Suspected Central Nervous System Infection Research Articles

Seven-year performance of a clinical metagenomic next-generation sequencing test for diagnosis of central nervous system infections.

Metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) is an agnostic method for broad-based diagnosis of central nervous system (CNS) infections. Here we analyzed the 7-year performance of clinical CSF mNGS testing of 4,828 samples from June 2016 to April 2023 performed by the University of California, San Francisco (UCSF) clinical microbiology laboratory. Overall, mNGS testing detected 797 organisms from 697 (14.4%) of 4,828 samples, consisting of 363 (45.5%) DNA viruses, 211 (26.4%) RNA viruses, 132 (16.6%) bacteria, 68 (8.5%) fungi and 23 (2.9%) parasites. We also extracted clinical and laboratory metadata from a subset of the samples (n = 1,164) from 1,053 UCSF patients. Among the 220 infectious diagnoses in this subset, 48 (21.8%) were identified by mNGS alone. The sensitivity, specificity and accuracy of mNGS testing for CNS infections were 63.1%, 99.6% and 92.9%, respectively. mNGS testing exhibited higher sensitivity (63.1%) than indirect serologic testing (28.8%) and direct detection testing from both CSF (45.9%) and non-CSF (15.0%) samples (P < 0.001 for all three comparisons). When only considering diagnoses made by CSF direct detection testing, the sensitivity of mNGS testing increased to 86%. These results justify the routine use of diagnostic mNGS testing for hospitalized patients with suspected CNS infection.

Epidemiological Characteristics of Neuro-Specific Antibodies Following Viral Infections.

This study aims to explore the epidemiological characteristics of neuro-specific antibodies (ns-Ab) induced by different viral infections within the central nervous system (CNS). Additionally, it seeks to compare the autoimmune effects following several typical viral infections in CNS. We conduct a retrospective study to compare and analyze the prevalence trends of ns-Ab in patients with different viral infections. Additionally, evaluate the intensity of CNS inflammatory responses postviral infection by correlating clinical characteristics and laboratory findings, and briefly demonstrate the immune effects in CNS following various viral infections. This study retrospectively collected data from 1037 patients hospitalized with suspected CNS infections. A total of 654 patients (63.1%) were included in the final analysis. A higher proportion of patients with pathogens present in their cerebrospinal fluid (CSF) (114 out of 332, 34.3%) tested positive for ns-Ab compared to those without pathogens (70 out of 322, 21.7%) (p = 0.0004). Specifically, the screening rate for ns-Ab in patients with CNS viral infections (83 out of 165, 50.3%) and the prevalence of ns-Ab (27 out of 83, 32.5%) were significantly higher than in those with other pathogen infections (p < 0.0001 and p = 0.016, respectively). Among these, human herpesvirus 7 (HHV7) patients had the highest detection rate of ns-Ab during the disease course (11 out of 26, 42.3%), but exhibited infection characteristics distinctly different from those of herpes simplex virus 1 (HSV1). Viral infections significantly promote the development of autoimmune responses in CNS. The production of ns-Ab and the subsequent autoimmune response vary across different viral infections. There is a strong statistical correlation between HHV7 and the presence of ns-Ab, suggesting that HHV7 may serve as an early indicator of secondary autoimmune response following CNS infections.

Computed Tomography of the Head Before Lumbar Puncture in Adults With Suspected Meningitis in High-HIV Prevalence Settings.

