Meningitis in the newborn--a 14 year review

Global Case Fatality of Bacterial Meningitis During an 80-Year Period: A Systematic Review and Meta-Analysis

Importance

The impact of vaccination, antibiotics, and anti-inflammatory treatment on pathogen distribution and outcome of bacterial meningitis over the past century is uncertain.

Objective

To describe worldwide pathogen distribution and case fatality ratios of community-acquired bacterial meningitis.

Data Sources

Google Scholar and MEDLINE were searched in January 2022 using the search terms bacterial meningitis and mortality.

Study Selection

Included studies reported at least 10 patients with bacterial meningitis and survival status. Studies that selected participants by a specific risk factor, had a mean observation period before 1940, or had more than 10% of patients with health care-associated meningitis, tuberculous meningitis, or missing outcome were excluded.

Data Extraction and Synthesis

Data were extracted by 1 author and verified by a second author. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Random-effects models stratified by age (ie, neonates, children, adults), Human Development Index (ie, low-income or high-income countries), and decade and meta-regression using the study period's year as an estimator variable were used.

Main Outcome and Measure

Case fatality ratios of bacterial meningitis.

Results

This review included 371 studies performed in 108 countries from January 1, 1935, to December 31, 2019, describing 157 656 episodes. Of the 33 295 episodes for which the patients' sex was reported, 13 452 (40%) occurred in females. Causative pathogens were reported in 104 598 episodes with Neisseria meningitidis in 26 344 (25%) episodes, Streptococcus pneumoniae in 26 035 (25%) episodes, Haemophilus influenzae in 22 722 (22%), other bacteria in 19 161 (18%) episodes, and unidentified pathogen in 10 336 (10%) episodes. The overall case fatality ratio was 18% (95% CI, 16%-19%), decreasing from 32% (95% CI, 24%-40%) before 1961 to 15% (95% CI, 12%-19%) after 2010. It was highest in meningitis caused by Listeria monocytogenes at 27% (95% CI, 24%-31%) and pneumococci at 24% (95% CI, 22%-26%), compared with meningitis caused by meningococci at 9% (95% CI, 8%-10%) or H influenzae at 11% (95% CI, 10%-13%). Meta-regression showed decreasing case fatality ratios overall and stratified by S pneumoniae, Escherichia coli, or Streptococcus agalactiae (P < .001).

Conclusions and Relevance

In this meta-analysis with meta-regression, declining case fatality ratios of community-acquired bacterial meningitis throughout the last century were observed, but a high burden of disease remained.

New Strategy Is Needed to Prevent Pneumococcal Meningitis

BACKGROUND

Polysaccharide conjugate vaccines (PCVs) target the pneumococcal capsular types that most commonly cause fatal pneumonia and sepsis. Because these types were eliminated by the vaccines, it became apparent that in immunized populations, most invasive pneumococcal diseases, including bacteremia, sepsis and complicated pneumonia, were greatly reduced. However, the protective effects of PCVs against another invasive disease, meningitis, has shown much less or no decrease in disease incidence.

METHODS

References were identified through searches of PubMed for articles published from January 1930 to the present by use of specific search terms. Relevant articles were also identified through searches in Google and Google Scholar. Relevant references cited in those articles were also reviewed.

RESULTS

Even in the presence of the PCVs, meningitis rates in children have been reported globally to be as high as 13 per 100,000 annually. Widespread use of vaccines resulted in the emergence of a broad diversity of replacement non-PCV type strains. These strains generally failed to cause sepsis, but caused meningitis of comparable severity and levels similar to, or in excess of, prior pneumococcal meningitis rates. This is probably because these non-PCV type strains do not survive well in the blood, therefore possibly entering the brain through nonhematogenous routes.

CONCLUSIONS

Because virtually all cases of pneumococcal meningitis lead to either permanent neurologic sequelae or death, it would be well worth the effort to develop a new vaccine capable of preventing pneumococcal meningitis regardless of capsular type. Such a vaccine would need to protect against colonization with most, if not all, pneumococci.

