How to Determine if It's the Flu
Feb 08, 2025
Source: Cainiu Health
Dr. Ren Yi
Introduction
Influenza refers to the flu. Methods to determine whether someone has the flu include taking an epidemiological history, observing clinical symptoms, antigen testing, nucleic acid testing, and serological testing. If necessary, testing is recommended under a doctor's guidance. Ask whether the patient had close contact with suspected or confirmed flu cases, or was exposed to an environment where clusters of flu-like illnesses occurred, within 7 days prior to symptom onset.
Influenza refers to the flu. Methods to determine whether it is influenza include inquiry about epidemiological history, observation of clinical symptoms, antigen testing, nucleic acid testing, and serological testing. If necessary, it is recommended to undergo these assessments under a doctor's guidance. Detailed explanations are as follows:
1. Inquiry about epidemiological history
Determine whether the patient had close contact with suspected or confirmed influenza cases, or was exposed to an environment with a cluster of influenza-like illnesses within 7 days before onset. Close contact with influenza patients or exposure in environments with high influenza prevalence increases the risk of infection.
2. Observation of clinical symptoms
Check whether the patient experiences sudden high fever, headache, generalized muscle pain, fatigue, loss of appetite, and other symptoms, along with possible sore throat, dry cough, nasal congestion, runny nose, and other respiratory symptoms. The presence of such symptoms may indicate influenza.
3. Antigen testing
Influenza virus antigen testing directly detects viral antigens by collecting nasopharyngeal or throat swab samples from the patient and using antigen-antibody reaction principles for testing. A positive result may indicate influenza.
4. Nucleic acid testing
Influenza virus nucleic acid testing detects the genetic material of the virus by collecting nasopharyngeal or throat swab samples from the patient and employing molecular biology techniques to detect influenza virus nucleic acid. A positive nucleic acid test result confirms influenza.
5. Serological testing
After the influenza virus infects the body, the immune system produces specific antibodies. By testing the levels of influenza-specific IgG antibodies in paired serum samples collected during the acute and recovery phases, a rise in antibody levels of four-fold or greater indicates a recent infection with the influenza virus.
In daily life, avoid crowded and poorly ventilated places as much as possible, and reduce close contact with individuals who have influenza.
