Legacy of bacterial meningitis in infancy. Many children continue to suffer functionally important deficits

The diagnostic value of metagenomic next-generation sequencing for identifying Streptococcus pneumoniae in paediatric bacterial meningitis

BACKGROUND

There is currently no research on the diagnostic value of metagenomic next-generation sequencing (mNGS) for a single pathogens in CSF. The aim of this study was to analyse the value of mNGS for identifying Streptococcus pneumoniae (S. pneumoniae) in paediatric bacterial meningitis.

METHODS

Bacterial meningitis (BM) cases from October 23, 2014, to December 31, 2016, and December 1, 2017, to July 31, 2018 at Beijing Children's Hospital were reviewed. Clinical features and pathogens were analysed.

RESULTS

We diagnosed 135 patients with BM in this study. A total of 43 S. pneumoniae were identified by combination methods. 26/135 (19.3%) patients had positive results in S. pneumoniae by blood and/or cerebrospinal fluid (CSF) culture. Alere BinaxNow®Streptococcus pneumoniae Antigen test was positive in 35/135(25.9%) cases. 32/135 (23.7%) S. pneumoniae were identified by mNGS. Six CSF samples were identified as S. pneumoniae only by mNGS technology. Taking culture as the gold standard, the sensitivity and specificity of mNGS for diagnosing S. pneumoniae meningitis were 73.1 and 88.1%, respectively. The positive predictive value (PPV) and negative predictive value (NPV) of diagnosing S. pneumoniae meningitis by mNGS were 59.4 and 93.2%, respectively. When comparison between mNGS and combined tests (culture and Alere BinaxNow®Streptococcus pneumoniae Antigen test), the sensitivity and specificity of mNGS for S. pneumoniae identification were 70.3 and 93.9%, the PPV and NPV in the identification of S. pneumoniae by mNGS were 81.4 and 89.3%, respectively. The difference in number of unique reads of S. pneumoniaein from CSF sample (< 14 days onset) and CSF sample (> 14 days from onset) was statistically significant (170.5 VS. 13, P = 0.019). The difference in the collected time of CSF for culture and mNGS was statistically significant (4 days VS. 14 days, P < 0.001).

CONCLUSIONS

mNGS has high sensitivity and specificity for S. pneumoniae identification. The pathogen load (number of unique reads) of S. pneumonia is related to the CSF collection time. mNGS was less affected than culture by the use of antibiotics before CSF collection.

Correlation between CD64 and PCT levels in cerebrospinal fluid and degree of hearing impairment sequelae in neonates with purulent meningitis

This study investigated the possible correlation between the degree of hearing impairment caused by neonatal purulent meningitis and the levels of CD64 and PCT in cerebrospinal fluid of patients, and assessed the prognostic value of such levels. We recorded data from 156 cases of neonatal purulent meningitis retrospectively. All the patients received brainstem response audiometry, and cerebrospinal fluid samples were collected within the first day after admission through lumbar puncture. Flow cytometry was used to detect CD64 levels and enzyme-linked fluorescent assay was used to detect PCT levels. The children with hearing impairment were followed up for 1 year and brainstem response audiometry was performed again in them. We found that 43.59% of the children showed different degrees of hearing impairment, and 55% of them did not fully recover. The levels of PCT and CD64 in cerebrospinal fluid of children with hearing impairment were significantly higher than those of children with normal hearing (P<0.01). The levels of PCT and CD64 in mild, moderate and severe hearing impaired children increased gradually with higher degrees of impairment, and the differences between groups were significant (P<0.01). During the follow-up, it was found that the levels of PCT and CD64 in children correlated well with the degree of hearing recovery, and the differences between groups were significant (P<0.01). In our study, approximately 1/4 children with purulent meningitis showed long-term hearing impairment. Based on our analyses, the levels of CD64 and PCT in cerebrospinal fluid can be used to predict the degree and long-term prognosis of hearing impairment caused by purulent meningitis in children.

Clinical analysis on 430 cases of infantile purulent meningitis

Background

Purulent meningitis (PM) usually caused by a variety of pyogenic infection, is a kind of central nervous system infectious disease mostly common in children. It is easily misdiagnosed and its symptoms are varied. Excessive application of broad-spectrum antibiotics results in increased sickness and death of infants and young children. In this study, clinical data of 430 cases of PM in infants were analyzed to summarize the clinical experiences so as to achieve early diagnosis and early treatment of PM.

