title: First molecular detection of Rickettsia africae in ticks from the Union of the Comoros.
abstract: BACKGROUND
  Rickettsia africae is the agent of African tick bite fever, a disease transmitted by ticks in sub-Saharan Africa. In Union of the Comoros, a recent study reported the presence of a Rickettsia africae vector but no information has been provided on the circulation of the pathogenic agent in this country.
  
  
  METHODS
  To evaluate the possible circulation of Rickettsia spp. in Comorian cattle, genomic DNA was extracted from 512 ticks collected either in the Union of the Comoros or from animals imported from Tanzania and subsequently tested for Rickettsia infection by quantitative PCR.
  
  
  RESULTS
  Rickettsia africae was detected in 90% (60/67) of Amblyomma variegatum, 1% (1/92) of Rhipicephalus appendiculatus and 2.7% (8/296) of Rhipicephalus (Boophilus) microplus ticks collected in the Union of the Comoros, as well as in 77.14% (27/35) of Amblyomma variegatum ticks collected from imported cattle. Partial sequences of both bacterial gltA and ompA genes were used in a phylogenetic analysis revealing the presence of several haplotypes, all included within the Rickettsia africae clade.
  
  
  CONCLUSIONS
  Our study reports the first evidence of Rickettsia africae in ticks collected from the Union of the Comoros. The data show a significant difference of infection rate of Rickettsia africae infected ticks between the Islands, with maximum rates measured in Grande Comore Island, sheltering the main entry port for live animal importation from Tanzania. The high infection levels reported herein indicate the need for an in-depth assessment of the burden of rickettsioses in the Union of the Comoros, especially among those at risk of infection, such as cattle herders.
authors.forename: Amina
authors.initials: A
authors.lastname: Yssouf
authors.forename: Cristina
authors.initials: C
authors.lastname: Socolovschi
authors.forename: Tahar
authors.initials: T
authors.lastname: Kernif
authors.forename: Sarah
authors.initials: S
authors.lastname: Temmam
authors.forename: Erwan
authors.initials: E
authors.lastname: Lagadec
authors.forename: Pablo
authors.initials: P
authors.lastname: Tortosa
authors.affiliation: Aix Marseille Université, Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63, CNRS 7278, IRD 198, Inserm 1095, WHO Collaborative Center for Rickettsioses and Other Arthropod-borne Bacterial Diseases, Faculté de Médecine, 27 bd Jean Moulin, 13385 Marseille cedex 5, France. philippe.parola@univ-amu.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Parola
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000469:parasitology; D017507:Comoros; D015511:Goat Diseases / Q000453:epidemiology / Q000469:parasitology; D006041:Goats; D010802:Phylogeny; D012281:Rickettsia / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D013984:Tick Infestations / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary; D013987:Ticks / Q000382:microbiology*