Effect of O antigen ligase gene mutation on oxidative stress resistance and pathogenicity of NMEC strain RS218

Escherichia coli is one of the primary causes of bacterial sepsis and meningitis in newborns. E. coli RS218, a prototype strain of neonatal meningitis E. coli (NMEC), is often used in research on the pathogenesis of NMEC. Phagocytes are crucial sentinels of immunity, and their antibacterial ability is largely determined by the capability to produce large amounts of ROS. The capacity of bacteria to endure oxidative pressure affects their colonization in the host. Here, we systematically screened the genes that plays key roles in the tolerance of the model of E. coli RS218 to peroxygen environment using a Tn5 mutant library. As a result, a gene encoding O antigen polymerase (O antigen ligase) that contains the Wzy_C superfamily domain (herein designated as Ocw) was identified in E. coli RS218. Furthermore, we constructed an isogenic deletion mutant of ocw gene and its complementary strain in E. coli. Our results revealed that ocw affects the lipopolysaccharide synthesis, ROS tolerance, and survival of E. coli in the host environment. The discovery of ocw provides important clues for better understanding the function of O-antigen.

Risk Factors in Predicting Prognosis of Neonatal Bacterial Meningitis-A Systematic Review

Background: Neonatal bacterial meningitis is a severe infection with high mortality and morbidity. It is necessary to identify factors associated with a high risk of a poor prognosis so that we can prevent them with more appropriate treatments. This study was performed to summarize the prognostic factors known to predict adverse outcomes in neonatal bacterial meningitis.

Methods: The Medline/PubMed, Cochrane Library and Embase databases were searched for studies of prognostic risk factors in neonates with bacterial meningitis. Studies published from the initiation of the database to April 30th, 2017 were included. The quality of cohort studies was assessed by the Newcastle-Ottawa Scale (NOS). The quality of cross-section studies was assessed by the Agency for Healthcare Research and Quality (AHRQ) scale. Each prognostic factor known to cause adverse outcomes is summarized.

Results: Sixteen studies were identified, including 7 cohort studies and 9 cross section studies. Seizure and high protein levels in the cerebrospinal fluid (CSF) predict a poor prognosis in this disease. Coma, the need for ventilation support, and leukopenia also had some value for predicting poor prognoses. A bulging anterior fontanelle was valuable for predicting mortality. Low CSF glucose levels, thrombocytopenia, gestational age (GA) < 37 weeks and an altered sensorium were correlated with a poor prognosis. A birth weight < 2500 g, early onset meningitis and positive CSF cultures were correlated with mortality.

Conclusions: This study provides a preliminary exploration of prognostic factors in neonatal bacterial meningitis and thereby fills some of the gaps in the study of prognoses in this disease. These prognostic factors can be used to predict and estimate outcomes in neonatal bacterial meningitis. Without a meta-analysis, the reliability of these factors cannot be assured. In addition, these results emphasize that there is an urgent need for a standardized protocol for follow-up and well-designed prognostic studies in neonatal bacterial meningitis.

Multi-lag tone-entropy in neonatal stress

Heart rate variability (HRV) has been analysed using linear and nonlinear methods. In the framework of a controlled neonatal stress model, we applied tone-entropy (T-E) analysis at multiple lags to understand the influence of external stressors on healthy term neonates. Forty term neonates were included in the study. HRV was analysed using multi-lag T-E at two resting and two stress phases (heel stimulation and a heel stick blood drawing phase). Higher mean entropy values and lower mean tone values when stressed showed a reduction in randomness with increased sympathetic and reduced parasympathetic activity. A ROC analysis was used to estimate the diagnostic performances of tone and entropy and combining both features. Comparing the resting and simulation phase separately, the performance of tone outperformed entropy, but combining the two in a quadratic linear regression model, neonates in resting as compared to stress phases could be distinguished with high accuracy. This raises the possibility that when applied across short time segments, multi-lag T-E becomes an additional tool for more objective assessment of neonatal stress.

Neonatal purulent meningitis in southern Tunisia: Epidemiology, bacteriology, risk factors and prognosis

OBJECTIVES

To study the epidemiological, clinical and bacteriological aspects and outcome of purulent neonatal meningitis (PNM).

METHODOLOGY

Retrospective analysis of 55 cases of PNM hospitalized in the pediatric ward of Hedi Chaker Hospital from 1990 to 2012. Infants less than 29 days of age were included. The diagnosis was made on either the presence of bacteria in the cerebrospinal fluid (CSF) or the combination of pleocytosis >30 cells/mm(3), protein level >1.3 g/l and glucose level <2.2 mmol/l or CSF/blood glucose ratio <0.4.

