Table 3 Variables and their associations with Plasmodium qPCR positive results and logistic regression models for the travellers arriving by boat

Sex

 Female

24 (19)

0.4736

Reference group

Reference group

 Male

43 (16)

0.82 (0.47, 1.42)

1.34 (0.71, 2.54)

Age (years)

  < 15

10 (21)

0.4341

Reference group

Reference group

 15 to 29

21 (19)

0.85 (0.37, 1.99)

1.01 (0.40, 2.56)

  ≥ 30

36 (15)

0.64 (0.29, 1.41)

0.88 (0.36, 2.13)

Origin (arriving from)^a

 Low incidence provinces

0 (0)

0.3983

Reference group

Reference group

 Medium incidence provinces

0 (0)

1 (-)

1 (-)

 High incidence provinces

67 (17)

1.21 (0.14, 10.23)

1.99 (0.19, 17.27)

Time away from Lihir (days)^a

  > 12 to 31

22 (10)

0.0003

Reference group

Reference group

 32 to 90

3 (12)

1.18 (0.33, 4.28)

1.20 (0.29, 4.89)

 91 or more

42 (26)

3.01 (1.71, 5.30)

2.35 (1.07, 5.18)

Place while on Lihir

 Mine accommodation

13 (9)

0.0011

Reference group

Reference group

 Londolovit Town

26 (28)

3.74 (1.80, 7.74)

1.64 (0.28, 9.63)

 Villages of Lihir

28 (17)

1.95 (0.97, 3.94)

0.87 (0.15, 5.07)

Intention of the visit

 Returning resident/VFR

25 (20)

0.0066

Reference group

Reference group

 Mine worker

13 (9)

0.39 (0.19, 0.79)

0.59 (0.10, 3.50)

 Trading unrelated to mining

23 (25)

1.29 (0.68, 2.46)

1.07 (0.54, 2.13)

 Other purpose

6 (14)

0.61 (0.23, 1.61)

0.55 (0.20, 1.53)

Frequency of sleeping under net while away from Lihir^a

 Never

32 (14)

0.6155

Reference group

Reference group

 Some nights

20 (19)

1.34 (0.73, 2.48)

1.23 (0.65, 2.34)

 Most of the nights

4 (12)

1.05 (0.38, 2.93)

0.72 (0.24, 2.19)

 Always

7 (21)

2.13 (0.91, 4.97)

2.14 (0.84, 5.48)

Slept under net while away from Lihir ^a

 No

32 (14)

0.1894

Reference group

Not considered for this analysis

 Yes

34 (9)

1.42 (0.84, 2.42)