Elevated levels of which laboratory parameter would suggest a viral infection?

• A. Monocytes
• B. Lymphocytes
• C. Neutrophils
• D. Eosinophils

Answer: (B)

Elevated levels of lymphocytes are indicative of a viral infection due to the role these white blood cells play in the immune response. Lymphocytes are primarily responsible for orchestrating the adaptive immune response, which is crucial in combating viral pathogens. When the body is exposed to a virus, lymphocyte counts typically increase as the immune system activates to identify and eliminate the viral agents.

In contrast, other types of white blood cells generally react differently based on the type of infection. For example, neutrophils are often elevated in bacterial infections, and eosinophils are usually associated with allergic reactions or parasitic infections. Monocytes may increase in certain infections, but they are not as specifically associated with viral infections as lymphocytes are. Therefore, a significant elevation in lymphocytes strongly points towards a viral etiology of the illness.