Streptococcal Invasive Disease - Group B, 2015: DCN - Minnesota Dept. of Health

Streptococcal Invasive Disease Group B, 2015

Five hundred twenty-seven cases of invasive group B streptococcal (GBS) disease (9.7 per 100,000 population), including 25 deaths, were reported in 2015. In 2013, 595 cases were reported, the largest number of GBS cases reported since surveillance was initiated in 1995.

By age group, annual incidence was highest among infants <1 year of age (56.2 per 100,000 population) and cases aged 70 years or older (36.8 per 100,000). Twelve (48%) of the 25 deaths were among cases age 65 years and older. Fifty-two percent of cases were residents of the metropolitan area. Bacteremia without a focus of infection occurred most frequently (33% of infections), followed by cellulitis (18%), septic arthritis (11%), abscess (7%), osteomyelitis (4%), and meningitis (2%). The majority (73%) of cases had GBS isolated from blood; other isolate sites included joint fluid (15%) and bone (2%).

Forty-two cases were infants or pregnant women (maternal cases), compared to 48 cases in 2014. Sixteen 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 of age [0.3 cases per 1,000 live births]). Two stillbirth/spontaneous abortions were 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 2015. Overall, 10 of 16 women who delivered GBS-positive infants underwent prenatal screening for GBS. Of these, 2 were positive and 8 negative. Two of the 6 women who did not receive prenatal screening were screened upon admission to the hospital and prior to delivery. Among the 16 women who delivered GBS-positive infants, 5 received intrapartum antimicrobial prophylaxis (IAP). One of the 2 women with a positive GBS screen after hospital admission received IAP.

Updated Friday, September 16, 2016 at 12:10PM