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Table 5 Predicted estimates of prevalence (%) of patent infection for a given (2-snip) sensitivity and observed prevalence of microfilariae

From: Modelling Neglected Tropical Diseases diagnostics: the sensitivity of skin snips for Onchocerca volvulus in near elimination and surveillance settings

Per ivermectin dose reduction in microfilarial production 1 year after last treatment 3 years after last treatment 5 years after last treatment
Sensitivitya Prevalence (%) Sensitivitya Prevalence (%) Sensitivitya Prevalence (%)
   Obsb Pred   Obsb Pred   Obsb Pred
0 % reduction per treatment          
  31 % 0.25 0.8 67 % 0.25 0.4 76 % 0.25 0.3
  0.5 1.6 0.5 0.7 0.5 0.7
  1.0 3.2 1.0 1.5 1.0 1.3
7 % reduction per treatment          
  18 % 0.25 1.4 51 % 0.25 0.5 62 % 0.25 0.4
  0.5 2.8 0.5 1.0 0.5 0.8
  1.0 5.6 1.0 2.0 1.0 1.6
35 % reduction per treatment          
  0.6 % 0.25 nac 3.0 % 0.25 8.3 4.7 % 0.25 5.3
  0.5 nac 0.5 nac 0.5 nac
  1.0 nac 1.0 nac 1.0 nac
  1. aSensitivity for 2 skin snips based on k m  = 0.42 (mean of the country-specific estimates for 1–10 adult female worms)
  2. bObserved prevalence based on 2 skin snips
  3. c na not applicable, we do not present predicted prevalence when greater than 10 % since eqn [6] is only valid when infection is rare