Results

Male-to-female ratio was 1.61:1, and the median age of incidence was 0.42 years. May was the modal month of onset (11.7%). Main clinical manifestations were fever (89.3%), vomiting (67.2%), mental fatigue (62.1%), anterior fontanelle full/bulging/high tension (54.2%), convulsion (52.6%), and meningeal irritation sign (24.7%). Cerebrospinal fluid (CSF) bacterial culture was done for 420 cases, of which 1.2% cases were positive. Blood culture was done for 146 cases of which 15.1% were positive. 175 (40.7%) cases had complications, among which 133 cases (76.0%) were subdural effusion, 21 cases (12.0%) were epilepsy.

Conclusion

Infantile PM is common in Spring, and May is the modal month of onset. The CSF/blood pathogen detection rate is very low and it is difficult to find evidence of cause. Fever, vomiting, mental fatigue and anterior fontanelle full/bulging/high tension, convulsion are the main clinical manifestations on which diagnosis depends. For those children diagnosed as PM and still having recurrent fever and prominent anterior fontanelle after treatment, clinicians should consider the probability of subdural effusion and treat them with brain imaging test on time.

Brain magnetic resonance imaging of infants with bacterial meningitis

OBJECTIVES

To describe the results of brain magnetic resonance imaging (MRI) of infants with bacterial meningitis and how the findings affected clinical management.

STUDY DESIGN

This retrospective study included all infants <12 months of age who were hospitalized at Children's Medical Center, Dallas and had culture-confirmed bacterial meningitis and a brain MRI from January 1, 2001 to December 1, 2011. Infants were identified by review of all positive bacterial cultures of cerebrospinal fluid (CSF) from the Children's Medical Center Microbiology Laboratory. Demographic, clinical, laboratory, and neuroimaging data were reviewed. Infants with ventriculoperitoneal shunt or whose CSF culture yielded skin commensals were excluded. A neuroradiologist blinded to clinical information reviewed all MRI studies.

RESULTS

Of the 440 infants who had a positive CSF culture result, 111 (25%) had a pathogen isolated from CSF and were enrolled in the study. Of these, 68% (75/111) had a brain MRI performed during the hospitalization; abnormalities included leptomeningeal enhancement (57%), cerebral infarct (43%), subdural empyema (52%), cerebritis (26%), hydrocephalus (20%), and abscess (11%). By multiple logistic regression analysis, infants with late seizures and an abnormal neurologic examination were more likely to have an abnormal MRI (P < .05). MRI results led to neurosurgical intervention in 23% of infants; a positive bacterial culture of CSF obtained >48 hours after initiation of antibiotic therapy was associated with neurosurgical intervention (P = .01). Fourteen (19%) infants with bacterial meningitis had a normal brain MRI.

CONCLUSIONS

Brain MRIs were performed frequently and often were abnormal in infants with bacterial meningitis, leading to changes in clinical management.

Protein conjugate polysaccharide vaccines: challenges in development and global implementation

Pneumonia and meningitis caused by Haemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis are among the leading causes of under five mortality and morbidity. Polysaccharide vaccines to prevent these infections are available since 1980s, but these are not effective in infants and children who are the common targets; therefore, protein conjugated were developed. The aim of this article is to understand the need for peumococcal protein conjugate vaccines, the challenges related to their development and global implementation, and the impact of these vaccines on global child health. Challenges in development of new vaccines are as follows:While pneumonia is a major threat in developing countries, available vaccine 7-valent pneumococcal conjugate vaccine (PCV7) protects against only 30% of invasive disease.Serogroup B of Neisseria meningitidis causes 32% of the cases in the USA and 45-80% or more in Europe. Due to similarity of its capsular polysaccharide with the cell surface glycoprotein on fetal brain tissue, developing a vaccine against this bacterium remains a challenge.Challenges in implementation are as follows:Replacement by nonvaccine serotypes;capsule switching;time duration of the antibody protective effect following vaccination;costs of the vaccines, programme costs, lack of knowledge of the disease burden, and targeting population groups for vaccination.

Bacterial meningitis in children and adolescents: an observational study based on the national surveillance system

Background

Bacterial meningitis is a group of life threatening infections that mostly affect children and adolescents, and may be the cause of severe neurological sequelae. Cuba has implemented massive vaccination programmes against both Neisseria meningitidis (serogroup C in 1979 and B in 1987), and Haemophilus influenzae type b (1999), two of the main causal pathogens. We described and discussed some epidemiological aspects of the current status of bacterial meningitis to learn from the Cuban experience.

Methods

A nationwide observational study on children and adolescents from 1 to 18 years old was carried out from 1998 to 2003, estimating the incidence and case-fatality rate by age group and causal pathogens, as well as the seasonality and frequency of overcrowded dormitories. The association between disease and attendance to day care centres or boarding schools was estimated by using relative risk (Chi-squared test and Fisher Exact Test).

