Diagnosis and management of bacterial meningitis in the paediatric population: a review

Pneumolysin contributes to dysfunction of nasal epithelial barrier for promotion of pneumococcal dissemination into brain tissue

Streptococcus pneumoniae is one of the major pathogens responsible for bacterial meningitis and neurological sequelae. The present study was conducted to identify a non-hematogenous route used by S. pneumoniae to gain access to brain tissue without causing bacteremia or pneumonia, as well as bacterial and host factors involved in this process. To investigate the molecular mechanisms and dissemination pathways of pneumococcal infection in brain tissue, mice were intranasally inoculated with S. pneumoniae strain EF3030, a clinical isolate from a patient with otitis media. Pneumococci were isolated from the frontal olfactory bulb, caudal cerebrum, and cerebellum, with neither bacteremia nor pneumonia observed in the present model. Immunostaining imaging revealed the presence of S. pneumoniae organisms in olfactory nerve fibers. Knockout of the ply gene encoding pneumolysin (PLY) markedly compromised the ability of the bacterial organisms to disseminate into brain tissue, whereas the dissemination efficiency of the complemented strain was restored to nearly the same level as the wild type. Notably, distinct upregulation of Gli1 and Snail1, which are involved in the transcriptional repression of junctional proteins, along with downregulation of E-cadherin, was detected in nasal lavage samples from mice infected with the wild-type or complemented strain, but not in those from mice infected with the ply mutant. Taken together, the present findings indicate that PLY induces Gli1-Snail1-dependent dysfunction of the nasal epithelial barrier, thus allowing pneumococcal dissemination to brain tissue that occurs in a non-hematogenous manner.IMPORTANCEBacterial meningitis, considered to be caused by bacteremia, can lead to blood-brain barrier disruption and bacterial dissemination into the central nervous system. Despite the availability of intravenously administered antibiotics with cerebrospinal fluid transferability, bacterial meningitis remains associated with high rates of morbidity and mortality. Here, we utilized Streptococcus pneumoniae strain EF3030, clinically isolated from otitis media, for the construction of a murine infection model to investigate the molecular mechanisms by which nasally colonized pneumococci disseminate into brain tissue. The obtained findings indicate that pneumolysin (PLY) induces Gli1-Snail1-dependent dysfunction of the nasal epithelial barrier, which facilitates pneumococcal dissemination to brain tissue in a non-hematogenous manner. Our results support the existence of an alternative route by which S. pneumoniae can reach the central nervous system and indicate the need for the development of novel therapeutic strategies, which would be an important contribution to the clinical management of bacterial meningitis.

Application of cell-free plasma next-generation sequencing technology in the diagnosis and management of pediatric meningitis

This retrospective study evaluates the clinical utility of CFPNGS in the diagnosis and management of pediatric meningitis. CFPNGS identified a causative pathogen in 36% of 28 subjects, compared to 50% for diverse conventional testing (57% combined). CFPNGS may be considered as an adjunct to standard testing.

Subdural Empyema in Pediatric Bacterial Meningitis: A Case Report

Bacterial meningitis in pediatric populations presents a formidable challenge, necessitating careful evaluation and swift intervention. The clinical spectrum of pediatric bacterial meningitis requires a clear understanding, considering its diverse presentations, risk factors, and evolving diagnostic and therapeutic approaches. We present the case of an eight-year-old male who presented with an acute onset of fever, severe headache, and vomiting following an upper respiratory tract infection. A physical examination revealed meningeal irritation signs, altered consciousness, and focal seizures. Laboratory results showed elevated inflammatory markers, and cerebrospinal fluid analysis indicated abnormalities. Initial imaging displayed sinus involvement, but the patient's condition deteriorated. Subsequent magnetic resonance imaging revealed subdural empyema and meningoencephalitis. Streptococcus pneumoniae was identified as the causative agent. Subsequently, tailored antibiotic therapy and urgent neurosurgical interventions were initiated. The patient recovered with the resolution of neurological deficits. This case underscores the complexity of pediatric bacterial meningitis and its potential complications, emphasizing the relationship between upper respiratory tract infections, sinus involvement, and meningitis development. A multidisciplinary approach, combining targeted antimicrobial therapy with neurosurgical intervention, proved crucial for optimal management and favorable outcomes. This detailed case report highlights the importance of early diagnosis and comprehensive management in pediatric bacterial meningitis cases.

