Neonatal group B streptococcal disease: how infection control teams can contribute to prevention efforts

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.

Polymerase chain reaction for Group B Streptococci (GBS) at labor highly correlates with vaginal GBS load

OBJECTIVE

To explore factors associated with a high vaginal GBS load during labor considering (1) the recto-vaginal GBS load at 35-37 weeks' gestation determined by culture and (2) the vaginal GBS colonization determined by a polymerase chain reaction (PCR) assay during labor.

METHODS

From an unselected cohort of 902 pregnant women, we obtained (1) recto-vaginal swabs for culture of GBS at 35-37 weeks' gestation (GBS_rectovag-36), (2) vaginal swabs for GBS PCR detection at labor (PCR_vag-labor), and (3) vaginal swabs for culture of GBS at labor (GBS_vag-labor). The GBS load was classified semi quantitatively according to a culture protocol without prior broth enrichment of the swab samples: none (0), few (+), some (++), or many (+++) GBS colonies.

RESULTS

Among 902 unselected pregnant women, 859 (95%) had a vaginal swab culture taken at labor, which was classified semi quantitatively. High load GBS_vag-labor (+++) were found in 31 participants. GBS_rectovag-36 showed a sensitivity of 90% (28/31) and a PPV of 23% (28/121), whereas PCR_vag-labor had a sensitivity of 98% (30/31, non-significant difference) and a PPV of 42% (30/71, p < .01). PCR at labor had a lower sensitivity (78%) for detection of vaginal colonization with GBS at labor (any load) compared to recto/vaginal colonization with GBS at 36 weeks (92%). Vaginal colonization with GBS at 36 weeks seemed to have a lower sensitivity for detecting GBS in vagina at labor for high load (48%) and for any load (39%).

CONCLUSION

PCR at labor has higher detection rate (non-significant) and PPV in identification of laboring women with a high load of vaginal GBS compared with recto-vaginal culture at 36 weeks' gestation.

Comparison of BD MAX GBS and GenomEra GBS assays for rapid intrapartum PCR detection of vaginal carriage of group B streptococci

Objective

To compare the diagnostic performance of BD MAX and GenomEra PCR assays for a rapid PCR detection of vaginal carriage of group B streptococci at delivery.

Methods

This is a retrospective laboratory analysis of vaginal swab samples taken intrapartum from a randomly selected cohort of pregnant women giving birth at a single childbirth and maternity unit.

Results

Ninety-one culture-positive and 279 culture-negative vaginal samples were included from a cohort of 902 women. One-hundred-and-two specimens were found positive with the BD MAX and 84 with the GenomEra PCR assay. No statistically significant difference was observed compared to culture, sensitivity of BD MAX 84.6% (77/91) [95%CI 75.5–91.3] and of GenomEra 71.4% (65/91) [95%CI 61.0–80.4]. When compared to a combined reference standard, no statistically significant differences were seen between culture, BD MAX and GenomEra PCR assays. The sensitivities were 82.7% (91/110) [95%CI 74.3–89.3], 87.3% (96/110) [95%CI 79.6–92.9], and 79.1% (87/110) [95%CI 70.3–86.3], respectively.

Conclusion

Both PCR assays performed comparably to culture of the intrapartum vaginal samples. In particular, the GenomEra assay is potentially an easy and rapid on-site PCR test for intrapartum detection of vaginal carriage of group B streptococci at a maternity ward to identify women who should receive intrapartum antibiotic prophylaxis.

Changes in the incidence and epidemiology of neonatal group B Streptococcal disease over the last two decades in Crete, Greece

Group B streptococcus (GBS) remains a leading cause of neonatal disease. However, GBS rates and prevention strategies vary considerably worldwide. Herein, we investigated the burden and epidemiological trends of neonatal GBS infections in our area (Greece) over the last two decades. We conducted a multicenter retrospective study that includes all cases of culture-proven GBS disease in infants <90 days old in the last 22 years. Neonatal GBS incidence was 0.17/1000 live births (95%CI: 0.11-0.21). A significant increase was noted during the second decade (0.23 vs 0.10/1000, P<0.05). Late onset disease (LOD) significantly increased during the second decade (0.08 vs 0.02, P<0.05). Infants in the LOD group had a higher risk of meningitis (RR 1.8, 95%CI: 1.23-2.71). Long-term neurological sequelae were reported in 42.8% of meningitis cases. The mortality rate was 8%. The incidence of neonatal GBS disease in our area is among the lowest reported, but an increase was noted the last decade mainly due a rise in the LOD. The burden of LOD, the mortality and long-term disability are still substantial, thus effective prevention strategies − including maternal vaccination for neonatal GBS − are needed.

