A Completed Vaccination Series at Play Will Not Always Keep Pneumococcal Sepsis Away
Authors: Tafti Mona Dehghani , Sitner-Medvedovsky Emily , Minkowitz Sheera , Orisamolu Fehintola , John Minnie , Sundaram Revathy 
Published: June 2024

Abstract

Presentation Date: 6/9/2024
Presentation Start Time: 1:15:00 PM

Background
Sickle cell disease (SCD) is an inherited blood disorder characterized by a single nucleotide polymorphism in the β-globin gene, resulting in the production of abnormal hemoglobin S (HbS). There are four subtypes of SCD, HbSS, HbSC and HbS β-thalassemia. Sickle cell disease is associated with a range of complications, including but not limited to vaso-occlusive crises, hemolytic anemia, organ damage, and an increased risk of infections with encapsulated organisms as a result of functional asplenia. With the introduction of pneumococcal vaccination and prophylactic daily oral penicillin, the morbidity and mortality from pneumococcal sepsis has been significantly reduced. Despite these preventive measures, the risk of invasive pneumococcal disease still exits. We will discuss the case of a vaccinated patient with Hemoglobin SC disease with pneumococcal bacteremia and associated septic shock.

Methods
We describe a16-year-old vaccinated female, with HbSC who presented with headache and fever. According to immunization records she had received six lifetime pneumococcal conjugate vaccinations (PCV 7 & 13) (Prevnar 7 & 13) and one dose of the pneumococcal polysaccharide vaccination (PPSV 23) (Pneumovax 23). The patient had been experiencing these symptoms for two days prior to admission however did not seek medical attention until the temperature reached 103F. In the emergency department she was found to be ill-appearing and tachycardiac, otherwise her physical examination was grossly unremarkable. Complete blood count and manual differential revealed leukocytosis with a left shift. Acute phase reactants were elevated as well, with a C-Reactive Protein 85 and Procalcitonin 7.01. Blood culture was drawn, and she received a dose of IV Ceftriaxone and was admitted for further workup and management.
Shortly after hospitalization, she had worsening of headache and was found to be hypotensive with a blood pressure of 86/52mmHg. Additionally, the blood culture was reported positive for Streptococcus Pneumoniae. She was transferred to the pediatric ICU for management of septic shock. Resuscitation efforts included fluid boluses, vasopressors, and broadened antibiotics while blood culture sensitivity pended. Given the worsening headache, a lumbar puncture was performed. The meningoencephalitis panel and CSF culture were negative. MRI and MRA brain were done, which were unremarkable. Streptococcus pneumoniae serotype was not identified. The patient received a full course of antibiotics for pneumococcal septicemia, made a full recovery and was discharged home.

Results
The introduction of pneumococcal conjugate and polysaccharide vaccines markedly reduced the incidence of invasive pneumococcal disease (IPD) in patients with sickle cell anemia. Interventions directed at ensuring patients have access to and are immunized with the recommended vaccinations are a cornerstone of current care of a patient with sickle cell anemia. In addition to the standard pneumococcal vaccination schedule for pediatric patients with PCV 13, PPSV 23 is recommended in patients living with SCD at age 2 and 5. This case raises awareness of the occurrence of invasive pneumococcal disease in patients with HbSC type. Educating patients and their families about this possible, albeit uncommon, complication is imperative, due to its potentially fatal consequences. Patients with sickle cell anemia should present for prompt evaluation of fever and early administration of antibiotics. Pneumococcal conjugate vaccines (PCV 15 & PCV 20) were approved in 2022 and 2023 that offer additional protection against additional serotypes. Our vaccination schedule and recommendations will likely evolve as more data is available as newer vaccines are developed.

Conclusions
This case aims to remind both patients and healthcare providers to the possibility of invasive pneumococcal disease even in vaccinated patients with sickle cell anemia. Despite the generally milder course experienced by individuals with HbSC in comparison to those with SS, healthcare providers are urged to maintain a heightened suspicion, particularly when there is fever and leukocytosis without a focus of infection. A completed vaccination series includes immunization against pneumococcal 13 and 23 serotypes with PCV 13 and PPSV 23 respectively. As new vaccines against IPD are developed the recommended vaccine schedule may change.