Recently, there is a high incidence of respiratory diseases in children, and how to quickly diagnose diseases based on routine blood results is particularly important
Influenza A and B virus infection.
Routine blood tests usually show a normal or decreased total white blood cell count, especially early in the course of the diseaseCRP may be normal or mildly elevated, and lymphocyte counts may be markedly low in severe cases, often elevated in monocytesNeutrophils may be in the normal range or low. However, when bacterial infection is comorbid, the total number of white blood cells and neutrophils increases, and the red blood cell and platelet counts are generally not affected. Timely detection of peripheral blood flow A and B antigens is of great significance for rapid diagnosis. Expert Consensus on the Diagnosis of Influenza in Children (2020 Edition).
Mycoplasma pneumoniae infection.
1. In the early stage of infection, the total number of white blood cells in the peripheral blood routine of the child was mostly normal or slightly low, CRP and neutrophils were normal, lymphocytes were normal or slightly increased, and monocytes were slightly increased
2. Children with severe infection usually have varying degrees of increase in the total number of white blood cells, the proportion of neutrophils, and CRP 3 days after fever.
It can be seen that in the early stage of Mycoplasma pneumoniae infection or mild infection, the clinical diagnostic value of routine blood + CRP testing is low.
Culture of Mycoplasma pneumoniae is the gold standard for diagnosing MP infection, but it is difficult to use for clinical diagnosis because culture requires special conditions and slow growth.
At present, the immunocolloidal gold method is widely used in clinical practice, and a positive LGM antibody indicates Mycoplasma pneumoniae infection, and a negative negative does not completely rule out Mycoplasma pneumoniae infection, which is suitable for rapid screening of children in outpatient and emergency departments, but false positives can also occur, so the determination of antibody test results also needs to be combined with clinical and imaging characteristics for comprehensive analysis.
Bacterial pneumonia is usually characterized by a marked increase in the total number of white blood cells, especially the total number and proportion of neutrophils, a marked increase in CRP, and a decrease in the proportion of lymphocytes. In addition, red blood cell counts are usually normal and platelet counts are normal or only mildly elevated.
However, in long-term or severe infections, peripheral white blood cell counts and red blood cell counts may be reduced. Summary of routine blood differences in influenza, Mycoplasma pneumoniae and bacterial infections:
Autumn and Winter Check-in Challenge