Table 4 Comparison of positive rates of environmental surveillance for H7N9 virus by residential area (urban and rural) — Zhejiang Province, China, March 2013-February 2015

Towns, % (positive towns/total towns)

2.9 (1/35)

7.3 (4/55)

0.645

25.4 (35/138)

15.6 (34/218)

0.028

29.1 (23/79)

40.3 (81/201)

0.099

33.7 (56/166)

31.0 (105/339)

0.543

0.008

<0.001

Premises, % (positive premises/total premises)

1.7 (1/60)

3.7 (4/108)

0.656

13.7 (49/358)

8.5 (42/497)

0.018

21.2 (35/165)

32.2 (101/314)

0.014

15.4 (85/551)

16.3 (145/889)

0.711

<0.001

<0.001

Environment samples of different premises, % positive specimens/ total specimens)

0.6 (3/472)

0.9 (8/879)

0.756

5.8 (188/3221)

2.1 (94/4444)

<0.001

8.0 (97/1207)

14.2 (382/2697)

<0.001

5.9 (288/4900)

6.0 (484/8020)

0.730

<0.001

<0.001

 Live poultry markets

1.2 (3/252)

1.7 (4/229)

0.714

7.1 (188/2637)

3.8 (92/2427)

<0.001

8.7 (59/675)

18.1 (343/1894)

<0.001

7.0 (250/3564)

9.6 (439/4550)

<0.001

<0.001

<0.001

 Poultry rearing farms

0.0 (0/128)

1.2 (4/337)

0.579

0.0 (0/184)

0.2 (2/944)

1.000

0.0 (0/165)

0.0 (0/287)

-

0.0 (0/477)

0.4 (6/1568)

0.346

-

0.019

 Concentrated areas of backyard poultry farms

0.0 (0/15)

0.0 (0/200)

-

0.0 (0/157)

0.0 (0/891)

-

0.0 (0/60)

1.1 (2/186)

1.000

0.0 (0/232)

0.2 (2/1277)

1.000

-

0.017

 Slaughtering and processing plants

0.0 (0/11)

0.0 (0/6)

-

0.0 (0/77)

0.0 (0/44)

-

9.2 (12/131)

9.1 (5/55)

1.000

5.5 (12/219)

4.8 (5/105)

1.000

0.010

0.057

 Habitats for migratory birds

0.0 (0/19)

0.0 (0/67)

-

0.0 (0/14)

0.0 (0/84)

-

0.0 (0/6)

0.0 (0/81)

-

0.0 (0/39)

0.0 (0/232)

-

-

-

 Others

0.0 (0/47)

0.0 (0/40)

-

0.0 (0/152)

0.0 (0/54)

-

15.3 (26/170)

16.5 (32/194)

0.776

7.0 (26/369)

11.1 (32/288)

0.073

<0.001

<0.001

Environment samples of different types, % (positive specimens/total specimens)

0.6 (3/472)

0.9 (8/879)

0.756

5.8 (188/3221)

2.1 (94/4444)

<0.001

8.0 (97/1207)

14.2 (382/2697)

<0.001

5.9 (288/4900)

6.0 (484/8020)

0.730

<0.001

<0.001

 Fecal dropping swab

0.0 (0/190)

0.5 (2/432)

1.000

2.7 (26/977)

1.7 (33/1897)

0.126

4.1 (17/410)

12.3 (156/1273)

<0.001

2.7 (43/1577)

5.3 (191/3602)

<0.001

0.004

<0.001

 Poultry cage swab

0.0 (0/114)

0.0 (0/167)

-

7.6 (60/786)

2.0 (19/970)

<0.001

8.7 (17/196)

12.4 (67/540)

0.190

7.0 (77/1096)

5.1 (86/1677)

0.039

0.013

<0.001

 Drinking water sample

0.0 (0/47)

1.5 (2/131)

1.000

5.5 (16/289)

1.2 (7/578)

<0.001

5.9 (6/102)

12.8 (28/219)

0.079

5.0 (22/438)

4.0 (37/928)

0.394

0.251

<0.001

 Sewage of cleaning poultry

0.0 (0/30)

2.7 (1/37)

1.000

6.3 (25/400)

3.5 (14/395)

0.100

14.0 (18/129)

26.2 (43/164)

0.013

7.7 (43/559)

9.7 (58/596)

0.252

0.001

<0.001

 Swab of tables for slaughtering or processing poultry

2.9 (1/34)

0.0 (0/23)

1.000

7.7 (39/509)

4.0 (15/375)

0.032

9.0 (20/223)

18.1 (73/403)

0.002

7.8 (60/766)

11.0 (88/801)

0.038

0.305

<0.001

 Others

3.5 (2/57)

3.4 (3/89)

1.000

8.5 (22/260)

2.6 (6/229)

0.006

12.9 (19/147)

15.3 (15/98)

0.706

9.3 (43/464)

5.8 (24/416)

0.056

0.029

0.001