Cardiopulmonary morbidity of streptococcal infections in a PICU

The streptococci are important bacteria that cause serious childhood infections. We investigated cardiopulmonary morbidity associated with streptococcal infection and pediatric intensive care unit (PICU) admission.

A retrospective study between 2002 and 2013 of all children with a laboratory isolation of streptococcus.

There were 40 (2.3%) PICU patients with streptococcal isolations including Streptococcus pyogenes (Group A streptococcus, GAS, n = 7), Streptococcus agalactiae (Group B streptococcus, GBS, n = 5), Streptococcus pneumoniae (SP, n = 20), alpha-hemolytic (n = 4), beta-hemolytic (n = 2) and gama-hemolytic (n = 2) streptococci. Comparing among GAS, GBS and SP, respiratory isolates were more likely positive for GAS or SP (P = 0.033), whereas cerebrospinal fluid was more likely positive for GBS (P = 0.002). All GAS and GBS, and the majority of SP (90%) were sensitive to penicillin. All SP specimens were sensitive to cefotaxime and vancomycin. These infections were associated with high PICU mortality of 43%, 20% and 25%, respectively. Isolation of streptococci was associated with a 30% mortality and high rates of need for mechanical ventilatory and inotropic supports. Patients with GAS, SP or any streptococcal isolation had relative risks [95% confidence interval (CI), P value] of PICU deaths of 7.5 (CI 3.1-18.1, P < 0.0001), 4.5 (CI 2.0-9.8, P < 0.0002) and 5.7 (CI 3.4-9.5, P < 0.0001), respectively. In SP, older children had significantly higher prevalence of premorbid conditions such as malignancy, mental retardation/cerebral palsy ± seizure disorders, chromosomal or genetic disorders (P = 0.003) than children <5 years of age. Serotypes were available for some of these specimens that included 19A, 6B, 3 and 6C. There were four SP deaths with multiorgan system failure and hemolytic uremic syndrome (two 19A and two serotype 3).

Severe streptococcal infections are associated with significant morbidity and mortality despite treatment with systemic antibiotics and intensive care unit support. GAS and SP affect the lungs of children, whereas GBS more likely causes meningitis in infants. The expanded coverage of newer polyvalent pneumococcal vaccines can probably prevent infections by serotypes 19A, 19F, 6B and 3.