The duration of the persistence of the plaque microbe in the body of the flea Citellophilus tesquorum altaicus

Experiments have established that the plague bacillus persists long in the flea C. tesquorum altaicus in the Tuva natural foci. Experimentally, 64.2 to 77.3% of the fleas inoculated in autumn survived winter. More than one-half preserved the plague bacillus. From 0.7 to 19.4% of the inoculated fleas survived from one summer to another. The plague persisted in 30% of the insects. Individual C. tesquorum altaicus females survived two winters, preserving the bacillus for 21.5-22.0 months. The fact that the fleas has survived both one and two winter periods in coma transmitted the plague bacillus to healthy sousliks has been recorded. Rather late periods (278-411 days) of blocking the fleas after the insects' inoculating feeding have been defined.