The natural focus of tick-borne encephalitis of sheep and man in the Rhodope mountains (Bulgaria)
Pavlov, P.; Daniel, M.; Georgiev, B.; Kolman, J.M.; Rashev, K.H.; Arnaudov, D.; Ignatov, D.
Folia Parasitologica 19(1): 33-40
1972
ISSN/ISBN: 0015-5683 PMID: 4670805 Document Number: 51213
This paper reports the results of a five-year investigation of a focus of tick-borne encephalitis in the dobrostan area (plovdiv). Clinical disease had been observed in sheep and goats for a number of years, and several human cases of tick-borne encephalitis had been diagnosed. Tick-borne encephalitis virus strains isolated from Haemaphysalis punctata and Dermacentor marginatus were antigenically similar to the standard Hypr strain. Antibody was demonstrated in 54% of 152 sheep and 22% of 205 goats. The brain tissue of four goats and 506 small mammals was negative. Of 15 sheep and two goats brought into the area and exposed to natural infection, five sheep developed signs of infection; one of these exhibited severe clinical symptoms and yielded the virus from the blood and from ticks feeding on it.