Changes in incidence and etiology of early-onset neonatal infections 1997-2017 - a retrospective cohort study in western Sweden

Background

The objective of the study was to evaluate data on early-onset neonatal invasive infections in western Sweden for the period 1997–2017. To identify changes in incidence, etiology and mortality and compare to previous studies from the same area starting from 1975.

Methods

Observational epidemiological, retrospective study on infants 0–6 days of age with a positive culture in blood and/or cerebrospinal fluid between 1997 and 2017. A comparison was made of the incidence between 2008 and 2017 compared to 1997–2007. Changes in the incidence of infections due to Group B streptococci, Staphylococcus aureus and aerobic Gram-negative rods were assessed from 1975.

Results

The total incidence, including both recognized pathogens and commensals as causative agents, was 1.1/1000 live births. The incidence declined from 1.4/1000 LB in 1997–2007 to 0.9/1000 LB in 2008–2017 but the case-fatality rate remained unchanged, (8/119 vs 7/90), at 7%. Among the 209 patients identified during 1997–2017 with sepsis or meningitis the most common organisms were Group B streptococci (40%, 84/209), S. aureus (16%, 33/209) and E. coli (9%, 18/209). The incidence of Group B streptococci infections went from 0.9/1000 live births 1987–1996 to 0.45/1000 live births 1997–2017 and all cases were within 72 h. The proportion of extremely preterm infants (< 28 weeks gestation) rose steadily during the study period but there was no rise in infections due to Gram-negative organisms. The spectrum of cultured organisms changed after 72 h as commensal organisms started to emerge.

Conclusion

There has been a decrease in the incidence of neonatal early-onset infections compared to previous studies in western Sweden. The incidence of GBS infections was not as low as in other reports. Further studies are needed to assess if screening-based intra partum antimicrobial prophylaxis instead of a risk factor-based approach for identifying candidates for intrapartum antimicrobial prophylaxis would be a better option for this study area.

Key notes

This study is one of the longest running follow-ups in the world, a follow-up of 43 years of early-onset neonatal infections.

The incidence of early-onset GBS infections is higher in Western Sweden compared to other local reports.

No difference in the incidence of early-onset GBS depending on the definition of early-onset being within 72 h or 7 days of life.

Developing a serocorrelate of protection against invasive group B streptococcus disease in pregnant women: a feasibility study

BACKGROUND

Group B streptococcus is the leading cause of infection in infants. Currently, intrapartum antibiotic prophylaxis is the major strategy to prevent invasive group B streptococcus disease. However, intrapartum antibiotic prophylaxis does not prevent maternal sepsis, premature births, stillbirths or late-onset disease. Maternal vaccination may offer an alternative strategy. Multivalent polysaccharide protein conjugate vaccine development is under way and a serocorrelate of protection is needed to expedite vaccine licensure.

OBJECTIVES

The ultimate aim of this work is to determine the correlate of protection against the major group B streptococcus disease-causing serotypes in infants in the UK. The aim of this feasibility study is to test key operational aspects of the study design.

DESIGN

Prospective cohort study of pregnant women and their infants in a 6-month period (1 July to 31 December 2018).

SETTING

Five secondary and tertiary hospitals from London and South England. National iGBS disease surveillance was conducted in all trusts in England and Wales.

PARTICIPANTS

Pregnant women aged ≥ 18 years who were delivering at one of the selected hospitals and who provided consent during the study period. There were no exclusion criteria.

INTERVENTIONS

No interventions were performed.

MAIN OUTCOME MEASURES

(1) To test the feasibility of collecting serum at delivery from a large cohort of pregnant women. (2) To test the key operational aspects for a proposed large serocorrelates study. (3) To test the feasibility of collecting samples from those with invasive group B streptococcus.

RESULTS

A total of 1823 women were recruited during the study period. Overall, 85% of serum samples were collected at three sites collecting only cord blood. At the two sites collecting maternal, cord and infant blood samples, the collection rate was 60%. A total of 614 women were screened for group B streptococcus with a colonisation rate of 22% (serotype distribution: 30% III, 25% Ia, 16% II, 14% Ib, 14% V and 1% IV). A blood sample was collected from 34 infants who were born to colonised women. Maternal and infant blood and the bacterial isolates for 15 newborns who developed invasive group B streptococcal disease during the study period were collected (serotype distribution: 29% III, 29% II, 21% Ia, 7% Ib, 7% IV and 7% V).

