Features of the course of influenza and its co-infection in children at the present stage

Influenza is an acute respiratory infection, mainly affecting the respiratory tract (often the trachea), with a tendency to develop symptoms rapidly and in most cases not requiring hospitalization. All acute respiratory infections are non-specific, with symptoms of intoxication, catarrhal symptoms (nasal congestion, rhinorrhoea, sore throat or pharyngeal discomfort), fever and cough. Improvement and widespread implementation of molecular methods to identify respiratory pathogens has led to the establishment of a higher frequency of co-infections. A literature review of the frequency of influenza co-infections is presented. Clinical cases of monoinfluenza and co-infections of influenza and respiratory syncytial infection are described, demonstrating the antagonistic effect of the two viruses on the course of the disease. In the first case, the patient, 1 year 1 month old, was hospitalised with a fever of 39 ºC in a moderate condition. A nasopharyngeal swab showed RNA of influenza A virus by PCR and was diagnosed with influenza. In the second case, the patient, 2 years old, at the beginning of the disease complained of an increase in body temperature to 38.7 ºC, cough, and difficulty in nasal breathing. On admission, the patient was in moderate condition with a body temperature of 36.6 ºC, clear consciousness and well-being. On auscultation, breathing in the lungs was rigid, single moist rales, scattered on both sides. A nasopharyngeal swab showed RNA of influenza A virus and respiratory syncytial virus by PCR. A viral acute respiratory infection of combined etiology and acute bronchitis was diagnosed. In the third case, a 14-year-old patient presented with complaints of fever up to 39 ºC, headache, weakness, muscle pain, dry cough. The condition was of moderate severity. The diagnosis of influenza A was confirmed by a rapid test for influenza A/B/C. In the treatment and prevention of both monoinfection and co-infections of influenza and other viruses, these clinical examples demonstrate the effectiveness of oseltamivir. These clinical examples highlight some key parameters: respiratory co-infections change the typical clinical picture of the disease, making it difficult to clinically diagnose the infection, highlighting laboratory diagnosis, which in turn facilitates rapid verification of the diagnosis and timely prescription of adequate therapy.

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