In the context of innate immunity, what is a primary pathogen?

• A. An organism that can cause disease in a healthy host
• B. An organism that is part of the normal flora
• C. A microorganism that only causes disease in immunocompromised individuals
• D. A pathogen that requires a vector for transmission

Answer: (A)

Verified step by step guidance

1. Understand the concept of innate immunity: Innate immunity is the body's first line of defense against pathogens, providing a non-specific response to invading organisms.
2. Define a primary pathogen: A primary pathogen is an organism that can cause disease in a healthy host, meaning it does not require the host to be immunocompromised or have any pre-existing conditions to cause illness.
3. Differentiate between primary and opportunistic pathogens: Opportunistic pathogens typically cause disease only in hosts with weakened immune systems, whereas primary pathogens can infect healthy individuals.
4. Consider the role of normal flora: Normal flora are microorganisms that reside in the body without causing disease under normal circumstances. They are not considered primary pathogens.
5. Evaluate the need for a vector: Some pathogens require a vector, such as a mosquito, for transmission. This characteristic does not define a primary pathogen, as primary pathogens can directly infect a host without a vector.