Newborn colonization and antibiotic susceptibility patterns of Streptococcus agalactiae at the University of Gondar Referral Hospital, Northwest Ethiopia

Background

Group B Streptococcus (GBS) that asymptomatically colonizing the recto-vaginal area of women is the most important cause of neonatal colonization. There is paucity of evidence about newborn colonization with GBS in Ethiopia. Thus, this study was aimed to determine the prevalence of newborn colonization with GBS, antibiotic susceptibility patterns of the isolates and associated risk factors at the University of Gondar Referral Hospital in Northwest Ethiopia

Methods

A prospective cross sectional study was conducted from December 2016 to November 2017. A total of 1,155 swabs from nasal, ear and umbilical areas of the newborns were collected from the 385 newborns. Identifications of the isolates and antibiotic susceptibility testing were done by using conventional methods.

Results

Sixty two (16.1%, 95% CI: 12.2% - 20%) of the newborns were colonized by GBS. Seven percent of the total specimens were positive for GBS. The antibiotics susceptibility rates of GBS (average of the three body sites tested) were 95.1%, 89.6%, 88.9%, 85.7%, 85.3%, 81.3%, 76.9%, 76.1%, 73.8%, and 34.4% to ampicillin, penicillin, ciprofloxacin, chloramphenicol, vancomycin, azitromycin, erythromycin, clindamycin, ceftriaxone, and tetracycline, respectively. A multilogistic regression analyses were shown that the newborns that were from mothers whose education status was below tertiary level, and newborns from mothers who were: being employed, being nullipara and multigravida were at risk for colonization with GBS.

Conclusion

Prevalence of neonatal colonization with GBS was higher than it was reported in three decades ago in Ethiopia. Ciprofloxacin, chloramphenicol, vancomycin and azithromycin were identified as the drug of choice next to ampicillin and penicillin.

Electronic supplementary material

The online version of this article (10.1186/s12887-018-1350-1) contains supplementary material, which is available to authorized users.

Group B streptococci cultured in urine during pregnancy associated with preterm delivery: a selection problem?

Objective: To investigate an association between Group B streptococci (GBS) in urine culture during pregnancy and preterm delivery. Methods: A population-based cohort consisted of all the pregnant women (n = 36,097) from the catchment area of Lillebaelt Hospital, Denmark, during the period January 2002 -December 2012. The cohort of 34,285 singleton pregnancies used in this study was divided into three groups. Group I (N = 249) included women whose urine culture was positive for GBS; group II (N = 5765) included women whose urine culture was negative for GBS; and group III (N = 28 271) included women whose urine had not been cultured during pregnancy. Primary outcome was preterm delivery before 37 weeks' gestation (PTD). Results: We did not find an association between PTD and GBS bacteriuria in the cultured groups (odds ratios (OR) = 0.89; 95% CI: 0.5-1.4) ( Table 1 ). After controlling for potential confounders, the PTD remained not associated with GBS bacteriuria (adjusted OR = 0.99; 95% CI: 0.6-1.6). Combined, the cultured groups (I and II) were associated with a statistically significant higher risk for PTD, when compared with the group with no urine specimens taken for culture (OR = 1.96; 95% CI: 1.8-2.2 and adjusted or 1.80; 95% CI 1.6-2.0). The cultured group of women differed considerably from the group of women with no urine specimens taken for culture on the vast majority of variables examined. Conclusions: No association between asymptomatic GBS bacteriuria and preterm delivery among women with singleton pregnancy and urine specimens cultured during pregnancy was found. Previous suggestions of such association may have been compromised by a selection problem for testing due to a high-risk profile of pregnancy complications in pregnant women selected for urine culture.

Frequency of Pathogenic Paediatric Bacterial Meningitis in Mozambique: The Critical Role of Multiplex Real-Time Polymerase Chain Reaction to Estimate the Burden of Disease

BACKGROUND

In Sub-Saharan Africa, including Mozambique, acute bacterial meningitis (ABM) represents a main cause of childhood mortality. The burden of ABM is seriously underestimated because of the poor performance of culture sampling, the primary method of ABM surveillance in the region. Low quality cerebrospinal fluid (CSF) samples and frequent consumption of antibiotics prior to sample collection lead to a high rate of false-negative results. To our knowledge, this study is the first to determine the frequency of ABM in Mozambique using real-time polymerase chain reaction (qPCR) and to compare results to those of culture sampling.

METHOD

Between March 2013 and March 2014, CSF samples were collected at 3 regional hospitals from patients under 5 years of age, who met World Health Organization case definition criteria for ABM. Macroscopic examination, cytochemical study, culture, and qPCR were performed on all samples.

