Someone who is infected by a disease but shows no signs or symptoms is called a

• A. Carrier
• B. Convalescent
• C. Sterile
• D. Resident

Answer: (A)

An individual who is infected but shows no signs is described as a carrier. This concept highlights asymptomatic carriage, where someone harbors the pathogen and can still pass it on to others even though they feel fine. Carriers are important in disease control because they can sustain transmission within a population without obvious illness.

The other terms don’t fit this situation: a convalescent person is someone who is recovering from illness; sterile means free from microorganisms; and a resident is simply someone living somewhere, with no implication about infection.