LIMITATIONS

Recruitment and sample collection were dependent on the presence of research midwives rather than the whole clinical team. In addition, individualised consent limited the number of women who could be approached each day, and site set-up for the national surveillance study and the limited time period of this feasibility study limited recruitment of all eligible participants.

CONCLUSIONS

We have verified the feasibility of collecting and processing rectovaginal swabs and blood samples in pregnant women, as well as samples from those with invasive group B streptococcal disease. We have made recommendations for the recruitment of cases within the proposed GBS3 study and for controls both within GBS3 and as an extension of this feasibility study.

FUTURE WORK

A large case-control study comparing specific immunoglobulin G levels in mothers whose infants develop invasive group B streptococcal disease with those in colonised mothers whose infants do not develop invasive group B streptococcal disease is recommended.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN49326091; IRAS project identification number 246149/REC reference number 18/WM/0147.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 67. See the NIHR Journals Library website for further project information.

Genomic analysis of urogenital and rectal Neisseria meningitidis isolates reveals encapsulated hyperinvasive meningococci and coincident multidrug-resistant gonococci

Objective

Invasive meningococcal disease (IMD) outbreaks in men who have sex with men (MSM) have been associated with meningococcal colonisation of the urethra and rectum, but little is known about this colonisation or co-colonisation with the closely related gonococcus. Whole genome sequencing (WGS) was employed to explore these phenomena.

Methods

Meningococci isolated from the urogenital tract and rectum (n=23) and coincident gonococci (n=14) were analysed by WGS along with contemporary meningococci from IMD (n=11). All isolates were obtained from hospital admissions in Brighton, UK, 2011–2013. Assembled WGS were deposited in the PubMLST/neisseria database (http://pubmlst.org/neisseria) and compared at genomic loci common to gonococci or meningococci.

Results

As expected, most meningococci from IMD were encapsulated and belonged to hyperinvasive lineages. So too were meningococci found in the urogenital tract and rectum, contrasting to those asymptomatically carried in the nasopharynx where such meningococci are rare. Five hyperinvasive meningococcal lineages and four distinct gonococcal genotypes were recovered, including multiresistant ST-1901 (NG MAST-1407) gonococci.

Conclusions

These data were consistent with a predisposition for potentially virulent encapsulated hyperinvasive meningococci to colonise the urethra and rectum, which suggests their involvement in MSM IMD outbreaks. The coincidence of multiresistant gonococci raises wider public health concerns.

Fatal meningitis due to a capsulated Neisseria

In this paper a fatal case of meningitis is reported in which a capsulated Diplococcus of the Neisserian group was isolated from the purulent cerebrospinal fluid. A capsulated Gram-negative Diplococcus growing readily on agar was isolated from the nasopharynx and the cerebrospinal fluid by von Lingelsheim (1906, 1908) and called by him D. mucosus. Similar organisms were also isolated from the nasopharynx by Elser & Huntoon (1909). Cowan (1938) reported two cases operated on for cerebral tumour in which D. mucosus was grown from the cerebrospinal fluid. These strains were regarded by him as contaminants setting up a low-grade infection in a brain which, exposed for operation, offered little resistance to infection. Two cases of meningitis due to a capsulated Diplococcus have been reported by McFarlan (1941) and Bray & Cruickshank (1943); both these patients responded well to sulphapyridine and recovered. Edwards (1944) described a fatal case of meningitis due to an atypical Neisseria which in many respects resembled D. mucosus, although it was not capsulated. The rarity with which capsulated Neisseriae are associated with pathogenicity is considered sufficient justification for reporting the following case.

BACTERIUM ANITRATUM AND MIMA POLYMORPHA INFECTION IN UGANDA

Eleven cases of infection with Bacterium anitratum and one with Mima polymorpha are described. Microscopically the organisms showed Gram-negative or Gram-variable diplococci with a tendency to form filaments. There appear to be a number of biochemical variants of B. anitratum. Serological cross-reactions with the genus Klebsiella was found. The antibiotic patterns are given and particular attention is drawn to the resistance of the organisms to chloramphenicol.