Analysis of clinical features of patients infected with influenza A virus in a district hospital

Abstract

Objective To analyze the clinical features of inpatients infected with influenza A virus, and then to provide evidence for the diagnosis, treatment and prevention of influenza A in primary hospital. Methods The clinical data of inpatients with influenza A in one district hospital from Dec 2016 to Mar 2017 were collected to analyze retrospectively. Results A total of 21 665 patients were admitted to hospital from Dec 2016 to Mar 2017. Among them 647 flu-like cases accepted influenza A nucleic acid detection, and 203 cases were positive, the positive rate was 31.4%. The median age of influenza A positive patients was 64.25 years, and 20.2% were 0 to 4 years, 49.26% were 65 years of age or older. 58.13% patients had at least one underlying medical condition. Fever, Cough and Sputum were the most symptoms of patients infected with influenza A. Compared with the patients under 60 years old, non-fever symptoms were more common in those 60 years or older, the difference was statistically significant (χ2=15.43, P<0.001). Laboratory examination indicated that lymphocytopenia were detected in 54.27% of patients, and increased level of C-reactive protein and procalcitonin (PCT) in 74.83% and 11.76% of patients respectively. Moreover, 75.58% of patients had high erythrocyte sedimentation rate (ESR), 8 patients (97.3%) had findings consistent with pneumonia. 78.33% of patients received anti-viral treatment with oseltamivir, the rate of antibiotic utilization was as high as 85.22%. The median of hospitalization expense of patients infected with influenza A was 4 280 (interquartile range 2 792-9 565) yuan, and the cost of inpatients who had combined underlying diseases were higher than that in inpatients who had no coexisting medical conditions, the difference was statistically significant (Z=7.106, P<0.01). No death occurred in this study. Conclusions Children and old people were at high risk for influenza A infection. Fever, cough and lymphocytopenia were the common clinical features of patients infected with influenza A. It is especially noteworthy for the patients who were 60 years of age or older with flu-like symptoms but without fever, or the patients who had one or more underlying medical conditions, and such patients should receive influenza virus nucleic acid tests as early as possible. Key words: Influenza A; Influenza A virus; Clinical feature