Epidemiological characteristics of severe pneumonia cases in Nanchang, Jiangxi, 2013-2018

ObjectiveTo understand the epidemiological characteristics of severe pneumonia cases in Nanchang, Jiangxi province, and provide evidence for clinical prevention and treatment of severe pneumonia cases.

MethodsThe respiratory samples and clinical data of severe pneumonia cases in Nanchang from April 2013 to March 2018 were collected for the etiological and epidemiological analyses.

ResultsA total of 261 cases of severe pneumonia from 17 medical institutions in Nanchang were detected, in which 81 were detected to be positive for influenza virus nucleic acid (31.03%), including 43 cases of influenza A (H1N1) pdm09 virus infection, 13 cases of influenza A (H3N2) virus infection, 18 cases of human infection with avian influenza A (H7N9) virus, 3 cases of human infection with avian influenza A (H10N8) virus and 4 cases of influenza B virus infection. The cases mainly occurred in winter and spring (from December to May), and the male to female ratio of the cases was 1.69∶1. The youngest case was 1 month old and the oldest case was 95 years old. Twenty one cases of human infection with H7N9/H10N8 viruses were reported in Nanchang during the 5 years with the case fatality rate of 33.33%. Up to 90.48% of the cases (19/21) were detected through the surveillance for unexplained pneumonia. The median age of the cases was 69 years, most cases had underlying diseases and clear history of poultry contact.

ConclusionThe major influenza virus causing severe pneumonia was influenza A (H1N1)pdm09 virus in Nanchang. It is necessary to conduct routine surveillance for the timely detection of novel influenza virus and better prevention and control of communicable diseases.