Long-term sequelae of pneumococcal meningitis in children

Ophthalmic diseases in meningitis within the pediatric population

OBJECTIVE

Meningitis may lead to ophthalmic complications in pediatric populations. The visual aftermath in developed countries has been poorly studied. This study aims to highlight the potential ocular and neuro-ophthalmic sequela of meningitis in the pediatric population of a tertiary pediatric hospital.

DESIGN

A retrospective chart review of all pediatric patients, between 2006 and 2015, diagnosed with meningitis at the Montreal Children's Hospital was conducted. Study approval was obtained by the Institutional Review Board of the McGill University Health Centre and adhered to the tenets of the Declaration of Helsinki.

METHODS

Records of all pediatric meningitis patients were extracted and further refined by isolating all who received an ophthalmology consultation. Relevant demographic data, general medical information, ocular findings, and imaging results were extracted. The proportion of ocular abnormalities was calculated and analyzed.

RESULTS

Seventy-two of 861 meningitis patients (8.4%) received an ophthalmology consultation. Forty-six patients met the inclusion criteria, and 31 of those (67.4%) demonstrated ocular abnormalities. Children presented most frequently with abnormalities involving visual acuity (8 of 32), extraocular movements and alignment (14 of 28), optic nerve (10 of 41), pupillary reactivity (4 of 35), and periorbital/orbital cellulitis (4 of 46). Older patients were more likely to have ophthalmologic findings.

CONCLUSION

This chart review highlights the ocular abnormalities found in children who suffer from meningitis and present to a tertiary-care centre in a high sociodemographic index country. Complications may be lasting. Treating ophthalmologists should be cognizant of potential ocular abnormalities among meningitis patients. We advocate for increased awareness of this association among health care providers.

Neurological sequelae of bacterial meningitis

OBJECTIVES

We reported on occurrence and impact of neurological sequelae after bacterial meningitis.

METHODS

We reviewed occurrence of neurological sequelae in children and adults after pneumococcal and meningococcal meningitis.

RESULTS

Most frequently reported sequelae are focal neurological deficits, hearing loss, cognitive impairment and epilepsy. Adults with pneumococcal meningitis have the highest risk of developing focal neurological deficits, which are most commonly caused by cerebral infarction, but can also be due to cerebritis, subdural empyema, cerebral abscess or intracerebral bleeding. Focal deficits may improve during clinical course and even after discharge, but a proportion of patients will have persisting focal neurological deficits that often interfere in patient's daily life. Hearing loss occurs in a high proportion of patients with pneumococcal meningitis and has been associated with co-existing otitis. Children and adults recovering from bacterial meningitis without apparent neurological deficits are at risk for long-term cognitive deficits. Early identification of neurological sequelae is important for children to prevent additional developmental delay, and for adults to achieve successful return in society after the disease.

CONCLUSIONS

Neurological sequelae occur in a substantial amount of patients following bacterial meningitis. Most frequently reported sequelae are focal neurological deficits, hearing loss, cognitive impairment and epilepsy.

Characteristics of brain stem auditory evoked potentials in children with hearing impairment due to infectious diseases

Among objective audiologic tests, the most important were tests of brain stem auditory evoked potentials. The objective of the study was to test the configuration, degree of hearing loss, and response characteristics of auditory brain stem evoked potentials in children with hearing loss occurred due to infectious disease. A case control study design was used. The study group consisted of 54 patients referred for a hearing test because of infectious diseases caused by other agents or that occurred as congenital infection. Infectious agents have led to the emergence of various forms of sensorineural hearing loss. We have found deviations from the normal values of absolute and interwave latencies in some children in our group. We found that in the group of children who had the diseases such as purulent meningitis, or were born with rubella virus and cytomegalovirus infection, a retrocochlear damage was present in children with and without cochlear damage.

Epidemiology of pediatric pneumococcal meningitis and bacteremia in Latin America and the Caribbean: a systematic review and meta-analysis

BACKGROUND

Pneumococcal meningitis and bacteremia pose a significant disease burden in Latin America and the Caribbean (LAC).

METHODS

To perform a systematic review of studies of pediatric pneumococcal meningitis and non-pneumonia, non-meningitis pneumococcal bacteremia in LAC, we conducted an exhaustive search from 2000 to 2010 in electronic databases and grey literature. Pairs of independently selected reviewers assessed the quality and extracted the studies' data. A STROBE-based checklist was used to assess the risk of bias in observational studies. Meta-analyses were performed.

RESULTS

Of 1218 retrieved studies, 39 were included. In children <5 years, the pooled 95% confidence interval (CI) percentage of pneumococcal etiology out of cases studied with cerebrospinal fluid/blood cultures was 6.0% (95% CI: 3.3-9.5) for meningitis and 8.0% (95% CI: 5.3-12.4) for bacteremia. The incidences per 100,000 children were 4.7 (95% CI: 3.2-6.1) and 3.9 (95% CI: 2.0-5.9) for pneumococcal meningitis and non-pneumonia, non-meningitis bacteremia, respectively. The mortality was 8.3 (95% CI: 0.0-21.0) and 0.5 (95% CI: 0.3.0-0.6)/100,000 for meningitis and sepsis, respectively. The case fatality ratio was 33.2% (95% CI: 21.3-46.2) for meningitis and 29.0% (95% CI: 21.9-36.8) for sepsis. The pooled serotype distribution from SIREVA surveillance data showed that 14, 5, 6B (for meningitis) and 14, 6B, 19F (for bacteremia) were the most frequent serotypes, all included in licensed vaccines.

CONCLUSION

Pneumococcal meningitis and bacteremia are important causes of morbidity and mortality in LAC children <5 years of age. This systematic review provided evidence about the burden of pneumococcal disease and the serotype distribution to assess the impact the pneumococcal vaccines and to assist decision makers in the region.