Predictive signs and symptoms of bacterial meningitis isolates in Northern Ghana

Cerebrospinal meningitis (CSM) is a public health burden in Ghana that causes up to 10% mortality in confirmed cases annually. About 20% of those who survive the infection suffer permanent sequelae. The study sought to understand the predictive signs and symptoms of bacterial meningitis implicated in its outcomes. Retrospective data from the Public Health Division, Ghana Health Service on bacterial meningitis from 2015 to 2019 was used for this study. A pre-tested data extraction form was used to collect patients' information from case-based forms kept at the Disease Control Unit from 2015 to 2019. Data were transcribed from the case-based forms into a pre-designed Microsoft Excel template. The data was cleaned and imported into SPSS version 26 for analysis. Between 2015 and 2019, a total of 2446 suspected bacterial meningitis cases were included in the study. Out of these, 842 (34.4%) were confirmed. Among the confirmed cases, males constituted majority with 55.3% of the cases. Children below 14 years of age were most affected (51.4%). The pathogens commonly responsible for bacterial meningitis were Neisseria meningitidis (43.7%) and Streptococcus pneumoniae (53.0%) with their respective strains Nm W135 (36.7%), Nm X (5.1%), Spn St. 1 (26.2%), and Spn St. 12F/12A/12B/44/4 (5.3%) accounting for more than 70.0% of the confirmed cases. The presence of neck stiffness (AOR = 1.244; C.I 1.026-1.508), convulsion (AOR = 1.338; C.I 1.083-1.652), altered consciousness (AOR = 1.516; C.I 1.225-1.876), and abdominal pains (AOR = 1.404; C.I 1.011-1.949) or any of these signs and symptoms poses a higher risk for testing positive for bacterial meningitis adjusting for age. Patients presenting one and/or more of these signs and symptoms (neck stiffness, convulsion, altered consciousness, and abdominal pain) have a higher risk of testing positive for bacterial meningitis after statistically adjusting for age.

Risk Factors for Severe Outcomes in Bacterial Meningitis

Objectives: This study aimed to define risk factors associated with suppurative complications, short-term sequelae, and death in pediatric patients with bacterial meningitis. Methods: A retrospective cohort study was conducted on children with bacterial meningitis, aged 0 months to 18 years, who were admitted to the Hospital Infantil João Paulo II, reference in infectious diseases, from 2005 to 2018. Results: In 178 cases, meningococcal meningitis was the most prevalent disease form (51%), followed by pneumococcal meningitis (31%) and Haemophilus influenzae type B meningitis (10%). The main clinical findings at admission were fever (93.1%), vomiting (67.9%), drowsiness (47.8%), headache (36.5%), irritability (28.3%), and seizures (26.4%). Suppurative complications were recorded in 19% of the patients. The prevalence of neurological sequelae during hospital discharge was 12.4%. Hearing (41%; n = 9) and cognitive (9%) impairments were prominent among the diagnosed sequelae. Incidences of epileptic crises, vestibular disorders, or hydrocephalus were noted in one case each (4.5%), and 12.4% of the patients died. Conclusions: Streptococcus pneumoniae and H. influenzae type B were associated with the diagnosis of sequelae during hospital discharge, seizures were considered a risk factor for suppurative complications, and gastrointestinal symptoms or signs of clinical severity were associated with death.

Pyrexia in a young infant - is height of fever associated with serious bacterial infection?

BACKGROUND

Febrile infants ≤ 90 days old make up a significant proportion of patients seeking care in the emergency department (ED). These infants are vulnerable to serious bacterial infections (SBIs) and early identification is required to initiate timely investigations and interventions. We aimed to study if height of an infant's temperature on presentation to the ED is associated with SBI.

METHODS

We performed a retrospective chart review on febrile infants ≤ 90 days old presenting to our ED between 31st March 2015 and 28th February 2016. We compared triage temperature of febrile infants with and without SBIs. We presented sensitivity, specificity, positive and negative predictive values (PPV and NPV) of fever thresholds at triage. A multivariable regression was performed to study the association between height of temperature and the presence of SBI, and presented the adjusted odds ratio (aOR) with corresponding 95% confidence intervals (CI).

RESULTS

Among 1057 febrile infants analysed, 207 (19.6%) had a SBI. Mean temperature of infants with a SBI was significantly higher than those without (mean 38.5 °C, standard deviation, SD 0.6 vs. 38.3 °C, SD 0.5, p < 0.005). For temperature ≥ 39 °C, sensitivity, specificity, PPV and NPV for SBI was 15.5% (95%CI 10.8-21.1%), 90.4% (95%CI 88.2-92.3%), 28.1% (95%CI 21.1-36.3%) and 81.4% (95%CI 80.5-82.4%) respectively. The height of fever was consistently associated with SBI after adjusting for age, gender and SIS (aOR 1.76, 95% CI 1.32-2.33, p < 0.001). However, 32 (15.5%) infants with SBIs had an initial triage temperature ≤ 38 °C.

