Farhang Babamahmoodi - Professor of Infectious Diseases Antimicrobial Resistance Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
Masoud Maboudi - Assistant Professor, Antimicrobial Resistance Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
Ghazale Hosainzade - Medical intern, medical school, AZAD University of Medical Science, Sari, Iran
Ata Ebrahimi - Medical intern, medical school, AZAD University of Medical Science, Sari, Iran
Faeze Asghari - Medical intern, Antimicrobial Resistance Research Center and Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
Fateme Ahangarkani - Assistant Professor of clinical sciences, Antimicrobial Resistance Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
Mahsa Kamali - MSC student in Biostatistics, Faculty of Health Mazandaran university of Medical Sciences, sari, Iran
Azadeh Khalatbari - Doctor of Medicine, Antimicrobial Resistance Research Centre and Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran

Background: Influenza is an acute respiratory viral infection that threatens global health. Regular assessment of clinical and paraclinical symptoms is a very important tool for early diagnosis and disease management, transmission, and prevention of influenza, epidemics. The main purpose of this study was to evaluate the clinical and paraclinical symptoms of patients with influenza in the north of Iran. Methods: This descriptive cross-sectional study was conducted on hospitalized patients through a convenience sampling method from September ۲۰۱۹ to February ۲۰۲۰ in a teaching hospital, in Iran. The inclusion criteria were age at least one year and the possibility of influenza based on at least one of the following clinical and paraclinical findings. Clinical manifestation, radiographic findings, and paraclinical findings had been assessed. Patients with hospitalization of fewer than three days and incomplete documents were excluded. Results: Most of the patients were male (۵۲.۰%) and had a history of contact with positive influenza patients (۸۸.۳%). The most common symptoms were fever (۸۹.۹%), chills (۷۶.۹%), cough (۶۷.۵%), and sore throat (۴۱.۲%), respectively. It was no significant difference between WBC, LDH, and CPK in less than ۱۲ years old vs. above ۱۲ years old (p>۰.۰۵). But, the platelet was a significant difference between less than ۱۲ years old vs. above ۱۲ years old. Conclusions: The results of the present study provide a rationale for annual vaccination and other preventive measures against influenza. Also, this study was the last study in relation to influenza before the COVID-۱۹ pandemic and the extracted data can be useful to compare influenza and COVID-۱۹.

Influenza Disease, Acute Respiratory Infection, Symptom of Disease