doi: 10.1590/S0036-46652014000400019 LETTER TO THE EDITOR HUMAN INFECTION WITH AVIAN INFLUENZA A (H7N9) VIRUS

Commission (NHFPC) of China announced that three fatal cases of rapidly progressive pneumonia, respiratory failure and acute respiratory distress syndrome (ARDS) were confirmed to be infected with a novel reassortant avian-origin influenza A (H7N9) virus9. As of February 18th, 2014, a total of 347 laboratory-confirmed cases and 109 deaths had been reported in mainland China7. The novel avian influenza virus has caused global concern as a potential pandemic threat. According to recent studies, the elderly have increased risk for H7N9 virus infection2,3. Furthermore, patients with underlying diseases are significantly associated with the infection1-3. It is reported that the median age of 111 patients with H7N9 virus infection was 61 and 42.3% of them were 65 years of age or older3. A total of 61.3 % of the patients had one or more underlying medical conditions, such as hypertension, diabetes, coronary heart disease, chronic obstructive pulmonary disease (COPD) and so on3