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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