This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Most important source of infection for meningococci: 
Select and explain. 
A. Case, B. Subclinical infection, C. Carriers, D. Latent case
C: Carriers
Answer: C: Carriers 
Explanation: During periods of endemic disease, about 10% of the general population harbour Neisseria meningitidis in the nasopharynx. 
Since N. meningitidis is a strict human pathogen and most patients have not been in contact with other cases, asymptomatic carriers are presumably the major source of the pathogenic strains.