Review Question - QID 210017

This patient’s known genetic mutation and normocytic anemia suggest an underlying diagnosis of sickle cell disease (SCD), and his current presentation is consistent with a diagnosis of sepsis. The most likely causative organism of sepsis in SCD patients is S. pneumoniae.

Infection is a leading cause of morbidity and mortality in patients with SCD. In particular, patients are at increased risk of infection by encapsulated organisms due to functional hyposplenism or asplenia. The most common infectious agent being S. pneumoniae. For these reasons, patients with SCD should receive prophylactic penicillin until age 5 in addition to the standard childhood vaccinations.

Incorrect Answers:
Answer 1: Haemophilus influenzae is an encapsulated organism and common cause of meningitis and bacteremia in patients with SCD, but it is less common than S. pneumoniae.

Answer 2: Listeria monocytogenes is a common cause of meningitis in neonates but would not be a common etiology of infection in this older child. Patients with SCD are also not thought to be at higher risk of infection with Listeria spp.

Answer 3: Neisseria meningitidis is another encapsulated organism that commonly causes meningitis, but it is less common than both S. pneumoniae and H. influenzae in children with SCD.

Answer 4: Salmonella is a common cause of osteomyelitis in patients with SCD, but this patient’s clinical presentation does not have any localizing features suggestive of osteomyelitis.

Bullet Summary:
The most common cause of sepsis in patients with SCD is S. pneumoniae, followed by H. influenzae.