Clinical characteristics of 75 pandemic H1N1 influenza patients from Turkey; risk factors for fatality.

BACKGROUND/AIM The 2009 influenza A (H1N1) pandemic caused mild to severe illnesses and led to death in some cases. In this study, we aimed to evaluate the relationship between the serum D-dimer levels, CURB-65 scores, and the severity of pneumonia among patients with H1N1 infections. MATERIALS AND METHODS Sixty-eight patients who had probable H1N1 infections were evaluated by clinical, radiological, and laboratory methods. The H1N1 strain was specified by reverse transcription-polymerase chain reaction. Of 55 patients diagnosed with pneumonia, 18 exhibited H1N1 positivity and 37 patients did not. RESULTS CURB-65 scores of pneumonia patients with H1N1 (group 1) were higher than those of patients without H1N1 (group 2) (P = 0.02). The D-dimer levels of group 1 were higher than those of group 2 (P = 0.001). Moreover, there was a positive correlation between D-dimer levels and CURB-65 scores in patients with H1N1-associated pneumonia (P = 0.001; r = 0.89). CONCLUSION Increased D-dimer levels were observed in pneumonia patients with H1N1 infection, which predicted the severity of pneumonia.