CONCLUSIONS

A higher temperature at triage was associated with a higher risk of SBI among febrile infants ≤ 90 days old. However, height of temperature must be used in conjunction with other risk factors to identify SBIs in young infants.

Delays in Time-To-Antibiotics for Young Febrile Infants With Serious Bacterial Infections: A Prospective Single-Center Study

INTRODUCTION

Fear of missed serious bacterial infections (SBIs) results in many febrile young infants receiving antibiotics. We aimed to compare the time to antibiotics between infants with SBIs and those without.

MATERIALS AND METHODS

We recruited febrile infants ≤ 90 days old seen in the emergency department (ED) between December 2017 and April 2021. SBI was defined as (1) urinary tract infection, (2) bacteremia or (3) bacterial meningitis. We compared the total time (median with interquartile range, IQR) from ED arrival to infusion of antibiotics, divided into (i) time from triage to decision for antibiotics and (ii) time from decision for antibiotics to administration of antibiotics.

RESULTS

We analyzed 81 and 266 infants with and without SBIs. Median age of those with and without SBIs were 44 (IQR 19-72) and 29 (IQR 7-56) days, respectively (p = 0.002). All infants with SBIs and 168/266 (63.2%) infants without SBIs received antibiotics. Among 249 infants who received antibiotics, the median total time from ED arrival to infusion of antibiotics was 277.0 (IQR 236.0-385.0) mins for infants with SBIs and 304.5 (IQR 238.5-404.0) mins for those without (p = 0.561). The median time to decision for antibiotics was 156.0 (IQR 115.0-255.0) mins and 144.0 (IQR 105.5-211.0) mins, respectively (p = 0.175). Following decision for antibiotics, infants with SBIs received antibiotics much faster compared to those without [107.0 (IQR 83.0-168.0) vs. 141.0 (94.0-209.5) mins, p = 0.017].

CONCLUSION

There was no difference in total time taken to antibiotics between infants with SBIs and without SBIs. Both recognition and administration delays were observed. While all infants with SBIs were adequately treated, more than half of the infants without SBIs received unnecessary antibiotics. This highlights the challenge in managing young febrile infants at initial presentation, and demonstrates the need to examine various aspects of care to improve the overall timeliness to antibiotics.

Metagenomic Next-Generation Sequencing for Diagnosis of Pediatric Meningitis and Encephalitis: A Review

Metagenomic next-generation sequencing is a novel diagnostic test with the potential to revolutionize the diagnosis of pediatric meningitis and encephalitis through unbiased detection of bacteria, viruses, parasites, and fungi in cerebrospinal fluid. Current literature is mostly observational with variable indications, populations, and timing of testing with resulting variability in diagnostic yield and clinical impact. Diagnostic stewardship strategies are needed to direct testing toward high-impact pediatric populations, to optimize timing of testing, to ensure appropriate interpretation of results, and to guide prompt optimization of antimicrobials. This review highlights the high clinical potential of this test, though future studies are needed to gather clinical impact and cost-effectiveness data for specific indications in pediatric populations.

Clinical Features and Outcomes of Streptococcus pneumoniae Meningitis in Children: A Retrospective Analysis of 26 Cases in China

BACKGROUND

Streptococcus pneumoniae is an important cause of pediatric meningitis.

OBJECTIVE

The aim of this study was to analyze the clinical features and outcomes of children with pneumococcal meningitis at our hospital in China, so as to provide basis for improving the clinical treatment effect.

METHODS

This retrospective analysis included patients aged <16 years treated for pneumococcal meningitis at the Department of Neurology, Children's Hospital of Shanxi (January 2014-February 2016). Clinical data were extracted from the medical records. Patients were followed up for 6 months after discharge.

