title: Tick (Amblyomma chabaudi) infestation of endemic tortoises in southwest Madagascar and investigation of tick-borne pathogens.
abstract: Little is known about the role of endemic ticks as vectors for bacterial and protozoan pathogens for animals and humans in Madagascar and their interaction in anthropogenic habitats where humans, their livestock and native Malagasy species (vectors and hosts) come into more frequent contact than in natural forest ecosystems. The aims of the study were (1) to test whether habitat degradation is associated with increased infestation of tortoises by ticks and (2) to investigate whether ticks carried Babesia, Borrelia or Rickettsia species that might be pathogenic for humans and livestock. We studied hard ticks of two endemic Malagasy tortoises, Astrochelys radiata and Pyxis arachnoides in March and April 2013 in southwest Madagascar. Two tortoise habitats were compared, the National Park of Tsimanampetsotsa and the adjacent degraded pasture and agricultural land at the end of the wet season. Ticks were screened for protozoan and bacterial pathogens via PCR on DNA isolated from ticks using genus-specific primers. Only one out of 42 A. radiata collected from both habitats had ticks. The low prevalence did not allow further analyses of the effect of habitat degradation. Forty-two P. arachnoides were found in the anthropogenic habitat and 36 individuals in the national park. Tick infestation rates of P. arachnoides differed significantly between the two study sites. Tortoises inside the park had lower tick prevalence than outside (8 of 36 (22%) versus 32 of 42 individuals (76%)) and infected animals tended to have fewer ticks inside than outside the park. All ticks collected in both habitats were adults of the ixodid tick Amblyomma chabaudi, which is supposed to be a host-specific tick of P. arachnoides. Screening for Borrelia sp. and Babesia sp. was negative in all ticks. But all A. chabaudi ticks were infected with Rickettsia africae, known to cause spotted fever in humans. Thus, habitat degradation seems to be linked to higher infestation of tortoises with ticks with possible consequences for humans and their livestock.
authors.affiliation: Biozentrum Grindel, University of Hamburg, Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Ehlers
authors.affiliation: Biozentrum Grindel, University of Hamburg, Hamburg, Germany. Electronic address: ganzhorn@uni-hamburg.de.
authors.forename: Jörg U
authors.initials: JU
authors.lastname: Ganzhorn
authors.affiliation: Vergleichende Tropenmedizin und Parasitologie, Ludwig-Maximilians-Universität München, Munich, Germany; National Center of Vector Entomology, Institute of Parasitology, University of Zurich, Zurich, Switzerland.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Silaghi
authors.affiliation: Military Hospital Hamburg, Department Tropical Medicine, Hamburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Krüger
authors.affiliation: Vergleichende Tropenmedizin und Parasitologie, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Pothmann
authors.affiliation: Biozentrum Grindel, University of Hamburg, Hamburg, Germany.
authors.forename: R Yedidya
authors.initials: RY
authors.lastname: Ratovonamana
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Veit
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; Institute of Virology, Philipps University Marburg, Marburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Keller
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; University Medical Center, Hamburg-Eppendorf, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Poppert
mesh_terms: D000328:Adult; D000818:Animals; D001096:Arachnid Vectors / Q000382:microbiology / Q000469:parasitology; D001403:Babesia / Q000235:genetics / Q000302:isolation & purification; D001898:Borrelia / Q000235:genetics / Q000302:isolation & purification; D017753:Ecosystem; D019353:Endemic Diseases / Q000662:veterinary*; D005260:Female; D006801:Humans; D026863:Ixodidae / Q000382:microbiology / Q000469:parasitology; D058751:Livestock; D008270:Madagascar / Q000453:epidemiology; D008297:Male; D012281:Rickettsia / Q000235:genetics / Q000302:isolation & purification; D013984:Tick Infestations / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D017282:Tick-Borne Diseases / Q000453:epidemiology* / Q000382:microbiology / Q000469:parasitology; D014426:Turtles / Q000382:microbiology / Q000469:parasitology
keywords: Amblyomma; Astrochelys radiata; Madagascar; Pyxis arachnoides; Rickettsia; Tortoise tick