Pneumoslide-M Technique for Rapid Detection of Atypical Pathogens in Critically ILL Children with Lower Respiratory Tract Infections

Progress in combating atypical pathogens is hampered by the lack of rapid and standardized diagnostic methods. Pneumoslide-M (Indirect immunofluorescence technique for IgM detection) was tested to validate its use as a rapid screening method for detection of atypical pathogens causing severe LRTI in Pediatric Intensive Care Unit (PICU) and to determine its sensitivity and specificity in the diagnosis of Respiratory Syncytial Virus (RSV) and Mycoplasma pneumoniae (M. pn.). Sixty children (mean age 3.92±2.74) with LRTI were recruited from PICU, Pediatric Hospital, Ain Shams University. A nasopharyngeal aspirate was collected for viral and M. pn. cultures, whereas a serum sample was taken for Pneumoslide-M and PCR for RSV and M. pn. detection. Pneumoslide -M test detected viruses in 25% of patients, whereas viral culture detected them in 16.7%. RSV was detected by Pneumoslide-M in 11.67% in comparison to 13.3% by RT-PCR. Sensitivity and specificity for detection of RSV was 75 and 98.1%, respectively. M.pn. was recorded by Pneumoslide-M test in 21.67%, 25% by RT-PCR and 3.3% by M. pn. culture. Sensitivity and specificity were 78 and 95%, respectively. Eight patients with severer LRTI showed evidence of mixed infection by Pneumoslide-M test. No characteristic symptom, sign, laboratory, or radiological findings could clearly identify the etiologic agent responsible for LRTI. Pneumoslide-M test was found to be a reasonably sensitive, highly specific, easy, rapid and cost-effective technique for detection of atypical pathogens. We recommend its use in PICU to ensure prompt initiation of the specific antibiotic or antiviral therapy.