Which term describes transmission within a population from a source to a vulnerable person, not from parent to child?

• A. Vertical Transfer
• B. Endemic
• C. Horizontal Transfer
• D. Pandemic

Answer: (C)

Horizontal transmission is about how an infectious agent spreads from an infected person to another person within the same generation, rather than from parent to child. It describes disease spread from source to susceptible individuals who are not offspring of the index case. This is different from vertical transfer, which occurs from parent to child during pregnancy, birth, or breastfeeding.

Endemic refers to a disease that is consistently present in a population or region at a baseline level, not about how it spreads between people. Pandemic describes a disease outbreak that has spread across many countries or continents, indicating geographic reach rather than the route of transmission.