The burden of pneumococcal meningitis in Austrian children between 2001 and 2008

The present study was conducted to evaluate the burden of pneumococcal meningitis in Austrian children between 2001 and 2008. Clinical outcome was retrospectively analyzed both on discharge and on follow-up investigations. This study was based on a prospective multicentre surveillance study on hospitalized invasive pneumococcal infections in Austrian children with a total annual "study population" of about 399,000 children aged below 5 years per year. Between 2001 and 2008, 74 cases of pneumococcal meningitis were identified in children aged below 5 years. The mean annual incidence rate for pneumococcal meningitis was 2.3 per 100,000 children in this age group. In 57/74 children (mean age on admission 14.5 ± 13.3 months), outcome data on hospital discharge were available: 5 deaths (8.8%), 20 children (35.1%) with sequelae and 32 children (56.1%) without sequelae were observed. Sequelae on discharge included motor impairment in 8 children (14.0%), hearing impairment in 9 children (15.8%) and/or other complications in 14 children (24.6%). In 7/8 children with motor deficits, matching cerebral lesions were identified by neuroimaging: cerebral infarction in five children, cerebral vasculitis and cerebral abscess in one child each. In 40/57 children, long-term outcome (18.9 ± 20.2 months after discharge) could be assessed: 1 child (2.5%) died 9 months after hospital discharge, 11 children (27.5%) had one or two long-term sequelae and 28 children (70.0%) had no sequelae. Long-term sequelae included motor impairment in three children (7.5%), hearing impairment in nine children (22.5%) and other deficits in two children (5.0%).

CONCLUSION

Our study confirms that pneumococcal meningitis causes high mortality and severe long-term sequelae. On long-term follow-up, we observed improvements of motor impairment, but not of hearing impairment.

Pneumococcal infections

Overwhelmingly consistent evidence from observational studies has demonstrated that the pneumococcal conjugate vaccine has reduced the burden of pneumococcal disease but continues to affect the epidemiology of pneumococcal infections caused by nonvaccine serotypes and antibiotic-resistant pneumococci. On the basis of strong evidence, susceptible pneumococci causing uncomplicated, noninvasive childhood infections (eg, otitis or pneumonia) should be treated with a narrow-spectrum antimicrobial (eg, amoxicillin). Severely ill patients and those with infections caused by resistant pneumococci may be treated with parenteral antibiotic agents based on the isolate’s susceptibility and the site of the infection.

Potential cost-effectiveness of pneumococcal conjugate vaccine (PCV) in Turkey

BACKGROUND

Pneumococcal infection is an important and preventable cause of morbidity and mortality. The Turkish government introduced 7-valent pneumococcal conjugate vaccine (PCV) into the national immunization program in 2009. This suggests that replacing 7-valent PCV with a higher-valent version could at least maintain "standard of care" if not improve it, and that it could be affordable.

OBJECTIVES AND METHODS

The aim of this analysis was to assess the potential direct cost-effectiveness of 13-valent PCV in Turkey, a country with a birth cohort of 1.4 million, against a "no vaccine" state, against the default 7-valent PCV state, and against a 10-valent PCV state, using a published cohort model with a 5-year horizon.

RESULTS AND CONCLUSIONS

The cost per life-year gained is below the 1 × per-capita gross domestic product threshold across large changes in key input parameters, indicating that the model is stable and suggesting that any PCV would be very cost-effective in a Turkish national pediatric immunization schedule.

Prognostic factors related to sequelae in childhood bacterial meningitis: data from a Greek meningitis registry

BACKGROUND

Bacterial meningitis (BM) is a life-threatening disease, often related with serious complications and sequelae. Infants and children who survive bacterial meningitis often suffer neurological and other sequelae.

METHODS

A total of 2,477 patients aged 1 month to 14 years old hospitalized in a Children's Hospital in Greece diagnosed with acute bacterial meningitis were collected through a Meningitis Registry, from 1974 to 2005. Clinical, laboratory and other parameters (sex, age, pathogen, duration of symptoms before and after admission) were evaluated through univariate and multivariate analysis with regard to sequelae. Analysis of acute complications were also studied but not included in the final model.

RESULTS

The rate of acute complications (arthritis and/or subdural effusion) was estimated at 6.8% (152 out of 2,251 patients, 95%CI 5.8-7.9) while the rate of sequelae (severe hearing loss, ventriculitis, hydrocephalus or seizure disorder) among survivors was estimated at 3.3% (73 out of 2,207 patients, 95%CI 2.6-4.2). Risk factors on admission associated with sequelae included seizures, absence of hemorrhagic rash, low CSF glucose, high CSF protein and the etiology of meningitis. A combination of significant prognostic factors including presence of seizures, low CSF glucose, high CSF protein, positive blood culture and absence of petechiae on admission presented an absolute risk of sequelae of 41.7% (95%CI 15.2-72.3).

CONCLUSIONS

A combination of prognostic factors of sequelae in childhood BM may be of value in selecting patients for more intensive therapy and in identifying possible candidates for new treatment strategies.

Long-term outcomes of pneumococcal meningitis in childhood and adolescence

A vaccine to prevent pneumococcal meningitis (PM) has recently been introduced. However, contemporary data to inform cost-effectiveness analysis and justify its routine use are sparse. We examined the cognitive, educational, psychological and social outcomes of PM in childhood. We completed a population-based case-control study in two regions of the UK. Children and young people currently between 3 and 20 years of age that had been diagnosed with PM ≤14 years of age were identified from active regional surveillance. Controls were siblings or neighbours of similar age. Standardised questionnaires and neuropsychological testing was administered to assess IQ, educational attainments, memory, psychological distress, quality of life and hearing impairment. Data were available on 97 patients and 93 controls. Eighty-four patients had a sibling/neighbour-matched control. Both matched and unmatched analyses were completed, and results of the 84 matched comparisons were highly similar to the unmatched. For the total sample, controls were similar in age, ethnicity and socioeconomic status. Median age at meningitis was 11 months. Median time between meningitis and assessment was 6.0 years. In the matched analysis, partial or profound hearing impairment was reported in 14% of patients and 1% of controls. Patients had significantly lower mean full-scale IQ (p = 0.05), verbal IQ (p = 0.0008), numeracy (p = 0.02), total quality of life (p = 0.04), school functioning (p = 0.005), psychosocial functioning (p = 0.001) and psychological difficulties (p = 0.01). Parents of patients reported greater functional disability (p = 0.008), impairment in all aspects of quality of life (p = 0.001) and psychological difficulties (p < 0.0006). Findings for IQ were not materially different when analyses were repeated only in those without hearing impairment. In multivariate regression analysis that included both case-control status and hearing status, both being a patient (p = 0.001) and having profound hearing impairment (p = 0.001) were independently associated with lower full-scale IQ. Conclusions Pneumococcal meningitis is associated with major sequelae. Our findings strongly support the introduction of pneumococcal conjugate vaccine as part of routine childhood vaccination programmes internationally.

