Clinical features of 26 patients with H7N9 avian influenza and characteris-tics of viral gene / 中国感染控制杂志

ABSTRACT

Objective To evaluate the clinical,epidemiological,and viral molecular biology features of 26 patients infected with H7N9 avian influenza A virus. Methods Clinical and epidemiological data of 26 patients with con-firmed avian influenza A (H7N9)infection in 2013 and 2014 were collected,virus isolated from human and poultry were identified and typed through sequencing.Results Of 26 patients,fever and cough were the most common symptoms,all patients had pneumonia;20 patients (76. 92% )developed acute respiratory distress syndrome (ARDS);25 patients (96.15% )had leucopenia or normal leukocytes at the initial diagnosis;treatment with antivi-ral drugs was initiated in 25 patients at a median of 10 days after the onset of illness;10 patients (38.46% )died. Gene sequencing indicated Gln226Leu and Gly186Val substitutions in human virus H7 gene and the PB2 Asp701Asn mutation. Conclusion Acute respiratory system damage is the main clinical manifestation of avian influenza (H7N9)virus infection in humans,live poultry exposure is an important risk factor for H7N9 infection in humans, adaptive mutation occurred at partial site of avian virus gene,which can be more easily be spread from birds to hu-man and cause serious diseases,it is necessary to strengthen the pathogen monitoring.