Veterinary Parasitology 178 (2011) 201–207 Contents lists available at ScienceDirect Veterinary Parasitology journal homepage: www.elsevier.com/locate/vetpar Molecular and serological prevalence of Babesia bovis and Babesia bigemina in water buffaloes in the northeast region of Thailand Mohamad Alaa Terkawi a , Nguyen Xuan Huyen a , Cao Shinuo a , Tawin Inpankaew b , Khuanwalai Maklon c , Mahmoud Aboulaila a , Akio Ueno a , Youn-Kyoung Goo a , Naoaki Yokoyama a , Sathaporn Jittapalapong b , Xuenan Xuan a , Ikuo Igarashi a,∗ a National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-13, Inada-cho, Obihiro, Hokkaido 080-8555, Japan b Department of Parasitology, Kasetsart University, Bangkok, Thailand c Department of Microbiology, Mahidol University, Bangkok, Thailand article info Article history: Received 10 September 2010 Received in revised form 14 January 2011 Accepted 18 January 2011 Keywords: Babesia bovis Babesia bigemina Nested PCR ELISA IFAT Water buffaloes Epidemiology Thailand abstract Bovine babesiosis is a tick-transmitted hemoprotozoan disease that is mainly caused by Babesia bovis and Babesia bigemina and is characterized by significant morbidity and mor- tality worldwide. The disease is widespread in the northeastern region of Thailand, where an increasingly large part of the livestock is composed of water buffaloes. The present study was therefore conducted to investigate the epidemiological distribution of B. bovis and B. bigemina in water buffaloes in the northeastern region of Thailand. A total of 305 buffalo blood samples were randomly collected from five provinces and simultaneously analyzed by the nested PCR (nPCR) assay, ELISA, and IFAT techniques. The overall prevalence of B. bovis and B. bigemina was 11.2% and 3.6% by nPCR, 14.7% and 5.9% by ELISA, and 16.8% and 5.6% by IFAT, respectively. The high concordance between the molecular and the serologi- cal detection tests revealed the specificity and sensitivity of the diagnostic assays used for the detection of infection as well as the endemic stability status of the parasites in the sur- veyed areas. Statistically significant differences in the prevalence of the two infections were observed on the basis of age and location but not gender. Our data provide valuable infor- mation regarding the epidemiology of B. bovis and B. bigemina infection in water buffaloes in the northeastern region of Thailand which will likely be very beneficial for management and control programs of this disease. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Bovine babesiosis is a tick-borne disease of cattle which is caused by the protozoan parasites of the genus Babesia, order Piroplasmida, phylum Apicomplexa and is generally characterized by significant morbidity and mortality worldwide (McCosker, 1981). Babesia bovis and Babesia bigemina are known as the most important species ∗ Corresponding author. Tel.: +81 155 49 5641; fax: +81 155 49 5643. E-mail address: igarcpmi@obihiro.ac.jp (I. Igarashi). because they are highly prevalent in tropical and sub- tropical regions of the world and cause enormous economic losses in the livestock industry (Bock et al., 2004; OIE, 2008). Although B. bovis and B. bigemina are phylogenet- ically related and transmitted by the same tick vector, Rhipicephalus microplus, they cause remarkably different diseases in cattle (Kuttler, 1988; Bock et al., 2004). The B. bovis infection is often more severe and results in higher mortality among susceptible cattle, most probably due to the ability of parasitized erythrocytes to sequester in microcapillaries of the kidneys, lungs, and brain, with con- sequent organ failure and systemic shock that lead to death 0304-4017/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.vetpar.2011.01.041