[Economic evaluation of an infant immunization program in Mexico, based on 13-valent pneumococcal conjugated vaccines]

OBJECTIVES

Vaccination is an effective intervention for reduce child morbidity and mortality associated to pneumococcus. The availability of new anti-pneumococcal vaccines makes it necessary to evaluate its potential impact on public health and costs related to their implementation. The aim of this study was to estimate the cost-effectiveness and cost-utility of immunization strategies based on pneumococcal conjugated vaccines (PCV's) currently available in Mexico from a third payer perspective.

MATERIAL AND METHODS

A decision tree model was developed to assess both, economic and health impact, of anti-pneumococcal vaccination in children <2 years (lifetime time horizon, discount rate: 5% annual). Comparators were: no-vaccination (reference) and strategies based on 7, 10 and 13-valent PCV's. Effectiveness measures were: child deaths avoided, life-years gained (LYG) and quality adjusted life years (QALY's) gained. Effectiveness, utility, local epidemiology and cost of treating pneumococcal diseases were extracted from published sources. Univariate sensitivity analysis were performed.

RESULTS

Immunization dominates no-vaccination: strategy based on 13-valent vaccine prevented 16.205 deaths, gained 331.230 LY's and 332.006 QALY's and saved US$1.307/child vaccinated. Strategies based on 7 and 10-valent PCV's prevented 13.806 and 5.589 deaths, gained 282.193 and 114.251 LY's, 282.969 and 114.972 QALY's and saved US$1.084 and US$731/child vaccinated, respectively. These results were robust to variations in herd immunity and lower immunogenicity of 10-valent vaccine.

CONCLUSIONS

In Mexico, immunization strategies based on 7, 10 and 13-valent PCV's would be cost-saving interventions, however, health outcomes and savings of the strategy based on 13-valent vaccine are greater than those estimated for 7 and 10-valent PCV's.

Should blood cultures be obtained in all infants 3 to 36 months presenting with significant fever?

CONTEXT

Fever without source (FWS) in children 3-36 months is a common presenting complaint. Because of changes in immunization practices and their effects on rates of bacteremia, older guidelines may no longer be applicable. We reviewed the literature regarding the necessity of obtaining a blood culture in non-toxic children in this age group with FWS.

DATA SOURCES

We conducted a MEDLINE search on the topic of bacteremia in febrile children 3-36 months from 2004-present.

RESULTS

Eight studies were included. Although the studies varied in terms of approach and analysis, all suggested a rate of bacteremia in a non-toxic, febrile child 3-36 months of age to be less than 1%.

CONCLUSIONS

Strong consideration should be given for foregoing blood culture in a non-toxic child 3-36 months of age with FWS.

Regional sensitivity to neuroinflammation: in vivo and in vitro studies

BACKGROUND

Neuroinflammation is involved in several acute-onset neuropathologies such as meningitis, encephalitis, stroke, and traumatic brain injury as well as in neurodegenerative diseases. All of these patholologies are associated with cognitive deficits. Using a model of pure neuroinflammation (intracisternal injection of endotoxin in mice), we tested the hypothesis that brain regions involved in cognition are the most vulnerable to inflammatory insults, and this vulnerability is an inherent property of neocortical neurons.

METHODS

Mice (n = 10/group) injected with endotoxin (LPS) or saline in the cisterna magna underwent neurobehavioral and cognitive testing followed by quantitative autoradiographic assessment of regional neuroinflammation with [3H]PK11195, an established marker of microgliosis. In parallel, cocultures of cortical and striatal neurons taken from embryonic day 19 rat embryos or postnatal day 1 mice expressing green fluorescent protein were exposed for 24 h to the proinflammatory cytokine TNFalpha, glutamate, or a combination of the two agents.

RESULTS

LPS-treated mice exhibited significant deficits in memory and significant increases in specific PK11195 binding in cortical and hippocampal regions, but not in striatum. Cultured neurons of cortical origin showed significantly lower survival rate relative to striatal neurons in response to TNFalpha, glutamate, or a combination of the two agents. Furthermore, TNFalpha exerted neuroprotective rather than neurotoxic effects in the striatal but not in the cortical neurons.

CONCLUSIONS

These results suggest that the cortex is inherently more sensitive than the striatum to the deleterious effects of neuroinflammation, and may offer an explanation for the preponderance of cognitive deficits in neuropathologies with a neuroinflammatory component.

The inhalation anesthetic isoflurane increases levels of proinflammatory TNF-α, IL-6, and IL-1β

Anesthetics have been reported to promote Alzheimer's disease (AD) neuropathogenesis by inducing β-amyloid protein accumulation and apoptosis. Neuroinflammation is associated with the emergence of AD. We therefore set out to determine the effects of the common anesthetic isoflurane on the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β, the proinflammatory cytokines, in vitro and in vivo, employing Western blot, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), and reverse transcriptase polymerase chain reaction (RT-PCR). Here, we show that a clinically relevant isoflurane anesthesia increased the protein and messenger ribonucleic acid (mRNA) levels of TNF-α, IL-6, and IL-1β in the brain tissues of mice. The isoflurane anesthesia increased the amounts of TNF-α immunostaining positive cells in the brain tissues of mice, the majority of which were neurons. Furthermore, isoflurane increased TNF-α levels in primary neurons, but not microglia cells, of mice. Finally, isoflurane induced a greater degree of TNF-α increase in the AD transgenic mice than in the wild-type mice. These results suggest that isoflurane may increase the levels of proinflammatory cytokines, which may cause neuroinflammation, leading to promotion of AD neuropathogenesis.

