Incidence of hemagglutination-inhibiting antibodies for Bhanja virus in humans along the north-west border of Yugoslavia.

By the hemagglutination-inhibition test with the Yugoslav strain of Bhanja virus, the sera of 380 youngsters residing in the region along the Yugoslav-Hungarian border (North Croatia) and 367 sera from newcomers to the area from various parts of Yugoslavia were examined. The testing included 154 sera of the youngsters who had came to the region along the Yugoslav-Italian border (Slovenia) without antibodies for Bhanja virus and were staying there for a year. Hemagglutination-inhibiting antibodies for BHA virus were found in the sera of 5.53% examined natives of North Croatia, while in the newcomers after one-year stay in the area HI antibodies for the virus were confirmed in 3.27% of the sera examined. HI antibodies for BHA virus were found in 1.95% sera of the 154 youngsters who had come to the study area along the Yugoslav-Italian border (after one-year stay in the area). These results suggest a recent circulation of Bhanja virus in the regions studied. It is important to point out that the presence of the tick Haemaphysalis punctata, the principal vector of Bhanja virus in Europe, was evidenced in both regions.