Probability models of the rate of infection with tick-borne encephalitis virus in Ixodes persulcatus ticks
Korenberg, E.I.; Horáková, M.; Kovalevsky, J.V.; Hubálek, Z.; Karavanov, A.S.
Folia Parasitologica 39(1): 85-92
1992
ISSN/ISBN: 0015-5683 PMID: 1644355 Document Number: 403519
A total of 3254 adults of I. persulcatus were collected in a taiga forest habitat situated in the Amgun river basin (Khabarovsk region, Russia) and examined individually for tick-borne encephalitis virus. The overall proportion of infected ticks was 6.6% and it varied between 3.4% and 9.4% during 1982-85. The amount of virus per tick was estimated by the gamma distribution, determining a probability that the number of plaque-forming units (PFU) per tick was not greater than a selected value. The number of infected ticks followed the negative binomial distribution, enabling the estimation of the number of infected ticks in the area. However, the parameters of both probability models (i.e. the PFU content per tick and the frequency of infected ticks) varied for particular years.