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

Abstract

Objectives: Mycoplasma 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.

Methods: A 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.

Results: MP 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.

Conclusions: The 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.