[Streptococcus agalactiae late-onset neonatal infections in Barcelona (1996-2010)]

Group B streptococcal infections in pregnancy and early life

SUMMARYBacterial infections with Group B Streptococcus (GBS) are an important cause of adverse outcomes in pregnant individuals, neonates, and infants. GBS is a common commensal in the genitourinary and gastrointestinal tracts and can be detected in the vagina of approximately 20% of women globally. GBS can infect the fetus either during pregnancy or vaginal delivery resulting in preterm birth, stillbirth, or early-onset neonatal disease (EOD) in the first week of life. The mother can also become infected with GBS leading to postpartum endometritis, and rarely, maternal sepsis. An invasive GBS infection of the neonate may present after the first week of life (late-onset disease, LOD) through transmission from caregivers, breast milk, and other sources. Invasive GBS infections in neonates can result in sepsis, pneumonia, meningitis, neurodevelopmental impairment, death, and lifelong disability. A policy of routine screening for GBS rectovaginal colonization in well-resourced countries can trigger the administration of intrapartum antibiotic prophylaxis (IAP) when prenatal testing is positive, which drastically reduces rates of EOD. However, many countries do not routinely screen pregnant women for GBS colonization but may administer IAP in cases with a high risk of EOD. IAP does not reduce rates of LOD. A global vaccination campaign is needed to reduce the significant burden of invasive GBS disease that remains among infants and pregnant individuals. In this narrative review, we provide a comprehensive overview of the global impact of GBS colonization and infection, virulence factors and pathogenesis, and current and future prophylactics and therapeutics.

Clinical Risk Factors Associated With Late-Onset Invasive Group B Streptococcal Disease: Systematic Review and Meta-Analyses

BACKGROUND

Group B streptococcal (GBS) infection remains one of the most significant causes of late-onset sepsis and meningitis (LOGBS) among young infants. However, transmission routes and risk factors for LOGBS are not yet fully understood.

METHODS

We conducted systematic reviews on clinical risk factors previously reported in the literature (prematurity, low birth weight [<2500 g], antenatal colonization, multiple-gestation pregnancy, maternal age <20 years, male infant sex, intrapartum fever, prolonged rupture of membranes) and meta-analyses to determine pooled estimates of risk.

RESULTS

We included 27 articles, reporting 5315 cases. Prematurity (odds ratio [OR] 5.66; 95% confidence interval [CI]: 4.43-7.22), low birth weight (OR 6.73; 95% CI: 4.68-9.67), maternal colonization (2.67; [2.07-3.45]), and multiple-gestation pregnancies (OR 8.01; 95% CI: 5.19-12.38) were associated with an increased risk of LOGBS.

CONCLUSIONS

Prematurity/low birth weight and maternal colonization are major risk factors for LOGBS. Future GBS vaccine studies should try to establish the optimal time for vaccination during pregnancy to protect preterm infants.

Incidence of invasive Group B Streptococcal infection and the risk of infant death and cerebral palsy: a Norwegian Cohort Study

BACKGROUND

Group B Streptococcus (GBS) is the leading cause of invasive neonatal infection worldwide. In high-income countries mortality rates are 4-10%, and among survivors of GBS meningitis 30-50% have neurodevelopmental impairments. We hypothesized that invasive GBS infection was associated with increased risk of infant mortality and cerebral palsy (CP).

METHODS

All children born alive in Norway during 1996-2012 were included. Data were collected from three national registers. Invasive GBS infection during infancy was categorized into early-onset disease (EOD), late-onset disease (LOD), and very late-onset disease (VLOD). Primary outcomes were infant mortality and CP.

RESULTS

Invasive GBS infection was diagnosed in 625 children (incidence: 0.62 per 1000 live births; 95% confidence interval (CI): 0.57-0.67). The incidence of EOD was 0.41 (0.37-0.45), of LOD 0.20 (0.17-0.23), and of VLOD 0.012 (0.007-0.021). The annual incidence of LOD increased slightly. Among infected infants, 44 (7%) died (odds ratio (OR): 24.5; 95% CI: 18.0-33.3 compared with the background population). Among survivors, 24 (4.1%) children were later diagnosed with CP, compared with 1887 (0.19%) in the background population (OR: 22.9; 95% CI: 15.1-34.5).

CONCLUSION

Despite a relatively low incidence of invasive GBS infection in Norway, the risk of death and CP remains high. Improvements in prevention strategies are needed.

IMPACT

During the first decade of the twenty-first century, invasive GBS disease in infancy is still associated with high mortality. Despite the overall low incidence of invasive GBS disease, the incidence of LOD increased during the study period. The finding that invasive GBS infection in the neonatal period or during infancy is associated with an excess risk of CP, comparable to the risk following moderate preterm birth and moderate low Apgar scores, adds to the existing literature. The results of this study emphasize the importance of adhering to guidelines and the need for better prevention strategies.

