Particularities of 2009 influenza A (H1N1) Infection in outpatients

Abstract

Summary. Emergence of a new influenza virus А / H1N1 / CA / 2009 (IA2009) in October–December, 2009, in Russia required to investigate clinical features of the infection and effectiveness of treatment in ambulatory practice. Information from outpatient medical cards of 44 patients seeking for medical aid because of acute respiratory viral infection (ARVI) during pandemic 2009 was analyzed. All patients were examined for the presence of influenza А / H1N1 / CA / 2009 virus RNA, seasonal influenza virus RNA and influenza B virus RNA in nasopharyngeal swabs using polymerase chain reaction (PCR). According to the PCR results, patients were identified as having influenza А / H1N1 (n = 21) or other ARVI (n = 23). Signs and symptoms, complete blood count test, urine test, and chest X-ray were analyzed. Retrospective analysis found that 76.2 % of influenza А / H1N1 patients had acute respiratory diseases during previous 12 months and 19.0 % of them were healthcare workers. Leading symptoms and signs in patients with influenza А / H1N1 were cough, headache, weakness, myalgia, fever, obstruction of upper and lower airways. Mild course of disease was observed only in 23.8 % of the cases with recovery during 10 days. Complications were found in 28.6 % of the patients, 14.3 % of them were hospitalized. The most frequent changes in complete blood count tests were accelerated erythrocyte sedimentation rate, neutropenia / leucopenia, lymphocytosis, monocytosis, anisocytosis, thrombocyte aggregation. In 31.3 % cases, changes in white cell count remained after clinical recovery and resolving all respiratory symptoms. Administration of antiviral antibiotic Ingavirin in patients with influenza А / H1N1 started in the first 2 days of the disease was more effective compared with immunomodulating drug Arbidol.