[A pediatric case of pneumococcal meningitis due to Streptococcus pneumoniae serotype 35F]

Pneumococci are one of the most common causes of bacterial meningitis in children. It's also responsible for the other invasive pneumococcal diseases (IPD) including bacteremia and pneumonia worldwide. Unvaccinated children are more prone to IPD. Although IPD tend to have a higher prevalence under 2 years of age and in children with primary/secondary immunodeficiencies, and various predisposing factors, older age groups with no underlying diseases also experience IPD. In this report, a pediatric case diagnosed with meningitis due to Streptococcus pneumoniae serotype 35F with no underlying condition and no history of pneumococcal vaccination was presented. An 11-year-old male patient was admitted to the hospital with the complaints of high (39.4°C) fever, headache, vomiting and sleepiness. On the basis of findings from physical examination and laboratory results, the patient was prediagnosed as bacterial meningitis and empirical ceftriaxone and vancomycin therapy was initiated. The cerebrospinal fluid culture of the patient yielded penicillin-susceptible pneumococci and the isolate was identified as serotype 35F by quellung reaction. Vancomycin treatment discontinued depending on the culture result, and the patient fully recovered with 14-days of ceftriaxone therapy without any complications during his follow-ups. Although effective antibiotics are available for IPD, vaccination is indispensable considering the high mortality rates. Seven serotypes (1, 5, 6A, 6B, 14, 19F, 23F) which are currently included in the vaccine, were the most common serotypes related to IPD globally. After mass infant vaccination has been introduced, invasive pneumococcal diseases due to the vaccine serotypes have tended to decrease in both vaccinated young children and non-vaccinated age groups due to herd immunity. Nevertheless, non-vaccine serotypes (NVTs) have emerged as the agents of IPD as a result of serotype replacement. 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in April, 2011 nationwide in our country. This case report was about a patient who had developed meningitis after the introduction of PCV13. There has been no data evaluating the pneumococcal serotype distribution after PCV13 in our country yet. On February, 2013, the Advisory Committee on Immunization Practices (ACIP) recommended routine use of PCV13 for children aged 6-18 years with underlying disease conditions. However, there is no recommendation for children with no underlying diseases in this age group. Vaccination can be extended for otherwise healthy children older than 6 years of age because of increasing trends in incidence of IPD both with vaccine and NVTs like serotype 35F. Recent studies have indicated the emergence of serotype 35F as a cause of IPD in children over 6 years of age and there have been also reports of IPD cases with 35F after the introduction of PCV13. Although serotype 35F is not yet a well-known serotype causing IPD, it might probably gain importance owing to its increasing frequency and virulence and might attract attention to be considered for inclusion in the future pneumococcal vaccines.