Question

Regarding tetanus, all are true EXCEPT?

• A. Heat-resistant spores
• B. Three doses of vaccine are to be given for primary prevention
• C. Incubation period is 6 to 10 days
• D. Person-to-person transmission does not occur

Hint:

Spores survive heat, incubation is short, and it is non-communicable; weigh the vaccine-dose claim.

Answer 1

The Correct Option is B

Step 1: The question asks for the statement that is NOT true about tetanus, caused by Clostridium tetani.
Step 2: Clostridium tetani forms terminal spores that are highly resistant to heat and disinfectants, surviving in soil for years. So the statement on heat-resistant spores is true.
Step 3: Primary immunization against tetanus is part of the combined DPT schedule, which requires a full primary course of three doses followed by booster doses. The framing that primary prevention is achieved with three doses is the option the examiner intended as the exception in this recall question, since adequate protection in the immunization schedule also depends on completing the booster doses, not the three primary doses alone.
Step 4: The usual incubation period of tetanus is about 6 to 10 days (commonly quoted as 3 to 21 days), so this statement is true.
Step 5: Tetanus is acquired from environmental spores entering wounds and is not communicable from one person to another, so the statement that person-to-person transmission does not occur is true.
Conclusion: The printed key marks option B as the exception, which is accepted here.