Meta-analysis On Seroprevalence Of Bluetongue In Domestic Animals Of India
Ramkumar , VinodhKumar O. R, R. Karthikeyan, Pruthvishree B.S., D.K. Sinha, K.P. Singh, Z.B. Dubal, V.K. Gupta, S. Nandi, B.R. Singh
Division Of Epidemiology, ICAR-Indian Veterinary Research Institute, Bareilly, India
Bluetongue (BT), an infectious insect-borne viral disease affecting a wide range of ruminants, and first reported in 1964 from central region of India. Sheep are the most susceptible hosts for BT, while cattle, buffalo and goats serve as reservoirs. In the light of lack of comprehensive information on the BT status in the country, a systematic review and meta-analysis was conducted to report the seroprevalence of BT in domestic animals of India. A literature search was conducted, and a systematic review was performed to identify the published articles reporting seroprevalence of BT in domestic animals from India from 2001-2018. Of 409 screened articles, 71 studies satisfied the inclusion criteria. Meta-analysis for seroprevalence was carried out and from these studies, 144 strata was extracted with a total sample size of 38,899 (sheep -14,048; goat- 14,696; cattle- 5,218; buffalo- 2,653; camel – 2,062; mithun- 222). A significant heterogeneity (I2 = 98%, df =143, p<0.01) between the selected studies was noted. The BT seroprevalence in goats was 43%, in sheep 39%, in cattle 38%, in buffaloes 35%, in camel 16% and in mithun 66%. Meta-regression suggested that serological tests, geographical region, and sample size were the moderators for BT seroprevalence. It indicates an estimated 25.35 million (95% CI: 21.5-29.9%) sheep, 58 million (95% CI: 51.3-66.2%) goats and 66.8 million (95% CI: 47.7–86%) cattle could be BT seropositive in India. The study highlights the endemicity of BT in different geographical regions of India and signifies the necessity for improving the diagnostic methods.