The role of computed tomography (CT) before lumbar puncture (LP) is unclear, with limited evidence for a causal link between LP and cerebral herniation or for the ability of CT to identify individuals at risk of herniation. The risks of LP delay or deferral are potentially greater in high-HIV prevalence, resource-limited settings; we analyzed data from such a setting to determine the impact of CT on time to LP and treatment, as well as mortality. Adults with suspected central nervous system (CNS) infection were enrolled prospectively into the Botswana National Meningitis Survey between 2016 and 2019. Inpatient mortality and clinical data including time of treatment initiation and CT were captured from medical records. Associations between preceding CT and outcomes were assessed using logistic regression. LPs were performed in 711 patients with suspected CNS infection; 27% had a CT before LP, and 73% were HIV positive. Time from admission to LP and time from admission to appropriate treatment were significantly longer in patients who had a CT before LP compared with those who did not (2.8 hours and 13.2 hours, respectively). There was some evidence for treatment delays being associated with increased mortality; however, there was no significant difference in mortality between those who had or did not have CT. Patients who had a CT had delays to diagnostic LP and initiation of appropriate treatment; although treatment delays were associated with increased mortality, our observational study could not demonstrate a causal association between delays in diagnosis and treatment introduced by CT and mortality.

Diagnostic prediction models for bacterial meningitis in children with a suspected central nervous system infection: a systematic review and prospective validation study

ObjectivesDiagnostic prediction models exist to assess the probability of bacterial meningitis (BM) in paediatric patients with suspected meningitis. To evaluate the diagnostic accuracy of these models in a broad population...

Clinical Metagenomic Next-Generation Sequencing for Diagnosis of Central Nervous System Infections: Advances and Challenges.

Central nervous system (CNS) infections carry a substantial burden of morbidity and mortality worldwide, and accurate and timely diagnosis is required to optimize management. Metagenomic next-generation sequencing (mNGS) has proven to be a valuable tool in detecting pathogens in patients with suspected CNS infection. By sequencing microbial nucleic acids present in a patient's cerebrospinal fluid, brain tissue, or samples collected outside of the CNS, such as plasma, mNGS can detect a wide range of pathogens, including rare, unexpected, and/or fastidious organisms. Furthermore, its target-agnostic approach allows for the identification of both known and novel pathogens. This is particularly useful in cases where conventional diagnostic methods fail to provide an answer. In addition, mNGS can detect multiple microorganisms simultaneously, which is crucial in cases of mixed infections without a clear predominant pathogen. Overall, clinical mNGS testing can help expedite the diagnostic process for CNS infections, guide appropriate management decisions, and ultimately improve clinical outcomes. However, there are key challenges surrounding its use that need to be considered to fully leverage its clinical impact. For example, only a few specialized laboratories offer clinical mNGS due to the complexity of both the laboratory methods and analysis pipelines. Clinicians interpreting mNGS results must be aware of both false negatives-as mNGS is a direct detection modality and requires a sufficient amount of microbial nucleic acid to be present in the sample tested-and false positives-as mNGS detects environmental microbes and their nucleic acids, despite best practices to minimize contamination. Additionally, current costs and turnaround times limit broader implementation of clinical mNGS. Finally, there is uncertainty regarding the best practices for clinical utilization of mNGS, and further work is needed to define the optimal patient population(s), syndrome(s), and time of testing to implement clinical mNGS.

Microbiomes detected by cerebrospinal fluid metagenomic next-generation sequencing among patients with and without HIV with suspected central nervous system infection.

