The transmission of diseases to a healthy person without intermediate agents is called ________.

Explanation

To solve the question "The transmission of diseases to a healthy person without intermediate agents is called ________," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Disease Transmission**:
- Diseases can be transmitted in various ways. The two primary modes of transmission are direct and indirect transmission.

2. **Defining Direct Transmission**:
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