RESULTS

The male:female sex ratio was 1.75. One or more maternal risk factors for infection were found in 24 cases. The main symptoms were fever and poor feeding. Soluble antigen was positive in four cases and cultures had isolated the bacteria in 28 cases. The mortality rate was 40%. The sequelae rate in the survivors was 16.4%.

CONCLUSION

This study emphasizes the severity of PNM with high rates of mortality and neurological sequelae.

Complete nucleotide sequence of pRS218, a large virulence plasmid, that augments pathogenic potential of meningitis-associated Escherichia coli strain RS218

BACKGROUND

Escherichia coli is the most predominant Gram-negative bacterial pathogen associated with neonatal meningitis. Previous studies indicated that the prototypic neonatal meningitis E. coli (NMEC) strain RS218 (O18:K1:H7) harbors one large plasmid. Objectives of the present study were to analyze the complete nucleotide sequence of this large plasmid (pRS218) and its contribution to NMEC pathogenesis using in vitro and in vivo models of neonatal meningitis.

RESULTS

The plasmid is 114,231 bp in size, belongs to the incompatibility group FIB/IIA (IncFIB/IIA), and contains a genetic load region that encodes several virulence and fitness traits such as enterotoxicity, iron acquisition and copper tolerance. The nucleotide sequence of pRS218 showed a 41- 46% similarity to other neonatal meningitis-causing E. coli (NMEC) plasmids and remarkable nucleotide sequence similarity (up to 100%) to large virulence plasmids of E. coli associated with acute cystitis. Some genes located on pRS218 were overly represented by NMEC strains compared to fecal E. coli isolated from healthy individuals. The plasmid-cured strain was significantly attenuated relative to the RS218 wild-type strain as determined in vitro by invasion potential to human cerebral microvascular endothelial cells and in vivo by mortalities, histopathological lesions in the brain tissue, and bacterial recovery from the cerebrospinal fluid of infected rat pups.

CONCLUSIONS

The pRS218 is an IncFIB/IIA plasmid which shares a remarkable nucleotide sequence similarity to large plasmids of E. coli associated with cystitis. Both in vitro and in vivo experiments indicated that pRS218 plays an important role in NMEC pathogenesis.

Intraventricular antibiotics for bacterial meningitis in neonates

BACKGROUND

Neonatal meningitis may be caused by bacteria, especially gram-negative bacteria, which are difficult to eradicate from the cerebrospinal fluid (CSF) using safe doses of antibiotics. In theory, intraventricular administration of antibiotics would produce higher antibiotic concentrations in the CSF than intravenous administration alone, and eliminate the bacteria more quickly. However, ventricular taps may cause harm.

OBJECTIVES

To assess the effectiveness and safety of intraventricular antibiotics (with or without intravenous antibiotics) in neonates with meningitis (with or without ventriculitis) as compared to treatment with intravenous antibiotics alone.

SEARCH METHODS

The Cochrane Library, Issue 2, 2007; MEDLINE; EMBASE; CINAHL and Science Citation Index were searched in June 2007. The Oxford Database of Perinatal Trials was searched in June 2004. Pediatric Research (abstracts of proceedings) were searched (1990 to April 2007) as were reference lists of identified trials and personal files. No language restrictions were applied.This search was updated in May 2011.

SELECTION CRITERIA

Selection criteria for study inclusion were: randomised or quasi-randomised controlled trials in which intraventricular antibiotics with or without intravenous antibiotics were compared with intravenous antibiotics alone in neonates (< 28 days old) with meningitis. One of the following outcomes was required to be reported: mortality during initial hospitalisation; neonatal or infant mortality, or both; neurodevelopmental outcome; duration of hospitalisation; duration of culture positivity of CSF and side effects.

DATA COLLECTION AND ANALYSIS

All review authors abstracted information for outcomes reported and one review author checked for discrepancies and entered data into RevMan 5.1. Risk ratio (RR), risk difference (RD), number needed to treat for an additional beneficial outcome (NNTB) or number needed to treat for an additional harmful outcome (NNTH), and mean difference (MD), using the fixed-effect model are reported with 95% confidence intervals (CI).

