Streptococcal Invasive Disease Group B, 2019

Six hundred six cases of invasive group B Streptococcus (GBS) disease (10.7 per 100,000 population), including 34 deaths, were reported in 2019. By age group, annual incidence was highest among infants <1 year of age (57.7 per 100,000 population) and cases aged ≥70 years (39.2 per 100,000). Twenty-two (65%) of the 34 deaths were among cases ≥65 years. Fifty percent of cases were residents of the metropolitan area. Bacteremia without a focus of infection occurred most frequently (28%), followed by cellulitis (23%), septic shock (9%), septic arthritis (8%), osteomyelitis (6%), abscess (5%), pneumonia (5%), and meningitis (2%). The majority (83%) of cases had GBS isolated from blood; other isolate sites included joint fluid (9%), peritoneal fluid (2%), cerebrospinal fluid (1%), and bone (1%).

Thirty-seven cases were infants and 5 were maternal cases, compared to 33 cases in 2018. Thirteen infants developed early-onset disease (occurred within 6 days of birth [0.2 cases per 1,000 live births]), and 24 infants developed late-onset disease (occurred at 7 to 89 days [0.4 cases per 1,000 live births]). One stillbirth/spontaneous abortion was associated with the 5 maternal GBS infections.

Since 2002, there has been a recommendation for universal prenatal screening of all pregnant women at 35 to 37 weeks gestation. In light of this, we reviewed the maternal charts for all early-onset cases reported in 2019. Overall, 7 of 13 women who delivered GBS-positive infants underwent prenatal screening for GBS. Of these, 3 were positive and 4 were negative. Two of the 6 women who did not receive prenatal screening were screened upon admission to the hospital and prior to delivery, and both were positive. Among the 13 women who delivered GBS-positive infants, 6 received intrapartum antimicrobial prophylaxis. An update of GBS perinatal prevention guidance was published by the American College of Obstetricians and Gynecologists, and by the American Academy of Pediatrics in July 2019.

• For up to date information see: Group B Streptococcus (GBS)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2019