Which of the following lists are types of communicable diseases?

• A. Bacteria and Virus
• B. Protozoa only
• C. Fungi only
• D. Bacteria, Virus, Fungi, and Protozoa

Answer: (D)

Communicable diseases are illnesses that can be spread from one person to another, from animals to humans, or through the environment. They can be caused by a variety of microorganisms, including bacteria, viruses, fungi, and protozoa. Because all four groups can produce infections that spread between hosts, the list that includes bacteria, viruses, fungi, and protozoa covers all the kinds of organisms capable of causing communicable diseases. Examples include bacteria causing strep throat, viruses like the flu, fungi such as ringworm, and protozoa like malaria. The other options miss one or more groups, so they don’t capture all the possible sources of communicable diseases.