Leukocytosis and neutrophilia are commonly seen in which type of infection?

Bacterial infections are typically associated with leukocytosis and neutrophilia, which are indicators of the body’s response to infection. Leukocytosis refers to an increased number of white blood cells (WBCs) in the bloodstream, while neutrophilia specifically denotes an increase in neutrophils, a type of WBC that plays a crucial role in fighting bacterial infections.

During a bacterial infection, the immune system responds by rapidly producing more neutrophils to combat the invading bacteria. This increase is often detectable through laboratory tests and serves as an important diagnostic marker. In many cases, healthcare providers look for these elevated levels of neutrophils when assessing patients suspected of having a bacterial infection, such as pneumonia, appendicitis, or sepsis.

In contrast, other types of infections—such as viral infections—often lead to different changes in white blood cell counts, typically showing lymphocytosis (an increase in lymphocytes) instead of a significant increase in neutrophils. Fungal and parasitic infections might also provoke distinct immune responses that do not primarily involve neutrophilia. Therefore, the specificity of neutrophilia to bacterial infections makes this the most accurate answer.