RESULTS

A total of 369 CSF samples were collected from children clinically suspected of ABM. qPCR showed a significantly higher detection rate of ABM-causing pathogens when compared to culture (52.3% [193/369] versus 7.3% [27/369], p = 0.000). The frequency of Streptococcus pneumoniae, Haemophilus influenzae, group B Streptococci, and Neisseria meningitidis were 32.8% (121⁄369), 12.2%, (45⁄369), 3.0% (16⁄369) and 4.3% (11⁄369), respectively, significantly higher compared to that obtained on culture (p < 0.001 for each).

CONCLUSION

Our findings demonstrate that culture is less effective for the diagnosis of ABM than qPCR. The common use of culture rather than qPCR to identify ABM results in serious underestimation of the burden of the disease, and our findings strongly suggest that qPCR should be incorporated into surveillance activities for ABM. In addition, our data showed that S. pneumoniae represents the most common cause of ABM in children under 5 years of age.

Early hospital discharge of infants born to group B streptococci-positive mothers: a decision analysis

OBJECTIVE

To compare the cost-effectiveness of an additional 24-hour inpatient observation for asymptomatic term neonates born to group B streptococcus (GBS)-colonised mothers with adequate intrapartum antibiotic prophylaxis (IAP) after an initial 24-hour in-hospital observation.

DESIGN

Cost-effectiveness analysis from a societal perspective.

SETTING

United States.

POPULATION

Asymptomatic term neonates born to GBS-colonised mothers with IAP after an initial 24-hour in-hospital observation.

METHODS

Monte Carlo simulation for a decision tree model incorporating the following chance events: development of GBS sepsis during the second 24 hours of life, development of GBS sepsis between 48 hours and 7 days of life, prompt versus delayed treatment for sepsis, neonatal mortality and long-term health sequelae.

MAIN OUTCOME MEASURES

Expected cost and quality-adjusted life years (QALYs), Incremental cost-effectiveness ratio (ICER).

RESULTS

Delayed, versus early, hospital discharge results in similar mean expected QALYs, but substantially higher expected cost. The mean difference in QALY is 0.00016 (95% CI 0.00005-0.00040), whereas the mean difference in cost is $1170.96 (95% CI $750.13-1584.32). The ICER is estimated to be $9,771,520.87 per QALY (95% CI $2,573,139.89-24,407,017.82). The proportion of early-onset GBS that develops during the second 24 hours of life, the cost of 24 hours of inpatient observation, and the probability of long-term sequelae following prompt versus delayed treatment play important roles in determining the cost-effectiveness of delayed hospital discharge.

CONCLUSION

Cost-effectiveness analysis suggests that with adequate IAP, discharging asymptomatic term neonates to home after 24 hours is the preferred approach compared with 48 hours inpatient observation.

Group B streptococcus serotype prevalence in reproductive-age women at a tertiary care military medical center relative to global serotype distribution

Background

Group B Streptococcus (GBS) serotype (Ia, Ib, II-IX) correlates with pathogen virulence and clinical prognosis. Epidemiological studies of seroprevalence are an important metric for determining the proportion of serotypes in a given population. The purpose of this study was to evaluate the prevalence of individual GBS serotypes at Madigan Healthcare System (Madigan), the largest military tertiary healthcare facility in the Pacific Northwestern United States, and to compare seroprevalences with international locations.

Methods

To determine serotype distribution at Madigan, we obtained GBS isolates from standard-of-care anogenital swabs from 207 women of indeterminate gravidity between ages 18-40 during a five month interval. Serotype was determined using a recently described molecular method of polymerase chain reaction by capsular polysaccharide synthesis (cps) genes associated with pathogen virulence.

Results

Serotypes Ia, III, and V were the most prevalent (28%, 27%, and 17%, respectively). A systematic review of global GBS seroprevalence, meta-analysis, and statistical comparison revealed strikingly similar serodistibution at Madigan relative to civilian-sector populations in Canada and the United States. Serotype Ia was the only serotype consistently higher in North American populations relative to other geographic regions (p < 0.005). The number of non-typeable isolates was significantly lower in the study (p < 0.005).

Conclusion

This study establishes PCR-based serotyping as a viable strategy for GBS epidemiological surveillance. Our results suggest that GBS seroprevalence remains stable in North America over the past two decades.

