title: Epidemiology of Trypanosoma evansi and Trypanosoma vivax in domestic animals from selected districts of Tigray and Afar regions, Northern Ethiopia.
abstract: BACKGROUND
  African animal trypanosomosis, transmitted cyclically by tsetse flies or mechanically by other biting flies, causes serious inflictions to livestock health. This study investigates the extent of non-tsetse transmitted animal trypanosomosis (NTTAT) by Trypanosoma (T.) evansi and T. vivax in domestic animals in the tsetse-free regions of Northern Ethiopia, Afar and Tigray.
  
  
  METHODS
  A cross sectional study was conducted on 754 dromedary camels, 493 cattle, 264 goats, 181 sheep, 84 donkeys, 25 horses and 10 mules. The microhaematocrit centrifugation technique was used as parasitological test. Plasma was collected for serodiagnosis with CATT/T.evansi and RoTat 1.2 immune trypanolysis (ITL) while buffy coat specimens were collected for molecular diagnosis with T. evansi type A specific RoTat 1.2 PCR, T. evansi type B specific EVAB PCR and T. vivax specific TvPRAC PCR.
  
  
  RESULTS
  The parasitological prevalence was 4.7% in Tigray and 2.7% in Afar and significantly higher (z = 2.53, p = 0.011) in cattle (7.3%) than in the other hosts. Seroprevalence in CATT/T.evansi was 24.6% in Tigray and 13.9% in Afar and was significantly higher (z = 9.39, p < 0.001) in cattle (37.3%) than in the other hosts. On the other hand, seroprevalence assessed by ITL was only 1.9% suggesting cross reaction of CATT/T.evansi with T. vivax or other trypanosome infections. Molecular prevalence of T. evansi type A was 8.0% in Tigray and in Afar and varied from 28.0% in horses to 2.2% in sheep. It was also significantly higher (p < 0.001) in camel (11.7%) than in cattle (6.1%), donkey (6%), goat (3.8%), and sheep (2.2%). Four camels were positive for T. evansi type B. Molecular prevalence of T. vivax was 3.0% and was similar in Tigray and Afar. It didn't differ significantly among the host species except that it was not detected in horses and mules.
  
  
  CONCLUSIONS
  NTTAT caused by T. vivax and T. evansi, is an important threat to animal health in Tigray and Afar. For the first time, we confirm the presence of T. evansi type B in Ethiopian camels. Unexplained results obtained with the current diagnostic tests in bovines warrant particular efforts to isolate and characterise trypanosome strains that circulate in Northern Ethiopia.
authors.affiliation: College of Veterinary Medicine, Mekelle University, P. O. Box 2084, Mekelle, Ethiopia. hadushbirhanu@yahoo.com.|Department of Biosystems, KU Leuven, Faculty of Bioscience Engineering, Kasteelpark Arenberg 30, B-3001, Leuven, Belgium. hadushbirhanu@yahoo.com.|Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, Antwerp, Belgium. hadushbirhanu@yahoo.com.
authors.forename: Hadush
authors.initials: H
authors.lastname: Birhanu
authors.affiliation: Department of Biosystems, KU Leuven, Faculty of Bioscience Engineering, Kasteelpark Arenberg 30, B-3001, Leuven, Belgium. fikruregassa@yahoo.com.|Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, Antwerp, Belgium. fikruregassa@yahoo.com.|College of Veterinary Medicine and Agriculture, Addis Ababa University, P.O. Box 34, Bishoftu, Ethiopia. fikruregassa@yahoo.com.
authors.forename: Regassa
authors.initials: R
authors.lastname: Fikru
authors.affiliation: Department of Statistics, College of Natural and Computational Sciences, Mekelle University, P.O.Box 231, Mekelle, Ethiopia. mussasaid3226@gmail.com.
authors.forename: Mussa
authors.initials: M
authors.lastname: Said
authors.affiliation: College of Veterinary Medicine, Mekelle University, P. O. Box 2084, Mekelle, Ethiopia. kidaneweldu21@yahoo.com.
authors.forename: Weldu
authors.initials: W
authors.lastname: Kidane
authors.affiliation: College of Veterinary Medicine, Mekelle University, P. O. Box 2084, Mekelle, Ethiopia. tadessse498@yahoo.com.
authors.forename: Tadesse
authors.initials: T
authors.lastname: Gebrehiwot
authors.affiliation: College of Veterinary Medicine and Agriculture, Addis Ababa University, P.O. Box 34, Bishoftu, Ethiopia. hagos83@yahoo.com.
authors.forename: Ashenafi
authors.initials: A
authors.lastname: Hagos
authors.affiliation: College of Veterinary Medicine and Agriculture, Addis Ababa University, P.O. Box 34, Bishoftu, Ethiopia. alemu.tola@yahoo.com.
authors.forename: Tola
authors.initials: T
authors.lastname: Alemu
authors.affiliation: School of Veterinary Medicine, Hawassa University, P.O. Box 05, Hawassa, Ethiopia. dawit89@yahoo.com.
authors.forename: Tesfaye
authors.initials: T
authors.lastname: Dawit
authors.affiliation: Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, Antwerp, Belgium. dberkvens@itg.be.
authors.forename: Dirk
authors.initials: D
authors.lastname: Berkvens
authors.affiliation: Department of Biosystems, KU Leuven, Faculty of Bioscience Engineering, Kasteelpark Arenberg 30, B-3001, Leuven, Belgium. bruno.goddeeris@kuleuven.be.
authors.forename: Bruno Maria
authors.initials: BM
authors.lastname: Goddeeris
authors.affiliation: Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, Antwerp, Belgium. pbuscher@itg.be.
authors.forename: Philippe
authors.initials: P
authors.lastname: Büscher
mesh_terms: D000818:Animals; D005002:Ethiopia / Q000453:epidemiology; D058751:Livestock / Q000469:parasitology*; D017720:Molecular Epidemiology; D014345:Trypanosoma / Q000145:classification* / Q000235:genetics; D014352:Trypanosomiasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*