RESULTS

The analysis included 26 children aged 2 months to 13 years, with 17 (65.4%) aged <3 years. Presenting symptoms included fever (100%), lethargy (100%), impaired consciousness (88.5%), neck stiffness (69.2%), seizures (53.8%), and headache (50.0%). All patients had positive cerebrospinal fluid (CSF) cultures. The final treatment was vancomycin combined with a third-generation cephalosporin or other antibiotics in 25 patients. Eleven patients (42.3%) were recovered, 3 (11.5%) had neurological sequelae, and 12 (46.2%) died. Impaired consciousness (p = 0.035), cerebral hernia (p = 0.037), respiratory failure (p = 0.004), heart failure (p = 0.044), septic shock (p = 0.037), low CSF white blood cell count (p = 0.036), high CSF protein levels (p = 0.028), low white blood cell count (p = 0.036), and low blood neutrophil ratio (p = 0.016) are associated with a poor prognosis to pneumococcal meningitis.

CONCLUSION

Pneumococcal meningitis is associated with a poor prognosis in many children. Poor prognosis might be related to early ineffective antibiotic therapy, a combination of systemic failure, neurological problems, and changed inflammatory response. It is important to rapid initiation of appropriate antibiotic therapy if meningitis is suspected.

Blood Procalcitonin Level as a Diagnostic Marker of Pediatric Bacterial Meningitis: A Systematic Review and Meta-Analysis

Early diagnosis and treatment of bacterial meningitis in children are essential, due to the high mortality and morbidity rates. However, lumbar puncture is often difficult, and cerebrospinal fluid (CSF) culture takes time. This meta-analysis aims to determine the diagnostic accuracy of blood procalcitonin for detecting bacterial meningitis in children. We conducted a systematic search on electronic databases to identify relevant studies. Pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated, and a hierarchical summary receiver operating characteristic curve and area under the curve (AUC) were determined. Eighteen studies with 1462 children were included in the analysis. The pooled sensitivity, specificity, and the DOR of blood procalcitonin for detecting bacterial meningitis were 0.87 (95% confidence interval (CI): 0.78–0.93); 0.85 (95% CI: 0.75–0.91), and 35.85 (95% CI: 10.68–120.28), respectively. The AUC for blood procalcitonin was 0.921. Blood procalcitonin also showed higher diagnostic accuracy for detecting bacterial meningitis than other conventional biomarkers, including serum C-reactive protein and leukocyte count, CSF leukocyte and neutrophil count, and CSF protein and glucose levels. Blood procalcitonin can be a good supplemental biomarker with high diagnostic accuracy in detecting bacterial meningitis in children.

Point-of-Care Approaches for Meningitis Diagnosis in a Low-Resource Setting (Southwestern Uganda): Observational Cohort Study Protocol of the "PI-POC" Trial

BACKGROUND

A timely differential diagnostic is essential to identify the etiology of central nervous system (CNS) infections in children, in order to facilitate targeted treatment, manage patients, and improve clinical outcome.

OBJECTIVE

The Pediatric Infection-Point-of-Care (PI-POC) trial is investigating novel methods to improve and strengthen the differential diagnostics of suspected childhood CNS infections in low-income health systems such as those in Southwestern Uganda. This will be achieved by evaluating (1) a novel DNA-based diagnostic assay for CNS infections, (2) a commercially available multiplex PCR-based meningitis/encephalitis (ME) panel for clinical use in a facility-limited laboratory setting, (3) proteomics profiling of blood from children with severe CNS infection as compared to outpatient controls with fever yet not severely ill, and (4) Myxovirus resistance protein A (MxA) as a biomarker in blood for viral CNS infection. Further changes in the etiology of childhood CNS infections after the introduction of the pneumococcal conjugate vaccine against Streptococcus pneumoniae will be investigated. In addition, the carriage and invasive rate of Neisseria meningitidis will be recorded and serotyped, and the expression of its major virulence factor (polysaccharide capsule) will be investigated.

METHODS

The PI-POC trial is a prospective observational study of children including newborns up to 12 years of age with clinical features of CNS infection, and age-/sex-matched outpatient controls with fever yet not severely ill. Participants are recruited at 2 Pediatric clinics in Mbarara, Uganda. Cerebrospinal fluid (for cases only), blood, and nasopharyngeal (NP) swabs (for both cases and controls) sampled at both clinics are analyzed at the Epicentre Research Laboratory through gold-standard methods for CNS infection diagnosis (microscopy, biochemistry, and culture) and a commercially available ME panel for multiplex PCR analyses of the cerebrospinal fluid. An additional blood sample from cases is collected on day 3 after admission. After initial clinical analyses in Mbarara, samples will be transported to Stockholm, Sweden for (1) validation analyses of a novel nucleic acid-based POC test, (2) biomarker research, and (3) serotyping and molecular characterization of S. pneumoniae and N. meningitidis.

