Plague is most commonly transmitted from reservoir species to people by

• A. Aerosol Transmission From Animals With Pneumonic Plague
• B. Bites From Infected Fleas
• C. Direct Transmission From Exudates Of Ruptured Bubos
• D. Bites From Infected Animals

Answer: (B)

The main idea is how the plague bacterium moves from rodent reservoirs into humans via a vector. Yersinia pestis cycles in rodent populations, and fleas that feed on these infected rodents become carriers. After the bacterium blocks the flea’s gut, the flea bites more aggressively and transmits the bacteria to humans during feeding. This flea-mediated transmission is the most common way humans acquire plague from reservoir species.

Direct contact with buboes or their exudates can cause infection if someone handles infected tissue, but this route is far less common in the typical reservoir-to-human spillover. Aerosol transmission from animals with pneumonic plague can occur, yet it’s not the usual route for transferring plague from reservoirs to people. Being bitten by an infected animal is possible, but the efficient and prevalent route is the flea bite.