The changes of prevalence and etiology of pediatric pneumonia from National Emergency Department Information System in Korea, between 2007 and 2014

Shin, Eun Ju; Kim, Yunsun; Jeong, Jin-Young; Jung, Yu Mi; Lee, Mi-Hee; Chung, Eun Hee

In time series trend test of annual incidence of bacterial pneumonia, pneumococcal pneumonia, pleural effusion and empyema per 100,000 population, there were not significant increasing or decreasing trend (Table 6 ). 7) The prevalence ED visits for pediatric pneumonia spiked during in 2009 due to an influenza epidemic and in 2011 and 2014 due to a cyclical MP epidemic that recurs every 3 to 4 years in Korea. [8] [9] [10] The pathogens for CAP varied widely based on age, region, and season. Bacteria and viruses were the most typical pathogens, with M. pneumoniae being a common pathogen among preschool-aged children. The difficulty in identifying the causative pathogen due to difficulty in collecting specimen, such a sputum or mouth culture, for microbiological diagnosis, likely explains why an etiology was not specified in two-thirds of our cases. Among those with a clear etiology, viral pathogens were the most common, followed by M. pneumoniae and bacteria. In our case series from 2007 through 2014, the highest prevalence of viral pneumonia occurred in 2009 due to an outbreak of H1N1 influenza, although the prevalence of viral pneumonia did increase from 2007 through 2014 (Table 3) . We speculate that the introduction of multiplex real time-polymerase chain reaction (RT-PCR) improved the diagnosis of viral pathogens of pneumonia in Korea over the 8-year period of our study. 11, 12) In fact, our data clearly indicate this, with an increase in the diagnosis of human metapneumovirus pneumonia using multiplex RT-PCR since 2011. Multiplex RT-PCR is a test for the addition of human metapneumovirus, coronavirus, and rhinovirus to conventional respiratory virus detection (respiratory syncytial virus, adenovirus, influenza virus, parainfluenza virus). In Korea, a study on respiratory virus using multiplex RT-PCR has been started in 2006 13, 14) and was gradually expanded. 11, 14) Human metapneumovirus was a newly discovered virus, and it would take time for the ICD code to be created and used in Korea.