RESULTS

A pilot study was performed from January to April 2019. The PI-POC trial enrollment of patients begun in April 2019 and will continue until September 2020, to include up to 300 cases and controls. Preliminary results from the PI-POC study are expected by the end of 2020.

CONCLUSIONS

The findings from the PI-POC study can potentially facilitate rapid etiological diagnosis of CNS infections in low-resource settings and allow for novel methods for determination of the severity of CNS infection in such environment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03900091; https://clinicaltrials.gov/ct2/show/NCT03900091.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/21430.

Pathology and Telepathology Methods in the Child Health and Mortality Prevention Surveillance Network

This manuscript describes the Child Health and Mortality Prevention Surveillance (CHAMPS) network approach to pathologic evaluation of minimally invasive tissue sampling (MITS) specimens, including guidelines for histopathologic examination and further diagnostics with special stains, immunohistochemistry, and molecular testing, as performed at the CHAMPS Central Pathology Laboratory (CPL) at the Centers for Disease Control and Prevention, as well as techniques for virtual discussion of these cases (telepathology) with CHAMPS surveillance locations. Based on review of MITS from the early phase of CHAMPS, the CPL has developed standardized histopathology-based algorithms for achieving diagnoses from MITS and telepathology procedures in conjunction with the CHAMPS sites, with the use of whole slide scanners and digital image archives, for maximizing concurrence and knowledge sharing between site and CPL pathologists. These algorithms and procedures, along with lessons learned from initial implementation of these approaches, guide pathologists at the CPL and CHAMPS sites through standardized diagnostics of MITS cases, and allow for productive, real-time case discussions and consultations.

Rapid Diagnosis of Meningococcal Meningitis in a Patient With Familial Mediterranean Fever by the FilmArray Meningitis/Encephalitis Panel: A Case Report

Familial Mediterranean fever (FMF) is a rare autoinflammatory disorder of the innate immune system. Patients with innate immune system defects are at a high risk of meningococcal disease, although it is unclear if patients with FMF also have increased susceptibility to invasive infection. Herein, we present a diagnostically challenging case of a male adolescent with a past medical history of FMF stabilized on colchicine who presented with some of the early clinical features of community-acquired bacterial meningitis. To our knowledge, this is the first case of meningococcal meningitis in a patient with FMF diagnosed with the FilmArray Meningitis/Encephalitis (ME) Panel. This case report demonstrates that rapid detection of Neisseria meningitidis by the ME Panel can aid in the early diagnosis and prompt treatment of patients with suspected meningitis and may be the only positive test in patients with early presentation and/or prior antimicrobial therapy.

Evolution of Different Bacterial Mningoencephalitis: Series of Case Presentations and Literature Review

Bacterial meningitis is one of the most important medical emergencies, a life-threatening condition that leads to death in all the cases in untreated patients. In infants and young children, especially under 5 years old, the most encountered and severe forms are caused by Streptococcus pneumoniae, Neisseria meningitidis and Hemophilus influenzae type b. The risk of neurological impairment after an acute episode of bacterial meningitis is relatively high. Worldwide, prevention through vaccination decreased dramatically incidence and mortality related to these disease. In Romania vaccination for Neisseria meningitides is optional available for just 6 months, vaccination for Streptococcus pneumoniae by one year, and for Haemophylus influenzae type B is available over 10 years.

We present evolution of a series of three cases with different bacterial meningoencephalitis with severe evolution and prolonged hospitalization. All these cases were reported in unvaccinated children for germs that cause meningitis.

Comparison of acridine orange fluorescent microscopy and gram stain light microscopy for the rapid detection of bacteria in cerebrospinal fluid

OBJECTIVE

Bacterial meningitis is a life threatening condition that requires prompt recognition and treatment. Currently, Gram stain is widely used for the microscopic detection of bacterial pathogens in cerebrospinal fluid (CSF). In Nepal, fluorescent microscopes have been installed in laboratories as a part of the National tuberculosis control program. However, information on the utility of the acridine orange (AO) stain for the direct detection of bacteria in CSF samples in Nepal is not available. Therefore, this study aims to compare Gram stain and AO stain for the rapid detection of bacterial pathogens in CSF of clinically suspected meningitis cases in Kathmandu, Nepal.

RESULTS

Bacterial pathogens were detected in 9.30% (36/387) by either of the three tests, 9.04% (35/387) by AO stain, 8.27% (32/387) by culture and 6.46% (25/387) by Gram's stain. Considering culture as a gold standard, the sensitivity of AO stain was higher than Gram stain. The specificity of AO stain was 98.87%. Detection and differentiation of the bacteria was much clear in AO staining than Gram staining. AO is a better alternative to Gram stain in the rapid detection of bacterial pathogens in CSF in the setting where fluorescent microscope is available.

