title: Colonization of Grande Comore Island by a lineage of Rhipicephalus appendiculatus ticks.
abstract: BACKGROUND
  Union of the Comoros suffered a severe East Coast Fever epidemic in 2004. Rhipicephalus appendiculatus was probably involved in pathogen transmission as this competent tick species, although previously absent from Comoros, was sampled on 4 animals on one geographical site during the epidemic. We carried out an entomological survey on all three islands of Union of the Comoros to establish cattle tick species distribution with a special emphasis on R. appendiculatus. We investigated R. appendiculatus intraspecific diversity as this species has been previously shown to be split off into two main cytoplasmic lineages with different ecology, physiology and vectorial competence. This survey also included sampling of live cattle imported from Tanzania to investigate the possibility of tick introduction through animal trade.
  
  
  RESULTS
  Our data show that Comoros cattle are infested with Amblyomma variegatum, Rhipicephalus microplus and R. appendiculatus. This latter species has established throughout Grande Comore but is absent from Anjouan and Moheli. Interestingly, 43 out of the 47 sequenced R. appendiculatus ticks belong to one single highly competent lineage while ticks from the other lineage where only found on imported cattle or on cattle parked at the vicinity of the harbor. At last, 2 ticks identified as R. evertsi, a species so far virtually absent on Comoros, were sampled on imported cattle.
  
  
  CONCLUSIONS
  This survey shows that importation of live cattle is clearly a source of vector introduction in Comoros. The wide distribution of one highly competent R. appendiculatus lineage on Grande Comore, together with the absence of this species on the two neighbouring islands is in accordance with the rapid and disastrous spread of East Coast Fever epidemics on Grande Comore Island only. Whether the other R. appendiculatus lineage as well as R. evertsi species will succeed in establishing permanently on Grande Comore needs to be monitored.
authors.affiliation: Centre de Recherche et de Veille sur les Maladies Emergentes dans l'Océan indien-GIP CYROI- 2, rue Maxime Rivière, 97490 Ste Clotilde, France.
authors.forename: Amina
authors.initials: A
authors.lastname: Yssouf
authors.forename: Erwan
authors.initials: E
authors.lastname: Lagadec
authors.forename: Annabelle
authors.initials: A
authors.lastname: Bakari
authors.forename: Coralie
authors.initials: C
authors.lastname: Foray
authors.forename: Frédéric
authors.initials: F
authors.lastname: Stachurski
authors.forename: Eric
authors.initials: E
authors.lastname: Cardinale
authors.forename: Olivier
authors.initials: O
authors.lastname: Plantard
authors.forename: Pablo
authors.initials: P
authors.lastname: Tortosa
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000469:parasitology*; D016000:Cluster Analysis; D017507:Comoros; D004199:Disease Vectors; D004772:Entomology / Q000379:methods; D005838:Genotype; D010802:Phylogeny; D048494:Rhipicephalus / Q000145:classification* / Q000254:growth & development*; D017422:Sequence Analysis, DNA; D013984:Tick Infestations / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*