Multiplex PCR testing revealed a polymicrobial landscape. Codetection of more than one pathogen occurred in 51.7 percent of cases, underscoring how frequently multiple organisms are simultaneously present in nasopharyngeal specimens in this cohort. Viruses predominated overall, accounting for 60.5 percent of detections. Rhinovirus/enterovirus led the viral profile at 32.1 percent, followed by influenza viruses at 26.1 percent, respiratory syncytial virus (RSV) at 16.6 percent, and adenovirus at 14.8 percent.

Bacterial targets also featured prominently among the expanded panel tests. Streptococcus pneumoniae was the most prevalent bacterial detection at 38.9 percent, with Haemophilus influenzae close behind at 31.6 percent. The authors emphasized, however, that molecular detection of commensal bacteria on nasopharyngeal specimens must be interpreted cautiously alongside systemic inflammatory markers, to avoid overattributing active disease to simple colonization.

The exploratory biomarker analysis produced distinct observational associations across detection groups. Influenza detections were associated with significantly lower median ANC (p < 0.001), whereas adenovirus detections showed both elevated CRP and elevated ANC (p < 0.001).

Mycoplasma pneumoniae detections were characterized by elevated CRP together with relative lymphopenia (p < 0.001), a distinct pattern among the bacterial detections evaluated in the study.

Notably, the two most common bacterial detections diverged in their biomarker associations. S. pneumoniae detection showed no significant correlation with CRP elevation (p = 0.181), a finding consistent with the possibility that its presence on nasopharyngeal sampling often reflects colonization rather than invasive disease. In contrast, H. influenzae detection was associated with higher median CRP levels (p < 0.001), suggesting a different relationship with systemic inflammation in this cohort.

The study’s design imposes important limits on interpretation. As a retrospective, single-center surveillance of PCR-positive cases, it captured the detection spectrum among children who were tested and found positive, and the biomarker associations are exploratory rather than causal. The authors framed the routine host markers as showing distinct observational associations across viral and bacterial PCR detection groups, not as diagnostic rules. Temporal dynamics were part of the evaluation, but the reported headline figures describe the cohort as a whole over the October 2024 to June 2025 window.

For clinicians, the practical message is one of calibrated caution. Multiplex PCR panels increasingly return multiple simultaneous detections, and the finding that S. pneumoniae detection did not track with CRP elevation, while H. influenzae and M. pneumoniae detections did, illustrates why molecular results should be read together with inflammatory and hematological context rather than in isolation. The study adds to the evidence base for interpreting pediatric respiratory PCR panels, while leaving open the question of how best to translate these observational associations into diagnostic decision-making.

Subject of Research: Respiratory pathogen profiles in children aged 0–18 years: a single-center experience (October 2024 – June 2025)

Article Title: Respiratory pathogen profiles in children aged 0–18 years: a single-center experience (October 2024 – June 2025)

Article References: Kilinc, F., Köklü, R., Kaya, N. S., Erdogan, F., & Türkmen, Z. (2026). Respiratory pathogen profiles in children aged 0–18 years: a single-center experience (October 2024 – June 2025). BMC Pediatrics. https://doi.org/10.1186/s12887-026-07916-x

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07916-x

Keywords: Respiratory, pathogen, profiles, children, aged, years, single-center, experience, October, June, scientific research