Mycoplasma pneumoniae in Korean children: The epidemiology of pneumonia over an 18-year period

SummaryObjectivesMycoplasma pneumoniae (MP) is a major cause of community-acquired pneumonia in children. The aim of this study was to investigate the long-term epidemiology of MP pneumonia in Korean children.MethodsA retrospective analysis of a database of 2405 patients with pneumonia at the Seoul National University Children's Hospital between 1986 and 2004 was performed. Serologic diagnosis for MP infection was made based on a 4-fold rise or single titers ≥1:640, which were measured by an indirect agglutination test.ResultsMP pneumonia was diagnosed in 568 patients over 18 years. The mean age was 5.7 years. Children younger than 5 years of age accounted for 44% of the cases. Six outbreaks were observed at intervals of 3–4 years. The earlier epidemics up until 1996 peaked in the summer, while the later epidemics peaked in the fall or early winter. Children <5 years old were more commonly affected during large epidemics compared to endemic periods. The geometric mean antibody titers were maintained ≥1:320 up to 7 months after the onset of illness.ConclusionsThe results of this study revealed community outbreaks of MP pneumonia at 3–4-year intervals among Korean children. A significant proportion of young Korean children were affected by MP pneumonia, especially during large epidemics.