Seroprevalence and Risk Factors of Bluetongue Virus Infection in Tibetan Sheep and Yaks in Tibetan Plateau, China

Table 1

Seroprevalence and risk factors of bluetongue virus (BTV) infection in Tibetan sheep and yaks in Tibetan Plateau, western China, by enzyme-linked immunosorbent assay (ELISA).

Variable	Tibetan sheep				Yak
	Number	Number	%	value	Number	Number	%	value
	Tested	Positive			Tested	Positive
Age group (years)
1 or less	447	82	18.3	0.6418	286	38	13.3	0.1148
1-2	413	90	21.8		292	38	13.0
2–4	1116	229	20.5		521	83	15.9
>4	211	42	19.9		485	52	10.7
Gender
Male	638	140	21.9	0.2076	471	70	14.9	0.2402
Female	1549	303	19.6		1113	141	12.7
Region
Tianzhu	962	197	20.5	0.9230	974	123	12.6	0.2178
Luqu	182	37	20.3		146	16	11.0
Maqu	588	122	20.8		464	72	15.5
Nyingchi	455	87	19.1
Season
Spring	480	103	21.5	0.1708	428	54	12.6	0.0293
Summer	398	93	23.4		354	55	15.5
Autumn	479	98	20.5		467	72	15.4
Winter	375	62	16.5		335	30	9.0
No information	455	87	19.1		—	—	—
Breed
White yak	—	—	—	—	974	123	12.6	0.3055
Black yak	—	—	—	—	610	88	14.4
Total	2187	443	20.3	—	1584	211	13.3	—