Subclinical cases are seen in all except-: (A) Measles, (B) Rubella, (C) Polio, (D) Influenza
Answer is A. The only source of infection is a case of measles Carriers are not known to occur. There is some evidence to suggest that subclinical measles occurs more frequently than previously thought. Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 159