MAIN RESULTS

The updated search in June 2011 did not identify any new trials. One study is included in the review. This study assessed the effect of intraventricular gentamicin in a mixed population of neonates (69%) and older infants (31%) with gram-negative meningitis and ventriculitis. Mortality was statistically significantly higher in the group that received intraventricular gentamicin in addition to intravenous antibiotics compared to the group receiving intravenous antibiotics alone (RR 3.43; 95% CI 1.09 to 10.74; RD 0.30; 95% CI 0.08 to 0.53); NNTH 3; 95% CI 2 to 13). Duration of CSF culture positivity did not differ significantly (MD -1.20 days; 95% CI -2.67 to 0.27).

AUTHORS' CONCLUSIONS

In one trial that enrolled infants with gram-negative meningitis and ventriculitis, the use of intraventricular antibiotics in addition to intravenous antibiotics resulted in a three-fold increased RR for mortality compared to standard treatment with intravenous antibiotics alone. Based on this result, intraventricular antibiotics as tested in this trial should be avoided. Further trials comparing these interventions are not justified in this population.

Molecular epidemiology of Escherichia coli causing neonatal meningitis

Escherichia coli is the second cause of neonatal meningitis which is a major cause of neonatal mortality and is associated with a high incidence of neurological sequelae. E. coli neonatal meningitis (ECNM) strains, as other extraintestinal pathogenic E. coli, mainly belong to the phylogenetic group B2 and to a lesser extent to group D, but are distributed in fewer clonal groups. One of these, the O18:K1:H7 clone is worldwide distributed meanwhile others such as O83:K1 and O45:K1 are restricted to some countries. Over the past few years, major progress has been made in the understanding of the pathophysiology of E. coli O18:K1:H7 neonatal meningitis. In particular, specific virulence factors have been identified and are known to be carried by ectochromosomal DNA in most cases. Molecular epidemiological studies, including characterization of virulence genotypes and phylogenetic analysis are important to lead to a comprehensive picture of the origins and spread of virulence factors within the population of ECNM strains. To date, all the known genetic determinants obtained in ECNM strains are not sufficient to explain their virulence in their globality and further studies on clonal groups different from the archetypal O18:K1:H7 clone are needed. These studies would serve to find common pathogenic mechanisms among different ECNM clonal groups that may be used as potential target for a worldwide efficacious prevention strategy.

Intraventricular antibiotics for bacterial meningitis in neonates

BACKGROUND

Neonatal meningitis may be caused by bacteria, especially gram-negative bacteria, which are difficult to eradicate from the cerebrospinal fluid (CSF) using safe doses of antibiotics. In theory, intraventricular administration of antibiotics would produce higher antibiotic concentrations in the CSF than intravenous administration alone, and eliminate the bacteria more quickly. However, ventricular taps may cause harm.

OBJECTIVES

To assess the effectiveness and safety of intraventricular antibiotics (with or without intravenous antibiotics) in neonates with meningitis (with or without ventriculitis) as compared to treatment with intravenous antibiotics alone.

SEARCH STRATEGY

MEDLINE, EMBASE, The Cochrane Library, Issue 2, 2004, Science Citation Index, and the Oxford Database of Perinatal Trials were searched in June 2004. Pediatric Research (abstracts of proceedings) were searched (1990 - April 2004) as were reference lists of identified trials and personal files. No language restrictions were applied.

SELECTION CRITERIA

Selection criteria for study inclusion were: Randomized or quasi-randomized controlled trials in which intraventricular antibiotics with or without intravenous antibiotics were compared with intravenous antibiotics alone in neonates (< 28 days old) with meningitis. One of the following outcomes was required to be reported: mortality during initial hospitalization, neonatal and/or infant mortality, neurodevelopmental outcome, duration of hospitalization, duration of culture positivity of CSF and side effects.

DATA COLLECTION AND ANALYSIS

All reviewers abstracted information for outcomes reported and one reviewer checked for discrepancies and entered data into RevMan 4.2. Relative risk (RR), risk difference (RD), number needed to treat (NNT) or number needed to harm (NNH), and mean difference (MD), using the fixed effects model are reported with 95% confidence intervals (CI). The fixed effect model was used for meta-analysis.

