Influence of climatic factors on tick-borne encephalitis incidence in the Czech Republic

Abstract number: P1840

Daniel M., Kriz B., Danielová V., Valter J., Kott I.

Objectives: The major objective was to find out whether there exist any demonstrable relationships between the incidence of human tick-borne encephalitis (TBE) infections and meteorological factors, to specify their character and make an attempt at an interpretation of the action of the latter.

Methods: Epidemiological data were extracted from the EPIDAT database (National Institute of Public Health, Prague). The basic datum characterising each case was the date of primary symptoms, whereby in comparisons with the course of the weather enabling to respect the incubation period (since the attachment of an infected tick). Analysed was a total of 4613 cases of disease in 1994–2001. The results obtained were compared with those in later years.

Meteorological data were from the database of the Czech Hydrometeorological Institute in Prague. That contained data (9 parameters) from 22 selected stations located in a region of the Czech Republic known for its continued incidence of TBE.

Statistical methods testing the relationship between TBE occurrence as a dependent variable with meteorological factors in the role of predictor, were carried out with the aid of the STATISTICA6 package.

Results: A linear relationship has been found between TBE incidence and temperature factors in all the years under study. Quadratic relations (with a shift in time by 6–15 days with respect to incubation of the infection) were demonstrably better in precipitation, relative humidity of the air and soil. In the period under follow-up, vast year-to-year differences in weather characteristics were observed over the warm period. In combination with data on TBE incidence it was possible in each year under follow-up to identify an extraordinary in character period of time fundamentally influencing this infection.

Conclusions: Effects of the current course of the meteorological situation (as well as long-term year-to-year changes) on TBE incidence are foremost mediated by the influence of climatic factors on Ixodes ricinus ticks and their host-seeking activity. These mutual connections have been demonstrated in parallel a long-term monitoring of this vector and the manifested human TBE virus infections. Under certain conditions there also have to be taken into account the effects the momentary meteorological situation has on human behaviour in as TBE in the Czech Republic is a recreational infection.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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