Following reports of human cases of Lyme borreliosis from the Ossola Valley, a mountainous area of Piemonte, north-western Italy, the abundance and altitudinal distribution of ticks, and infection of these vectors with Borrelia burgdorferi sensu lato were evaluated.
A total of 1662 host-seeking Ixodes ricinus were collected by dragging from April to September 2011 at locations between 400 and 1450 m above sea level. Additional 104 I. ricinus were collected from 35 hunted wild animals (4 chamois, 8 roe deer, 23 red deer).
Tick density, expressed as the number of ticks per 100 m(2), resulted highly variable among different areas, ranging from 0 to 105 larvae and from 0 to 22 nymphs. A sample of 352 ticks (327 from dragging and 25 from wild animals) was screened by a PCR assay targeting a fragment of the 16S rRNA gene of B. burgdorferi s.l.
Positive samples were confirmed with a PCR assay specific for the 5S-23S rRNA intergenic spacer region and sequenced. Four genospecies were found: B. afzelii (prevalence 4.0%), B. lusitaniae (4.0%), B. garinii (1.5%) and B. valaisiana (0.3%). Phylogenetic analysis based on the ospC gene showed that most of the Borrelia strains from pathogenic genospecies had the potential for human infection and for invasion of secondary body sites.
© 2014 The Authors. Zoonoses and Public Health published by Blackwell Verlag GmbH.
Source: Pintore MD1, Ceballos L2, Iulini B1, Tomassone L2, Pautasso A1, Corbellini D1, Rizzo F1, Mandola ML1, Bardelli M3, Peletto S1, Acutis PL1, Mannelli A2, Casalone C1. Zoonoses Public Health. 2015 Aug;62(5):365-74. doi: 10.1111/zph.12156. Epub 2014 Sep 15.