Opportunistic infections in the central nervous system (CNS) can be a serious threat to people living with HIV. Early aetiological diagnosis and targeted treatment are crucial but difficult. Metagenomic next-generation sequencing (mNGS) has significant advantages over traditional detection methods. However, differences in the cerebrospinal fluid (CSF) microbiome profiles of patients living with and without HIV with suspected CNS infections using mNGS and conventional testing methods have not yet been adequately evaluated. We conducted a retrospective cohort study in the first hospital of Changsha between January 2019 and June 2022 to investigate the microbiomes detected using mNGS of the CSF of patients living with and without HIV with suspected CNS infections. The pathogens causing CNS infections were concurrently identified using both mNGS and traditional detection methods. The spectrum of pathogens identified was compared between the two groups. Overall, 173 patients (140 with and 33 without HIV) with suspected CNS infection were enrolled in our study. In total, 106 (75.7%) patients with and 16 (48.5%) patients without HIV tested positive with mNGS (p = 0.002). Among the enrolled patients, 71 (50.7%) with HIV and five (15.2%) without HIV tested positive for two or more pathogens (p < 0.001). Patients with HIV had significantly higher proportions of fungus (20.7% vs. 3.0%, p = 0.016) and DNA virus (59.3% vs. 21.2%, p < 0.001) than those without HIV. Epstein-Barr virus (33.6%) was the most commonly identified potential pathogen in the CSF of patients living with HIV using mNGS, followed by cytomegalovirus (20.7%) and torque teno virus (13.8%). The top three causative pathogens identified in patients without HIV were Streptococcus (18.2%), Epstein-Barr virus (12.1%), and Mycobacterium tuberculosis (9.1%). In total, 113 patients living with HIV were diagnosed as having CNS infections. The rate of pathogen detection in people living with HIV with a CNS infection was significantly higher with mNGS than with conventional methods (93.8% vs. 15.0%, p < 0.001). CSF microbiome profiles differ between patients living with and without HIV with suspected CNS infection. mNGS is a powerful tool for the diagnosis of CNS infection among people living with HIV, especially in those with mixed infections.

Nanopore targeted sequencing-based diagnosis of central nervous system infections in HIV-infected patients

BackgroundEarly and accurate etiological diagnosis is very important for improving the prognosis of central nervous system (CNS) infections in human immunodeficiency virus (HIV)-infected patients. The goal is not easily achieved by conventional microbiological tests. We developed a nanopore targeted sequencing (NTS) platform and evaluated the diagnostic performance for CNS infections in HIV-infected patients, with special focus on cryptococcal meningitis (CM). We compared the CM diagnostic performance of NTS with conventional methods and cryptococcal polymerase chain reaction (PCR).MethodsThis study included 57 hospitalized HIV-infected patients with suspected CNS infections from September 2018 to March 2022. The diagnosis established during hospitalization includes 27 cases of CM, 13 CNS tuberculosis, 5 toxoplasma encephalitis, 2 cytomegalovirus (CMV) encephalitis and 1 Varicella-zoster virus (VZV) encephalitis. The 2 cases of CMV encephalitis also have co-existing CM. Target-specific PCR amplification was used to enrich pathogen sequences before nanopore sequencing. NTS was performed on stored cerebrospinal fluid (CSF) samples and the results were compared with the diagnosis during hospitalization.Results53 (93.0%) of the patients were male. The median CD4 cell count was 25.0 (IQR: 14.0–63.0) cells/uL. The sensitivities of CSF culture, India ink staining, cryptococcal PCR and NTS for CM were 70.4% (95%CI: 51.5 − 84.1%), 76.0% (95%CI: 56.6 − 88.5%), 77.8% (59.2 − 89.4%) and 85.2% (95%CI: 67.5 − 94.1%), respectively. All those methods had 100% specificity for CM. Our NTS platform could identify Cryptococcus at species level. Moreover, NTS was also able to identify all the 5 cases of toxoplasma encephalitis, 2 cases of CMV encephalitis and 1 VZV encephalitis. However, only 1 of 13 CNS tuberculosis cases was diagnosed by NTS, and so did Xpert MTB/RIF assay.ConclusionsNTS has a good diagnostic performance for CM in HIV-infected patients and may have the ability of simultaneously detecting other pathogens, including mixed infections. With continuing improving of the NTS platform, it may be a promising alterative microbiological test for assisting with the diagnosis of CNS infections.

