Question

Given below are two statements:
Statement (I): Scarlet fever is caused by Streptococcus pyogenes
Statement (II): Dick test is used for screening susceptible individuals to scarlet fever.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are true
• B. Both Statement (I) and Statement (II) are false
• C. Statement (I) is true but Statement (II) is false
• D. Statement (I) is false but Statement (II) is true

Hint:

Remember these classical diagnostic skin tests:
- Dick Test \(\rightarrow\) Susceptibility to Scarlet Fever (Streptococcus pyogenes erythrogenic toxin).
- Schick Test \(\rightarrow\) Susceptibility to Diphtheria (Corynebacterium diphtheriae toxin).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Scarlet fever is an acute, contagious infectious disease that historically posed a significant public health challenge, often transmitted through contaminated raw milk.
Diagnostic and screening tests are used to determine susceptibility or immunity to the toxins produced by the causative organism.

Step 2: Detailed Explanation:
Let us evaluate both statements:
-Statement (I): "Scarlet fever is caused by Streptococcus pyogenes."
This statement is true.
Scarlet fever (scarlatina) is caused by Group A \(\beta\)-hemolytic streptococci, primarily Streptococcus pyogenes.
The characteristic red skin rash and strawberry tongue associated with the disease are caused by erythrogenic (pyrogenic) exotoxins released by the bacteria.
-Statement (II): "Dick test is used for screening susceptible individuals to scarlet fever."
This statement is true.
The Dick test, developed by George and Gladys Dick, is a skin test used to determine susceptibility or immunity to scarlet fever.
In this test, a small, standardized dose of diluted erythrogenic toxin is injected intradermally into the forearm.
- Apositive reaction (redness and local inflammation at the injection site after 24 hours) indicates that the individual lacks neutralizing antibodies and is susceptible to the disease.
- Anegative reaction (no inflammation) indicates the presence of protective antitoxin antibodies, representing immunity to the erythrogenic toxin.
Thus, both Statement (I) and Statement (II) are true.

Step 3: Final Answer:
Both Statement (I) and Statement (II) are true, which corresponds to Option (A).