Evaluation of diagnostic accuracy of PCR versus serology in diagnosing mycoplasma pneumoniae infection

Abstract

The present study is designed to evaluate the accuracy of PCR versus serology for diagnosing M. pneumoniae infections among the throat specimens. Samples for PCR testing were obtained from nasoopharyngeal aspirate. Serum samples were collected on the first visit and at least 2–4 weeks later. For the PCR assay, a rapid DNA extraction protocol was used. IgG antibodies were measured using the Serion Elisa Mycoplasma pneumoniae IgG kit. Overall, prevalence of M. pneumoniae was diagnosed in among 7.9% (23/290) of the patients. The median age of the patients positive for M. pneumoniae was 37 years and 38 years among negative patients which was statistically insignificant (p>0.05). Out of the total positive patients for M. pneumoniae in throat swabs, 70% (16/23) were observed to be positive by PCR and 78% (18/23) by serology. The high sensitivity (72.2%) and specificity (98.9%) of PCR was observed with positive and negative predictive value being 81.3% and 98.2% respectively. The accuracy of PCR was found to be 97.2%. The use of PCR, using either semi-nested or quantitative real-time methods, was superior to serology for diagnosing acute Mycoplasma Pneumoniae infections.