While waiting for a vaccine: opportunities for optimization of neonatal group B streptococcal (GBS) disease prevention in Israel

Group B Streptococcus real-time PCR may potentially reduce intrapartum maternal antibiotic treatment

BACKGROUND

Protocols for preventing early-onset group B streptococcal (GBS) neonatal infection may result in unnecessary antibiotics administration. Real-time polymerase chain reaction (PCR) can provide a result within 30-60 min and has been found to be specific and sensitive for defining intrapartum GBS status.

OBJECTIVE

To evaluate whether implementation of GBS fast real-time PCR to all women who require GBS prophylaxis may reduce the use of maternal prophylactic antibiotics.

METHODS

This prospective cohort study included women admitted to a single delivery ward who required prophylactic antibiotics either due to a positive antepartum GBS culture screening performed at 35-37 weeks or due to an unknown GBS status with an intrapartum risk factor. All the women were tested by a double vaginal swab (real-time PCR and culture) as soon as it became apparent, they required antibiotic prophylaxis and prior to its administration.

RESULTS

Between May 2019 and August 2020, 303 women met eligibility criteria and were enrolled, but four were excluded from the analysis due to failed culture or PCR tests. Of 299 women included in the study, 208 (69.5%) and 180 (60.2%) women, showed no evidence of GBS on intrapartum culture or PCR, respectively. Of 89 GBS antepartum carriers, 43 (48.3%) and 32 (35.9%) had negative intrapartum culture and PCR results, respectively. Of the 210 women with risk factors, 165 (78.5%) were culture negative and 148 (70.4%) had a negative PCR. Using intrapartum culture as the gold standard, intrapartum GBS real-time PCR was found to have a sensitivity of 97.8% (95% confidence interval [CI] 92.3, 99.7) and a specificity of 85.6% (95% CI 80.1, 90.1).

CONCLUSIONS

Compared with antepartum universal culture screening or intrapartum risk-factor assessment, the need for maternal antibiotic treatment may be substantially reduced by implementation of intrapartum GBS real-time PCR, without compromising the sensitivity of GBS detection.

Regional Variation of Early-onset Neonatal Group B Streptococcal Disease Prevention Strategies in Mainland China

BACKGROUND

Prevention strategies can reduce the incidence of early-onset group B Streptococcus (GBS) neonatal sepsis (EOGBS). Rates of GBS colonization and infection vary among regions within China. China has not adopted a unified prevention strategy.

METHODS

To assess strategies to reduce EOGBS in China, models were developed to quantify residual EOGBS rates with intrapartum antibiotic prophylaxis in infants ≥ 35 weeks' gestation in risk factor-based and antepartum screening-based strategies. Maternal GBS colonization rates and EOGBS incidence in 3 regions of China (A: Xiamen of Fujian province, B: Shanghai and C: Liuzhou of Guangxi province) were estimated from published data.

RESULTS

Estimates for GBS colonization and attack rates were 21.6%, 11.7% and 6.1% and 1.79, 1.79 and 0.58 per 1000 live births for regions A, B and C, respectively. Modeling predicted that strategies including screening cultures beginning at 36 weeks' gestation and intrapartum antibiotic prophylaxis in 90% of eligible parturients could reduce EOGBS incidence to 0.44, 0.50 and 0.16 per 1000 live births in these regions. In region C, the expected EOGBS rate could be reduced to 0.28 per 1000 using a risk factor-based strategy.

CONCLUSIONS

Different strategies for preventing EOGBS may be needed in different regions of mainland China. Screening strategies may be most appropriate in regions with higher attack rates, even with moderate levels of maternal GBS colonization. In areas with low attack rates, risk factor strategies that reduce morbidity by at least one-third may suffice.

Evaluation of Implementation of Early-Onset Sepsis Calculator in Newborns in Israel

OBJECTIVE

To evaluate the recommendations based on the early-onset sepsis (EOS) calculator in the first 2 years of its implementation in Israel.

STUDY DESIGN

Prospective 2-year surveillance of a cohort of infants born at gestational age of ≥34 weeks in Bnai Zion Medical Center, who were evaluated using the EOS calculator because of peripartum risk factors.

RESULTS

We evaluate 1146 newborns with peripartum risk factors using the EOS calculator. The percentage of infants who had laboratory evaluation decreased to 4.6%, and the EOS calculator recommended empiric antibiotic therapy in only 2.2%. During the study period, there were 4 early-onset infections (EOS incidence of 0.6 in 1000 live births). Three had group B streptococcus (GBS) and one had Escherichia coli infection. Only 2 of these infants had perinatal risk factors and the EOS calculator identified them and recommended laboratory evaluation and empiric antibiotics. However, 2 infants with GBS EOS had no perinatal risk factors or clinical symptoms at delivery, and were discovered clinically at older ages.

CONCLUSIONS

The Israeli EOS calculator-based guidelines seem to be appropriate and are associated with less laboratory evaluations, and little use of empiric antibiotics. Concerns are related to the current recommendation of no GBS universal screening in Israel, and the inability of the calculator-based approach to identify GBS EOS in infants born to mothers with unknown GBS who have no peripartum risk factors before presentation of clinical symptoms.