Increasing incidence of late-onset neonatal invasive group B streptococcal infections in Iceland

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.

Group B streptococcal infections in infants in Iceland: clinical and microbiological factors

Introduction. Group B streptococcus (GBS) is a leading cause of invasive neonatal infections. These have been divided into early-onset disease (EOD; <7 days) and late-onset disease (LOD; 7-89 days), with different GBS clonal complexes (CCs) associated with different disease presentations.Hypothesis. Different GBS CCs are associated with timing of infection (EOD or LOD) and clinical presentation (sepsis, meningitis or pneumonia).Aim. To study infant GBS infections in Iceland from 1975 to 2019. Are specific GBS CCs related to disease presentation? Is CC17 overrepresented in infant GBS infections in Iceland?Methodology. All culture-confirmed invasive GBS infections in infants (<90 days) in Iceland from 1975 to 2019 were included. Clinical information was gathered from medical records.Results. A total of 127 invasive GBS infections in infants were diagnosed, but 105 infants were included in the study. Of these, 56 had EOD and 49 had LOD. The incidence of GBS infections declined from 2000 onwards but increased again at the end of the study period. Furthermore, there was a significant increase in LOD over the study period (P=0.0001). The most common presenting symptoms were respiratory difficulties and fever and the most common presentation was sepsis alone. Approximately one-third of the cases were caused by GBS CC17 of serotype III with surface protein RIB and pili PI-1+PI-2b or PI-2b. CC17 was significantly associated with LOD (P<0.001).Conclusion. CC17 is a major cause of GBS infection in infants in Iceland. This clone is associated with LOD, which has been increasing in incidence. Because intrapartum antibiotic prophylaxis only prevents EOD, it is important to continue the development of a GBS vaccine in order to prevent LOD infections.

Late-onset Neonatal Infections 1997 to 2017 Within a Cohort in Western Sweden-The Last 21 Years of a 43-Year Surveillance

BACKGROUND

The objective of the study was to assess the epidemiology of late-onset (LO) neonatal invasive infections with surveillance covering 43 years, starting from 1975.

METHODS

Observational epidemiologic, retrospective study including a cohort of infants born in western Sweden in 1997-2017, who had a positive blood and cerebral spinal fluid culture between 3 and 120 days of age. A comparison was made of the incidence between 1997-2007 and 2008-2017. Data on LO infections during 3-27 days of life were assessed from 1975.

RESULTS

A total of 473 cases of LO infections were registered in 437 patients. The incidence increased from 2.0 to 3.1/1000 live births (LB) between 1997-2007 and 2008-2017 (P < 0.001). The increase in incidence was most pronounced among infants born <28 weeks gestation (from 255 to 398/1000 LB, P < 0.001). The most frequent pathogens were Staphylococcus aureus (25%), coagulase-negative staphylococci (17%), and Escherichia coli (13%). Infections due to group B Streptococci rose from 0.16/1000 LB to 0.33 (P = 0.03). During the whole surveillance period from 1975 to 2017, there were 579 cases between 3 and 27 days of life. Although the incidence increased in 2008-2017 to 1.9/1000 LB after first declining in 1997-2007, the case-fatality rate continued to decline from 27/284 (9.5%) between 1975 and 1996 to 6/182 (3.3%) in 2008 and 2017 (P = 0.01).

CONCLUSIONS

The incidence of LO neonatal invasive infections increased during the study period (1997-2017), but the case-fatality rate remained lower than in the previous surveillance period (1975-1996). Further surveillance and interventions with focus on prevention is critical to counteract the increasing incidence among high-risk infants.

Neonatal Group B Streptococcal Infection in a Tertiary Care Hospital in Saudi Arabia: A 13-year Experience

BACKGROUND

Group B streptococcus (GBS) is a leading cause of neonatal bacterial sepsis and meningitis globally. Studies concerning the incidence and burden of neonatal GBS disease in Saudi Arabia are lacking. This study determined the incidence and burden of GBS infection among neonates in association with maternal GBS screening.