MAIN RESULTS

One study was included in the review. This study assessed the effect of intraventricular gentamicin in a mixed population of neonates (69%) and older infants (31%) with gram negative meningitis and ventriculitis. Mortality was statistically significantly higher in the group that received intraventricular gentamicin in addition to intravenous antibiotics compared to the group receiving intravenous antibiotics alone [RR 3.43 (95% CI, 1.09, 10.74; RD 0.30 (95% CI, 0.08, 0.53); NNH was 3 (95% CI; 2 ,13)]. Duration of CSF culture positivity did not differ significantly (MD -1.20 days (95% CI, -2.67, 0.27).

REVIEWERS' CONCLUSIONS

In one trial, enrolling infants with gram negative meningitis and ventriculitis, the use of intraventricular antibiotics in addition to intravenous antibiotics resulted in a 3 fold increased RR for mortality compared to standard treatment with intravenous antibiotics alone. Based on this result, intraventricular antibiotics as tested in this trial should be avoided. Further trials comparing these interventions are not justified in this population.

Meningitis in the Neonate

Group B beta-hemolytic streptococci and Escherichia coli strains account for approximately two thirds of all cases of neonatal meningitis, while bacteria that typically account for meningitis in older age groups (Haemophilus influenzae type B, Neisseria meningitidis, and Streptococcus pneumoniae) are infrequent causes of meningitis in the neonatal population. As with other medical problems in neonates, signs and symptoms of bacterial infection of the central nervous system are generally few in number and nonspecific in nature. Manifestations that can suggest meningitis, as well as other serious illnesses, include temperature instability, lethargy, respiratory distress, poor feeding, vomiting, and diarrhea. Signs suggestive of meningeal irritation, including stiff neck, bulging fontanelle, convulsions, and opisthotonus, occur only in a minority of neonates with bacterial meningitis and cannot be relied on solely to identify such patients. Ampicillin and either gentamicin or cefotaxime are recommended for initial empiric therapy of neonatal meningitis. When the results of the cerebrospinal fluid (CSF) culture and susceptibilities are known, therapy can be narrowed to cover the specific pathogen identified. In general, penicillin G or ampicillin is preferred for group B streptococcal meningitis, ampicillin for Listeria monocytogenes meningitis, and ampicillin plus either an aminoglycoside or cefotaxime for gram-negative meningitis. For the very low birth weight neonate who has been in the nursery for a prolonged period of time, organisms such as enterococci and gentamicin-resistant gram-negative enteric bacilli must also be considered. In patients with long-term vascular catheters, Staphylococcus aureus or coagulase-negative staphylococci must also be considered. Empiric combinations of antibiotics for such patients would include ampicillin or vancomycin, plus amikacin or cefotaxime. All neonates should undergo repeat CSF examination and culture at 48 to 72 hours after initiation of therapy. If organisms are observed on gram stain, modification of the therapeutic regimen should be considered, and neuroimaging should be performed. In general, therapy should be continued for 14 to 21 days for neonatal meningitis caused by group B streptococci or L. monocytogenes, and for at least 21 days for disease caused by gram-negative enteric bacilli. All patients with neonatal meningitis should have hearing and development monitored serially. The first audiologic evaluation should occur 4 to 6 weeks after resolution of the meningitis.

Neonatal bacterial meningitis

Despite major improvements in infant intensive care, neonatal meningitis remains a devastating disease. Survivors of bacterial meningitis are at high-risk for life-long neurological handicaps, and despite a reduction in mortality, the morbidity of neonatal meningitis has not changed substantially over the last thirty years. A substantial improvement in outcome is unlikely to result from further refinements in ICU technology or new antibiotics. However, recent advancements in our understanding of the pathogenesis of meningitis and the pathophysiology of brain injury in meningitis may provide the opportunity to interrupt the mechanisms that allow bacteria to enter the central nervous system and initiate the inflammatory response. Strategies aimed at modulating the inflammatory response must be chosen carefully, so as not to disrupt normal host responses needed for the infant to recover from the infectious episode.

