What is a vector mode of transmission?

• A. Water, blood, or food
• B. a tick, flea, or mosquito
• C. Direct contact with contaminated objects
• D. Something expelled from coughing, sneezing, or talking

Answer: (B)

Vector transmission occurs when a living organism, typically an arthropod such as a tick, flea, or mosquito, carries a pathogen from one host to another. These vectors are not usually sick themselves, but their biology allows the pathogen to move between people or animals—often through their bite or feeding activity. That’s why a tick, flea, or mosquito is the classic example of a vector: they acquire the pathogen from an infected source and then pass it to a new host during contact.

Understanding this helps distinguish vector transmission from other routes. Water, blood, or food can transport pathogens as a vehicle, direct contact with contaminated objects is fomite transmission, and coughing, sneezing, or talking can spread droplets or airborne particles.