Background and Objective: Novel H1N1 influenza virus is a unique type of influenza virus which has developed due to abrupt structural alterations (Shift and Drift). This virus can lead to a pandemic disease. Since manifestations and severity of this disease may be affected by environmental, cultural and economic factors, therefore this epidemiological and regional study was carried out to reveal the clinical and demographic manifestations of the disease.
Materials and Methods: Since October till December 2009 40 patients with novel H1N1 infection documented with RT-PCR was collected. The demographic and laboratory data were carefully collected. Pulmonary involvement and the need for ICU were identified.
Results: 40 patients with H1N1 infection in the age range of 36.80±13.02 years hospitalized in Sina Hospital of Tabriz. Twenty- one of them transfered to ICU and 37.5% of the patients had risk factors. Pneumonia was the most prevalent lung involvement. The most prominent radiographic finding was bilateral ground glass opacity. ARDS were seen in 25%. Cough and fever were the most prevalent, and vertigo and abdominal pain were the rarest clinical symptoms. Independent risk factors as related to death included the need for being hospitalized in ICU, and mechanical ventilation (odd ratio = 5.51, CI= 95 %).
Conclusion: The patients in this study had clinical manifestations similar to other centers but the majority of them did not show any underlying risk factor. Mortality was rare except for pneumonia and ARDS. Some cases with bilateral pulmonary thromboembolism were seen. Consequently, all of the patients with this complication were discharged after treatment.