An Invasive Pneumococcal Infection Due to Streptococcus pneumoniae Serotype 24.

Abstract

To the Editors: Levy et al1 report a 67% decrease of pediatric pneumococcal meningitis due to serotypes contained in the 13-valent pneumococcal conjugate vaccine (PCV13). Non-PCV13 serotypes that dominate in their setting are 12F, 24F, 22F and 15B/C. We report the recent case of a previously healthy 9-month-old child who presented with septic shock, purpura fulminans, multiorgan failure and meningitis. He received 2 doses of PCV13 at 2 and 4 months of age. Streptococcus pneumoniae serotype 24 was isolated from blood and cerebrospinal fluid. His clinical course was marked by acute renal failure, rhabdomyolysis and intravascular disseminated coagulation. His skin condition worsened with large areas of necrosis. Amputation of 3 necrotic extremities and prolonged course of antibiotics resulted in a slow recovery. It is yet unclear whether PCV13 will lead to the emergence of new dominant serotypes similarly to what has been observed previously with 19A in the PCV7 era.2 Yet, the present case and the study by Levy et al raise the question of the potential invasiveness and replacement capacity of serotype 24. Levy et al reported that 15% of pneumococcal meningitis was attributed to serotype 24F, in 2012, in France. However, evidence of an increased proportion of serotype 24 IPD has not been documented in the actual post-PCV13 era in other settings. Besides, low prevalence of invasive pneumococcal diseases due to serotype 24 has been reported after PCV7 and before PCV13 implementation.3 In addition, increased incidence of invasive pneumococcal diseases due to non-PCV13 serotypes as observed in many settings is not related to the emergence of clearly dominant serotypes.4 If this trend is confirmed by ongoing microbiologic surveillance, the development of new conjugated vaccines will no longer be the appropriate strategy. Tarahomjoo5 in a recent review article details new potential options for vaccine development, including the use of surface protein vaccines that could be coadministered with conjugated vaccines to reach a wider coverage of invasive strains. We hope that these potential new vaccines will contribute to the disappearance of such devastative infections in properly vaccinated children, in the future. Eugénie Gradoux Department of Paediatrics Sandra Asner, MD, MSc, MER1 Unit of Paediatric Infectious Diseases Department of Paediatrics Marie-Hélène Perez, MD Paediatric Intensive Care Unit Department of Paediatrics Pierre A. Crisinel, MD Unit of Paediatric Infectious Diseases Department of Paediatrics University Hospital Centre Lausanne, Switzerland