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Table 1 Transmission by Pulex irritans infected using human blood and fed sterile human blood daily starting from day 1–2 after infection (group I)

From: Poor vector competence of the human flea, Pulex irritans, to transmit Yersinia pestis

Day post-infection Total fleas Fed flea number Infection rate (%) Mean CFU/flea Blocked (B) fleas Partially blocked (PB) fleas B + PB fleas (%) Total CFU transmitted CFU transmitted per fed flea
Exp#1 (owl; Fig. 1A)
 0 27 19 80 1.3 × 105
 1 19 15 ND ND 0 0 0 188 12.5
 3 19 19 60 1.7 × 106 0 0 0 0 0
 5 14 14 ND ND 0 0 0 ND ND
 7 12 10 75 1.9 × 106 0 0 0 0 0
Exp #2 (owl; Fig. 1B)  
 0 29 16 100 3.9 × 104
 1 15 13 ND ND 0 0 0 0 0
 3 15 15 60 1.9 × 106 0 0 0 0 0
 5 11 9 91 2.5 × 106 0 0 0 0 0
Exp #3 (fox; Fig. 1C)  
 0 ND 60 100 5.5 × 104
 2 59 49 ND ND 0 0 0 ND ND
 5 43 40 ND ND 0 0 0 0 0
 9 34 24 ND ND 0 0 0 13 0.5
 13 18 15 ND ND 0 0 0 0 0
 16 12 10 75 4.6 × 106 0 0 0 0 0
Exp #4 (fox; Fig. 1D)
 0 70 52 88 1.8 × 106
 2 49 41 ND ND 0 0 0 0 0
 4 47 42 20 1.8 × 106 0 0 0 0 0
 6 37 32 ND ND 0 0 0 0 0
 8 37 36 ND ND 0 0 0 0 0
 10 31 27 ND ND 0 0 0 0 0
 12 28 25 ND ND 0 0 0 ND ND
 14 25 18 ND ND 0 0 0 0 0
 16 25 22 ND ND 0 0 0 0 0
 18 25 24 ND ND 0 0 0 0 0
 20 21 18 23 2.0 × 106 0 0 0 0 0
  1. ND not determined. The source of the fleas used for the experiments (owl or fox) is indicated