[Bacterial meningitis in infants 1 to 8 weeks old]

Bacterial meningitis in the newborn and infant remains a serious problem, with a mortality rate of 24% and a morbidity rate ranging from 30 to 50%. This retrospective study conducted between January 1982 and December 1997, aims to characterize the epidemiology of bacterial meningitis in infants less than 60 days of age. Thirty-five infants between 6 and 60 days of age, hospitalized for bacterial meningitis in the pediatric units of Edouard-Herriot Hospital in Lyon, France, were included. The clinical presentation was not specific for most cases, hyperthermia being the most common symptom (97%). Neurological symptoms such as bulging fontanelle or nuchal rigidity were present in 30% and 8% of the cases, respectively. The four predominant meningeal pathogens were: group B streptococcus (36%), Escherichia coli (28%), meningogoccus (8.6%) and Staphylococcus aureus (8.6%). This study emphasizes the importance of prompt diagnosis, including CSF evaluation, and antimicrobial therapy in infants less than 2 months of age presenting an isolated fever.

Bacterial meningitis and the newborn infant

Bacterial meningitis in the neonate differs from meningitis in the older infant and child in a number of ways. Bacterial pathogens primarily are associated with the maternal genitourinary tract. Symptoms and physical findings may be nonspecific, and a high index of suspicion is needed. Management may vary depending on the maturity of the infant and the bacterial pathogen that is isolated.

Differential regulation of vasopressin gene expression in the hypothalamus of endotoxin-treated 14-day-old rat

The E. coli endotoxin 0111 B4, a lipopolysaccharide (LPS), in a dose of 200 ng/kg body weight/50 microl artificial cerebrospinal fluid (CSF) was given intracisternally to 14-day-old rats. Four hours later CSF, blood and urine were sampled, and consecutive brain sections from the hypothalamic area of the brain were prepared for in situ hybridization. The LPS treatment resulted in a significant (p<0.001) pleocytosis and an elevation of the protein content of the CSF. There were no changes observed in the chemical parameters of the CSF, plasma, blood or urine, i.e. vasopressin (VP) levels, osmolality, Na+ and K+ concentrations, glucose level, pH, bicarbonate or PaCO2, PaO2 values. LPS injection, however, resulted in a significantly (p<0.01) increased VP mRNA level (121% of the control value) in the supraoptic nuclei (SON), but not in the paraventricular nuclei (PVN), as compared to controls. Our findings suggest an early effect of LPS on VP gene expression selectively in the SON of 14-days-old rats. This animal model might be suitable for studying the regulation of VP gene expression and the role of this peptide in the pathogenesis of bacterial meningitis in pediatric patients.

Bacterial meningitis in the newborn: a prospective study of mortality and morbidity

Neonatal bacterial meningitis is a serious disease around the world, with the incidence changing little in the past 30 years. Group B streptococci, Escherichia coli, and Klebsiella pneumoniae are common causative organisms and lumbar puncture remains the definitive method of diagnosis. The mortality rate has declined in industrialized countries over the years, from almost 50% in the 1970s to less than 10% in 1997. However, neurological sequelae are still frequently observed despite major changes in treatment. Preliminary analysis of our own data from a prospective study of cases in the United Kingdom suggests that treatment with third generation cephalosporins is related to a decrease in mortality but not morbidity.

Neonatal meningitis in England and Wales: a review of routine national data

The objective of this study was to describe trends in neonatal meningitis in England and Wales during the years 1975-91. Laboratory reports and, for the years 1983-91, data on statutory notifications and deaths from neonatal meningitis were reviewed. The mean annual total of laboratory reports of neonatal bacterial meningitis 1975-91 was 109 cases (range 69-133) with a slight upward trend apparent in the latter half of the study period. The mean annual number of reports of neonatal viral meningitis was only 14 cases with no trend apparent. The leading bacteria isolated were group B streptococci, Escherichia coli, and Listeria monocytogenes accounting for 34.1%, 28.5%, and 6.8% of reports, respectively. There was a change in the pattern of causative bacteria from 1981 onwards with the group B streptococcus displacing E coli as the leading cause. With respect to neonatal viral meningitis, echoviruses and coxsackie viruses accounted for 55.4% and 38.6% of cases, respectively. Neonatal meningitis was seriously undernotified; the ratio of laboratory reported cases to cases notified ranged from 12:1 in 1985 to 4:1 in 1989. The annual numbers of deaths ranged from 18 to 39. The laboratory reporting system provided the most useful data on secular trends and causative organisms for neonatal meningitis. The slight upward trend in the number of reports of bacterial meningitis merits continued surveillance.

