Bacterial vs. Viral Infection – Blood Test Results
Complete Blood Count (CBC) is a common and well-known blood test that doctors use to assess general health and detect various disorders, including infections.
When it comes to distinguishing between bacterial and viral infections, certain CBC parameters provide key insights – reports Sombor.info.
Key CBC Components Related to Infection
Leukocytes – These cells help our body fight infections. The total white blood cell count shows whether there is an infection present in the body.
Neutrophils – A type of white blood cell that is most commonly elevated in bacterial infections.
Lymphocytes – Another type of white blood cell, typically elevated in viral infections.
Monocytes, eosinophils, and basophils – Other types of leukocytes that provide additional insight into our immune response.
Differences in CBC Results for Bacterial and Viral Infections
Total White Blood Cell Count:
Bacterial Infections – Often cause an increase in the total number of white blood cells. This is known as leukocytosis.
Viral Infections – May not significantly increase the total white blood cell count and can sometimes lead to a decrease (leukopenia).
Neutrophils:
Bacterial Infections – Usually cause an increase in neutrophils, especially immature ones (known as band neutrophils). This phenomenon is called a "left shift."
Viral Infections – Typically do not cause an increase in neutrophils and may even decrease their absolute number.
Lymphocytes:
Bacterial Infections – Typically do not cause an increase in lymphocytes.
Viral Infections – Usually lead to an increase in lymphocytes. This is known as lymphocytosis.
Example of a Bacterial Infection:
A patient with a bacterial infection may have a high white blood cell count, a large number of neutrophils, and possibly an increased number of immature neutrophils (bands).
Example of a Viral Infection:
A patient with a viral infection may have a normal or slightly reduced white blood cell count, with a higher proportion of lymphocytes.
Why Is This Important?
“Understanding these differences helps doctors decide on treatment and therapy plans. Bacterial infections are often treated with antibiotics, while viral infections are not,” explains biochemist Mr. Sonja Šuput for Stetoskop.
The misuse of antibiotics can lead to resistance, which is why properly identifying the type of infection is crucial.
“Although CBC results can provide important clues for treatment, they are just one part of the diagnostic puzzle. Clinicians consider these results along with symptoms, physical examination findings, and other test results to make a comprehensive diagnosis,” she adds.
