title: Borrelia burgdorferi sensu lato infection in larval Ixodes ricinus (Acari: Ixodidae) feeding on blackbirds in northwestern Italy.
abstract: Birds belonging to 59 species (n = 1,206) were live captured in Piemonte, northwestern Italy, in 2001. Ixodes ricinus (L.) larvae were collected from 59 birds belonging to nine species, and nymphs were recovered on 79 birds belonging to 10 species. Eurasian blackbirds, Turdus merula L., had significantly higher levels of infestation by ticks than other passerine species. Larval I. ricinus of blackbirds peaked in summer, when prevalence was 39% (95% confidence interval 24.2-55.5) and mean number of ticks per host was 3.3 (1.6-7.2), whereas nymphs peaked in spring, when prevalence was 72.2% (54.8-85.8) and mean number of ticks per host was 6.9 (4.4-10.7). Immature I. ricinus were coincidentally aggregated on blackbirds, with 15 blackbirds feeding 67.4% of nymphs and 40.3% of larvae, and coinfestation by both stages was relatively high in summer: Kappa = 0.64 (0.40-0.88). Borrelia burgdorferi sensu lato was identified by polymerase chain reaction (PCR) in 58.3% (35.9-78.5) of larvae with engorgement ratio > or = 3 that were collected from blackbirds. Larvae that were collected from other passerine species gave negative PCR results. Sixteen of 21 PCR-positive samples belonged to B. garinii (76.2%), and five (23.8%) were Borrelia valaisiana. Results of this study suggest that blackbirds play an important role as hosts for immature I. ricinus and as reservoir of Borrelia garinii in northwestern Italy.
authors.affiliation: Dipartimento di Produzioni Animali, Epidemiologia, Ecologia, Facoltà di Medicina Veterinaria, Università degli Studi di Torino, Via Leonardo da Vinci, 44, 10095 Grugliasco (TO), Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mannelli
authors.forename: Patrizia
authors.initials: P
authors.lastname: Nebbia
authors.forename: Clara
authors.initials: C
authors.lastname: Tramuta
authors.forename: Elena
authors.initials: E
authors.lastname: Grego
authors.forename: Laura
authors.initials: L
authors.lastname: Tomassone
authors.forename: Romina
authors.initials: R
authors.lastname: Ainardi
authors.forename: Lucia
authors.initials: L
authors.lastname: Venturini
authors.forename: Daniele
authors.initials: D
authors.lastname: De Meneghi
authors.forename: Pier Giuseppe
authors.initials: PG
authors.lastname: Meneguz
mesh_terms: D000818:Animals; D015748:Borrelia burgdorferi Group / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis; D007303:Insect Vectors; D007558:Italy; D018884:Ixodes / Q000254:growth & development / Q000382:microbiology*; D007814:Larva / Q000382:microbiology*; D009758:Nymph; D046109:Passeriformes / Q000469:parasitology*; D016133:Polymerase Chain Reaction; D012621:Seasons
chemical_list: D004269:DNA, Bacterial