Prospective surveillance of neonatal meningitis

Neonatal meningitis is a serious problem with a high mortality and frequent neurological sequelae. The incidence of neonatal meningitis was calculated and the aetiology, clinical and laboratory features, and the treatment of cases recorded prospectively over a 7 year 8 month period was documented. It was further investigated whether secondary meningitis had occurred after lumbar puncture. The estimated incidence of bacterial, viral, and fungal meningitis was 0.25, 0.11, and 0.02 per 1000 live births respectively. There were eight cases of early onset meningitis (seven definite, one probable) and group B streptococci accounted for six (75%) of these. Blood cultures were negative in only one of seven cases of definite early bacterial meningitis. Of the 15 late onset cases, Gram negative organisms accounted for six of the seven bacterial cases. The overall mortality was 26%. Of the 11 survivors of bacterial meningitis, three (27%) had significant neurological sequelae at follow up (between three months to three years later). As in the first 48 hours after birth an initial blood culture is unlikely to be negative if bacterial meningitis is present, lumbar puncture can be deferred if the procedure might exacerbate respiratory distress. Although approximately 1880 infants had a lumbar puncture during the review period, only one case of meningitis was found where it was possible that lumbar puncture in a bacteraemic infant may have caused meningeal infection. The incidence of this potential complication must therefore be low.

Epidemiology of bacterial meningitis

This 10 year retrospective study of all causes of bacterial meningitis for children resident in Nottingham District Health Authority area reports an annual incidence rate per 100,000 children aged 0-16 years of 16.0 (95% confidence interval 14.0 to 18.1). There was a steady increase in incidence from 9.6/100,000 in 1980 to 24.3/100,000 in 1989. This was mainly due to an increase in the incidence of meningococcal infections in the age group 1 month to 5 years. Incidence rates varied with age being: 37.2/100,000 (25.9 to 53.5) for 0-28 days of age, 115.5/100,000 (93.9 to 141.9) for 1-11 months of age, 28.5/100,000 (23.1 to 35.3) for 12-59 months of age, and 2.8/100,000 (1.9 to 4.1) for 5-16 years of age. Overall annual mortality incidence per 100,000 was 1.8 (1.2 to 2.8). For the different age groups this was: 10.1 (4.8 to 21.1) for 0-28 days, 11.5 (6.0 to 22.2) for 1-11 months, 1.0 (0.3 to 3.1) for 12-59 months, and 0.4 (0.1 to 1.2) for 5-16 years of age. There were interactions between the type of meningitis and the year of the infection on the mortality rate. Mortality decreased in those with infections caused by bacteria other than Neisseria meningitidis and Haemophilus influenzae.

Neonatal bacterial meningitis in the middle belt of Nigeria

A three-year prospective study of neonatal meningitis in a tertiary hospital in Nigeria was carried out to determine its clinical spectrum and particular characteristics. The 36 infants studied represented a high incidence of 1.9 per 1000 live births, and the infection was significantly higher among low-birthweight babies. Non-specific signs and symptoms were common, and temperature instability was a constant finding. Specific neurological manifestations were noted that differed from other reports in the literature and contributed significantly to outcome. The most common aetiological pathogen isolated was Gram-positive Staphylococcus aureus and the most common Gram-negative organisms were Klebsiella spp: there was no case of group B streptococci. The pathogens isolated were also at variance with other reports. The mortality rate was 33 per cent and was higher for females. There was no significant difference in outcome between inborn and referred infants, nor between early onset and late onset of the disease. A bulging anterior fontanelle was a significant indicator of poor prognosis. Gentamicin and ceftazidime were the most appropriate antibiotics.

