Seroprevalences of Mycoplasma pneumoniae IgM Antibodies among Children Living in Jeju Island, Korea

ABSTRACT

BACKGROUND: Mycoplasma pneumoniae (MP) is a major cause of community-acquired pneumonia in children. The particle agglutination (PA) assay is a clinical test routinely used to detect MP infection and to determine total MP antibody titers. Using this assay, however, it is difficult to differentiate between IgM and IgG antibodies. The aim of this study was to investigate the seroprevalence of MP IgM antibodies in children living in Jeju Island. METHODS: We investigated the seroprevalence of mycoplasma IgM antibodies in 1,693 patients in the age of 0-10 yr who were ordered for mycoplasma IgM antibody testing in Cheju Halla Hospital between April 2011 and March 2013. Results were classified according to age, sex and the month and year during which the samples were obtained. RESULTS: The overall positive rate for mycoplasma IgM antibody was 24.7% and was higher in females than in males (P=0.012). The positive rate was lowest in infants under 6 months of age, and gradually rose with increasing age until the age of 4 yr. A major increase in positive rates was observed between January-April of 2012 and minor cyclical increases were also observed at 2-4 month intervals during the study period. CONCLUSIONS: The seroprevalence of mycoplasma IgM antibodies rises gradually with age until the age of 4 yr. A major peak in MP IgM antibody-positive cases was observed in early 2012, with minor cyclical increases at every 2-4 months. These results will be helpful in the interpretation and diagnosis of MP in children living in Jeju Island.