Question

Wild rodents are the major reservoir of the plague organism, Yersinia pestis, but pandemic plagues were historically associated with crowded, unsanitary urban areas. Why is this the case?

Answer 1

Yersinia pestis can be transmitted by fleas from wild rodents to urban rats, which quickly die of the disease. Humans are accidental hosts due to fleas seeking out blood meals after most rats have succumbed to the disease.

Step-by-step explanation: