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Table 4 An. gambiae entry risks modelled for holes representing the minimum, mid-point and maximum diameters (modelled as widths) for each WHOPES pHI size class

From: How many holes is too many? A prototype tool for estimating mosquito entry risk into damaged bed nets

pHI size class

Size class diameters (mm)

Modelled riska

Risk range

Minimum

Mid-range

Maximum

Minimum

Mid-range

Maximum

Within classification

Mid-range to mid-range

Smaller than thumb

5b

12.5

20

0.002

0.044

0.141

70.5×

NA

Thumb-fist

20

60

100

0.141

2.074

6.711

47.6×

47.1×

Fist-head

100

175

250

6.711

20.286

41.180

6.1×

9.8×

Larger than head

250

300c

NA

41.180

59.177

NA

1.4×

2.9×

  1. aRisk expressed as average number of mosquitoes expected to enter the net per hour through a round hole of given dimensions in the roof assuming the ‘one-mosquito-constantly-present’ model. Numbers expected to enter through same size holes in the sides is much smaller but ratios of risk (risk range) are similar to those for roof hole
  2. bThe tool assigns zero risk to holes 5 mm in diameter and smaller; therefore, minimum risk for this size class calculated using 6 mm diameter
  3. c30 cm (300 mm) used as ‘middle of range’ value in pHI calculations