Pneumococcal diagnosis and serotypes in childhood community-acquired pneumonia

Area of Science:

• Pediatric Infectious Diseases
• Vaccinology
• Microbiology

Background:

• The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in the UK in 2006, replaced by the 13-valent PCV13 in 2010.
• Pneumonia remains a significant cause of childhood illness.
• Understanding the circulating pneumococcal serotypes is crucial for vaccine efficacy assessment.

Purpose of the Study:

• To investigate the prevalence of pneumococcal infections in children with radiologically confirmed pneumonia.
• To compare detection methods for pneumococci in pediatric pneumonia cases.
• To identify the specific pneumococcal serotypes causing infections in children post-PCV7 introduction.

Main Methods:

• Prospective study of 160 children (≤16 years) with radiologically confirmed pneumonia between 2009 and 2011.
• Detection of *Streptococcus pneumoniae* using both culture and polymerase chain reaction (PCR).
• Serotyping of detected pneumococci to determine vaccine type coverage.

Main Results:

• Likely pneumococcal infections were identified in 26% of children with pneumonia.
• Polymerase chain reaction significantly improved pneumococcal detection rates compared to culture (21.6% vs. 6%, P = 0.0004).
• All 23 serotyped isolates belonged to non-PCV7 but PCV13 serotypes, with serotypes 1, 3, 7A/F, and 19A being most common.

Conclusions:

• Pneumococcal infections are a notable cause of pneumonia in UK children.
• PCR is a more sensitive method for detecting pneumococci in pediatric pneumonia.
• The identified pneumococcal serotypes causing pneumonia were predominantly covered by the PCV13 vaccine, not the earlier PCV7.