Predicting sequelae and death after bacterial meningitis in childhood: a systematic review of prognostic studies

Background

Bacterial meningitis (BM) is a severe infection responsible for high mortality and disabling sequelae. Early identification of patients at high risk of these outcomes is necessary to prevent their occurrence by adequate treatment as much as possible. For this reason, several prognostic models have been developed. The objective of this study is to summarize the evidence regarding prognostic factors predicting death or sequelae due to BM in children 0-18 years of age.

Methods

A search in MEDLINE and EMBASE was conducted to identify prognostic studies on risk factors for mortality and sequelae after BM in children. Selection of abstracts, full-text articles and assessment of methodological quality using the QUIPS checklist was performed by two reviewers independently. Data on prognostic factors per outcome were summarized.

Results

Of the 31 studies identified, 15 were of moderate to high quality. Due to substantial heterogeneity in study characteristics and evaluated prognostic factors, no quantitative analysis was performed. Prognostic factors found to be statistically significant in more than one study of moderate or high quality are: complaints >48 hours before admission, coma/impaired consciousness, (prolonged duration of) seizures, (prolonged) fever, shock, peripheral circulatory failure, respiratory distress, absence of petechiae, causative pathogen Streptococcus pneumoniae, young age, male gender, several cerebrospinal fluid (CSF) parameters and white blood cell (WBC) count.

Conclusions

Although several important prognostic factors for the prediction of mortality or sequelae after BM were identified, the inability to perform a pooled analysis makes the exact (independent) predictive value of these factors uncertain. This emphasizes the need for additional well-conducted prognostic studies.

Global and regional risk of disabling sequelae from bacterial meningitis: a systematic review and meta-analysis

Few data sources are available to assess the global and regional risk of sequelae from bacterial meningitis. We aimed to estimate the risks of major and minor sequelae caused by bacterial meningitis, estimate the distribution of the different types of sequelae, and compare risk by region and income. We systematically reviewed published papers from 1980 to 2008. Standard global burden of disease categories (cognitive deficit, bilateral hearing loss, motor deficit, seizures, visual impairment, hydrocephalus) were labelled as major sequelae. Less severe, minor sequelae (behavioural problems, learning difficulties, unilateral hearing loss, hypotonia, diplopia), and multiple impairments were also included. 132 papers were selected for inclusion. The median (IQR) risk of at least one major or minor sequela after hospital discharge was 19.9% (12.3-35.3%). The risk of at least one major sequela was 12.8% (7.2-21.1%) and of at least one minor sequela was 8.6% (4.4-15.3%). The median (IQR) risk of at least one major sequela was 24.7% (16.2-35.3%) in pneumococcal meningitis; 9.5% (7.1-15.3%) in Haemophilus influenzae type b (Hib), and 7.2% (4.3-11.2%) in meningococcal meningitis. The most common major sequela was hearing loss (33.9%), and 19.7% had multiple impairments. In the random-effects meta-analysis, all-cause risk of a major sequela was twice as high in the African (pooled risk estimate 25.1% [95% CI 18.9-32.0%]) and southeast Asian regions (21.6% [95% CI 13.1-31.5%]) as in the European region (9.4% [95% CI 7.0-12.3%]; overall I(2)=89.5%, p<0.0001). Risks of long-term disabling sequelae were highest in low-income countries, where the burden of bacterial meningitis is greatest. Most reported sequelae could have been averted by vaccination with Hib, pneumococcal, and meningococcal vaccines.

The risk of sequelae due to pneumococcal meningitis in high-income countries: a systematic review and meta-analysis

OBJECTIVES

To determine the risk of various kinds of sequelae in survivors of meningitis due to Streptococcus pneumoniae, as well as the influence of co-factors such as study design, study population and treatment on this risk.

METHODS

MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched from 1 September 1991 to 18 June 2009 for original articles on pneumococcal meningitis sequelae. Prevalence of sequelae was pooled using random effects meta-analysis. Studies were appraised for the influence of referral bias, external validity of study populations, testing procedure and publication bias.

RESULTS

Data were extracted from 63 studies involving 3408 pneumococcal meningitis survivors. The pooled prevalence of any reported sequelae from 48 studies was 31.7% (95% confidence interval 27.2-36.3%) using a random effects model (Cochran-Q = 277, p < 0.01). Differences in studies due to design, study population and treatment were not significant. The pooled prevalence of hearing loss, seizures, hydrocephalus, spasticity/paresis, cranial nerve palsies and visual impairment was 20.9% (17.1-24.7%), 6.5% (3.3-9.7%), 6.8% (3.3-10.2%), 8.7% (6.4-11.0%), 12.2% (5.3-19.1%) and 2.4% (0-5.7%) respectively.

CONCLUSIONS

The burden of sequelae due to pneumococcal meningitis remains high in the reviewed studies.

