A Study of Antibody Conversion Rate During a Mycoplasma pneumoniae Epidemic Period(the Second Half of 2003)

Kim, Do Kyun; Yoo, Young; Yu, Jinho; Koh, Young Yull

Abstract

PURPOSE
This study was designed to estimate the prevalence of Mycoplasma pneumoniae infection during an epidemic period by means of examining the antibody conversion rate and to investigate the association of the antibody conversion with age, initial antibody titer, and atopy.
METHODS
We chose 191 children whose antibody titer to M. pneumoniae was negative, 1:40, or 1:80 during the first half of 2003. After the second half of 2003 when the M. pneumoniae epidemic occurred, follow-up collection of sera was performed during the first half of 2004. M. pneumoniae antibody titer was measured by Serodia-Myco II particle agglutination test.
RESULTS
Of 191 children, antibody conversion was detected in 83 children(43.5 percent). No significant difference was found between the conversion and non-conversion group with respect to age, sex and atopy. Dividing the subjects into four groups by age, results on the antibody conversion rate revealed no significant differences between the groups. Assessed by initial antibody titer, a diminished trend of conversion rate was observed in children with 1:80 titer but the difference was not significant. There was no significant difference in the antibody conversion rate between atopic and non-atopic children.
CONCLUSION
Based on the antibody conversion rate in this study, the prevalence of M. pneumoniae infection during an epidemic period was estimated to be 43.5 percent. This high infection rate suggests that during an epidemic, we should bear in mind M. pneumoniae as an important etiologic agent for respiratory infection in children.