Table 2 Participant’s risk factors of COVID-19 exposure at screening and the first month of follow-up

Number of cohabitants (median, IQR)

2

[1–3]

1.5

[1–3]

1

[1–3]

2

[1–3]

 Confirmed cases (median, IQR)

1

[1–1]

1

[1–1]

1

[1–1]

1

[1–1]

 Suspected cases (median, IQR)

3

[3–3]

3

[3–3]

3

[3–3]

3

[3–3]

Used public transportation^a

54

43.2

55

38.7

56

48.7

58

42.3

Close contact with animals^a

26

20.8

36

25.5

39

33.6

52

38.0

Use of COVID-19 recommended PPE at work^a,b

 Always

107

86.3

117

82.4

111

95.7

135

98.5

 Almost always

8

6.5

11

7.7

4

3.4

2

1.5

 Sometimes

2

1.6

5

3.5

1

0.9

0

0.0

 Occasionally

2

1.6

1

0.7

0

0.0

0

0.0

 Never

5

4.0

8

5.6

0

0.0

0

0.0

Close contact with a confirmed COVID-19 case without using PPE^a

35

28.0

34

23.9

17

14.7

7

5.1

If yes, how many

 1

20

57.1

11

32.4

9

56.2

3

42.9

 2–3

10

28.6

18

59.2

7

43.8

3

42.9

 ≥ 4

5

14.3

5

14.7

0

0

1

14.3

If yes, how frequently

 Every day

16

48.5

13

38.2

2

11.8

0

0.0

 ≥ 1/week

8

24.2

10

29.4

8

47.1

5

83.3

 < 1/week

9

27.3

13

38.2

9

42.1

1

16.7

Close contact with a suspected COVID-19 case without using PPE^a

19

15.2

15

10.6

5

4.3

6

4.4

If yes, how many

 1

7

36.8

6

40.0

1

20.0

3

50.0

 2–3

6

31.6

7

46.7

2

40.0

2

33.3

 ≥ 4

6

31.6

2

13.3

2

40.0

1

16.7

If yes, how frequently

 Every day

8

44.4

3

20.0

1

20.0

1

16.7

 ≥ 1/week

6

33.3

8

53.3

2

40.0

4

67.7

 <  1/week

4

22.2

4

26.7

2

40.0

1

16.7