Table 3. The comparison of the seroprevalence surveys of brucellosis, leptospirosis and Q fever carried out in different areas among butchers and slaughter workers.

Studies Disease	Region	Number of tested	Seropositivity (%)	P-value	OR (%95 CI)	Ref.
Brucellosis	This study	190	7.9	Ref.
	Iran: Gilan	186	9.8	0.54	0.8 (0.38, 1.65)	[22]
	Iran: Shiraz	250	11.7	0.20	0.65 (0.33, 1.25)	[23]
	Iran: Kurdistan	50	12	0.37	0.63 (0.23, 1.86)	[2]
	Iran: Urmia	154	13	0.13	0.57 (0.28, 1.17)	[24]
	Iran: Khorasan Razavi	250	48	<0.001	0.9 (0.05, 0.16)	[25]
	Iran: Kerman	75	58.6	<0.001	0.06 (0.03, 0.12)	[4]
	South-Korea	1482	0.8	<0.001	10.47 (4.79, 23.29)	[32]
	Brazil	551	4.2	0.06	1.97 (0.98, 3.85)	[31]
	Tanzania	41	19.5	0.04	0.36 (0.14, 0.95)	[6]
	Pakistan	260	21.7	<0.001	0.31 (0.17, 0.55)	[30]
	Pakistan	251	22	<0.001	0.31 (0.16, 0.55)	[29]
	India	165	25.5	<0.001	0.3 (0.15, 0.56)	[28]
	Saudi Arabia	269	35	<0.001	0.16 (0.19, 0.28)	[27]
Leptospirosis	This study	184	23.4	Ref.
	Iran: Khoy	30	13	0.22	1.98 (0.69, 6.96)	[36]
	Iran: Zanjan	98	34.7	0.02	0.57 (0.33, 0.98)	[5]
	Iran: Tehran	120	58	<0.001	0.23 (0.14, 0.37)	[37]
	Brazil	150	4	<0.001	7.28 (3.15, 19.38)	[38]
	Mexico	292	8.2	<0.001	3.97 (1.99, 3.90)	[39]
	New Zealand	567	11	<0.001	2.48 (1.60, 3.82)	[40]
	India	20	30	0.25	0.71 (0.26, 2.13)	[41]
Q Fever	This study	187	22.5	Ref.
	Iran: Kurdistan	50	38	0.03	0.47 (0.24, 0.93)	[2]
	Iran: Kerman	75	68	<0.001	0.14 (0.07, 0.25)	[3]
	Brazil	144	29	0.17	0.70 (0.43, 1.16)	[51]
	Turkey	118	50.9	<0.001	0.28 (0.17, 0.46)	[52]