Intracranial electrode implantation produces regional neuroinflammation and memory deficits in rats

Deep brain stimulation (DBS) is an established treatment for advanced Parkinson's disease (PD). The procedure entails intracranial implantation of an electrode in a specific brain structure followed by chronic stimulation. Although the beneficial effects of DBS on motor symptoms in PD are well known, it is often accompanied by cognitive impairments, the origin of which is not fully understood. To explore the possible contribution of the surgical procedure itself, we studied the effect of electrode implantation in the subthalamic nucleus (STN) on regional neuroinflammation and memory function in rats implanted bilaterally with stainless steel electrodes. Age-matched sham and intact rats were used as controls. Brains were removed 1 or 8 weeks post-implantation and processed for in vitro autoradiography with [(3)H]PK11195, an established marker of microglial activation. Memory function was assessed by the novel object recognition test (ORT) before surgery and 2 and 8 weeks after surgery. Electrode implantation produced region-dependent changes in ligand binding density in the implanted brains at 1 as well as 8 weeks post-implantation. Cortical regions showed more intense and widespread neuroinflammation than striatal or thalamic structures. Furthermore, implanted animals showed deficits in ORT performance 2 and 8 weeks post-implantation. Thus, electrode implantation resulted in a widespread and persistent neuroinflammation and sustained memory impairment. These results suggest that the insertion and continued presence of electrodes in the brain, even without stimulation, may lead to inflammation-mediated cognitive deficits in susceptible individuals, as observed in patients treated with DBS.

Economic evaluation of universal infant vaccination with 7vPCV in Hong Kong

OBJECTIVES

The purpose of this study was to evaluate the clinical and economic benefits of routine infant vaccination with seven-valent pneumococcal conjugate vaccine (7vPCV) in Hong Kong.

METHODS

A decision-analytic model was populated with local age-specific incidence data to simulate the expected health outcomes resulting from 7vPCV vaccination of a birth cohort of 57,100 children compared with an unvaccinated cohort over a 10-year horizon. Primary analyses were conducted from a payer perspective, using local inpatient and outpatient costs associated with the treatment of pneumococcal disease. Vaccine efficacy rates were consistent with results from pivotal clinical trials. The reduction in adult invasive pneumococcal disease (IPD) and associated cost avoidance due to the indirect effect of vaccination were estimated in line with published overseas rates.

RESULTS

Universal 7vPCV vaccination was estimated to prevent 524 cases of IPD and more than 2580 cases of otitis media in the birth cohort over a 10-year period, leading to a reduction of HK$28.7 million (US$3.7 million) in direct medical costs. Additional cost savings from the indirect prevention of 919 adult cases of IPD during this time period also resulted. Overall, 7vPCV vaccination was estimated to have an incremental cost per life-year gained of HK$50,456 (US$6460) from a payer perspective or HK$46,308 (US$5929) when both direct and indirect costs were included.

CONCLUSION

With reference to the World Health Organization's threshold for cost-effectiveness, results from this study indicate that routine infant vaccination with 7vPCV is a cost-effective intervention because of the added cost savings resulting from the indirect effect of vaccination on adult disease.

Validating and updating a prediction rule for neurological sequelae after childhood bacterial meningitis

Recently, a prediction rule for developing neurological sequelae after childhood bacterial meningitis was developed on a small derivation set. Before implementing in practice a prediction rule must first be tested in new patients (external validation). Our aim was to study the external validity of this rule and, if necessary, to update the rule. The prediction rule was tested on newly available data (validation set) by assessing the rule's calibration and discrimination. We updated the prediction rule by adding extra predictors and re-estimating the regression coefficients of the original predictors in the combined datasets. The rule showed poor agreement between predicted risks and observed frequencies. The ROC area was 0.65 (95% CI 0.57-0.72), which was statistically significantly lower than in the derivation set (0.87 (0.78-0.96)), p-value<0.01. The updated prediction rule showed adequate performance in the combined data sets; the ROC area was 0.77 (95% CI 0.72-0.82). Further study of the generalizability of this updated rule may stimulate application in clinical practice.

Prevalence of occult bacteremia in children aged 3 to 36 months presenting to the emergency department with fever in the postpneumococcal conjugate vaccine era

OBJECTIVES

The goal of this study was to identify the prevalence of occult bacteremia (OB) in well-appearing, previously healthy children aged 3 to 36 months who present to the emergency department (ED) with fever without source in the post-pneumococcal conjugate vaccine (PCV) era.

METHODS

This was a retrospective cohort study of children presenting to an urban pediatric ED between July 1, 2004, and June 30, 2007. Children were included if they were aged 3 to 36 months, febrile, and previously healthy; had no source of infection on examination; had a blood culture drawn; and were discharged from the ED. Outcome measures were rates of OB and contaminant rates.

RESULTS

A total of 8,408 children met all inclusion criteria. There were 21 true-positives, yielding an OB rate of 0.25% (95% confidence interval [CI] = 0.16% to 0.37%). There were 159 contaminant cultures yielding a contaminant rate of 1.89% (95% CI = 1.61% to 2.19%), or a ratio of 7.6 contaminants for each true-positive. There were 14 included patients who grew Streptococcus pneumoniae from the blood, for a rate of 0.17% (95% CI = 0.09% to 0.27%).

CONCLUSIONS

Given the current rate of OB in the post-PCV era, it may no longer be cost-effective to send blood cultures on well-appearing, previously healthy children aged 3 to 36 months who have fever without source.

Epidemiology, etiology, pathogenesis, and diagnosis of recurrent bacterial meningitis

Recurrent bacterial meningitis is a rare phenomenon and generally poses a considerable diagnostic challenge to the clinician. Ultimately, a structured approach and early diagnosis of any underlying pathology are crucial to prevent further episodes and improve the overall outcome for the affected individual. In this article, we are reviewing the existing literature on this topic over the last two decades, encompassing 363 cases of recurrent bacterial meningitis described in 144 publications. Of these cases, 214 (59%) were related to anatomical problems, 132 (36%) were related to immunodeficiencies, and 17 (5%) were related to parameningeal infections. The review includes a detailed discussion of the underlying pathologies and microbiological aspects as well as recommendations for appropriate diagnostic pathways for investigating this unusual entity.

Behaviour is not really at risk after surviving meningitis in childhood

AIM

To examine behaviour problems, personality, self-perceived competence and academic deficits in children who had recovered from non-Haemophilus influenzae type b (Hib) bacterial meningitis (BM) without obvious medical sequelae.

METHODS

Assessments in 182 children, mean age 10 (range 5-14) years, 4-10 years after surviving meningitis, were compared to scores of norm reference groups.

