Veterinary Parasitology 196 (2013) 258–264 Contents lists available at ScienceDirect Veterinary Parasitology journal homepage: www.elsevier.com/locate/vetpar Sero-surveillance for surra in cattle using native surface glycoprotein antigen from Trypanosoma evansi Krishnendu Kundu a , Anup Kumar Tewari a,∗ , Samarchith P. Kurup a,1 , Surajit Baidya a,2 , Jammi Raghavendra Rao a,3 , Paritosh Joshi b a Division of Parasitology, Indian Veterinary Research Institute, Izatnagar 243122, UP, India b Division of Animal Biochemistry, Indian Veterinary Research Institute, Izatnagar 243122, UP, India article info Article history: Received 9 July 2012 Received in revised form 12 March 2013 Accepted 6 April 2013 Keywords: Glycoprotein ELISA India Prevalence Trypanosoma evansi abstract Surra, caused by Trypanosoma evansi affects a wide range of domestic and wild animals in the tropics, taking a huge toll on the already impoverished economy here. In bovines surra normally develops into a chronic infection that is often associated with severe production losses, yet with no distinct clinical signs making its adequate diagnosis vital. Though direct microscopic observation of T. evansi in circulation may be the diagnostic gold standard for surra, it is insensitive and impractical for population prevalence studies, making sero- diagnosis the preferred choice for the latter. In this study, we standardize an ELISA with Concanavalin-A (Con-A) affinity purified T. evansi surface glycoprotein antigen and compare its sensitivity and specificity to direct microscopy of stained thin smears and molecular (PCR) diagnostics. The ELISA was then put on field trial for sero-surveillance of cattle for surra in three geographically distinct populations in the Indian subcontinent, to yield an overall sensitivity and specificity of 100% and 89.15% compared to standard stained thin smear examinations and 95.23% and 90.84% compared to blood PCR examinations. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Surra, caused by Trypanosoma evansi is a disease syn- drome affecting a wide range of domestic and wild animals with high prevalence in the tropical world, leading to severe economic losses. The disease pathology varies with the host, with an acute, clinically severe disease in canines and equines, and a more chronic, latent disease in ∗ Corresponding author. Tel.: +91 5812315194; fax: +91 5812302368. E-mail addresses: anuptewari1@rediffmail.com, tewarianup@gmail.com (A.K. Tewari). 1 Current address: Center for Tropical and Emerging Global Diseases, The University of Georgia, Athens, GA 30605, USA. 2 Current address: Department of Veterinary Parasitology, West Ben- gal University of Animal and Fisheries Sciences, 37&68 Kshudiram Bose Sarani, Kolkata, WB, India. 3 Current address: Emeritus Scientist, NAARM, Hyderabad, AP, India. ruminants. Though an acute form of the disease can occur in bovines, the latent form of the infection is most widespread and responsible for the production losses in dairy herds (Tuntasuvan et al., 1997). There may also be sudden clini- cal outbreaks in the chronically infected individuals, owing to the various physiological, climatic or nutritional stress- ors (Otte et al., 1994; Seed et al., 1984), which may then serve as foci for future epidemics. The semi-intensive nature of animal husbandry practices in the tropics puts other susceptible animal species also under severe risk in such outbreaks. Moreover, the general immunosuppress- ive character of surra (Bajyana-Songa et al., 1987; Holland et al., 2003; Tewari et al., 2009) also contributes to vacci- nation failures (Onah et al., 1997; Holland et al., 2001) and co-infections. These considerations make adequate diag- nosis of latent surra in cattle a priority in the field. Since the standard trypanosome detection methods (STDMs) like direct microscopy of stained thin smears and mice hemo-transfer assays lack adequate diagnostic 0304-4017/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.vetpar.2013.04.013