Seroprevalence and Risk Factors of Chlamydia abortus Infection in Tibetan Sheep in Gansu Province, Northwest China

Table 1

Seroprevalence of Chlamydia abortus infection in Tibetan sheep associated with different factors in Gansu province, northwest China, by indirect hemagglutination assay (IHA).

Factor	Category	Tested numbers	Positive numbers	Prevalence (%)
Region	Tianzhu County	962	157	16.32
	Maqu County	588	133	22.62
	Luqu County	182	33	18.13
Sex	Male	530	114	21.51
	Female	1202	209	17.39
Season	Spring	480	89	18.54
	Summer	398	88	22.11
	Autumn	479	98	20.46
	Winter	375	48	12.80
Age (yr)	0 < yr ≤ 1	335	25	7.46
	1 < yr ≤ 2	392	62	15.82
	2 < yr ≤ 3	194	38	19.59
	yr > 3	811	198	24.41
Total		1732	323	18.65