A screening for serum markers of arbovirus infections in healthy blood donors from the Volgograd Region

Abstract

Volgograd region is considered to be endemic West Nile fever (WNF) area due to the established circulation of the West Nile virus (WNV) therein. Some previous independent studies examining samples collected on the territory of the Volgograd region revealed markers related to the California serogroup (CSG), Sindbis and Ukuniemi viruses. WNF, CSG, Sindbis and Ukuniemi fever mainly being asymptomatic posing thereby a threat of virus spread due to transfusiological manipulations along with vector-borne transmission are manifested by diverse clinical signs. The study was aimed at detection of antibodies specific to West Nile, tick-borne encephalitis, California serogroup (Tyaginya, Inko), Sidbis, and Ukuniemi viruses in blood donors from the Volgograd region. For this, 404 blood sera samples collected from blood donors residing in the Volgograd as well as the Volgograd region were examined by ELISA. It was found that percentage of blood serum samples positive for arbovirus-specific antibodies was 18.32%. Among the, 67 out of 404 (16.58%) samples contained anti-WNV antibodies, 3 out of 279 (1.08%) samples — to tick-borne encephalitis virus, 1 out of 92 (1.09%) — to California serogroup fever and Ukuniemi viruses, and 2 out of 92 (2.17%) — to Sindbis fever virus. Importantly, the peak number of IgG and IgM WNV-positive samples was found among residents of Volgograd (29 out of 110, 26%) and Oktyabrsky district (7 out of 25, 28%). In addition, anti-Sindbis, Ukuniemi and CSG virus antibodies were detected in blood serum samples from blood donors residing in the Kalachevsky region and the city of Volgograd. Analyzing age-related distribution and percentage of seropositive subjects in each age group showed as follows: the lowest percentage (14.5%) was positive for anti-WNV, Sindbis, Ukuniemi and CSG virus antibodies in blood donors aged 32–41 years, whereas the peak percentage (25%) — in the subjects aged 52–61 years. Thus, virus specific antibodies detected in healthy individuals in the aforementioned region evidence about potential recovery after asymptomatic infections. In this regard, further research is required to determine a role of the such arboviruses in the structure of regional infectious diseases. The data obtained suggest a need to continue serological arbovirus monitoring in the Volgograd region.

Keywords

• arboviruses
• wnv
• sindbis
• ukuniemi fever
• california serogroup
• elisa
• serological monitoring