Clinical characteristics of infants younger than 90 days diagnosed with invasive group B streptococcal infection in the emergency department

Abstract

Purpose: We aimed to characterize invasive group B streptococcal infection (IGBSI) in young infants hospitalized through the emergency department.Methods: We analyzed medical records of infants younger than 90 days with IGBSI, defined as group B streptococcus bacteremia or meningitis, who visited the emergency department from January 2009 through December 2021. Their clinical features were compared as per 2 criteria, neonates and meningitis. For the comparisons, we defined 2 composite outcomes, “clinically important abnormality (any of the followings: temperature > 38.5℃, leukocytes < 5,000/mm3 or > 15,000/mm3, absolute neutrophils > 4,000/mm3 or C-reactive protein > 2.0 mg/dL)”and “poor outcomes (any of the followings: intensive care unit, transfer, seizure or complications).”Percentages are rounded to the first decimal places.Results: A total of 35 infants, of whom 15 (43%) were neonates and 17 (49%) were boys, had IGBSIs, including 23 infants (66%) with isolated bacteremia, 11 (31%) with bacteremia with meningitis, and 1 (3%) with isolated meningitis. Ill appearances were noted in 27 infants (77%) who encompassed all with meningitis. The other 8 infants (23%) looking well had 1 or more components of the clinically important abnormality. The neonates showed a higher frequency of vaginal delivery (87% vs. 35%; P = 0.002) and a lower frequency of a temperature > 38.5℃, compared to their counterparts (47% vs. 80%; P = 0.040). The infants with meningitis had a longer median time required to visit (5.0 vs. 2.0 hours; P = 0.011), and higher frequencies of ill appearance (100% vs. 65%; P = 0.032), leukocytes < 5,000/mm3 (67% vs. 13%; P = 0.002), and the poor outcomes (75% vs. 0%; P < 0.001).Conclusion: Young infants with ill-looking appearance or abnormality in any of the fever or inflammatory markers may have IGBSIs, particularly meningitis.