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Table 4 Transmission by Pulex irritans using rat blood and subsequently fed sterile rat blood every 2 to 3 days (group IV)

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. 4A)         
 0 ND 54 100 4.9 × 103
 3 29 25 ND ND 0 0 0 0 0
 6 21 19 ND ND 0 4 21 0 0
 8 17 13 ND ND 1 3 31 59 4.5
 10 8 7 50 2.9 × 106 0 0 0 0 0
Exp #2 (owl; Fig. 4B)        
 0 ND 57 100 6.1 × 104
 3 36 36 ND ND 0 4 11 23 0.6
 6 19 19 ND ND 0 0 0 107 5.6
 8 11 11 89 ND 3 4 64 306 28
 10 4 4 100 4.2 × 106 0 1 25 97 24
Exp #3 (fox; Fig. 4C)         
 0 ND 108 100 2.1 × 104
 3 97 90 100 3.3 × 106 0 1 1 81 0.9
 5 94 30 92 1.9 × 106 0 7 23 0 0
 7 55 43 90 2.3 × 106 0 0 0 0 0
 9 30 26 ND ND 4 1 19 7 0.3
 11 20 14 ND ND 1 0 7 4 0.3
 13 11 6 58 3.4 × 105 0 0 0 0 0
Exp #4 (fox; Fig. 4D)          
 0 ND 111 100 5.3 × 103
 2 101 78 88 1.9 × 106 0 0 0 3 0.04
 4 73 61 ND ND 0 0 0 ND ND
 6 48 41 ND ND 1 0 2 25 0.6
 8 39 32 ND ND 1 1 3 27 0.8
 10 22 15 ND ND 1 0 7 0 0
 12 10 6 58 2.9 × 106 0 0 0 0 0
Exp #5 (fox; Fig. 4E)        
 0 ND 124 88 3.7 × 103
 2 117 94 ND ND 0 0 0 0 0
 4 74 58 20 5.4 × 105 0 0 0 0 0
 6 63 53 ND ND 0 0 0 0 0
 8 45 35 ND ND 0 0 0 0 0
 10 42 22 ND ND 0 1 5 2 0.1
 12 37 25 ND ND 0 0 0 0 0
 14 49 22 ND ND 0 0 0 0 0
 16 53 47 ND ND 0 0 0 0 0
 18 45 15 ND ND 0 0 0 0 0
 20 44 36 ND ND 0 0 0 0 0
 22 38 9 ND ND 0 0 0 0 0
 24 36 35 ND ND 0 0 0 0 0
 26 35 30 0 0 0 0 0 0 0
  1. ND not determined. The source of the fleas used for the experiments (owl or fox) is indicated