[Diagnosis of an acute respiratory infection outbreak in children under 3 years of age in Santiago de Cuba]. / Diagnóstico de un brote de infección respiratoria aguda en niños menores de 3 años en Santiago de Cuba.

In November, 1996, there was an outbreak of acute respiratory infection in children under 3 in the province of Santiago de Cuba. 7 samples of nasopharyngeal exudates were received to determine the causal agent of the outbreak by indirect immunofluorescence technique (4 positive samples, 57.14%). They were inoculated in MDCK cells culture and those cases that presented positive hemadsorption (6 isolates, 85.71%) were analyzed by indirect immunofluorescence techniques (6 positive samples, 100%) and immunoperoxidase (5 positive samples, 83.3%). All the positive samples were classified as influenza A (subtype H3N2) which confirms what is reported in literature in relation to the circulation of this virus during that year at the national and international level. This paper allowed to know the causal agent of the studied outbreak of acute respiratory infection and to determine the circulation of the influenza A subtype H3N2 in that province.

[Fast detection and characterization of influenza A and B viruses in nasopharyngeal secretions by the immunoperoxidase method]. / Detección y caracterización rápida de los virus de influenza A y B en secreciones nasofaríngeas mediante el método de la inmunoperoxidasa.

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.