Streptococcal Invasive Disease Group B 
Annual Summary of Reportable Diseases

Streptococcus group B is a common bacterium that can cause a variety of diseases, ranging from mild to severe. Invasive disease is defined when bacteria invade parts of the body that are typically free from bacteria, such as the blood. Five-hundred-forty-three cases of invasive group B Streptococcus (GBS) disease (9.6 per 100,000 population), including 32 deaths, were reported in 2022. By age group, annual incidence was highest among infants less than one year of age (48.2 per 100,000 population) and cases aged ≥70 years (33.9 per 100,000). Twenty-three (72%) of the 32 deaths were among cases ≥65 years. Forty-eight percent of cases were residents of the metropolitan area. Bacteremia without a focus of infection occurred most frequently (30%), followed by cellulitis (25%), septic arthritis (14%), septic shock (12%), osteomyelitis (10%), pneumonia (10%), abscess (6%), and meningitis (2%). The majority (84%) of cases had GBS isolated from blood; other isolate sites included joint fluid (9%), peritoneal fluid (2%), bone (1%), and cerebrospinal fluid (<1%). Thirty-one cases were infants and two were maternal cases, compared to 34 cases in 2021. Nine infants developed early-onset disease (occurred within 6 days of birth [0.1 cases per 1,000 live births]), and 22 infants developed lateonset disease (occurred at 7 to 89 days [0.3 cases per 1,000 live births]). One stillbirth/spontaneous abortion was associated with the 2 maternal GBS infections. Since 2002, there has been a recommendation for universal prenatal screening of all pregnant women for GBS at 35 to 37 weeks gestation. MDH reviewed the maternal charts for all early-onset cases reported in 2021. Overall, 6 of 9 women who delivered GBS-positive infants underwent prenatal screening for GBS. Of these, two were positive and four were negative. One of the three women who did not receive prenatal screening was screened upon admission to the hospital prior to delivery and was positive. Among the 9 women who delivered GBS-positive infants, four 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)

Five-hundred-eighty-four cases of invasive group B Streptococcus (GBS) disease (10.3 per 100,000 population), including 41 deaths, were reported in 2021. By age group, annual incidence was highest among infants <1 year of age (49.7 per 100,000 population) and cases aged ≥70 years (30.1 per 100,000). Nineteen (46%) of the 41 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 (27%), followed by cellulitis (20%), septic arthritis (10%), osteomyelitis (9%), septic shock (9%), pneumonia (6%), abscess (5%), and meningitis (1%). The majority (85%) of cases had GBS isolated from blood; other isolate sites included joint fluid (9%), peritoneal fluid (3%), cerebrospinal fluid (<1%), and bone (<1%). 

Thirty-four cases were infants and 4 were maternal cases, compared to 33 cases in 2020. Thirteen infants developed early-onset disease (occurred within 6 days of birth [0.2 cases per 1,000 live births]), and 17 infants developed late-onset disease (occurred at 7 to 89 days [0.3 cases per 1,000 live births]). One stillbirth/ spontaneous abortion was associated with the 4 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 2021. Overall, 7 of 13 women who delivered GBS-positive infants underwent prenatal screening for GBS. Of these, 2 were positive and 5 were negative. One of the 6 women who did not receive prenatal screening was screened upon admission to the hospital prior to delivery and was positive. Among the 13 women who delivered GBS-positive infants, 7 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)

Group B Five hundred forty-two cases of invasive group B Streptococcus (GBS) disease (9.6 per 100,000 population), including 30 deaths, were reported in 2020. By age group, annual incidence was highest among infants <1 year of age (49.3 per 100,000 population) and cases aged ≥70 years (33.5 per 100,000). Eighteen (60%) of the 30 deaths were among cases ≥65 years. Forty-seven percent of cases were residents of the metropolitan area. Bacteremia without a focus of infection occurred most frequently (29%), followed by cellulitis (21%), septic arthritis (8%), osteomyelitis (8%), septic shock (7%), pneumonia (7%), abscess (5%), and meningitis (1%). The majority (84%) of cases had GBS isolated from blood; other isolate sites included joint fluid (9%), peritoneal fluid (1%), cerebrospinal fluid (1%), and bone (1%). 

Thirty-three cases were infants and 2 were maternal cases, compared to 42 cases in 2019. Twelve infants developed early-onset disease (occurred within 6 days of birth [0.2 cases per 1,000 live births]), and 21 infants developed late-onset disease (occurred at 7 to 89 days [0.3 cases per 1,000 live births]). No stillbirth/spontaneous abortion were associated with the 2 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 2020. Overall, 8 of 12 women who delivered GBS-positive infants underwent prenatal screening for GBS. Of these, 4 were positive and 4 were negative. One of the 4 women who did not receive prenatal screening was screened upon admission to the hospital and prior to delivery and was positive. Among the 12 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)

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)

Five hundred seventy-nine cases of invasive group B streptococcal (GBS) disease (10.4 per 100,000 population), including 28 deaths, were reported in 2018. By age group, annual incidence was highest among infants <1 year of age (44.7 per 100,000 population) and cases aged ≥70 years (39.9 per 100,000). Fifteen (54%) of the 28 deaths were among cases ≥65 years. Fifty-one percent of cases were residents of the metropolitan area. Bacteremia without a focus of infection occurred most frequently (31%), followed by cellulitis (24%), septic arthritis (9%), septic shock (8%), abscess (5%), pneumonia (5%), osteomyelitis (4%), and meningitis (3%). The majority (83%) of cases had GBS isolated from blood; other isolate sites included joint fluid (10%), peritoneal fluid (3%), cerebrospinal fluid (1%), and bone (1%).

Twenty-nine cases were infants and 4 were maternal cases, compared to 42 cases in 2017. Twelve infants developed early-onset disease (occurred within 6 days of birth [0.2 cases per 1,000 live births]), and 17 infants developed late-onset disease (occurred at 7 to 89 days [0.2 cases per 1,000 live births]). Four stillbirth/ spontaneous abortions were associated with the 4 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 2018. Overall, 6 of 12 women who delivered GBS positive infants underwent prenatal screening for GBS. Of these, 1 was positive and 5 were negative. One of the 6 women who did not receive prenatal screening was screened upon admission to the hospital and prior to delivery, and was positive. Among the 12 women who delivered GBS-positive infants, 7 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)

• Archive of Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health
  Archive of past summaries (years prior to 2023 are available as PDFs).