Principles of Management of Central Nervous System Infections

CNS infections in children are medical emergency and are associated with high mortality and morbidity. For diagnosis, a high index of suspicion is required. Clinical assessment should be supplemented by laboratory investigations including CSF Gram stain and cultures, blood culture, PCR on CSF, serological tests, and imaging. Commonly associated life threatening complications include coma, seizure, raised intracranial pressure (ICP), focal deficits, shock, respiratory failure, and fluid and electrolyte abnormalities. Immediate management should first address control of airway, breathing and circulation; protocolized management of raised ICP and status epilepticus; maintaining adequate intravascular volume; and close monitoring for early detection of complications. Appropriate antimicrobial agents should be administered promptly according to the suspected pathogen. Clinical evaluation, laboratory workup, specific antimicrobial therapy, supportive treatment, and management of associated complications should go hand in hand in a protocolized way for better outcome.

The Relationship Between Blood Sample Volume and Diagnostic Sensitivity of Blood Culture for Typhoid and Paratyphoid Fever: A Systematic Review and Meta-Analysis

Background

Blood culture is the standard diagnostic method for typhoid and paratyphoid (enteric) fever in surveillance studies and clinical trials, but sensitivity is widely acknowledged to be suboptimal. We conducted a systematic review and meta-analysis to examine sources of heterogeneity across studies and quantified the effect of blood volume.

Methods

We searched the literature to identify all studies that performed blood culture alongside bone marrow culture (a gold standard) to detect cases of enteric fever. We performed a meta-regression analysis to quantify the relationship between blood sample volume and diagnostic sensitivity. Furthermore, we evaluated the impact of patient age, antimicrobial use, and symptom duration on sensitivity.

Results

We estimated blood culture diagnostic sensitivity was 0.59 (95% confidence interval [CI], 0.54-0.64) with significant between-study heterogeneity (I2, 76% [95% CI, 68%-82%]; P < .01). Sensitivity ranged from 0.51 (95% CI, 0.44-0.57) for a 2-mL blood specimen to 0.65 (95% CI, 0.58-0.70) for a 10-mL blood specimen, indicative of a relationship between specimen volume and sensitivity. Subgroup analysis showed significant heterogeneity by patient age and a weak trend towards higher sensitivity among more recent studies. Sensitivity was 34% lower (95% CI, 4%-54%) among patients with prior antimicrobial use and 31% lower after the first week of symptoms (95% CI, 19%-41%). There was no evidence of confounding by patient age, antimicrobial use, symptom duration, or study date on the relationship between specimen volume and sensitivity.

Conclusions

The relationship between the blood sample volume and culture sensitivity should be accounted for in incidence and next-generation diagnostic studies.

Ultrasound diagnosis and therapeutic intervention in the spine

Spine pathology afflicts people across the globe and is responsible for a large portion of physician visits and healthcare costs. Imaging such as plain radiographs, CT, MRI, and ultrasound is vital to assess structure, function, and stability of the spine and also provide guidance in therapeutic interventions. Ultrasound utilization in spine conditions is less ubiquitous, but provides benefits in low costs, portability, and dynamic imaging. This study assesses ultrasound efficacy in diagnosis and therapeutic interventions for spine pathology. A systematic review conducted via PubMed, MEDLINE, and Google Scholar identified 3,630 papers with eventual inclusion of 73 papers with an additional 21 papers supplemental papers subsequently added. Findings highlighted ultrasound utilization for different structural elements of the spine such as muscle, bone, disc, ligament, canal, and joints are presented and compared with radiographs, CT, and MRI imaging where relevant. Spinal curvature and mobility are similarly presented. Ultrasound efficacy for guided therapeutics about the spine is presented and assessed against other modalities. Ultrasound is a widely used and efficacious modality to guide injections about the spine. Diagnostic utility is less well studied, but shows promise in assessing fractures, posterior ligamentous stability, and intra-operative hardware placement. The low cost, portability, and dynamic imaging ability make it an attractive modality particularly for developing health systems and resource limited environments such as combat settings and the International Space Station. Further study is recommended before broad adoption in diagnostics.

