Risk factors for avian influenza virus in backyard poultry flocks and environments in Zhejiang Province, China: a cross-sectional study

Table 3 Univariate analysis of risk factors for avian influenza virus in backyard poultry

Factors	n	Influenza A virus		χ ²	P-value
Factors	n	Negative (%)	Positive (%)	χ ²	P-value
Polyculture of flocks from various sources
No	229	221 (96.51)	8 (3.49)	–	0.77^a
Yes	123	118 (95.93)	5 (4.07)
Types of live poultry
1	195	191 (97.95)	4 (2.05)	6.170	0.013^b
2	135	129 (95.56)	6 (4.44)
3	22	19 (86.36)	3 (13.64)
Number of live poultry
≤ 19	230	225 (97.83)	5 (2.14)	–	0.07^a
≥ 20	122	114 (93.44)	8 (6.56)
Type of nesting area
Enclosed	127	121 (95.28)	6 (4.72)	0.305	0.581
Open	200	193 (96.50)	7 (3.50)
Nesting area(m²)
≤ 19	161	154 (96.65)	7 (4.35)	0.604	0.437^b
20–49	105	101 (96.19)	4 (3.81)
≥ 50	86	84 (97.67)	2 (2.33)
Type of raising
Free ranging	200	194 (97.00)	6 (3.00)	1.284	0.257
In captivity	127	120 (94.49)	7 (5.51)
Clean practice of premises
No	241	229 (95.02)	12 (4.98)	–	0.197^a
Yes	82	81 (98.78)	1 (1.22)
Disinfection practice of premises
No	291	279 (95.88)	12 (4.12)	–	1.000^a
Yes	22	32 (9.88)	1 (3.03)
Sanitary condition of premises
Poor	131	121 (92.37)	10 (7.63)	7.407	0.006^b
Average	189	186 (98.41)	3 (1.59)
Good	8	8 (100)	0 (0.00)
Flocks vaccination history
Yes	65	64 (98.46)	1 (1.54)	–	0.477^a
No	261	249 (95.40)	12 (4.60)
Human infection(H7N9) identified nearby
Yes	46	43 (93.48)	3 (6.52)	–	0.405^a
No	281	271 (96.44)	10 (3.56)
Sick or dead flock
Yes	341	329 (96.48)	12 (3.52)	–	0.236^a
No	7	6 (85.71)	1 (14.29)
Poultry source
From market	280	268 (95.71)	12 (4.29)	–	0.481^a
Not from market	72	71 (98.61)	1 (1.39)

ISSN: 2049-9957