Invasive pneumococcal disease by serotype 23B in an asplenic unvaccinated patient: A case report

Invasive pneumococcal disease (IPD) is a life-threatening infection caused by Streptococcus pneumoniae, particularly in immunocompromised individuals, such as those with asplenia. Although pneumococcal vaccination has reduced the incidence of vaccine-covered serotypes, non-vaccine serotypes, including serotype 23B, have emerged as the predominant cause of IPD. This case report describes a 67-year-old woman with asplenia who developed IPD　caused by multidrug-resistant Streptococcus pneumoniae serotype 23B, which led to meningitis, septic arthritis, and endophthalmitis. The patient, who had declined pneumococcal vaccination after her splenectomy, presented with fever, pain in her left hip and right shoulder, and visual issues. The diagnosis confirmed S. pneumoniae serotype 23B, resistant to multiple antibiotics. The treatment involved a combination of vancomycin, ceftriaxone, and rifampicin, followed by vitrectomy for the eye infection. Despite severe complications, including worsening vision, the patient's vision in the right eye improved after surgery, and the joint pain subsided with long-term antibiotic therapy. This case underscores the challenges posed by non-vaccine S. pneumoniae serotypes, particularly in asplenic patients. Currently, we can use the 21-valent pneumococcal conjugate vaccine (PCV21), which includes the 23B serotype. Vaccination and early recognition, combined with a multidisciplinary treatment approach involving both antimicrobial therapy and surgical intervention, are crucial for improving the outcomes of patients with severe IPD.