Ixodes density and infection prevalence of Bb in Switzerland

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Yvonne
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Ixodes density and infection prevalence of Bb in Switzerland

Post by Yvonne » Thu 2 Aug 2007 16:22

Vector Borne Zoonotic Dis. 2007 Spring

Ixodes ricinus density and infection prevalence of Borrelia burgdorferi sensu lato along a North-facing altitudinal gradient in the Rhône Valley (Switzerland)

Burri C, Cadenas FM, Douet V, Moret J, Gern L.
Institut de Biologie, University of Neuchâtel, Switzerland.

Questing Ixodes ricinus ticks were sampled monthly along a north-facing altitudinal gradient in the canton of Valais, Switzerland, from March 2004 to February 2005. Tick density and infection with Borrelia burgdorferi sensu lato were monitored. Ticks were collected by flagging vegetation at three different altitudes (750 m, 880 m, and 1020 m above sea level). Ticks were examined for Borrelia by polymerase chain reaction (PCR) followed by reverse line blot. At the three altitudes, questing tick activity was not observed under 10 degrees C and was reduced when saturation deficit was higher than 5 mm Hg, most questing tick activity was occurred between 2 mm Hg and 7 mm Hg. Tick density and peak tick density were highest at 1020 m. High saturation deficits at the lowest altitudes appear to impair the tick population. The prevalence of B. burgdorferi infection in nymphs and adults decreased with altitude. The prevalence of infection was higher in adult ticks (47%) than in nymphs (29%). Four B. burgdorferi sensu lato genospecies were detected: B. afzelii (40%), B. garinii (22%), B. valaisiana (12%) and B. burgdorferi sensu stricto (6%). Mixed infections were detected in 13% of infected ticks.

PMID: 17417957
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Yvonne
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Re: Ixodes density and infection prevalence of Bb in Switzerland

Post by Yvonne » Tue 25 Mar 2008 15:32

Int J Med Microbiol. 2008 Mar 14 [Epub ahead of print] Links

Influence of some climatic factors on Ixodes ricinus ticks studied along altitudinal gradients in two geographic regions in Switzerland.

Gern L, Morán Cadenas F, Burri C.
Institut de Biologie, Emile-Argand 11, CH-2009 Neuchâtel, Switzerland.

In the context of climate change, the seasonal activity of questing Ixodes ricinus and their infection with Borrelia burgdorferi sensu lato (s.l.) were examined in relation to some climatic data along altitudinal gradients in Switzerland. The first study took place in an Alpine area (Valais) from 750 to 1020m above sea level. The other gradient was located on a mountain in the foothills of the Jura chain (Neuchâtel) from 620 to 1070m above sea level. In the Alpine area, the highest questing tick density was observed at the highest altitude. At the lowest altitudes (750 and 880m), very high saturation deficits, >10mmHg, were present during most of the tick activity season and they seem to have impaired the thriving of tick populations. The second study in Neuchâtel (2003-2005) was a follow-up of a previous study (1999-2001) in which it was observed that tick density decreased with increasing altitude. During the follow-up study, substantial differences in questing tick density and phenology of ticks were observed: At high elevations, questing tick densities were 2.25 and 3.5 times higher for nymphs and adults, respectively, than during 1999-2001. As observed during 1999-2001, questing tick density decreased with increasing altitude in this site in 2003-2005. Tick questing density remained higher at the lowest altitude. Increased temperatures during summer months, more favorable for ticks, reaching values similar to those registered in the first study at the lowest elevations are probably responsible for the higher tick questing density at high altitudes. B. burgdorferi s.l. infection prevalence in ticks decreased with increasing altitudes along both altitudinal gradients. Long-lasting high saturation deficit values may limit the development of tick populations as too high a moisture stress has a negative effect on tick survival. This factor may have a permanent impact, as it is probably the case at the lowest altitudes in the Alpine area or a more transient effect like in the Neuchâtel gradient.

PMID: 18343724
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Yvonne
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Re: Ixodes density and infection prevalence of Bb in Switzerland

Post by Yvonne » Fri 6 Jun 2008 16:42

PRESENCE OF POTENTIALLY PATHOGENIC BABESIA SP. FOR HUMAN IN IXODES RICINUS IN SWITZERLAND

Abstract:
We have designed and performed a new PCR method based on the 18S
rRNA in order to individuate the presence and the identity of Babesia parasites. Out of
1159 Ixodes ricinus (Acari: Ixodidae) ticks collected in four areas of Switzerland, nine
were found to contain Babesia DNA. Sequencing of the short amplicon obtained (411-
452 bp) allowed the identification of three human pathogenic species: Babesia microti,
B. divergens, for the first time in Switzerland, Babesia sp. EU1. We also report coinfections
with B. sp. EU1-Borrelia burgdorferi sensu stricto and Babesia sp. EU1-B. afzelii.

http://www.aaem.pl/pdf/13065.pdf
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Yvonne
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Re: Ixodes density and infection prevalence of Bb in Switzerland

Post by Yvonne » Sun 6 Sep 2009 13:51

Power Point Presentation

Tick- borne infections and pathogenic agents identified in ticks of Switzerland:

http://www.swiss-paediatrics.org/agenda ... ues-en.pdf
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