Epidemiological Characteristics and Risk Factors for Admission to Intensive Care Unit and Death in Patients with H1N1 Influenza

In 2009، the novel H1N1 virus pandemic appeared with the ability of transmitting from human to human. In our country، the epidemic occurred between 2009 and 2010. This study assessed the epidemiology of patients with H1N1 influenza and its risk factors، also، needing care in intensive care units، and the prevalence of death. In a cross-sectional study، all the patients with influenza H1N1 admitted to Al-zahra medical center (Isfahan، Iran) during the epidemic period were entered. Demographic characteristics، clinical symptoms، laboratory and radiological findings، and underlying diseases were recorded. The data were analyzed by chi-square، One-way ANOVA and t tests. 74 women and 76 men with H1N1 influenza were admitted. Fever (87%)، cough (76%)، and dyspnea (48. 7%) were the most common clinical findings and lymphopenia (48. 3%) was the most common paraclinical finding. 28% of patients needed ventilation support and 23 (15. 3%) were died. The neurological symptoms (OR = 5. 83)، lymphopenia (OR = 2. 87) and infiltration in the chest X-ray (OR = 1. 67) were effective factors in increasing need for admission to the intensive care unit. The most prevalent risk factors for death were neurologic symptoms (OR = 17. 04)، abdominal pain (OR = 5. 60)، increased creatinine kinase (OR = 4. 89)، respiratory distress (OR = 3. 67) and lymphopenia (OR = 2. 27). According to our findings، neurological symptoms، lymphopenia، infiltration in the chest X-ray، abdominal pain، increased creatinine kinase (OR = 4. 89)، and respiratory distress are very critical sign and symptoms which should be carefully considered in patients with H1N1 Influenza.