Prevalence of Borrelia burgdorferi in Ixodes ricinus ticks in urban recreational areas of Helsinki

Citation
T. Junttila et al., Prevalence of Borrelia burgdorferi in Ixodes ricinus ticks in urban recreational areas of Helsinki, J CLIN MICR, 37(5), 1999, pp. 1361-1365
Citations number
36
Categorie Soggetti
Clinical Immunolgy & Infectious Disease",Microbiology
Journal title
JOURNAL OF CLINICAL MICROBIOLOGY
ISSN journal
00951137 → ACNP
Volume
37
Issue
5
Year of publication
1999
Pages
1361 - 1365
Database
ISI
SICI code
0095-1137(199905)37:5<1361:POBBII>2.0.ZU;2-6
Abstract
Lyme borreliosis, an infection caused by the tick-borne spirochete Borrelia burgdorferi, is a major health problem for populations in areas of endemic ity in the Northern Hemisphere. In the present study we assessed the densit y of ticks and the prevalence of B, burgdorferi sensu late among ticks in p opular urban recreational areas of Helsinki, Finland, Altogether 1,688 Ixod es ricinus ticks were collected from five areas located within 5 km of the downtown section of Helsinki, and 726 of them (303 nymphs, 189 females, and 234 males) were randomly chosen for laboratory analysis. The midguts of th e ticks were divided into three pieces, one for dark-field microscopy, one for cultivation in BSK-II medium, and one for PCR analysis. Ticks were foun d in all the study areas; their densities varied from I to 36 per 100 m alo ng which a cloth was dragged. The rate of tick infection with B, burgdorfer i sensu lato varied from 19 to 55%, with the average being 32%. Borellia af zelii was the most predominant genospecies in all the areas, and no B. burg dorferi sensu stricto isolates were detected. Only two ticks were concurren tly infected with both B. afzelii and Borrelia garinii, Dark-field microsco py gave more positive results for B. burgdorferi than did cultivation or PC R analysis. However, the agreement between all three methods was fairly goo d. We conclude that Lyme borreliosis can be contracted even in urban enviro nments not populated with large mammals like deer or elk. The disease shoul d be taken into account in the differential diagnosis of certain symptoms o f patients from these areas, and the use of measures to improve the awarene ss of the general population and health care officials of the risk of contr acting the disease is warranted.