Clinical characteristics of 74 pandemic H1N1 influenza patients from Turkey. Risk factors for fatality

OBJECTIVE: To evaluate the clinical characteristics and certain risk factors that may be associated with fatal outcome in patients with H1N1 influenza.

METHODS: This retrospective study was conducted between October and December 2009 in the Department of Infectious Diseases and Clinical Microbiology, SB Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey. Data regarding the epidemiological and clinical characteristics of 74 hospitalized cases of confirmed pandemic H1N1 influenza were reviewed.

RESULTS: The median age was 49 (18-83) years, and 34 (46%) were males. The most common symptom and signs on admission were cough (91.9%) and fever more than 38 degrees Centigrade (71.7%). More than two-thirds of patients (68.9%) had at least one underlying condition; most frequently chronic respiratory disease, including asthma and diabetes. Seventy-seven percent had evidence of pneumonia on their chest x-rays at presentation. Of the 74 cases, 16 (21.6%) were followed up in the Intensive Care Unit, and 10 (13.5%) died. Obesity and oxygen saturation below 92% at the time of admission were found to be significantly related with fatal outcome. In addition, fatal patients had significantly higher levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), urea, creatinine, d-dimer on admission and prothrombin time (PT), activated partial thromboplastin time, and the international normalized ratio (INR) was longer.

CONCLUSION: Timely identification and management of patients with higher risk for fatality may improve outcomes.