Risk factors and drug resistance in early-onset neonatal group B streptococcal disease

In recent years, group B streptococcus (GBS) has become an important pathogen that causes infections in many neonatal organs, including the brain, lung, and eye (Ballard et al., 2016). A series of studies performed on GBS infections in western countries have revealed that GBS is one of the primary pathogens implicated in perinatal infection, and GBS infections are a major cause of neonatal morbidity and mortality in the United States (Decheva et al., 2013). In China, GBS is mainly found by screens for adult urogenital tract and perinatal infections, and neonatal GBS infections have been rarely reported. The incidence rate of early-onset neonatal GBS disease is thought to be lower in China than in western countries; however, this data is controversial since it also reflects the clinical interest in GBS (Dabrowska-Szponar and Galinski, 2001).

Infant Group B Streptococcal Disease Incidence and Serotypes Worldwide: Systematic Review and Meta-analyses

Background

Group B Streptococcus (GBS) remains a leading cause of neonatal sepsis in high-income contexts, despite declines due to intrapartum antibiotic prophylaxis (IAP). Recent evidence suggests higher incidence in Africa, where IAP is rare. We investigated the global incidence of infant invasive GBS disease and the associated serotypes, updating previous estimates.

Methods

We conducted systematic literature reviews (PubMed/Medline, Embase, Latin American and Caribbean Health Sciences Literature [LILACS], World Health Organization Library Information System [WHOLIS], and Scopus) and sought unpublished data regarding invasive GBS disease in infants aged 0–89 days. We conducted random-effects meta-analyses of incidence, case fatality risk (CFR), and serotype prevalence.

Results

We identified 135 studies with data on incidence (n = 90), CFR (n = 64), or serotype (n = 45). The pooled incidence of invasive GBS disease in infants was 0.49 per 1000 live births (95% confidence interval [CI], .43–.56), and was highest in Africa (1.12) and lowest in Asia (0.30). Early-onset disease incidence was 0.41 (95% CI, .36–.47); late-onset disease incidence was 0.26 (95% CI, .21–.30). CFR was 8.4% (95% CI, 6.6%–10.2%). Serotype III (61.5%) dominated, with 97% of cases caused by serotypes Ia, Ib, II, III, and V.

Conclusions

The incidence of infant GBS disease remains high in some regions, particularly Africa. We likely underestimated incidence in some contexts, due to limitations in case ascertainment and specimen collection and processing. Burden in Asia requires further investigation.

Brachial Plexus Palsy in Young Infants Harboring Osteomyelitis of the Humerus: Case Report and Review of the Literature

We present an infant with brachial plexus palsy who had osteomyelitis of the humerus and summarize previously reported cases. Although Staphylococcus aureus is the most common pathogen in osteomyelitis in infants, group B Streptococcus is responsible for 40% of humeral osteomyelitis. Early diagnosis is critical to prevent long-term sequalae but is hampered by infants frequently being well and afebrile at presentation.

Associations between nasopharyngeal carriage of Group B Streptococcus and other respiratory pathogens during early infancy

BACKGROUND

In West Africa, the carriage of Group B Streptococcus (GBS), among infants is poorly characterised. We investigated co-carriage of GBS with other respiratory pathogens in the infants' nasopharynx in The Gambia.

METHODS

We assessed the carriage, serotypes and antibiotic susceptibility of Beta-haemolytic Streptococci (BHS) groups A-G; along with the carriage of Streptococcus pneumoniae; Haemophilus influenzae; Staphylococcus aureus and Moraxella catarrhalis in 1200 two-month old infants.

RESULTS

The BHS prevalence was 20.0 % and GBS dominated (13.8 %), particularly serotypes V and II; serotype V being negatively associated with H. Influenzae carriage (OR 0.41 [95 % CI: 0.18-0.93], p = 0.033). Although co-colonization of GBS and other BHS was not seen, colonization with GBS was positively associated with S. aureus (OR 1.89 [95 % CI: 1.33-2.69], P < 0.001) and negatively associated with S. pneumoniae (OR 0.47 [95 % CI: 0.33-0.67], p < 0.001) and M. catarrhalis (OR 0.61 [95 % CI: 0.40-0.92], p = 0.017). ≥ 89 % of GBS isolates were susceptible to most antibiotics tested, except for tetracycline resistance, which was 89 %.

CONCLUSION

This study provides baseline data on the carriage of GBS in two month old infants from West Africa. The dominant serotypes of GBS in this setting are serotypes V and II. This may be important for future GBS vaccine development for the West African sub-region.