Changing molecular epidemiology of group B streptococcus in Korea

The prevalence of group B streptococcus (GBS) among pregnant women and disease burdens in neonates and adults are increasing in Korea. Colonizing isolates, collected by screening pregnant women (n=196), and clinical isolates collected from clinical patients throughout Korea (n=234), were serotyped and screened for antibiotic resistance. Serotype III (29.8%) and V (27.7%) predominated, followed by Ia (17.0%). Antibiotic resistance was higher among clinical than colonizing isolates for erythromycin (35.1% and 26.9%; P=0.10) and for clindamycin (49.4% and 42.1%; P=0.17). erm(B) occurred in 91.9% of erythromycin resistant isolates, and 84.0% of isolates resistant to clindamycin. Only five isolates (4.2%) resistant to erythromycin were susceptible to clindamycin; by contrast, and unique to Korea, 34% of isolates resistant to clindamycin were erythromycin susceptible. Among these 60 erythromycin-susceptible & clindamycin-resistant isolates, 88% was serotype III, and lnu(B) was found in 89% of strains. Four fifths of the serotype V isolates were resistant to both erythromycin and clindamycin. Further characterization of the genetic assembly of these resistance conferring genes, erm(B) and lnu(B), will be useful to establish the clonal lineages of multiple resistance genes carrying strains.

Evaluation of StrepB carrot broth versus Lim broth for detection of group B Streptococcus colonization status of near-term pregnant women

The performance of StrepB Carrot Broth (SCB) versus group B Lim broth (LIM) for detection of group B streptococcus (GBS) colonization status in near-term pregnant women (35 to 37 weeks of gestation) was evaluated. Dually collected vaginal/rectal swabs from 279 women enrolled from a single large maternity clinic were analyzed. Fifty (18%) women were colonized by GBS according to both methods. SCB had excellent diagnostic performance compared to LIM, with sensitivity, specificity, positive predictive value, and negative predictive value of 92%, 100%, 100%, and 98.3%, respectively. Improved diagnostic efficiency due to direct reporting of GBS cases based on an orange color change in the SCB decreased overall labor and material costs.

Report from the CDC. Awareness of Perinatal Group B Streptococcal Infection among Women of Childbearing Age in the United States, 1999 and 2002

BACKGROUND

The issuance in 2002 of new guidelines recommending universal screening for group B Streptococcus (GBS), a leading cause of neonatal sepsis in the United States, has created a new opportunity to educate women of childbearing age to be active partners in prevention.

METHODS

To assess baseline levels of awareness about perinatal GBS, we analyzed responses to a question included in a health communications/social marketing survey in 1999 and 2002.

RESULTS

Among the 2917 women under 50 who responded, 47% reported ever having heard of perinatal GBS. Among women pregnant at the time of the survey, awareness was 66%. Women with a high school education or less (OR = 0.60, 95% CI 0.50-0.73), household income <25,000 US dollars (OR 0.65, 95% CI 0.54-0.79), or reporting black, Asian/Pacific Islander, or other race (ORs [95% CI] 0.70 [0.57-0.87], 0.61 [0.41-0.90], 0.41 [0.20-0.85], respectively) had lower awareness of perinatal GBS than other women. Women currently pregnant (OR 2.2, 95% CI 1.5-3.3) had higher awareness.

CONCLUSIONS

Awareness of perinatal GBS is high among currently pregnant women, for whom this issue is most important. Efforts to raise awareness should be targeted to women from traditionally underserved populations, such as those who are of nonwhite race or who have lower educational attainment or household income.

The epidemiology of severe sepsis in children in the United States

Despite extensive research into the etiology and treatment of severe sepsis, little is known about its epidemiology in children. We sought to determine the age- and sex-adjusted incidence, outcome, and associated hospital costs of severe sepsis in United States children using 1995 hospital discharge and population data from seven states (24% of the United States population). Of 1,586,253 hospitalizations in children who were 19 years old or less, 9,675 met International Classification of Diseases, 9th revision, clinical modification-based severe sepsis criteria or 42,364 cases of pediatric severe sepsis per year nationally (0.56 cases per 1,000 population per year). The incidence was the highest in infants (5.16 per 1,000), fell dramatically in older children (0.20 per 1,000 in 10 to 14 year olds), and was 15% higher in boys than in girls (0.60 versus 0.52 per 1,000, p < 0.001). Hospital mortality was 10.3%, or 4,383 deaths nationally (6.2 per 100,000 population). Half of the cases had underlying disease (49.0%), and over one-fifth (22.9%) were low-birth-weight newborns. Respiratory infections (37%) and primary bacteremia (25%) were the most common infections. The mean length of stay and cost were 31 days and $40,600, respectively. Estimated annual total costs were 1.97 billion US dollars nationally. Severe sepsis is a significant health problem in children and is associated with the use of extensive healthcare resources. Infants are at highest risk, especially those with a low birth weight.