title: Comparative clinico-haematological analysis in young Zebu cattle experimentally infected with Trypanosoma vivax isolates from tsetse infested and non-tsetse infested areas of Northwest Ethiopia.
abstract: BACKGROUND
  Ethiopia, particularly in the Northwest region, is affected by both tsetse and non-tsetse fly transmitted trypanosomosis, with significant impact on livestock productivity. The aim of this study was to determine and compare clinical findings and haematological values between experimental infections induced by Trypanosoma vivax isolates from areas of either transmission mode. Sixteen young (aged between 6 and 12 months) Zebu cattle (Bos indicus), purchased from a trypanosome-free area and confirmed to be trypanosome-negative, were randomly assigned into four groups of four animals. Groups 1, 2 and 3 were infected with an isolate from a tsetse infested or one of two isolates from a non-tsetse infested area, and group 4 was a non-infected control. All animals in the infected groups were inoculated intravenously with 2 × 10(6) trypanosomes from donor animals. The experimental animals were monitored for eight consecutive weeks post infection for clinical signs, parasitaemia and haematological changes in packed cell volume (PCV), haemoglobin concentration (Hgb), total red blood cell (RBC) and white blood cell (WBC) counts, differential WBC count and blood indices (mean corpuscular volume [MCV], mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration).
  
  
  RESULTS
  Infection was characterized by reduced feed intake, weakness, pyrexia, parasitaemia, rough hair coat, enlarged prescapular lymph nodes, lacrimation, weight loss, pallor mucus membrane and dehydration. Body weight loss in all infected groups was significantly higher than in the non-infected control. Similarly, body weight loss was higher (P < 0.001) in animals infected with the tsetse infested isolate than with the non-tsetse infested isolates. The mean PCV, Hgb, total RBC and WBC counts were lower (P < 0.001), and mean MCV was higher (P = 0.01) in all infected groups than in non-infected control animals at different time points during the study period. Except for minor variations in haematological values, the overall changes were similar in all infected groups.
  
  
  CONCLUSIONS
  Clinical signs and significant reduction in haematological values in the infected groups indicated the pathogenicity of the T. vivax parasites. Pathogenicity of T. vivax from the non-tsetse infested area can be considered as nearly as important as that of its counterpart derived from the tsetse infested area.
authors.affiliation: Department of Pathology and Parasitology, College of Veterinary Medicine and Agriculture of Addis Ababa University, P.O. Box: 34, Debre Zeit, Ethiopia. dagne2121@gmail.com.|Department of Biosystems, Faculty of Bioscience Engineering, Catholic University of Leuven, 30 bus 2456, B-3001, Heverlee, Belgium. dagne2121@gmail.com.|Faculty of Veterinary Medicine, University of Gondar, P.O. Box: 196, Gondar, Ethiopia. dagne2121@gmail.com.
authors.forename: Shimelis
authors.initials: S
authors.lastname: Dagnachew
authors.affiliation: Department of Pathology and Parasitology, College of Veterinary Medicine and Agriculture of Addis Ababa University, P.O. Box: 34, Debre Zeit, Ethiopia. mbeziethevet@gmail.com.
authors.forename: Melkamu
authors.initials: M
authors.lastname: Bezie
authors.affiliation: Department of Pathology and Parasitology, College of Veterinary Medicine and Agriculture of Addis Ababa University, P.O. Box: 34, Debre Zeit, Ethiopia. getachew_terefe@yahoo.com.
authors.forename: Getachew
authors.initials: G
authors.lastname: Terefe
authors.affiliation: Food and Agriculture Organization of the United Nations, Addis Ababa, Ethiopia. Getachew.Abebe@fao.org.
authors.forename: Getachew
authors.initials: G
authors.lastname: Abebe
authors.affiliation: Wellcome Trust Centre for Molecular Parasitology, College of Medicine, Veterinary and Life Sciences, University of Glasgow, 120 University Place, G12 8TA, Glasgow, UK. Dave.Barry@glasgow.ac.uk.
authors.forename: J David
authors.initials: JD
authors.lastname: Barry
authors.affiliation: Department of Biosystems, Faculty of Bioscience Engineering, Catholic University of Leuven, 30 bus 2456, B-3001, Heverlee, Belgium. Bruno.Goddeeris@kuleuven.be.
authors.forename: Bruno M
authors.initials: BM
authors.lastname: Goddeeris
mesh_terms: D063147:Animal Distribution; D000818:Animals; D001774:Blood Chemical Analysis / Q000662:veterinary; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology*; D005002:Ethiopia; D005260:Female; D008297:Male; D018512:Parasitemia / Q000469:parasitology / Q000503:physiopathology / Q000662:veterinary*; D016689:Trypanosoma vivax / Q000502:physiology*; D014353:Trypanosomiasis, African / Q000469:parasitology / Q000503:physiopathology / Q000662:veterinary*; D014370:Tsetse Flies / Q000469:parasitology / Q000502:physiology; D014774:Virulence