Can a blood routine test detect infection

Blood routine examination can assist in determining the presence of infection. Abnormal indicators such as white blood cell count, neutrophil ratio, and lymphocyte ratio in blood routine examination may be related to infection, but cannot directly determine the specific pathogen type or site of infection.

Blood routine examination is a commonly used basic examination item in clinical practice, which provides clues for infection diagnosis by analyzing the quantity and morphological changes of various cells in the blood. During bacterial infection, the total number of white blood cells and the proportion of neutrophils usually increase, and there may be a phenomenon of left shift of neutrophil nuclei. When infected with a virus, the total number of white blood cells may be normal or low, and the proportion of lymphocytes may increase. Some special infections, such as parasitic infections, may result in an increase in eosinophils. However, it should be noted that these changes are not unique to infections, and factors such as stress, inflammation, and medication can also cause similar changes. In severe infections or sepsis, in addition to changes in white blood cells, there may also be manifestations such as thrombocytopenia and decreased hemoglobin. Chronic infection may lead to an increase in monocytes. The infection symptoms in infants, young children or immunocompromised patients may be atypical, and the white blood cell response may not be significant. Long term use of antibiotics or immunosuppressants may interfere with blood routine results. Blood system diseases, tumors and other non infectious diseases may also lead to abnormal blood routine, which should be identified in combination with other examinations.

Blood routine examination has screening value for infection, but the diagnosis of infection requires comprehensive judgment based on clinical manifestations, pathogen examination, imaging examination, etc. It is recommended to complete relevant examinations under the guidance of a doctor, clarify the diagnosis, and standardize treatment. Daily attention should be paid to personal hygiene, balanced diet, moderate exercise, enhancing immunity, and seeking medical attention promptly when symptoms of infection such as fever occur.