Emergence of oriental theileriosis in cattle and its transmission through Rhipicephalus (Boophilus) microplus in Assam, India

Abstract

Aim:The aim of the present study was to investigate the presence of Theileria in blood samples of crossbred and indigenous adult cows raised under unorganized small scale farming system in a Babesia and Anaplasma endemic geographical area from Assam, India and to see its transmission through Rhipicephalus (Boophilus) microplus ticks.Materials and Methods:For the present study, 57 clinical cases of cattle suspected to be of hemoparasitic infections were taken into consideration. The parasites were identified based on morphology in giemsa stained blood smear followed by polymerase chain reaction (PCR). Sera samples were tested for T. annulata antibodies in plate and Dot-ELISA. PCR was also conducted in eggs of Rhipicephalus (Boophilus) microplus tick collected from a Theileria orientalis positive animal.Results:PCR amplified 1124, 776, and 160 bp DNA fragments of B. bigemina (64.91%), T. orientalis (21.05%) and A. marginale (14.03%), respectively. This assay further conducted in 12 T. orientalis positive blood samples with primers of Buffeli, Chitose, and Ikeda variants of T. orientalis showed 3 samples positive to Ikeda type and none for Buffeli and Chitose. Babesia bovis and Theileria annulata specific primers also did not amplify any fragment during the PCR assay of the blood samples. Further, all sera samples tested negative to T. annulata antibodies in Plate and Dot-ELISA. PCR conducted in eggs of R (B).microplus tick collected from a T. orientalis positive animal revealed presence of the parasite DNA. Gradual improvement in physical condition leading to complete recovery in 10 out of 12 T. orientalis infected clinical cases treated with buparvaquone(at 2.5mg/kg.b.wt I/M) was the feedback obtained from field veterinarians and the cattle owners.Conclusion:The present investigation represents the first report of occurrence of T. orientalis in cattle of Assam with involvement of pathogenic Ikeda strain in clinical outbreaks and its possible natural transmission by R (B). microplus through the transovarian mode.

Molecular identification of tick-borne pathogens infecting cattle in Mymensingh district of Bangladesh reveals emerging species ofAnaplasmaandBabesia

“…T. orientalis was the most prevalent TBP (55.2%) in the study area (Table ). Although T. orientalis infections have been documented in cattle from the neighbouring countries like India (Aparna et al., ; Kakati et al., ) and Myanmar (Bawm et al., ), T. orientalis had so far not been reported from Bangladesh. T. orientalis has long been considered as a benign Theileria species, but a number of clinical outbreaks have recently been reported from cattle in Asia‐Pacific regions, causing considerable production losses (Gebrekidan, Nelson, Smith, Gasser, & Jabbar, ; Islam, Jabbar, Campbell, Cantacessi, & Gasser, ; Izzo, Poe, Horadagoda, De Vos, & House, ; McFadden et al., ).…”

A U.S. Isolate of Theileria Orientalis, Ikeda Genotype, is Transmitted to Cattle by the Invasive Asian Longhorned Tick, Haemaphysalis Longicornis

“…It is thus likely some indigenous North American tick species are also capable of transmitting T. orientalis Ikeda. There is one report of T. orientalis acquisition and transmission by Rhipicephalus microplus ticks in India [12]. As R. microplus ticks are also native to regions of the U.S. near the southern border, and are competent vectors of Theileria equi [36][37][38][39], it is possible that they have been involved in T. orientalis transmission in the past, and could prove competent vectors of T. orientalis Ikeda.…”

“…The primary tick vector of T. orientalis is Haemaphysalis longicornis (AKA the Asian longhorned tick) [3,11]; however, other tick species [3,12] and mechanical vectors, including contaminated needles [13], biting ies [13], and lice [14], have been implicated in parasite spread. Regardless, T. orientalis Ikeda can spread rapidly and cause signi cant losses when introduced to naïve cattle in areas with competent tick vectors.…”

“…In addition to H. longicornis, several other tick species are competent biological vectors of T. orientalis, including other species of Haemaphysalis ticks [3] and Rhipicephalus (Boophilus) microplus [12]. Interestingly, T. orientalis Buffeli isolated from a historical U.S. outbreak was not transmissible by Korean H. longicornis ticks [1,32].…”

Prevalence of carrier state theileriosis in lactating cows

“…Most of the research work in India are focused on bovine tropical theileriosis caused by Theileria annulata . However, during the past few years, reports on Theileria orientalis associated clinical infections have been accumulated from different states of India such as Tamil Nadu, Kerala, and Assam [ 6 - 9 ]. Thus, identification of species-specific theileriosis is essentially required to unveil the picture of bovine theileriosis in the areas of interest.…”