RESULTS

More children were estimated to have academic deficits (27%) than behaviour problems as perceived by the parents (9%). The mean deviation from normal was absent to moderate on behaviour problems, personality variables and self-perceived competence.

CONCLUSION

Children who survived non-Hib BM without severe medical sequelae hardly differ from normal children with respect to personality and self-perceived competence. A small proportion deviates from normal in behaviour problems.

Does cause of deafness influence outcome after cochlear implantation in children?

OBJECTIVES

The objective of this study was to evaluate long-term speech perception abilities of comparable groups of postmeningitic and congenitally deaf children after cochlear implantation.

METHODS

This prospective longitudinal study comprised 46 postmeningitic deaf children and 83 congenitally deaf children with age at implantation of < or = 5.6 years. Both groups were comparable with respect to educational setting and mode of communication and included children with additional disabilities.

RESULTS

Both postmeningitic and congenitally deaf children showed significant progress after implantation. Most (73% and 77%, respectively) could understand conversation without lip-reading or use the telephone with a known speaker 5 years after implantation, whereas none could do so before implantation. At the same interval, the postmeningitic and congenitally deaf children scored a mean open-set speech perception score of 47 (range: 0-91) and 46 (range: 0-107) words per minute, respectively, on connected discourse tracking. The respective mean scores at the 3-year interval were 22 and 29 correct words per minute, respectively. None of these children could score a single correct word per minute before implantation. The progress in both groups was statistically significant. When the 2 groups were compared, there was no statistically significant difference.

CONCLUSION

Postmeningitic and congenitally deaf children showed significant improvement in their auditory receptive abilities at the 3- and 5-year intervals after cochlear implantation. There was no statistically significant difference between the outcomes of the 2 groups, suggesting that, provided that children receive an implant early, cause of deafness has little influence on outcome. Although the prevalence of other disabilities was similar in both groups, for individual children, their presence may have profound impact. The study supports the concept of implantation early in life, irrespective of the cause of deafness.

Sleep disorders are long-term sequelae of both bacterial and viral meningitis

BACKGROUND

Many bacterial meningitis patients experience neurological or neuropsychological sequelae, predominantly deficits in short-term memory, learning, and attention. Neuropsychological symptoms after viral meningitis are observed less frequently. Sleep disturbance has been reported after both viral and bacterial meningitis.

OBJECTIVES

To examine systematically the frequency and extent of sleep disturbance in meningitis patients.

METHODS

Eighty six viral or bacterial meningitis (onset of acute disease at least 1 year previously) patients were examined using two standardised questionnaires (Schlaffragebogen B and the Pittsburgh Sleep Quality Index, PSQI) in conjunction with a standardised neurological examination, and compared to a control group of 42 healthy age-matched volunteers.

RESULTS

Patients after both viral and bacterial meningitis described their sleep as reduced in quality and less restful than that of healthy control subjects; both patient groups had a pathological mean PSQI total score. Impaired sleep scores after meningitis were not correlated to either the Glasgow Coma Scale or the Glasgow Outcome Scale. Moreover, no relationship between residual neurological dysfunction or depressivity and sleep quality was observed.

CONCLUSIONS

Impaired sleep is a long-term consequence of meningitis. Additional, so far undetermined, factors other than the severity of concomitant neurological deficits are responsible for the development of this sequela.

Pneumococcal meningitis in Western Australian children: epidemiology, microbiology and outcome

OBJECTIVES

Pneumococcal meningitis is now vaccine-preventable but continues to cause high rates of neurological sequelae internationally. Population-based epidemiology, outcome and microbiology data are necessary to target vaccination strategies. This study outlines these key areas for Western Australian children diagnosed 1990-2000.

METHODS

The charts of all rural and metropolitan children with International Classification of Disease 9 and 10 discharge codes of pneumococcal or streptococcal meningitis from the Health Department's Hospital Morbidity Data System were reviewed.

RESULTS

Over 10.5 years, 94 episodes were confirmed. The average annual incidence for children under 2 years was 13.45 per 100 000 and 0.66 per 100 000 for children 2 years or older. Indigenous children had an almost seven-fold increased risk compared to non-Indigenous (with 78.55 per 100 000 in the under two-year Indigenous group). Eight children died and 24 of the survivors had neurological sequelae. Penicillin resistance occurred in four of 87 isolates. One quarter of the cohort qualify under the current Australian policy of vaccination of high-risk children with seven-valent conjugate (7vPCV) vaccine. Most isolates (49/58) were 7vPCV serotypes, however, Indigenous populations were less well-covered (58.3% covered vs 91.3% of isolates from non-Indigenous children). Indigenous coverage would be improved to 75% with 11-valent conjugate vaccine.

CONCLUSIONS

Indigenous children and those under 2 years are most affected by pneumococcal meningitis and remain primary vaccination targets. Three quarters of these children would not be protected by a policy of vaccination of only high-risk children with 7vPCV--improved protection requires higher valencies for Indigenous populations and universal infant vaccination.

Pneumococcal meningitis: clinical course and resource use in Western Australian children

OBJECTIVES

Paediatric pneumococcal meningitis causes high rates of neurological sequelae and is presenting challenges due to the emergence of antibiotic resistance. Diagnosis can be difficult and management is frequently complicated and resource intensive. This population-based study outlines the diagnosis, clinical course and initial resource use of Western Australian (WA) children diagnosed between 1990 and 2000.

METHODS

The charts of all rural and metropolitan children discharged from all WA hospitals with International Classification of Disease 9 and 10 codes of pneumococcal or streptococcal meningitis from the Health Department's Hospital Morbidity Data System were reviewed retrospectively.

RESULTS

Ninety-four episodes of pneumococcal meningitis were confirmed (median age 12.4 months). Initial diagnosis was often difficult with a suggestive prodrome in less than one quarter of cases and a median of two reviews until diagnosis (range 1-7). The median duration of hospitalization was 11.6 days, 41.5% were admitted to the Intensive Care Unit (ICU), and 47.9% had seizures. There were eight related deaths and neurological sequelae occurred in 24. Initial hospitalization cost on average $A 19,900. Penicillin resistance was first noted in 1993 and occurred in 4.6% of isolates. Most cases (84.5%) were caused by serotypes contained in the currently available seven-valent conjugate vaccine.