[Neonatal bacterial meningitis: etiological agents in 109 cases during a 10 year period]

The etiology of purulent meningitis was investigated in 109 newborn infants admitted in a neonatal intensive care unit throughout a ten year period. Bacterial pathogens were isolated from the CSF in 57 (52.2%) neonates. There was a predominance of Gram-negative bacilli isolated in 38 (34.9%) neonates. Gram-positive cocci were isolated from CSF in only 12 (11.0%) neonates. Microorganisms associated with nosocomial septicemia and meningitis in neonates--Klebsiella sp, Salmonella sp. Enterobacter sp, Pseudomonas sp, Flavobacterium meningosepticum and Serratia marcescens--were responsible for presumptive etiology in 38 (49.3%) among 77 patients with positive cultures in "closed sites". They were isolated from 22 (57.0%) neonates with prior hospitalization but only from 12 (34.3%) neonates coming directly from their households (chi 2 = 4.08; p < 0.05). The mortality rate was significantly higher in patients with positive CSF cultures (47.4%) in comparison to patients with negative cultures (18.4%) (X2 = 5.01; p < 0.05). It is possible to conclude that Gram-negative bacilli, many of them of hospital origin, are the major pathogens in this study. An improvement on neonatal health care and a scrupulous control of neonatal nosocomial infections are recommended.

The changing spectrum of neonatal meningitis over a fifteen-year period

One hundred seventy-seven cases of neonatal meningitis treated at the University of Texas Medical Branch at Galveston over a 15-year period (1974-1988) were reviewed. Over this period, the incidence of bacterial meningitis decreased, the incidence of aseptic meningitis remained stable, and the diagnosis of enteroviral meningitis increased in frequency. During 1984-1988, enterovirus was the most common cause of meningitis in neonates older than seven days and accounted for one third of all cases of neonatal meningitis. Half of all neonates with bacterial meningitis had negative blood cultures. We recommend that 1) diagnostic lumbar puncture remain part of the routine assessment of the neonate with suspected sepsis, and 2) CSF be cultured for enterovirus as well as for bacteria when a neonate older than seven days presents with suspected sepsis.

Survey of neonatal meningitis in Australia: 1987-1989

OBJECTIVE

To identify incidence, bacterial aetiology, outcome after treatment and risk factors for poor outcome of neonatal meningitis.

DESIGN

Retrospective survey of neonatal meningitis occurring in Australia between January 1987 and December 1989. Data were obtained from Medical Records and Microbiology Departments of hospitals with neonatal nurseries.

SETTING

Neonatal nurseries throughout Australia.

PATIENTS

116 infants under 6 weeks of age with bacterial or fungal meningitis.

RESULTS

The minimum incidence was 0.17 per 1000 live births. Traditional neonatal pathogens were responsible for 60% of cases (group B streptococci, 35%; Escherichia coli, 22%), childhood meningeal pathogens for 10% and opportunistic pathogens for 30%. Risk factors for meningitis, including prematurity, were more common among those with meningitis due to E. coli or opportunistic pathogens than among those with infections due to group B streptococci, Listeria monocytogenes or the childhood pathogens (46/60 v. 11/55; P less than 0.0001). Meningitis was more likely to be due to Gram-negative bacteria in premature infants (less than 36 weeks gestation) than in full-term infants (19/30 v. 20/86; P = 0.0002). The mortality overall was 26% but was higher in extremely premature infants (less than 29 weeks) (6/9 v. 24/107; P = 0.009) and among 13 patients who were judged to have had inappropriate initial therapy (7/13 v. 21/97; P = 0.04). Long-term sequelae occurred in at least 23% of survivors, but were more common in those with Gram-negative meningitis (6/10 v. 13/76; P = 0.012).

CONCLUSIONS

Initial therapy with penicillin or amoxycillin plus cefotaxime is appropriate for most infants with bacterial meningitis. Since some less common Gram-negative bacteria isolated in this survey were resistant to cefotaxime, an aminoglycoside should be added, initially, in Gram-negative meningitis.

Meningitis and midline facial deformity

A baby with unilateral cleft lip, midline cleft palate and hypertelorism developed meningitis in the first 48 h of life. Examination of the nasopharynx showed a soft tissue mass, which was confirmed as a basal encephalocele by computed tomography. There was also congenital hydrocephalus and the corpus callosum was absent. Surgical treatment included repair of the anterior basal skull defect, repair of the lip and palate, and ventriculo-peritoneal shunt. There is currently evidence of developmental delay and right-sided visual impairment due to Morning Glory syndrome. This case demonstrates that basal encephalocele should be considered in any baby with midline facial deformity who develops meningitis.