METHODS

A retrospective cohort chart review study included all neonatal GBS disease cases identified through microbiology lab records within the first 90 days of life in the hospital from January 2004 to December 2016. Charts were reviewed to collect maternal and neonatal characteristics using a standardized form.

RESULTS

Over 13 years, of 108,609 live births, 55 GBS disease cases were identified (overall incidence, 0.51/1000 live births), 69.1% (n = 38) of those had early onset disease (EOD). The annual incidence in 2015 and 2016 was significantly higher than in any previous year (P < 0.0001), coinciding with the discontinuation of routine universal maternal GBS screening. Median age at presentation was 1 day (range, 0-54 days). We found that 67.3% (n = 37) of mothers were not screened antenatally, 72.9% (n = 27) of whom had neonates present with EOD. Neonates of unscreened mothers were more likely to have GBS disease (P = 0.01) and to present with EOD (P = 0.005). Urinary tract infection was the most common manifestation (47.3%, n = 26), followed by sepsis (43.6%, n = 24). Mortality rate was 3.6% (n = 2).

CONCLUSIONS

The incidence of neonatal GBS infection in Saudi Arabia is similar to the worldwide incidence. Universal antenatal screening discontinuation was significantly associated with an increase in EOD incidence.

Group B Streptococcal Neonatal and Early Infancy Infections in Iceland, 1976-2015

BACKGROUND

Despite a risk-based peripartum chemoprophylaxis approach in Iceland since 1996, Streptococcus agalactiae [group B streptococci (GBS)] remains an important cause of early-onset [<7 days, early-onset disease (EOD)] and late-onset disease (LOD; 7 days to 3 months).

METHODS

We studied GBS invasive disease in children <1 year in Iceland in 1976-2015. Bacteria (n = 98) were characterized by susceptibility to a panel of antimicrobials, capsular serotyping, resistance genes, surface protein and pilus-locus profiling and multilocus sequence typing.

RESULTS

Both EOD and LOD increased during the early years, but while EOD subsequently decreased from 0.7/1000 live births in 1991-1995 to 0.2/1000 in 2011-2015, LOD showed a nonsignificant decrease from its peak value of 0.6/1000 in 2001-2005 to 0.4/1000 in 2006-2015. Serotype III was the most frequently found (n = 48), represented mostly by the hypervirulent lineage CC17/III/rib/PI-1+PI-2b (62%), but also by CC19/III/rib/PI-1+PI-2a (35%) frequently associated with colonization. Serotype Ia (n = 22) was represented by CC23/Ia/eps/PI-2a (68%) and CC7/Ia/bca/PI-1+PI-2b (23%) of possible zoonotic origin. Resistance to erythromycin and clindamycin was increasingly detected in the last years of the study (5 of the 9 cases were isolated after 2013), including representatives of a multiresistant CC17/III/rib/PI-2b sublineage described recently in other countries and expressing resistance to erythromycin, clindamycin and streptomycin.

CONCLUSIONS

The risk-based chemoprophylaxis adopted in Iceland possibly contributed to the decline of EOD but has had limited effect on LOD. GBS causing neonatal and early infancy invasive infections in Iceland are genetically diverse, and the recent emergence of antimicrobial resistant lineages may reduce the choices for prophylaxis and therapy of these infections.

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.

