Depressed levels of neutrophils usually indicate what disease or condition?

• A. Active bacterial infection
• B. Active viral infection
• C. Past parasitic infection
• D. Leukemia

Answer: (B)

Neutrophils are the first responders to infections, and their levels rise with bacterial infections. When neutrophils are depressed (neutropenia), it’s commonly seen with viral infections because viruses can transiently suppress bone marrow production or cause neutrophils to migrate out of circulation. So a lower neutrophil count fits the pattern of an active viral infection more than an active bacterial infection, which would usually elevate neutrophils. Leukemia can cause variable counts and isn’t the typical explanation for depressed neutrophils in this question, and past parasitic infection doesn’t specifically explain neutropenia.