How do mice transmit plague? - briefly
Mice harbor Yersinia pestis and pass it to humans primarily through flea vectors that feed on the rodents and then bite people. Direct exposure to infected mouse blood or tissues can also result in transmission.
How do mice transmit plague? - in detail
Mice act as reservoirs for Yersinia pestis, the bacterium that causes plague. The pathogen persists in the animal’s bloodstream, allowing several mechanisms of spread.
When an infected mouse dies, its body decomposes, releasing bacteria into the surrounding environment. Scavengers and other rodents may ingest contaminated tissue, acquiring the infection and continuing the cycle.
Ectoparasites, primarily fleas, feed on the blood of infected mice. During a blood meal, a flea ingests bacteria, which multiply within the insect’s foregut. The flea becomes blocked, a condition that forces it to attempt repeated feeding. Each unsuccessful bite injects bacteria into new hosts, including other mice, rats, and occasionally humans.
Direct contact also contributes to transmission. Handling of live or dead rodents without protective equipment can transfer bacteria to skin abrasions or mucous membranes. Laboratory or field workers who capture mice may acquire infection through accidental inoculation.
Environmental contamination plays a secondary role. Excreta from infected mice contain viable bacteria, which can survive for days in cool, moist conditions. Human exposure to contaminated dust or soil, especially in rural settings, may result in inhalation of aerosolized particles, leading to pneumonic forms of the disease.
Key points of the transmission process:
- Bacterial persistence in mouse bloodstream and tissues.
- Flea-mediated blockage causing repeated inoculation.
- Scavenger and rodent predation on carcasses.
- Direct handling without protective barriers.
- Environmental reservoirs in feces and carcass remnants.
Control measures focus on reducing rodent populations, applying insecticides to limit flea vectors, and implementing strict hygiene protocols for individuals who handle rodents. Monitoring rodent plague prevalence through serological testing informs timely intervention and prevents spillover to human populations.