Results

The overall number of cases was 1023; the incidence ranged from 3.4 to 8.5 per 100 000 population, with the higher figures in children 1–5 years old (16.8 per 100 000 population). Streptococcus pneumoniae, Haemophilus influenzae type b and Neisseria meningitidis serogroup B were the main identified agents. The average case-fatality rate was 10.5% and the most lethal agents were Streptococcus pneumoniae (27%) and Haemophilus influenzae type b (10.7%). Overall percentage of cases who slept in overcrowded dormitories was 15%, reaching 30.6% in adolescents. Seasonality was only evident among meningococcal meningitis cases between September–October. The attendance to boarding high school showed an association with disease only in 1998 and 1999 (RR = 2.1; p > 0.05).

Conclusion

The highest incidence of bacterial meningitis was observed among children from 1–5 years old. Pneumococcus was both the leading causal and the most lethal agent. Sleeping in overcrowded dormitories was more frequent among adolescents. No strong association was observed between the bacterial meningitis and attendance to day care centres or boarding schools. The incidence of bacterial meningitis in Cuba is declining after massive vaccination programmes against Neisseria meningitidis serogroup B and C and Haemophilus influenzae type b through a national immunisation program.

[The use of magnetic resonance and MR angiography in the detection of cerebral infarction--a complication of pediatric bacterial meningitis]

BACKGROUND

Association of both cerebral infarction and acute bacterial meningitis is more common in younger patients than in the elderly. The rate of mortality and the frequency of sequela are very high inspite of the use of modern antibiotic therapy. In more than 30% of the cases of childhood bacterial meningitis, both arterial and venous infarctions can occur. The aim of this study was to present the role of the use of magnetic resonance (MRI), and MR angiography (MRA) in the detection of bacterial meningitis in children complicated with cerebral infarctions.

METHOD

In the Centre for MR, the Clinical Centre of Serbia, 25 patients with the diagnosis of bacterial meningitis, of which 9 children with cerebral infarction whose clinical condition deteriorated acutely, despite the antibiotic therapy, underwent MRI and MR angiography examination on a 1T scanner. Examination included the conventional spin-echo techniques with T1-weighted saggital and coronal, and T2- weighted axial and coronal images. Coronal fluid attenuated inversion recovery (FLAIR) and the postcontrast T1-weighted images in three orthogonal planes were also used. The use MR angiography was accomplished by the three-dimensional time-of-flight (3D TOF) technique.

RESULTS

The findings included: multiple hemorrhagic infarction in 4 patients, multiple infarctions in 3 patients, focal infarction in 1 patient and diffuse infarction (1 patient). Common sites of involvement were: the frontal lobes, temporal lobes and basal ganglia. The majority of infarctions were bilateral. In 3 of the patients empyema was found, and in 1 patient bitemporal abscess was detected. In 8 of the patients MR angiography confirmed inflammatory vasculitis.

CONCLUSION

Infarction is the most common sequela of severe meningitis in children. Since the complication of cerebral infarction influences the prognosis of meningitis, repetitive MRI examinations are very significant for the evaluation of the time course of vascular involvement. The use of MRI, especially FLAIR imaging, confirmed its value in the detection and determination of the site and the extent of cerebral infarction. Non-invasive technique of examination, 3D TOF MR angiography clearly shoud show the presence of inflammatory vasculitis.

Diffusion-weighted imaging in acute bacterial meningitis in infancy

Bacterial meningitis is frequently fatal or leads to severe neurological impairment. Complications such as vasculitis, resulting in infarcts, should be anticipated and dealt with promptly. Our aim was to demonstrate the complications of meningitis by diffusion weighted imaging (DWI) in patients who deteriorated despite therapy. We studied 13 infants between the ages of 1 day and 32 months who presented with symptoms ranging from fever and vomiting to seizures, encephalopathy and coma due to bacterial meningitis, performing MRI, including DWI, 2-5 days after presentation. Multiple infarcts were found on DWI in 12 of the 13, most commonly in the frontal lobes (in 10). Global involvement was seen in four children, three of whom died; the fourth had a very poor outcome. In one case abnormalities on DWI were due to subdural empyemas. We diagnosed vasculitis in three of five patients studied with MRA. We think DWI an important part of an MRI study in infants with meningitis. Small cortical or deep white-matter infarcts due to septic vasculitis can lead to tissue damage not easily recognized on routine imaging and DWI can be used to confirm that extra-axial collections represent empyemas.