Table 3 Bivariate analysis of factors associated with A(H5N1) virus infection in humans, data from matched case-control studies in 2006, 2007, 2009, Cambodia

All ages

(n = 115)

(n = 35)

Poultry cage or nest located under or adjacent to the house

36/68 (52.9)

14/18 (77.8)

3.2

0.9−11.0

0.060

Having a pond in the house yard

49/115 (42.6)

10/35 (28.6)

0.4

0.1−1.2

0.109

Swimming or bathing in ponds accessed by poultry

35/115 (30.4)

14/35 (40.0)

2.1

0.9−4.8

0.099

Swimming or bathing in ponds visited by domestic and wild poultry

19/65 (29.2)

8/17 (47.1)

2.2

0.7−6.8

0.157

Feeding poultry

84/115 (73.0)

20/35 (57.1)

0.4

0.2−1.0

0.055

Collecting poultry feces for use as fertilizer

22/91 (24.2)

3/28 (10.7)

0.4

0.1−1.4

0.141

Presence of SD animals in the house or house yard

59/92 (64.1)

11/25 (44.0)

0.4

0.2−1.1

0.083

Presence of SD poultry in neighboring households

61/90 (67.8)

12/28 (42.9)

0.4

0.1−0.9

0.023

Handling SD with bare hands

64/115 (55.7)

15/35 (42.9)

0.6

0.3−1.3

0.181

Preparing SD poultry for food

34/115 (29.6)

7/35 (20.0)

0.5

0.1−1.4

0.178

Eating food prepared from SD poultry

57/91 (62.6)

10/28 (35.7)

0.3

0.1−0.8

0.015

Handling SD wild birds

8/92 (8.7)

5/25 (20.0)

2.4

0.8−7.8

0.131

Transporting poultry to trade

2/92 (2.2)

3/25 (12.0)

6.0

1.0−35.9

0.050

Presence of a household member with flu-like illness during the outbreak

60/115 (52.2)

15/35 (42.9)

0.5

0.2−1.2

0.108

Providing care for the case during his/her illness or for the case's corpse

21/92 (22.8)

2/25 (8.0)

0.3

0.1−1.4

0.120

Age <20 years old

(n = 77)

(n = 22)

Poultry cage or nest located under or adjacent to the house

23/43 (53.5)

9/11 (81.8)

4.1

0.8−21.7

0.095

Having a pond in the house yard

37/77 (48.1)

7/22 (31.8)

0.1

0.02−1.2

0.076

Swimming or bathing in ponds also accessed by poultry

28/77 (36.4)

12/22 (54.6)

2.6

0.9−7.3

0.065

Swimming or bathing in ponds also accessed by wild birds

16/42 (38.1)

7/11 (63.6)

2.9

0.8−11.4

0.119

Feeding poultry

59/77 (76.6)

12/22 (54.6)

0.2

0.05−0.8

0.027

Presence of SD poultry in neighboring households

33/53 (62.3)

6/15 (40.0)

0.4

0.1−1.4

0.145

Handling SD with bare hands

44/77 (57.1)

9/22 (40.9)

0.5

0.2−1.4

0.161

Eating food prepared from SD poultry

31/53 (58.5)

5/15 (33.3)

0.3

0.08−1.2

0.096

Handling SD wild birds

6/67 (9.0)

5/18 (27.8)

3.3

0.9−11.7

0.059

Eating food prepared from wild birds

18/67 (26.9)

9/18 (50.0)

3.5

0.98−12.7

0.054

Age ≥20 years old

(n = 38)

(n = 13)

Gathering and placing poultry in their cages or area

15/38 (39.5)

9/13 (69.2)

3.0

0.8−11.6

0.104

Presence of SD animals in the house of house yard

16/38 (64.0)

2/13 (28.6)

0.2

0.02−1.8

0.142

Presence of SD poultry in neighboring households

28/37 (75.7)

6/13 (46.2)

0.3

0.07−1.2

0.079

Eating food prepared from SD poultry

26/38 (68.4)

5/13 (38.5)

0.2

0.05−1.2

0.075