What is the most common cause of sepsis in children with sickle cell disease?

In children with sickle cell disease, the most common cause of sepsis is non-vaccine serotypes of Streptococcus pneumoniae. This is primarily due to the impaired function of the spleen, which is a key organ involved in filtering bacteria from the bloodstream and mounting an immune response. In sickle cell disease, splenic dysfunction occurs early in life due to repeated splenic infarctions, leading to functional asplenia.

Children with sickle cell disease are particularly vulnerable to infections caused by encapsulated bacteria; however, while vaccination has helped reduce the incidence of infections from certain strains of Streptococcus pneumoniae, non-vaccine serotypes remain a significant threat. Thus, even though Streptococcus pneumoniae is part of the normal flora, its non-vaccine variants can lead to severe illness in these patients who lack effective splenic filtration.

Other bacteria like Group A Streptococcus, Escherichia coli, and Haemophilus influenzae are indeed pathogens of concern in the broader pediatric population, but they do not match the prevalence of non-vaccine serotypes of Streptococcus pneumoniae in the context of sepsis among children specifically suffering from sickle cell disease.