Comparison of the transmission efficiency and plague progression dynamics associated with two mechanisms by which fleas transmit Yersinia pestis
Fig 5
Distribution of outcomes following early-phase transmission challenges by fleas infected using mouse blood (blue bars) or rat blood (red bars); or following bites by blocked fleas (grey bars).
Data are from Table 1. Productive transmission (Outcome I) is defined as terminal sepsis and bacteremia required to continue the Y. pestis life cycle; the solid portion of the bars represents the percentage of rapid onset (Outcome IA) and the hatched portion prolonged onset (Outcome IB) terminal disease. Nonproductive transmission (Outcome II) is defined as an infection that is resolved before systemic dissemination and terminal sepsis, thus precluding continuation of the flea-borne transmission cycle of Y. pestis. These mice mount an immune response and are at least temporarily removed from the pool of susceptibles in the population. No evidence of infection (no transmission; Outcome III) was detected in other mice following flea bite challenge.