All Posts Tagged With: "Ixodes ricinus and"

Link: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=21083369&retmode=ref&cmd=prlinks

Excerpt:

Abstract In a countrywide investigation of the ecological factors that
contribute to Lyme borreliosis risk, a longitudinal study on population
dynamics of the sheep tick Ixodes ricinus and their infections with Borrelia
burgdorferi sensu lato (s.l.) was undertaken at 24 sites in The Netherlands
from July 2006 to December 2007. Study sites were mature forests, dune
vegetations, or new forests on land reclaimed from the sea. Ticks were
sampled monthly and nymphal ticks were investigated for the presence of
Borrelia spp. I. ricinus was the only tick species found. Ticks were found
in all sites, but with significant spatial and temporal variations in
density between sites. Peak densities were found in July and August, with
lowest tick numbers collected in December and January. In some sites,
questing activities of I. ricinus nymphs and adults were observed in the
winter months. 
Mean monthly Borrelia infections in nymphs varied from 0% to 29.0% (range:
0%-60%), and several sites had significantly higher mean nymphal Borrelia
infections than others. Four genospecies of Borrelia burgdorferi s.l. were
found, with B. afzelii being dominant at most sites.
Borrelia infection rates in nymphal ticks collected in July, September, and
November 2006 were significantly higher (23.7%, p < 0.01) than those in the
corresponding months of 2007 (9.9%). 
The diversity in Borrelia genospecies
between sites was significantly different (p < 0.001). Habitat structure
(tree
cover) was an effective discriminant parameter in the determination of
Borrelia infection risk, as measured by the proportion of nymphal ticks
infected with B.
burgdorferi s.l. Thickness of the litter layer and moss cover were
positively related to nymphal and adult tick densities. The study shows that
Borrelia-infected ticks are present in many forest and dune areas in The
Netherlands and suggests that in such biotopes, which are used for a wide
variety of recreational activities, the infection risk is high.