Epidemiology and Antibiotic Resistance of Neonatal Invasive Group B Streptococcus Disease: a Retrospective Study in Fuzhou, China, 2012 - 2021.

Background: Group B streptococcus (GBS) causes neonatal invasive disease, mainly sepsis and meningitis. Understanding the clinical characteristics, laboratory tests, and antibiotic resistance patterns of GBS invasive infections provides reliable epidemiological data for preventing and treating GBS infections.

Methods: Clinical characteristics and laboratory test results from 86 patients with neonatal invasive disease (45 cases of early-onset disease [EOD] and 41 cases of late-onset disease [LOD]) recruited from Fujian Maternity and Child Health Hospital between January 2012 and December 2021 were analyzed.

Results: The number of neonates with invasive GBS infections declined for 10 years. Respiratory symptoms, the first clinical presentation in EOD, were predominant (71.1%), including groan, tachypnea, and cyanosis, whereas LOD more often presented with fever (78%). Pneumonia was the most common complication (57.0%). There were 35 patients (77.8%) with pneumonia and 18 patients (40.0%) with respiratory failure in the EOD cases, which were more than those in LOD cases. Neonates in the EOD cases were more prone to myocardial damage, cerebral injury, and metabolic acidosis than those in the LOD cases. The proportion of purulent meningitis (63.4%) and anemia (29.3%) in LOD was higher than those in EOD. White blood cell count of the EOD group was higher than that of the LOD group, whereas the proportion of patients with leukopenia was lower in the EOD group (24.4%) than in the LOD group (46.3%). All the GBS strains were susceptible to penicillin, ampicillin, linezolid, quinupristin, vancomycin, or tigecycline. Erythromycin and clindamycin resistance rates were 82.6% and 84.9%, respectively. A D-test revealed 48.6% iMLSB phenotype (inducible clindamycin resistant), and cMLSB phenotype (47.3%), L-phenotypes (2.7%), and M-phenotypes (1.4%) were also found.

Conclusions: The number of cases of neonatal invasive GBS infections has decreased in recent years. Patients with invasive GBS-EOD infections have insidious onset symptoms and should be diagnosed early based on clinical symptoms and laboratory examination results. GBS strains are resistant to erythromycin and clindamycin, which is not suitable for prophylactic and empirical treatment in the neonatal population in this region.