CONCLUSIONS

Pneumococcal meningitis is often difficult to diagnose, necessitates long and frequently complicated in-patient stays and has high rates of neurological sequelae. It is possible to prevent most cases with new conjugate vaccines.

Neuro-cognitive impairment following acquired central nervous system infections in childhood: a systematic review

The morbid consequences of central nervous system (CNS) infections are often overlooked in the face of high mortality rates. However, neurological impairments not only affect the child's development and future prospects but also place an economic and social burden on communities and countries that often have few resources to deal with such problems. We conducted a systematic review to investigate the occurrence and pattern of persisting neurological impairment after common CNS infections. A comprehensive search of MEDLINE, EMBASE and PsycINFO databases, supplemented by hand-searches of key journals, resulted in forty-six eligible studies, five of which gave information on the spectrum of developmental domains. Despite the lack of comprehensive, methodologically-sound studies, the results show that postinfectious neurological impairment persists, most commonly in cognition and motor functions. Deficits include more subtle problems, which can be difficult to detect on gross neurological assessment but may still be deleterious to the child's social and educational functioning. Higher morbidity for similar mortality in acute bacterial meningitis compared with cerebral malaria in the epidemiological data may suggest future research directions for clinical research to devise more effective interventions.

The cost-burden of paediatric pneumococcal disease in the UK and the potential cost-effectiveness of prevention using 7-valent pneumococcal conjugate vaccine

We modelled the epidemiology and cost of pneumococcal disease in children in the UK and the cost-effectiveness of immunisation with 7-valent pneumococcal conjugate vaccine (PCV). We estimated the incidence of pneumococcal meningitis, pneumococcal septicaemia, all-cause pneumonia and all-cause otitis media (OM). We further estimated the impact of vaccination with associated costs and outcomes. Vaccine cost was pound 39.25 per dose with a pound 10 administration cost; vaccination schedule and efficacy were taken from a recent trial. We estimated that in each UK annual birth cohort there are 881,146 episodes of these infections and 149 deaths associated with pneumococcal meningitis, pneumococcal septicaemia or all-cause pneumonia and that PCV would prevent 54,384 episodes and 29 deaths. NHS cost per life year gained was estimated at pound 31,512, close to the limit at which PCV would be considered cost-effective.

Sequelae after bacterial meningitis in childhood

The neurological outcome of bacterial meningitis in children was evaluated retrospectively. Data were obtained from a large study on children aged between 1 month and 15 y who initially visited the emergency department of Sophia Children's Hospital, Rotterdam, The Netherlands with meningeal signs. This study presents data from 103 patients in whom bacterial meningitis was diagnosed. Neisseria meningitidis was the dominant pathogen of meningitis. We found a 2% case-fatality rate in children with bacterial meningitis and a 13% rate of sequelae among survivors: 7% hearing impairment and 7% neurological sequelae. Children with bacterial meningitis caused by Streptococcus pneumoniae and those with acute focal neurological symptoms tended to have the worst prognosis.

Pathogenesis and pathophysiology of pneumococcal meningitis

Until the introduction of antibiotics in the 1930s and 1940s, acute bacterial meningitis was fatal in most cases. Since then it has become curable with a variable mortality and morbidity rate for individual pathogens and patients. Neuropathological and clinical studies have shown that a fatal outcome of the disease is often due to central nervous system (CNS) complications including cerebrovascular involvement, brain oedema formation, and hydrocephalus resulting in increased intracranial pressure and seizure activity. During recent years, experimental studies with animal models have substantially increased our knowledge of the interactions of bacterial pathogens with mammalian cells and their entry into the CNS, and the complex pathophysiological mechanisms of brain dysfunction during acute bacterial meningitis. There is now a substantial body of evidence that cytokines, chemokines, proteolytic enzymes, and oxidants are involved in the inflammatory cascade that leads to tissue destruction in bacterial meningitis. Genetic targeting and/or pharmacological blockade of these pathways was beneficial in experimental bacterial meningitis. Apart from dexamethasone, these treatment strategies hold major promise for the adjunctive therapy of acute bacterial meningitis in clinical practice.

Region-selective effects of neuroinflammation and antioxidant treatment on peripheral benzodiazepine receptors and NMDA receptors in the rat brain

Following induction of acute neuroinflammation by intracisternal injection of endotoxin (lipopolysaccharide) in rats, quantitative autoradiography was used to assess the regional level of microglial activation and glutamate (NMDA) receptor binding. The possible protective action of the antioxidant phenyl-tert-butyl nitrone in this model was tested by administering the drug in the drinking water for 6 days starting 24 hafter endotoxin injection. Animals were killed 7 days post-injection and consecutive cryostat brain sections labeled with [3H]PK11195 as a marker of activated microglia and [125I]iodoMK801 as a marker of the open-channel, activated state of NMDA receptors. Lipopolysaccharide increased [3H]PK11195 binding in the brain, with the largest increases (two- to threefold) in temporal and entorhinal cortex, hippocampus, and substantia innominata. A significant (> 50%) decrease in [125I]iodoMK801 binding was found in the same brain regions. Phenyl-tert-butyl nitrone treatment resulted in a partial inhibition (approx. 25% decrease) of the lipopolysaccharide-induced increase in [3H]PK11195 binding but completely reversed the lipopolysaccharide-induced decrease in [125I]iodoMK80 binding in the entorhinal cortex, hippocampus, and substantia innominata. Loss of NMDA receptor function in cortical and hippocampal regions may contribute to the cognitive deficits observed in diseases with a neuroinflammatory component, such as meningitis or Alzheimer's disease.

