Ticks are important human and animal parasites and vectors of many infectious disease agents. Control of tick activity is an effective tool to reduce the risk of contracting tick-transmitted diseases. The castor bean tick (Ixodes ricinus) is the most common tick species in Europe. It is also a vector of the causative agents of Lyme borreliosis and tick-borne encephalitis, which are two of the most important arthropod-borne diseases in Europe. In recent years, increases in tick activity and incidence of tick-borne diseases have been observed in many European countries. These increases are linked to many ecological and anthropogenic factors such as landscape management, climate change, animal migration, and increased popularity of outdoor activities or changes in land usage. Tick activity is driven by many biotic and abiotic factors, some of which can be effectively managed to decrease risk of tick bites. In the USA, recommendations for landscape management, tick host control, and tick chemical control are well-defined for the applied purpose of reducing tick presence on private property. In Europe, where fewer studies have assessed tick management strategies, the similarity in ecological factors influencing vector presence suggests that approaches that work in USA may also be applicable. In this article we review key factors driving the tick exposure risk in Europe to select those most conducive to management for decreased tick-associated risk.
- MeSH
- hodnocení rizik MeSH
- klíště * patogenita MeSH
- klíšťová encefalitida * terapie MeSH
- lidé MeSH
- lymeská nemoc * terapie MeSH
- nemoci přenášené klíšťaty * terapie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Geografické názvy
- Evropa MeSH
The altitudinal shift in the limit of Ixodes ricinus occurrence above the previously established altitude of 750 m above sea level has been monitored over the long-term (2002-2008) in the Krkonose Mts. (Giant Mts.), the highest in the Czech Republic, along two vertical transects in their eastern and central parts (600-1020 and 600-1270 m). Ticks were collected by flagging three times annually, and examined individually by PCR or RT-PCR for the presence of Borrelia burgdorferi sensu lato or tick-borne encephalitis virus (TBEV). A total of 5999 I. ricinus ticks were tested. TBEV RNA was detected in 26 ticks at up to 1140 m. Demonstration of TBEV in two larvae of I. ricinus indicates transovarial transmission. Similar infection rates in larvae and nymphs show vertical transmission in TBEV circulation to be very important under these mountain conditions. B. burgdorferi sensu stricto was found at up to 1040-1065 m, Borrelia garinii and Borrelia afzelii up to 1080-1140 m, and Borrelia valaisiana up to 1270 m. The total infection rates of nymphs and larvae were 7.3% and 2%, respectively. B. garinii was the most prevalent (37%), followed by B. afzelii (29%), B. burgdorferi s.s. (11%), and B. valaisiana (9%). Double to quadruple coinfections were detected in 32% of the infected ticks, most frequently B. garinii/B. afzelii. Predominance of B. garinii and B. valaisiana over B. afzelii suggests that small passerine birds moving on the ground are responsible for permanent local populations of I. ricinus in mountain localities with low numbers of small terrestrial mammals. The detection of B. burgdorferi sensu lato and TBEV in host-seeking larvae indicates an autochthonic infection. Upon analysis of the local climate we consider climate warming to be responsible for the spreading of ticks and tick-transmitted pathogens to higher altitudes.
- MeSH
- arachnida jako vektory mikrobiologie virologie MeSH
- Borrelia burgdorferi komplex fyziologie MeSH
- ekosystém MeSH
- genotyp MeSH
- klíště mikrobiologie virologie MeSH
- nadmořská výška MeSH
- viry klíšťové encefalitidy fyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
An attenuated strain (263) of the tick-borne encephalitis virus, isolated from field ticks, was either serially subcultured, 5 times in mice, or at 40 degrees C in PS cells, producing 2 independent strains, 263-m5 and 263-TR with identical genomes; both strains exhibited increased plaque size, neuroinvasiveness and temperature-resistance. Sequencing revealed two unique amino acid substitutions, one mapping close to the catalytic site of the viral protease. These observations imply that virus adaptation from ticks to mammals occurs by selection of pre-existing virulent variants from the quasispecies population rather than by the emergence of new random mutations. The significance of these observations is discussed.
- MeSH
- financování organizované MeSH
- genetika MeSH
- klíšťata virologie MeSH
- klíšťová encefalitida mortalita patofyziologie virologie MeSH
- kojená zvířata MeSH
- molekulární modely MeSH
- mozek virologie MeSH
- mutace MeSH
- myši inbrední ICR MeSH
- myši MeSH
- RNA-helikasy genetika chemie MeSH
- sekvence aminokyselin MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- selekce (genetika) MeSH
- serinové endopeptidasy genetika chemie MeSH
- sériové pasážování MeSH
- substituce aminokyselin MeSH
- virové nestrukturální proteiny genetika chemie MeSH
- virulence MeSH
- viry klíšťové encefalitidy genetika izolace a purifikace patogenita MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Geografické názvy
- Evropa MeSH
