This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
The following statements about meningococcal meningitis are true except - 
Select and explain. 
A. The source of in fection is mainly clinical cases, B. The disease is more common in dry and cold month of the year, C. Chemoprophylaxis of close contacts of cases is recommended, D. The vacciens is not effective in children below 2 year of age
A: The source of in fection is mainly clinical cases
Answer: A: The source of in fection is mainly clinical cases 
Explanation: The meningococcal organism is found in the nasopharynx of cases and carriers. Clinical cases present only a negligible source of infection. Reference : Park&;s Textbook of preventive and social medicine, 24th edition.Pg no. 175