Question

Which of the following is not an example of direct transmission in communicable diseases ?

• A. Transplacental (vertical)
• B. Soil
• C. Respiratory
• D. STD

Answer 1

The Correct Option is C

Step 1: The key is to separate routes where the host meets the agent without an intermediary (direct) from routes that use an external vehicle or air column (indirect).
Step 2: Transplacental passage is mother-to-fetus by direct continuity, soil contact is direct skin contact with contaminated earth, and STDs pass by direct intimate contact. All three are direct.
Step 3: Airborne or respiratory spread relies on droplet nuclei and dust that stay suspended and travel before being inhaled. Because an air medium carries the agent, this is grouped with indirect transmission.
Step 4: Hence the one that is not direct is respiratory.
\[\boxed{\text{Respiratory}}\]