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Published on: February 23, 2014
Urinary pneumococcal serotype detection among children with and without community-acquired pneumonia
Lilliam Ambroggio1,2, Lindsay R Grant3, Jillian M Cotter4
1Section of Emergency Medicine, Department of Pediatrics, Children's Hospital Colorado, University of Colorado, Aurora, CO, USA. Lilliam.Ambroggio@cuanschutz.edu.
Insights
Urinary antigen detection (UAD) assays show promise for pneumococcal serotype surveillance in children. While UAD identified different serotypes than nasal swabs, it may help monitor serotype distribution in community-acquired pneumonia (CAP).
Area of Science:
- Pediatric Infectious Diseases
- Microbiology
- Diagnostic Assay Development
Background:
- Culture-based identification of Streptococcus pneumoniae presents diagnostic challenges.
- Urinary antigen detection (UAD) assays offer a potential solution for identifying pneumococcal serotypes.
- Evaluating novel UAD assays is crucial for improving diagnostic capabilities.
Purpose of the Study:
- To assess the utility of Pfizer's UAD1 and UAD2 assays for pneumococcal serotype surveillance.
- To investigate the role of UAD in diagnosing community-acquired pneumonia (CAP) and upper respiratory tract infections (URI) in children.
- To compare pneumococcal serotypes identified by UAD with those detected via nasal swabs.
Main Methods:
- Children aged 3 months to 5 years with respiratory symptoms (CAP or URI) and healthy controls were enrolled.
- Nasal swabs were analyzed for Streptococcus pneumoniae using PCR.
- UAD assays were employed to detect pneumococcal serotypes in urine samples.
- Descriptive statistics were used to compare findings across groups.
Main Results:
- Pneumococcal nasal swab positivity was 23% in CAP, 17% in URI, and 3% in controls.
- UAD identified pneumococcal serotypes in 13% of CAP cases and 5% of URI cases.
- Serotypes 19F, 22F, and 9N were most common in urine, differing from nasal swab findings (3, 15B/C, 19F, 35B).
- Concordance between nasal swab and UAD serotypes was low (3.7% in CAP, 1.5% in URI).
Conclusions:
- UAD assays show potential for differentiating pneumococcal serotypes in pediatric respiratory infections.
- Discrepancies between nasal and urine serotypes suggest UAD positivity is not solely due to carriage.
- Pfizer's UAD assay could be valuable for population-level monitoring of pneumococcal serotype distribution in children with CAP.
Background:
Urinary antigen detection (UAD) assays can address diagnostic challenges with culture-based identification of S. pneumoniae. We aimed to evaluate the utility of Pfizer's UAD1 and UAD2 assays for pneumococcal serotype surveillance in children with community acquired pneumonia (CAP) or upper respiratory tract infections (URI).
Methods:
From March 2021-December 2023, children 3 months to 5 years who presented to the Children's Hospital Colorado Emergency Department with respiratory symptoms were enrolled as CAP or URI; healthy children served as controls. Nasal swabs were tested for pneumococcus by PCR. UAD assays identified pneumococcal serotypes from urine. Groups were compared using descriptive statistics.
Results:
We enrolled 407 controls, 202 with URI, and 280 with CAP. Positivity thresholds were set for all UAD serotypes. Pneumococcal nasal swab positivity was 23% for CAP, 17% for URI, and 3% in controls. Serotypes 3, 15B/C, 19 F, and 35B were frequent in nasal swabs in children with CAP or URI. UAD identified serotypes in 13% with CAP and 5% with URI. The most common urine serotypes were 19 F, 22 F, and 9 N. Among children with a nasal swab collected, 28/190 (15%) with CAP and 4/135 (3%) with URI had a positive UAD; 7 (3.7%) and 2 (1.5%), respectively, were the same serotype identified by nasal swab.
Conclusions:
UAD may be useful in differentiating pneumococcal serotypes in children with CAP and URI from controls. For most, serotypes identified in nasal swabs were not those identified by UAD suggesting UAD positivity was not due to pneumococcal carriage. The Pfizer UAD assay could be utilized for population monitoring of serotype distribution among children with CAP.
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