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: Social & Preventive Medicine
[{'content': 'True about carriers ? \nSelect and explain. \nA. Infection with clinical symptoms, B. Serves as source of infection, C. More infectious than cases, D. Less dangerous than cases', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is \'b\' i.e., Serves as source of infection A carrier is defined as "an infected person or animal that harbours a specific infectious agent in the absence of clinical disease and serves as a potential source of infection". As a rule carriers are less infectious than cases, but epidemiologically they are more dangerous than cases because they escape recognition, and continuing as they do to live a normal life among the population or comunity, they readily infect the susceptible individuals over a wider area and longer period of time.', 'role': 'assistant'}]