Emerging Infections and Pertinent Infections Related to Travel for Patients with Primary Immunodeficiencies

In today's global economy and affordable vacation travel, it is increasingly important that visitors to another country and their physician be familiar with emerging infections, infections unique to a specific geographic region, and risks related to the process of travel. This is never more important than for patients with primary immunodeficiency disorders (PIDD). A recent review addressing common causes of fever in travelers provides important information for the general population Thwaites and Day (N Engl J Med 376:548-560, 2017). This review covers critical infectious and management concerns specifically related to travel for patients with PIDD. This review will discuss the context of the changing landscape of infections, highlight specific infections of concern, and profile distinct infection phenotypes in patients who are immune compromised. The organization of this review will address the environment driving emerging infections and several concerns unique to patients with PIDD. The first section addresses general considerations, the second section profiles specific infections organized according to mechanism of transmission, and the third section focuses on unique phenotypes and unique susceptibilities in patients with PIDDs. This review does not address most parasitic diseases. Reference tables provide easily accessible information on a broader range of infections than is described in the text.

Current meningitis outbreak in Ghana: Historical perspectives and the importance of diagnostics

Bacterial meningitis continues to be one of the most dreaded infections in sub-Saharan Africa and other countries that fall in the "meningitis belt" due to recurrent nature of the infection and the sequel of deliberating effects among survivors even after treatment. Ghana has had recurrent epidemics in the past but has been free from high mortality levels. Whereas reasons for the low reported number of deaths in the past are unclear, we hypothesize that it may be due to increased vaccination from expanded program on immunization (EPI) and consequent herd immunity of the general population. As at the end of February, 2016, 100 individuals were reported to have died out of 500 recorded cases. The infection may cause severe brain damage and kills at least 1 out of 10 individuals if quick interventions are not provided. The Ghana Health Service (GHS) and the Ministry of Health (MoH), together with other local and international stakeholders are working intensely to control the spread of the infection in affected communities with treatment and other health management programmes. This review presents a quick overview of meningitis in Ghana with emphasis on S. pneumoniae (responsible for about 70% of cases in the recent epidemic) together with some recommendations aimed at ensuring a "meningitis-free Ghana".

Free Sialic Acid Acts as a Signal That Promotes Streptococcus pneumoniae Invasion of Nasal Tissue and Nonhematogenous Invasion of the Central Nervous System

Streptococcus pneumoniae (pneumococcus) is a leading cause of bacterial meningitis and neurological sequelae in children worldwide. Acute bacterial meningitis is widely considered to result from bacteremia that leads to blood-brain barrier breakdown and bacterial dissemination throughout the central nervous system (CNS). Previously, we showed that pneumococci can gain access to the CNS through a nonhematogenous route without peripheral blood infection. This access is thought to occur when the pneumococci in the upper sinus follow the olfactory nerves and enter the CNS through the olfactory bulbs. In this study, we determined whether the addition of exogenous sialic acid postcolonization promotes nonhematogenous invasion of the CNS. Previously, others showed that treatment with exogenous sialic acid post-pneumococcal infection increased the numbers of CFU recovered from an intranasal mouse model of infection. Using a pneumococcal colonization model, an in vivo imaging system, and a multiplex assay for cytokine expression, we demonstrated that sialic acid can increase the number of pneumococci recovered from the olfactory bulbs and brains of infected animals. We also show that pneumococci primarily localize to the olfactory bulb, leading to increased expression levels of proinflammatory cytokines and chemokines. These findings provide evidence that sialic acid can enhance the ability of pneumococci to disseminate into the CNS and provide details about the environment needed to establish nonhematogenous pneumococcal meningitis.

Specific detection of common pathogens of acute bacterial meningitis using an internally controlled tetraplex-PCR assay

Accurate and timely diagnosis of acute bacterial meningitis is critical for antimicrobial treatment of patients. Although PCR-based methods have been widely used for the diagnosis of acute meningitis caused by bacterial pathogens, the main disadvantage of these methods is their high cost. This disadvantage has hampered the widespread use of molecular assays in many developing countries. The application of multiplex assays and "in-house" protocols are two main approaches that can reduce the overall cost of a molecular test. In the present study, an internally controlled tetraplex-PCR was developed and validated for the specific detection of Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae in cerebrospinal fluid (CSF) samples. The analysis of a panel of other human pathogens showed no cross-reactivity in the assay. The analytical sensitivity of the in-house assay was 792.3 copies/ml, when all three bacteria were presentin the specimens. This value was calculated as 444.5, 283.7, 127.8 copies/ml when only S. pneumoniae, N. meningitidis and H. influenzae, respectively, were present. To demonstrate the diagnostic performance of the assay, a total of 150 archival CSF samples were tested and compared with a commercial multiplex real-time PCR kit. A diagnostic sensitivity of 92.8% and a specificity of 95.1% were determined for the present tetraplex-PCR assay. The results indicate that the established method is sensitive, specific and cost-effective, and can be used particularly in situations where the high cost of commercial kits prevents the use of molecular methods for the diagnosis of bacterial meningitis.

