Mycoplasma pneumoniae as a causative agent of community-acquired pneumonia in children: clinical features and laboratory diagnosis

BACKGROUND: Mycoplasma pneumoniae is a common cause of community-acquired pneumonia (CAP) in children. The aim of this study was to assess the prevalence of Mycoplasma pneumoniae infection in children with CAP and find clinical, radiological and laboratory features helpful to diagnose Mycoplasma pneumoniae pneumonia. Furthermore, we evaluated the value of serology, real-time PCR (RT-PCR) and culture for the accurate diagnosis of Mycoplasma pneumoniae pneumonia. METHODS: The study included 166 children aged between 1 and 15 years with radiologically confirmed pneumonia. Throat swab specimens were cultured and assessed by RT-PCR for the presence of Mycoplasma pneumoniae. Mycoplasma pneumoniae-specific IgM and IgG antibodies were determined using ELISA in paired sera. RESULTS: Mycoplasma pneumoniae pneumonia was diagnosed in 14.5% CAP cases. Cough (p=0.029), headache (p=0.001) and wheezing (p=0.036) were more frequent in children with Mycoplasma pneumoniae pneumonia compared to children with pneumonia caused by other pathogens. Logistic regression analysis showed that headache (odds ratio [OR] =36.077, p=0.001) and wheezing (OR=5.681, p=0.003) were significantly associated with MP pneumonia. Neither radiological findings, nor common laboratory parameters distinguished Mycoplasma pneumoniae infection in children with CAP. Using IgG serology in paired sera as the gold standard, we found that sensitivity of IgM serology, RT-PCR and culture was equal (81.82%), while specificity values were 100%, 98.6% and 100% respectively. We observed that combination of IgM detection in acute-phase serum and RT-PCR was positive for 91.7% of cases with Mycoplasma pneumoniae infection. CONCLUSIONS: There are no characteristic radiological findings, or routine laboratory tests that would distinguish CAP caused by Mycoplasma pneumoniae from other CAP. It was found that clinical features such as headache and wheezing are indicative for Mycoplasma pneumoniae infection. Furthermore, it was found that during the acute phase of disease, detection of IgM antibodies in combination with RT-PCR allows for precise and reliable diagnosis of Mycoplasma pneumoniae infections in children.