Streptococcus agalactiae Causing Neonatal Infections in Portugal (2005-2015): Diversification and Emergence of a CC17/PI-2b Multidrug Resistant Sublineage

The molecular characterization of 218 GBS isolates recovered from neonatal invasive infections in Portugal in 2005–2015 revealed the existence of a small number of genetically distinct lineages that were present over a significant time-span. Serotypes III and Ia were dominant in the population, together accounting for >80% of the isolates. Clonal complex 17 included 50% of all isolates, highlighting the importance of the hypervirulent genetic lineage represented by serotype III ST17/rib/PI-1+PI-2b. Serotype Ia was represented mainly by ST23, previously reported as dominant among invasive disease in non-pregnant adults in Portugal, but also by ST24, showing an increased frequency among late-onset disease. Overall erythromycin resistance was 16%, increasing during the study period (p < 0.001). Macrolide resistance was overrepresented among CC1 and CC19 isolates (p < 0.001 and p = 0.008, respectively). While representatives of the hypervirulent CC17 lineage were mostly susceptible to macrolides, we identified for the first time in Europe a recently emerging sublineage characterized by the loss of PI-1 (CC17/PI-2b), simultaneously resistant to macrolides, lincosamides, and tetracycline, also exhibiting high-level resistance to streptomycin and kanamycin. The stability and dominance of CC17 among neonatal invasive infections in the past decades indicates that it is extremely well adapted to its niche; however emerging resistance in this genetic background may have significant implications for the prevention and management of GBS disease.

Changing epidemiology of group B streptococcal infections among adults in Iceland: 1975-2014

We studied the bacterial characteristics and incidence of invasive infections caused by group B streptococci (GBS) in adults in Iceland in 1975-2014. A total of 145 isolates were characterized by serotyping, antimicrobial susceptibility, multilocus sequence typing and surface protein gene profiling. Disease incidence increased during the studied period (p <0.001), reaching 2.17 cases/100 000 person-years in 2013-14. Overall, serotype Ia was the most frequently found (23%), but serotypes Ib, II, III and V showed similar prevalence (14%-17%). Although there were notable changes in the proportion of most serotypes during the study period, only the decline of serotype III was statistically supported (p = 0.003) and was reflected in a decrease of clonal complexes CC17 and CC19 that included most serotype III isolates (p <0.04). On the other hand, the increase in frequency of CC1 was caused by two lineages expressing distinct serotypes: ST1/V/alp3 and ST196/IV/eps. Underlying the relative stability of serotype Ia were major changes in the lineages expressing this serotype, with an increase in the relative importance of CC23, including both ST23/Ia/eps and ST24/Ia/bca lineages, and a decrease in CC7. Nine cases of invasive GBS disease were caused by ST7, of possible zoonotic origin. All isolates were susceptible to penicillin. Rates of erythromycin and clindamycin resistance were 8.3% and 9.7%, respectively. An over-representation of resistance solely to clindamycin was associated with the unusual lsaC gene and serotype III ST19/rib lineage (p <0.001).

Serotypes of group B streptococci in western Sweden and comparison with serotypes in two previous studies starting from 1988

Background

Group B Streptococci (GBS) are the most common neonatal pathogens and infect immunocompromised and elderly individuals. The species has 10 different serotypes. Serotypes have been studied in the south-west area of Sweden in 1988–1997 and 1998–2001. The aim of this study was to study serotypes in the same area from 2004 to 2009.

Methods

Invasive GBS isolates were collected prospectively from 2004 to 2009 in two counties in western Sweden with a population of 1.8 million, and were serotyped by latex agglutination. Clinical data were obtained from hospital records. During the study period 410 invasive GBS isolates from 398 patients were collected (multiple episodes ≥1 month apart). Clinical data were not available for two patients who are excluded. Four isolates were from stillborn neonates, 88 were from live born neonates and infants, and 318 from adults.

Results

Serotype III was the most common serotype (48 %) in neonates and infants followed by serotypes Ia (18 %) and V (16 %). In adults serotype V (39 %) dominated followed by serotypes III (20 %) and Ib (14 %). There was a significant increase of serotype V in comparison with the first study (1988–1997) but there were no significant changes in the serotype distribution between the present study and the second study (1998–2001). There were a few cases of serotype VI-IX, both in children and adults, not seen in the previous studies. Serotype V was more common among patients with arthritis than with any other manifestation.

Conclusions

Changes in GBS serotypes occur over time in the same region, which must be considered when GBS vaccines are formulated.