Invasive pneumococcal disease in children after introduction of pneumococcal conjugate vaccine

Abstract number: P2204

Cendejas E., Romero M., Baquero F., Gomez-Gil R., Gutierrez A.

Objectives: Determination of antibiotic susceptibility and serotype distribution causing invasive pneumococcal disease (IPD) in children after comercialisation of the 7- pneumococcal valent conjugate vaccine (7PCV).

Methods: We analysed the clinical and microbiological data from paediatric patients with invasive strains of S. pneumoniae. We included all paediatric patients with isolation of S. pneumoniae in blood, cerebrospinal fluid or pleural fluid. Bacterial identification testing was performed using the VITEK 2 automated system (bioMerieux, France). Serotyping and antibiotic susceptibility were conducted in The National Reference Laboratory of Pneumococci, at the Nacional Center for Microbiology of Majadahonda, Madrid. Antimicrobial susceptibilities were interpreted according to Clinical Laboratory Standards Institute (CLSI) methodology and interpretive meningitis breakpoints.

Results: From January 2005 to December 2006, a total of forty-four S. pneumoniae invasive isolates were recovered from clinical specimens: 38 blood, 5 cerebrospinal fluid and 1 pleural fluid. Overall, 79.54% isolates were serotypes no contained in 7PCV. The most frequently isolated serotypes were 1 (9/44), 19A (9/44), 7 (6/44), 5 (5/44). The others 15 isolates were divided among the remaining serotypes 6A, 23F, 9V, 6B, 35F, 15C, 10A, 18C, 16, 14, 19F.

The main clinical manifestations included sepsis/bacteraemia (15.9%), pneumonia (50%) and meningitis (18.18%).

One case of meningitis, among NVS group, showed intermediate resistance to cefotaxime.

Isolates in NVS group showed a low level of resistance to penicillin (resistant 2.85%, intermediate 8.57%, susceptible 88.57%) and cefotaxime (resistant 0.0%, intermediate 5.71%, susceptible 94.28%) and moderate resistance to erythromycin (resistant 17.14%, intermediate 0.0%, susceptible 82.85%).

The VS group showed reduced susceptibility to penicillin (resistant 22.22%, intemediate 44.44%, susceptible 33.33%) and cefotaxime (resistant 0.0%, intermediate 22.22%, susceptible 77.78%) and high resistance to erythromycin (resistant 44.44%, intermediate 0.0%, susceptible 55.55%).

Conclusions: Our findings suggest a replacement of vaccine serotypes (VS) by nonvaccine serotypes (NVS) betwen the distribution of pneumococcal serotypes causing IPD in paediatric patients.

NVS isolates showed a lower level of resistance to antibiotics used as first choice treatment in pneumococcal invasive disease, penicillin and cefotaxime, than VS.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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