First detection of spotted fever group rickettsiae in Ixodes ricinus and Dermacentor reticulatus ticks in the UK

Published Date
Journal
Epidemiology and Infection
Citation
Epidemiol Infect. 2011 Apr;139(4):524-9
DOI
10.1017/S0950268810002608
Authors
Tijsse-Klasen E
Jameson LJ
Fonville M
Leach S
Sprong H
Medlock JM
Abstract

A preliminary study was conducted to determine the presence of spotted fever rickettsiae in two species of British tick (Ixodes ricinusand Dermacentor reticulatus). The 16S rRNA gene of Rickettsia spp. was detected in 39/401 (9·7%) of ticks tested, including 22/338 (6·5%) I. ricinus and 17/63 (27%) D. reticulatus. Some positive I. ricinus samples showed 100% homology with Rickettsia helvetica (10/22), and most positive D. reticulatus showed 100% homology with R. raoultii (13/17). Five other Rickettsia spp. were detected exhibiting 96-99% homology. Ticks positive for rickettsiae were collected from various hosts and from vegetation from eight counties across Great Britain. The distribution of R. helvetica in various engorged and unfed stages of I. ricinus suggests that R. helvetica is widespread. R. raoultii was found in questing adult D. reticulatus in Wales and England. This is the first evidence of potentially pathogenic spotted fever rickettsiae in British ticks.