[Fast detection and characterization of influenza A and B viruses in nasopharyngeal secretions by the immunoperoxidase method].

One hundred and fourty eight samples from patients with a symptomatology compatible with the influenza virus were studied aimed at identifying in a fast way these viruses. A rapid MDCK-L cell culture was developed on 96 well plates, where nasopharingeal exudates or gargarisms were inoculated and incubated all night long at 37 degrees C. The medium was removed and cells were washed with PBS and fixed with methanol. Viral antigens were detected through the immunoperoxidase staining by using two monoclonal antibody pools for the identification of influenza A and influenza B viruses. The HA1-71 monoclonal antibody, specific for influenza A (H3N2) and the HA2-76, which react with both A (H3N2) and A (H1N1) were used for subtyping. Of all the positive samples (136), 72% corresponded to type A while 34.6% and 37.5% corresponded to subtypes H1 and H3, respectively. Influenza B was detected in 27.9% of the 148 samples studied. Only 12 were negative (8.1%). The use of this technique is recommended as a rapid, convenient and sensitive method that is easy to carry put and to interpretate for the detection and characterization in type and subtype of the influenza viruses starting from the nasopharyngeal exudates or gargarisms.