[Study of combined foci of mosquito-transmitted arbovirus infections]

A total of 5227 serum specimens from humans, horses and swine collected in the seasons of 1968--1976 in 15 administrative areas of the Primorskiy Kray were examined with antigens of a number of mosquito-borne arboviruses: Japanese encephalitis (JE), West Nile (WN), Getah, and Sindbis. Both independent and combined circulation of these viruses in the region was established. Sindbis virus was found to be circulating separately most frequently, West Nile virus the least frequently. According to the results of the serological analysis, the conditions for combined circulation are most closely related for JE and Getah, and JE and WN viruses. The interpretation of the results of examinations of the sera reacting simultaneously with JE and WN virus is most difficult because of close antigenic relationship of these viruses. A set of methods for serological differentiation of bivalent sera to JE and WN viruses and the criteria for the assessment of the results are recommended.