Abstract
Mycoplasma pneumoniae (Mp) is a major pathogen causing pneumonia in children. We have used the loop-mediated isothermal amplification (LAMP) method to detect Mp DNA from patients, and here, we report our results obtained over the last 5 years. From April 2009 to March 2014, we collected pharyngeal swabs from 2,215 children who were hospitalized with pneumonia, and performed the LAMP method to detect Mp DNA. Among the 2,215 children, 712 (32%) were positive for Mp DNA. Their ages ranged from 1 month to 15 years and 6 months, and the median age was 7 years and 2 months. Regarding the annual number of patients positive for Mp DNA, there were 37 patients in 2009, 161 in 2010, 308 in 2011, 147 in 2012, and 59 in 2013. In 2011, there was a nationwide epidemic of Mp pneumonia, and the highest number of patients with Mp pneumonia was also seen in September 2011 at our hospital. When we examined the number of patients by calendar month, there was a seasonal trend for more Mp DNA-positive patients from summer to early winter and fewer patients in spring. In all the 712 children, we measured the antibody titer in paired serum samples and confirmed seroconversion or an increase in the titer by 4-fold or more in 559 patients (79%). In conclusion, Mp DNA detection by the LAMP method can be performed simply and quickly with high sensitivity, making it a useful laboratory diagnostic method for children with Mp pneumonia.
