title: Active infection and morphometric study of Trypanosoma evansi among horses in Peninsula Malaysia.
abstract: Apart from occasional reports of clinical disease affecting horses, there is no information about Trypanosoma evansi in horses in Peninsula Malaysia. Thus, a cross-sectional study was conducted in eight states in Peninsula Malaysia to determine the active presence of T. evansi in horses. A total of 527 blood samples were obtained and examined by haematocrit centrifugation technique (HCT), Giemsa-stained thin blood smear (GSS), morphometric measurements, polymerase chain reaction (PCR) and cloning of PCR products. The results showed an overall parasitological prevalence of 0.57% (3/527, CI: 1.6-0.19%) with both HCT and GSS. Morphometric study revealed the mean total length of the trypanosomes including the free flagellum was 27.94 ± 2.63 μm. PCR successfully amplified a trypanosome specific 257 bp in 1.14% of samples (6/527, CI: 2.4-0.52%) and was confirmed by nucleotide sequences. The mean packed cell volume (PCV) for the positive cases detected by HCT was lower (23% ± 7.00) compared to the positive cases detected by PCR alone in the state of Terengganu (35% ± 4.73). In conclusion, this study showed T. evansi infection occurred in low frequency in horses in Peninsula Malaysia, and anaemia coincided with parasitaemic animals. PCR is considered as a sensitive diagnostic tool when parasitaemia is undetectable. The slight lengthier mean of parasite and anaemia may indicate a virulent strain of T. evansi circulating throughout the country. Thus, it's highly recommended to shed light on host-parasite relationship for better epidemiological understanding.
authors.affiliation: Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 Selangor, Malaysia.
authors.forename: E I
authors.initials: EI
authors.lastname: Elshafie
authors.forename: R A
authors.initials: RA
authors.lastname: Sani
authors.forename: L
authors.initials: L
authors.lastname: Hassan
authors.forename: R
authors.initials: R
authors.lastname: Sharma
authors.forename: A
authors.initials: A
authors.lastname: Bashir
authors.forename: I A
authors.initials: IA
authors.lastname: Abubakar
mesh_terms: D000740:Anemia / Q000175:diagnosis / Q000209:etiology / Q000662:veterinary; D000818:Animals; D001769:Blood / Q000469:parasitology; D019411:Clinical Laboratory Techniques / Q000379:methods; D006734:Horse Diseases / Q000453:epidemiology* / Q000469:parasitology / Q000473:pathology; D006736:Horses; D008296:Malaysia; D010274:Parasitology / Q000379:methods; D015995:Prevalence; D014345:Trypanosoma / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D014352:Trypanosomiasis / Q000150:complications / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D014730:Veterinary Medicine / Q000379:methods