What are the inspection items for influenza? How is influenza diagnosed?

What are the inspection items for influenza? How is influenza diagnosed?

What are the inspection items for influenza? What is influenza?

An examination
1. Peripheral blood test
The total number of white blood cells is generally not high or decreased, and lymphocytes are increased. Severe cases can also be elevated. If combined with bacterial infection, the total number of white blood cells and neutrophils rise.

2. Blood biochemical examination
In some cases, hypokalemia occurred, and in a few cases, creatine kinase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and creatinine were elevated.

3. Pathogen related examination
It mainly includes virus isolation, viral antigen, nucleic acid and antibody detection. Virus isolation is the primary method of laboratory testing; viral antigen and nucleic acid detection can be used for early diagnosis; antibody testing can be used for retrospective investigation, but it is of little significance for early diagnosis of cases.

4. Imaging examination
Some patients may present with signs of bronchial infection with increased bronchial texture. In severe cases, pulmonary invasive lesions or pleural effusion may occur, or even fused into a piece.


Diagnosis
Diagnosis can be made based on the cause, clinical manifestations, and laboratory tests.
Etiology-related tests: mainly include virus isolation, viral antigens, nucleic acids and antibody detection. Virus isolation is the "gold standard" for the diagnosis of the disease; viral antigen and nucleic acid detection can be used for early diagnosis; antibody testing can be used for retrospective investigation, but it is of little significance for early diagnosis of the case.

1.Viral nucleic acid detection
Influenza virus nucleic acids in respiratory specimens (throat swabs, nasal swabs, nasopharyngeal or tracheal extracts, sputum) were detected by RT-PCR (preferably by real-time RT-PCR). Viral nucleic acid detection is the most specific and sensitive, and can quickly distinguish between virus types and subtypes, and generally results in 4-6 hours.

2. Virus isolation and culture
The influenza virus was isolated from respiratory specimens. In the influenza season, patients with negative antigenic diagnosis and immunofluorescence detection of influenza-like cases are also recommended for virus isolation.

3. Virus antigen detection (rapid diagnostic reagent detection)
Rapid antigen detection method can use immunofluorescence method to detect respiratory specimens (pharyngeal swabs, nasal swabs, mucosal epithelial cells in nasopharyngeal or tracheal extracts), and use monoclonal antibodies to distinguish between influenza A and B, generally Get results within a few hours. Others have colloidal gold tests, which generally yield results in 10 to 30 minutes. The interpretation of the rapid test results should be considered in combination with the patient's epidemiological history and clinical symptoms: in the non-epidemic period, the positive screening results may be false positives; in the epidemic period, the negative screening test results may be false negatives; Conditions should be considered for further confirmation using RT-PCR or virus isolation culture.

4. Serological diagnosis
Influenza virus-specific IgM and IgG antibody levels were measured. The recovery period of dynamically detected IgG antibody levels is 4 times or more higher than that of the acute phase.