.
© 2014 Elsevier B.V.
Copyright 2014 Elsevier B.V., All rights reserved.
- Human strain
- Rotavirus vaccine
- Zoonotic transmission