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

According to research data published outside of Korea, since its introduction in 2010, the PCV13 seems to be more effective than the PCV7. 23) In a French study evaluating the effectiveness of the PCV13 in pediatric patients, 1 month to 15 years of age who were radiologically diagnosed with pneumonia at the ED between 2009 and 2012, the prevalence of CAP decreased by 16% after the introduction of PCV13, with a 63% decrease in pneumococcal pneumonia and a 53% decrease in pleural effusion. The decreased prevalence of CAP was more evident in children under the age of 2 years. 23) The PCV7 was introduced in Korea in November 2003, with the PCV10 and PCV13 introduced in June 2010 as an optional. In May 2014, PCV10 and PCV13 were incorporated in the national immunization program in Korea. 21) With regard to the immunization rate achieved, about 40% of the candidates for vaccination are estimated to have received the PCV7 as of 2007. 15) The 2011 national immunization rate survey of 3-year-old children (born in 2007) reported a PCV vaccination rate of 67.1% for the first dose, 60.5% for the second dose, 56.7% for the third dose, and 51.4% for the fourth dose, with a complete vaccination rate of 49.7%. 24) The 2013 national immunization rate survey of three-year-old children (born in 2009) showed an increased rate of PCV vaccination, with a vaccination rate of 83.4% for the first dose, 80.5% for the second dose, 77.8% for the third dose, and 70.4% for the fourth dose. 25) Although we could not evaluate immunization rate among the patients included in our analysis, we were able to confirm a vaccination rate of 50% among 3 years old in our 2007 cohort, which increased to about 70% for this age group in 2013. A limitation of our data set, which spans 2007-2014, is the difficulty in determining if the decline in pleural effusion and empyema could be explained by an increase rate of vaccination with the PCV7 or the introduction of the PCV10 and the PCV13 in 2010. The cyclical MP epidemic in Korea also influences the prevalence of pneumonia, making difficult to clearly distinguish the effects of PCV7 from those of the PCV10 or the PCV13.