title: Comparative clinico-pathological observations in young Zebu (Bos indicus) cattle experimentally infected with Trypanosoma vivax isolates from tsetse infested and non-tsetse areas of Northwest Ethiopia.
abstract: BACKGROUND
  The Northwest region of Ethiopia is affected by both tsetse and non-tsetse transmitted trypanosomosis with a huge impact on livestock productivity. The objective of this experimental study was to determine clinical and pathological findings in young Zebu cattle experimentally infected with Trypanosoma vivax isolates from tsetse infested and non-tsetse infested areas of Northwest Ethiopia. A total of 18 cattle (Bos indicus) aged between 6 and 12 months, purchased from a trypanosome-free and confirmed to be trypanosome negative divided into three groups of six animals were used. Animals in the first two groups (Group TT: tsetse infested isolate infected and Group NT: non-tsetse infested isolate infected) received 2 mL of infected blood from donor animals at 10(6) trypanosomes/mL, and the remaining group was non-infected control (NIC). Each group was observed for a period of eight consecutive weeks, daily for clinical signs and once per week for parasitaemia. Postmortem examinations were done on euthanized animals, and tissue samples were taken for histopathological analysis.
  
  
  RESULTS
  The prepatent period of the disease was earlier in the NT group 6 days post infection (dpi) than TT group 12 dpi. The infection was characterized by reduced feed intake, intermittent pyrexia and parasitaemia, enlarged lymph nodes, lacrimation, reduced feed intake and emaciation. Less frequently diarrhea, oedema and nervous signs were observed in both groups of infected animals. At necropsy, infected animals showed enlarged spleen, enlarged lymph nodes, pneumonic and emphysematous lung, enlarged liver, and haemorrhages on the brain and intestine. Histopathological analysis revealed lymphoid hyperplasia of the spleen, necrosis of the liver, encephalitis and hyperplasia of lymph nodes.
  
  
  CONCLUSIONS
  Trpanosoma vivax isolates from both tsetse infested and non-tsetse areas showed a variety of virulence factors leading to the development of acute clinical signs, gross and histopathological lesions. However, the parasitaemia and clinical signs appeared earlier in the NT compared to TT infected groups.
authors.affiliation: Addis Ababa University, College of Veterinary Medicine and Agriculture, Debre Zeit, Ethiopia. dagne2121@gmail.com.
authors.forename: Shimelis
authors.initials: S
authors.lastname: Dagnachew
authors.affiliation: Addis Ababa University, College of Veterinary Medicine and Agriculture, 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: National Animal Health and Disease Investigation Center, Sebeta, Ethiopia. ejigua@yahoo.com.
authors.forename: Asegedech
authors.initials: A
authors.lastname: Sirak
authors.affiliation: University of Turin, DSV, Turin, Italy. enrico.bollo@unito.it.
authors.forename: Enrico
authors.initials: E
authors.lastname: Bollo
authors.affiliation: University of Glasgow, CMVLS, Glasgow, UK. Dave.Barry@glasgow.ac.uk.
authors.forename: Dave
authors.initials: D
authors.lastname: Barry
authors.affiliation: Catholic University of Leuven, Faculty of Bioscience Engineering, Leuven, Belgium. Bruno.Goddeeris@kuleuven.be.
authors.forename: Bruno
authors.initials: B
authors.lastname: Goddeeris
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000469:parasitology* / Q000473:pathology; D005002:Ethiopia / Q000453:epidemiology; D016689:Trypanosoma vivax; D014353:Trypanosomiasis, African / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D014370:Tsetse Flies