Question

Choose the correct sequence of natural course of infectious disease:
• [A.] First symptom development
• [B.] End of infectivity
• [C.] Entry of pathogenic Micro-organism and start of infectivity
• [D.] Clinical Recovery Choose the correct answer from the options given below:

• A. C, A, D, B
• B. A, B, C, D
• C. D, B, A, C
• D. B, A, D, C

Hint:

The course of infectious disease generally follows: Infection $\rightarrow$ Symptoms $\rightarrow$ Recovery $\rightarrow$ End of infectivity.

Answer 1

The Correct Option is A

Concept: The natural course of an infectious disease follows a sequential progression from infection to recovery. The major stages are:
• Entry of pathogen into the body
• Development of symptoms
• Clinical recovery
• End of infectivity This sequence explains how an infection develops and resolves in an individual.

Step 1: Identify the first stage.
The disease begins when the pathogenic microorganism enters the body and infectivity starts. Thus, the first stage is: \[ C \; (\text{Entry of pathogenic Micro-organism and start of infectivity}) \]

Step 2: Identify the second stage.
After the incubation period, symptoms begin to appear. Thus, the second stage is: \[ A \; (\text{First symptom development}) \]

Step 3: Identify the third stage.
The patient then gradually recovers clinically. Thus, the third stage is: \[ D \; (\text{Clinical Recovery}) \]

Step 4: Identify the final stage.
Finally, the infectivity ends and the person no longer transmits the disease. Thus, the last stage is: \[ B \; (\text{End of infectivity}) \]

Step 5: Determine the correct sequence.
Therefore, the correct order is: \[ C \rightarrow A \rightarrow D \rightarrow B \] Hence, the correct answer is: \[ \boxed{(A)\ C, A, D, B} \]