Burden of Invasive Group B Streptococcus Infection Among Omani Infants Less Than 90 Days Old: A Multicenter Study

Background: Group B Streptococcus (GBS) infection is the leading cause of neonatal morbidity and mortality worldwide. This study aims to investigate the incidence of invasive GBS disease among infants less than 90 days old in Oman and to describe their risk factors, clinical presentations and clinical outcomes. Methods: We retrospectively collected the data of less than 90-day-old Omani infants with culture-positive GBS from sterile samples. This study was conducted in 3 tertiary hospitals in Oman from 2009 to 2018. Results: Over 10 years, we identified 92 cases of culture-confirmed invasive GBS infection from 178,285 live births in the 3 hospitals, giving an overall incidence of 0.53 per 1000 live births [95% confidence interval (CI): 0.4–0.7)]. Of those, 59 (64.1%) had early-onset neonatal GBS disease and 33 (35.9%) had late-onset neonatal GBS disease. The incidence of invasive GBS disease was significantly higher in the last 5 years from 2014 to 2018 (0.69 per 1000 live births, 95% CI: 0.5–0.9) compared to the previous years from 2009 to 2013 (0.36 per 1000 live births, 95% CI: 0.2‒0.5), (P = 0.004). Infants with late-onset neonatal GBS disease had a higher risk of meningitis compared to infants with early-onset neonatal GBS disease (30.3% vs. 10.2%, P = 0.021). The mortality rate was 13.5%. Conclusions: The incidence of invasive GBS disease in Oman is similar to what was reported worldwide, however, the burden of the disease in terms of mortality is high. In addition, a significant increase in the annual incidence of invasive GBS disease in Omani infants was found over the study period.