test for influenza is carried out to confirm the role of influenza virus is establishing flu-like symptoms.
Sputum collection is done early in the morning. The patient must refrain from eating or drinking before the test. It is also essential to brush teeth and rinse mouth well prior to the test. Avoid using antiseptic mouthwash. Sputum may be brought up by deep coughing (expectorated) or it may be or induced with the help of sterile saline or glycerin aerosol. The coughed up sputum is collected into a sterile cup provided by the laboratory.
Although influenza is usually diagnosed on the basis of clinical symptoms, the gold standard laboratory test is the 14 day culture. However the test results take too long and hence, is not often done.
Instead the sputum sample that is collected is subjected to rapid diagnostic tests such as a fluorescent optical immune assay (OIA).Antigens are extracted from the sputum samples and a conjugate added and incubated for 6-7 minutes. It is then washed and blotted. A single drop of substrate was added to the test surface and further incubated for 6-7 minutes.Physiology : Influenza
, commonly known as the “Flu”, is a respiratory epidemic infection caused by a number of viruses. The illness usually last for a week while the symptoms may persist for a couple of weeks longer. The complications from influenza can be severe.
The influenza test is carried out to detect the cause of the flu-like symptoms
which include fever
, malaise, headache
, body pain
. The combination of symptoms are non specific and may vary with patients.Normal Range :
NegativeInterpretation : Positive
If a blue or purple reaction zone appears in the center of the test surface, the result is positive for Influenza A and B.
If no color change appears, the result is negative for influenza virus A and B.