[Diversity of flea vectors as a function of plague foci]

Area of Science:

• Epidemiology
• Infectious Diseases
• Zoology

Background:

• The traditional Indian model posits Xenopsylla cheopis as the primary vector for plague transmission.
• This model, while widely accepted, has faced scrutiny regarding its accuracy and completeness.

Purpose of the Study:

• To critically evaluate the role of Xenopsylla cheopis in plague transmission.
• To identify the key factors contributing to the historical spread and persistence of plague.

Main Methods:

• Review of historical data on plague epidemiology.
• Analysis of the life cycle and ecological niche of Xenopsylla cheopis.
• Examination of the relationship between Yersinia pestis, rodent populations, and flea vectors.

Main Results:

• Xenopsylla cheopis is unlikely to be the primitive or sole vector of plague.
• Proventriculus blocking in X. cheopis impairs its life cycle.
• Plague's global spread resulted from a combination of synanthropic rats, X. cheopis, Yersinia pestis, and human seafaring.

Conclusions:

• The established plague transmission model requires revision, acknowledging the limitations of Xenopsylla cheopis as the sole vector.
• Plague's pandemic potential was amplified by its dissemination across diverse biogeographical zones.
• The long-term persistence of plague involves adaptation to various endemic fleas and animal hosts, with X. cheopis not always implicated in sylvatic plague maintenance.