Hsin-Yu Chang1, Luan-Yin Chang1, Pei-Lan Shao1, Ping-Ing Lee1, Jong-Min Chen1, Chin-Yun Lee1, Chun-Yi Lu2, Li-Min Huang3. 1. Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan. 2. Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: cylu@ntu.edu.tw. 3. Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: lmhuang@ntu.edu.tw.
Abstract
BACKGROUND: Mycoplasma pneumoniae is a common pathogen of respiratory tract infection in children, and its correct and rapid diagnosis is a clinical challenge. Real-time polymerase chain reaction (RT-PCR) has been used frequently for the detection of this pathogen. MATERIALS AND METHODS: Medical records from all children with a clinical diagnosis of mycoplasma pneumonia and whose respiratory samples were tested for M. pneumoniae (using RT-PCR) during 2011 were reviewed retrospectively. We compared the sensitivity and specificity of serological assays versus those of RT-PCR for diagnosis of M. pneumoniae infections. We also reviewed retrospectively clinical characteristics, and laboratory and imaging findings of children with laboratory evidence of M. pneumoniae infection. RESULTS: In 2011, 290 children were diagnosed to have mycoplasma pneumonia clinically and had their respiratory samples tested for M. pneumoniae by RT-PCR. Fifty-four children (19%) had a positive result. Meanwhile, 63% (182/290) of these children also underwent serological tests, out of whom 44 (24%) were found to be positive for immunoglobulin M (IgM). Using PCR as a gold standard, M. pneumoniae IgM assay was found to show a sensitivity of 62.2% and a specificity of 85.5%. Positive and negative predictive values of IgM were 52.3% and 89.9%, respectively. In M. pneumoniae IgM-positive children, a negative PCR result was associated with more coinfection by other pathogens and longer duration of prehospitalization fever. Bacterial loads of M. pneumoniae were not correlated with clinical outcomes. CONCLUSION: The majority of clinically diagnosed mycoplasma pneumonia was unconfirmed. Mycoplasma pneumoniae IgM has poor sensitivity and a positive predictive value. Interpretation of Mycoplasma pneumoniae IgM should be done with caution.
BACKGROUND: Mycoplasma pneumoniae is a common pathogen of respiratory tract infection in children, and its correct and rapid diagnosis is a clinical challenge. Real-time polymerase chain reaction (RT-PCR) has been used frequently for the detection of this pathogen. MATERIALS AND METHODS: Medical records from all children with a clinical diagnosis of mycoplasma pneumonia and whose respiratory samples were tested for M. pneumoniae (using RT-PCR) during 2011 were reviewed retrospectively. We compared the sensitivity and specificity of serological assays versus those of RT-PCR for diagnosis of M. pneumoniae infections. We also reviewed retrospectively clinical characteristics, and laboratory and imaging findings of children with laboratory evidence of M. pneumoniae infection. RESULTS: In 2011, 290 children were diagnosed to have mycoplasma pneumonia clinically and had their respiratory samples tested for M. pneumoniae by RT-PCR. Fifty-four children (19%) had a positive result. Meanwhile, 63% (182/290) of these children also underwent serological tests, out of whom 44 (24%) were found to be positive for immunoglobulin M (IgM). Using PCR as a gold standard, M. pneumoniae IgM assay was found to show a sensitivity of 62.2% and a specificity of 85.5%. Positive and negative predictive values of IgM were 52.3% and 89.9%, respectively. In M. pneumoniae IgM-positive children, a negative PCR result was associated with more coinfection by other pathogens and longer duration of prehospitalization fever. Bacterial loads of M. pneumoniae were not correlated with clinical outcomes. CONCLUSION: The majority of clinically diagnosed mycoplasma pneumonia was unconfirmed. Mycoplasma pneumoniae IgM has poor sensitivity and a positive predictive value. Interpretation of Mycoplasma pneumoniae IgM should be done with caution.