Group B Streptococcus Carriage in Pregnancy: Burden of Early-onset Neonatal Disease and Estimation of the Cost of Universal Antenatal Screening in a Hospital of the Eastern Region of Saudi Arabia

Introduction: Group B streptococcus (GBS) is recognized as a significant cause of neonatal infections worldwide. The study investigated the burden of early-onset neonatal disease and assessed the cost of routine GBS screening in a hospital of the eastern region of Saudi Arabia. Materials and Methods: Pregnancy-related information and laboratory-related data for pregnant women for the period of 2016-2017 were used to determine the colonization rate of GBS. The efficiency of intrapartum antibiotic prophylaxis (IAP) was examined among pregnant women carrying GBS and delivered at the hospital. The cost of GBS routine screening was estimated based on the cost of rectovaginal swab enrichment in BBLTM LIM broth and confirmation by polymerase chain reaction. The burden of early-onset disease and rates of resistance to antibiotics among vaginal and invasive neonatal isolates were investigated for seven years. Results: Screening of 2,476 samples from 1,162 pregnant women in two years showed a GBS colonization rate of 23% (270/1162). Of the 270 GBSpositive women, only 98 (37%) delivered at the hospital, of whom 42% received IAP. Cesarean delivery was associated with significantly higher rates of IAP administration (odds ratio 5.2; p value 0.001). The annual incidence of early-onset disease increased from a baseline level of 0.5 in 2012 to 3.9 per 1,000 births in 2018. These included 23 cases of invasive infections with three fatal cases caused by meningitis or sepsis (3/23, 13%). Group B streptococcus isolates remained uniformly sensitive to penicillin and vancomycin but exhibited resistance to clindamycin in 35.2%. The annual estimated costs of routine screening would be $110,880 ($41 per delivery) and $161,280 ($60 per delivery) for the BD MAXTM system and GeneXpert (R) System, respectively. Conclusion: While the incidence of early-onset GBS disease was increasing, improved compliance with the IAP is needed to inform the costeffectiveness of routine GBS