Long-term outcomes of childhood meningitis

Meningitis and meningococcal disease remain a major source of anxiety to paediatricians and parents alike. Survival rates have improved with rapid diagnosis and appropriate management. However, survivors remain at risk of long-term neurodevelopmental sequelae.

Management of fever without source in infants and children

Twenty percent of febrile children have fever without an apparent source of infection after history and physical examination. Of these, a small proportion may have an occult bacterial infection, including bacteremia, urinary tract infection (UTI), occult pneumonia, or, rarely, early bacterial meningitis. Febrile infants and young children have, by tradition, been arbitrarily assigned to different management strategies by age group: neonates (birth to 28 days), young infants (29 to 90 days), and older infants and young children (3 to 36 months). Infants younger than 3 months are often managed by using low-risk criteria, such as the Rochester Criteria or Philadelphia Criteria. The purpose of these criteria is to reduce the number of infants hospitalized unnecessarily and to identify infants who may be managed as outpatients by using clinical and laboratory criteria. In children with fever without source (FWS), occult UTIs occur in 3% to 4% of boys younger than 1 year and 8% to 9% of girls younger than 2 years of age. Most UTIs in boys occur in those who are uncircumcised. Occult pneumococcal bacteremia occurs in approximately 3% of children younger than 3 years with FWS with a temperature of 39.0 degrees C (102.2 degrees F) or greater and in approximately 10% of children with FWS with a temperature of 39.5 degrees C (103.1 degrees F) or greater and a WBC count of 15, 000/mm(3) or greater. The risk of a child with occult pneumococcal bacteremia later having meningitis is approximately 3%. The new conjugate pneumococcal vaccine (7 serogroups) has an efficacy of 90% for reducing invasive infections of Streptococcus pneumoniae. The widespread use of this vaccine will make the use of WBC counts and blood cultures and empiric antibiotic treatment of children with FWS who have received this vaccine obsolete.

Predicting the outcome of neonatal bacterial meningitis

OBJECTIVE

To build predictive models of severe adverse outcome at various times in the course of neonatal bacterial meningitis.

STUDY DESIGN

Retrospective cohort study with follow-up to a minimum age of 1 year of term and near-term infants, admitted between 1979 and 1998 to a regional tertiary care center. Predictors of adverse outcome detectable at 1 year of age (death or moderate or severe neurosensory impairment) were identified by univariate analysis. Independent predictors of adverse outcome were identified by multivariate analysis. Predictive tree models were constructed at 12, 24, 48, and 96 hours after admission and at discharge.

RESULTS

Of 101 infants admitted with definitive bacterial meningitis, 13 died and 17 had moderate or severe disability at 1 year of age. Outcomes are known for all patients, to 1 year of age. Twelve hours after admission the important predictors of adverse outcome were presence of seizures, presence of coma, use of inotropes, and leukopenia (sensitivity: 68%; specificity: 100%). At 96 hours the predictors were seizure duration of >72 hours, presence of coma, use of inotropes, and leukopenia (sensitivity: 88%; specificity: 99%).

CONCLUSIONS

Most infants at risk for adverse outcome can be identified within 12 hours of admission. Duration of seizures for >72 hours, presence of coma, use of inotropes, and leukopenia were the most important predictors of adverse outcome. Although these models have good predictive accuracy, they need to be validated in a contemporary cohort in large multicenter studies.

Matrix metalloproteinase (MMP)-8 and MMP-9 in cerebrospinal fluid during bacterial meningitis: association with blood-brain barrier damage and neurological sequelae

To evaluate the spectrum and regulation of matrix metalloproteinases (MMPs) in bacterial meningitis (BM), concentrations of MMP-2, MMP-3, MMP-8, and MMP-9 and endogenous inhibitors of metalloproteinases (TIMP-1 and TIMP-2) were measured in the cerebrospinal fluid (CSF) of 27 children with BM. MMP-8 and MMP-9 were detected in 91% and 97%, respectively, of CSF specimens from patients but were not detected in control patients. CSF levels of MMP-9 were higher (P<.05) in 5 patients who developed hearing impairment or secondary epilepsy than in those who recovered without neurological deficits. Levels of MMP-9 correlated with concentrations of TIMP-1 (P<.001) and tumor necrosis factor-alpha (P=.03). Repeated lumbar punctures showed that levels of MMP-8 and MMP-9 were regulated independently and did not correlate with the CSF cell count. Therefore, MMPs may derive not only from granulocytes infiltrating the CSF space but also from parenchymal cells of the meninges and brain. High concentrations of MMP-9 are a risk factor for the development of postmeningitidal neurological sequelae.

Matrix metalloproteinases contribute to brain damage in experimental pneumococcal meningitis

The present study was performed to evaluate the role of matrix metalloproteinases (MMP) in the pathogenesis of the inflammatory reaction and the development of neuronal injury in a rat model of bacterial meningitis. mRNA encoding specific MMPs (MMP-3, MMP-7, MMP-8, and MMP-9) and the inflammatory cytokine tumor necrosis factor alpha (TNF-alpha) were significantly (P < 0.04) upregulated, compared to the beta-actin housekeeping gene, in cortical homogenates at 20 h after infection. In parallel, concentrations of MMP-9 and TNF-alpha in cerebrospinal fluid (CSF) were significantly increased in rats with bacterial meningitis compared to uninfected animals (P = 0.002) and showed a close correlation (r = 0.76; P < 0. 001). Treatment with a hydroxamic acid-type MMP inhibitor (GM6001; 65 mg/kg intraperitoneally every 12 h) beginning at the time of infection significantly lowered the MMP-9 (P < 0.02) and TNF-alpha (P < 0.02) levels in CSF. Histopathology at 25.5 +/- 5.7 h after infection showed neuronal injury (median [range], 3.5% [0 to 17.5%] of the cortex), which was significantly (P < 0.01) reduced to 0% (0 to 10.8%) by GM6001. This is the first report to demonstrate that MMPs contribute to the development of neuronal injury in bacterial meningitis and that inhibition of MMPs may be an effective approach to prevent brain damage as a consequence of the disease.