Trends of pneumococcal meningitis in children after introduction of the 13-valent pneumococcal conjugate vaccine in France

BACKGROUND

Streptococcus pneumoniae remains an important cause of bacterial meningitis in children younger than 2 years. Here, we analyzed data from an active surveillance network established 12 years ago by the Pediatric Infectious Disease Group and the Pediatric Clinical and Therapeutical Association to analyze the impact of pneumococcal conjugate vaccine (PCV7 implemented in 2002 and PCV13 in 2010) on pneumococcal meningitis (PM).

METHODS

Two hundred twenty-seven pediatric wards working with 168 microbiology departments throughout France were asked to report all cases of PM.

RESULTS

From 2001 to 2012, among 4808 bacterial meningitis cases, 1406 cases of PM (29.2%) were reported. After PCV13 implementation, from 2009 to 2012, the number of cases significantly decreased by 27.4% (P = 0.041, Cuzick trend test). For children younger than 2 years, the decrease was 28.2% (P = 0.039, Cuzick trend test). In the same period, the decrease was 66.7% in cases due to 6 additional PCV13 types, and the number of cases due to nonvaccine types remained stable. In 2012, the non-PCV13 serotype represented 67.6% of cases and were mainly represented by 12F (15%), 24F (15%), 22F (7%) and 15B/C (7%). For 88.6% of cases, initial antibiotic treatment was vancomycin with a third-generation cephalosporin. Overall mortality was 10.6%, most deaths (86.4%) occurred before day 15.

CONCLUSIONS

Two years after the PCV13 implementation, we found an impact on PM cases particularly for children younger than 2 years.

Factors associated with ceftriaxone nonsusceptibility of Streptococcus pneumoniae: analysis of South African national surveillance data, 2003 to 2010

It is important to monitor β-lactam antimicrobial nonsusceptibility trends for Streptococcus pneumoniae to inform empirical treatment guidelines. In this study, we describe penicillin and ceftriaxone susceptibility trends using national laboratory-based pneumococcal surveillance data from 2003 to 2010. A sentinel enhanced-site patient subset (2009 to 2010) contributed to the risk factor and mortality analyses. We included 9,218 invasive pneumococcal disease (IPD) cases for trend analyses and 2,854 IPD cases for risk factor and mortality analyses. Overall, we detected no significant changes in penicillin (patients <5 years of age, P = 0.50; patients ≥ 5 years of age, P = 0.05) or ceftriaxone nonsusceptibility rates (patients <5 years of age, P = 0.21; patients ≥ 5 years of age, P = 0.60). Factors associated with ceftriaxone nonsusceptibility on multivariate analysis were an age of <5 years (<1 year of age: adjusted odds ratio [aOR], 2.87; 95% confidence interval [CI], 1.70 to 4.86; 1 to 4 years of age: aOR, 2.58; 95% CI, 1.53 to 4.35, versus 25 to 44 years of age), province (Gauteng [aOR, 2.46; 95% CI, 1.26 to 4.84], and Northern Cape [aOR, 4.52; 95% CI, 1.95 to 10.52] versus KwaZulu-Natal), β-lactam use within 24 h preceding admission (aOR, 2.52; 95% CI, 1.41 to 4.53), and 13-valent vaccine serotypes (aOR, 51.64; 95% CI, 7.18 to 371.71). Among patients ≥ 5 years of age with meningitis who were treated according to current guidelines, HIV-infected patients (aOR, 2.94; 95% CI, 1.32 to 6.54) and patients infected with ceftriaxone-nonsusceptible isolates (aOR, 3.17; 95% CI, 1.27 to 7.89) had increased mortality rates. Among children <5 years of age with meningitis, mortality was increased in HIV-infected patients (aOR, 3.04; 95% CI, 1.40 to 6.56) but not in those with ceftriaxone-nonsusceptible isolates. Penicillin and ceftriaxone nonsusceptibility remained stable over the study period. Ceftriaxone nonsusceptibility was associated with increased mortality among patients ≥5 years of age with meningitis. The introduction of a pneumococcal conjugate vaccine may reduce ceftriaxone-nonsusceptible meningitis.