The aim of this review is to follow the history of studies on endemiv arboviruses and the diseases they cause which were detected in the Czech lands (Bohemia, Moravia and Silesia (i.e., the Czech Republic)). The viruses involve tick-borne encephalitis, West Nile and Usutu flaviviruses; the Sindbis alphavirus; Ťahyňa, Batai, Lednice and Sedlec bunyaviruses; the Uukuniemi phlebovirus; and the Tribeč orbivirus. Arboviruses temporarily imported from abroad to the Czech Republic have been omitted. This brief historical review includes a bibliography of all relevant papers.

• Keywords
• arthropods, birds, mammals, mosquitoes, ticks,
• MeSH
• Arbovirus Infections history   MeSH
• Arboviruses physiology   MeSH
• History, 20th Century MeSH
• History, 21st Century MeSH
• Humans MeSH
• Animals MeSH
• Check Tag
• History, 20th Century MeSH
• History, 21st Century MeSH
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Historical Article MeSH
• Review MeSH
• Geographicals
• Czech Republic epidemiology   MeSH

Tick-borne encephalitis (TBE) is a serious acute neuroinfection of humans caused by a tick-borne flavivirus. The disease is typically seasonal, linked to the host-seeking activity of Ixodes ricinus (predominantly nymphs), the principal European tick vector species. To address the need for accurate risk predictions of contracting TBE, data on 4,044 TBE cases reported in the Czech Republic during 2001-2006 were compared with questing activity of I. ricinus nymphs monitored weekly at a defined location for the same 6-year period. A time shift of 21 days between infected tick bite and recorded disease onset provided the optimal model for comparing the number of cases of TBE with numbers of questing nymphs. Mean annual distribution of TBE cases and tick counts showed a similar bimodal distribution. Significantly, the ratio of TBE cases to questing nymphs was highest in the summer-autumn period even though the number of questing nymphs peaked in the spring-summer period. However, this pattern changed during a period of extreme meteorological events of flooding and abnormally high temperatures, indicating that changes in climate affect the incidence of TBE. Previous studies failed to link human behavior with changes in incidence of TBE but showed extrinsic temperature impacts arbovirus replication. Hence, we hypothesize the apparent discrepancy between peak nymphal tick activity and greatest risk of contracting TBE is due to the effect of temperature on virus replication in the tick vector. Relative proportions of questing nymphs and the numbers of weeks in which they were found were greater in summer-autumn compared with spring-summer at near-ground temperatures >5°C and at standard day and weekly average temperatures of >15°C. Thus, during the summer-autumn period, the virus dose in infected tick bites is likely greater owing to increased virus replication at higher microclimatic temperatures, consequently increasing the relative risk of contracting TBE per summer-autumn tick bite. The data support the use of weather-based forecasts of tick attack risk (based on daytime ambient temperature) supplemented with weekly average temperature (as a proxy for virus replication) to provide much-needed real-time forecasts of TBE risk.

• Keywords
• Ixodes ricinus, TBEV, arbovirus, climate change, seasonality, tick-borne encephalitis,
• MeSH
• Arachnid Vectors physiology   virology   MeSH
• Incidence MeSH
• Ixodes physiology   virology   MeSH
• Encephalitis, Tick-Borne epidemiology   transmission   virology   MeSH
• Humans MeSH
• Weather MeSH
• Seasons MeSH
• Temperature MeSH
• Encephalitis Viruses, Tick-Borne genetics   isolation & purification   physiology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Czech Republic epidemiology   MeSH

The objective was to discover whether there any demonstrable relationships exist between the incidence of human tick-borne encephalitis (TBE) cases and current meteorological factors and to specify their character. Epidemiological data were extracted from the EPIDAT database (National Institute of Public Health, Prague). Analyzed were a total of 4,613 TBE cases registered in the whole Czech Republic (1994-2001) and 4,637 cases registered in the territory of Bohemia (1994-2004). Meteorological data were from the database of the Czech Hydrometeorological Institute in Prague. A linear relationship has been found between TBE incidence and temperature factors in all the years under study. Lagged cross correlation was used (with the lags in time respective to incubation period from infected tick attack to initial TBE symptoms) and close relations were found for daily mean air temperature and lags 6-14 days (with a peak of 9 days). 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; under certain conditions, also by the effects of momentary weather on human behavior as TBE in the Czech Republic is a recreational disease connected with outdoor activities.

• MeSH
• Incidence MeSH
• Ixodes growth & development   MeSH
• Encephalitis, Tick-Borne epidemiology   MeSH
• Humans MeSH
• Meteorological Concepts * MeSH
• Statistics as Topic MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic epidemiology   MeSH