Clinical presentation, management, and outcome of suspected central nervous system infections in Indonesia: a prospective cohort study

BackgroundLittle is known about the etiology, clinical presentation, management, and outcome of central nervous system (CNS) infections in Indonesia, a country with a high burden of infectious diseases and a rising prevalence of HIV.MethodsWe included adult patients with suspected CNS infections at two referral hospitals in a prospective cohort between April 2019 and December 2021. Clinical, laboratory, and radiological assessments were standardized. We recorded initial and final diagnoses, treatments, and outcomes during 6 months of follow-up.ResultsOf 1051 patients screened, 793 were diagnosed with a CNS infection. Patients (median age 33 years, 62% male, 38% HIV-infected) presented a median of 14 days (IQR 7–30) after symptom onset, often with altered consciousness (63%), motor deficits (73%), and seizures (21%). Among HIV-uninfected patients, CNS tuberculosis (TB) was most common (60%), while viral (8%) and bacterial (4%) disease were uncommon. Among HIV-infected patients, cerebral toxoplasmosis (41%) was most common, followed by CNS TB (19%), neurosyphilis (15%), and cryptococcal meningitis (10%). A microbiologically confirmed diagnosis was achieved in 25% of cases, and initial diagnoses were revised in 46% of cases. In-hospital mortality was 30%, and at six months, 45% of patients had died, and 12% suffered from severe disability. Six-month mortality was associated with older age, HIV, and severe clinical, radiological and CSF markers at presentation.ConclusionCNS infections in Indonesia are characterized by late presentation, severe disease, frequent HIV coinfection, low microbiological confirmation and high mortality. These findings highlight the need for earlier disease recognition, faster and more accurate diagnosis, and optimized treatment, coupled with wider efforts to improve the uptake of HIV services.

A prospective study of nanopore-targeted sequencing in the diagnosis of central nervous system infections.

This study aims to prospectively evaluate the ability of nanopore-targeted sequencing (NTS) in the detection of pathogens in cerebrospinal fluid (CSF). It was the first time combining mNGS and microbial culture to verify the NTS-positive results also using 16S rDNA amplification with Sanger sequencing. Although microbial culture was thought to be the gold standard for pathogens detection and diagnosis of infectious diseases, this study suggested that microbial culture of CSF is not the most appropriate way for diagnosing central nervous system (CNS) infection. NTS should be recommended to be used in CSF for diagnosing CNS infection. When evaluating the value of NTS for diagnosis of CNS infections, the results of CSF TNC should be combined, and NTS-positive result is observed to be more reliable in patients with CSF TNC level >10 cells/μL.

Predictors of unfavourable outcome in adults with suspected central nervous system infections: a prospective cohort study

Suspected central nervous system (CNS) infections may pose a diagnostic challenge, and often concern severely ill patients. We aim to identify predictors of unfavourable outcome to prioritize diagnostics and treatment improvements. Unfavourable outcome was assessed on the Glasgow Outcome Scale at hospital discharge, defined by a score of 1 to 4. Of the 1152 episodes with suspected CNS infection, from two Dutch prospective cohorts, the median age was 54 (IQR 37–67), and 563 episodes (49%) occurred in women. The final diagnoses were categorized as CNS infection (N = 358 episodes, 31%), CNS inflammatory disease (N = 113, 10%), non-infectious non-inflammatory neurological disorder (N = 388, 34%), non-neurological infection (N = 252, 22%), and other systemic disorder (N = 41, 4%). Unfavourable outcome occurred in 412 of 1152 (36%), and 99 died (9%). Predictors for unfavourable outcomes included advanced age, absence of headache, tachycardia, altered mental state, focal cerebral deficits, cranial nerve palsies, low thrombocytes, high CSF protein, and the final diagnosis of CNS inflammatory disease (odds ratio 4.5 [95% confidence interval 1.5–12.6]). Episodes suspected of having a CNS infection face high risk of experiencing unfavourable outcome, stressing the urgent need for rapid and accurate diagnostics. Amongst the suspected CNS infection group, those diagnosed with CNS inflammatory disease have the highest risk.

MNGS facilitates the accurate diagnosis and antibiotic treatment of suspicious critical CNS infection in real practice: A retrospective study.

Whether metagenomic next-generation sequencing (mNGS) could benefit patients with suspected severe central nervous system (CNS) infection in terms of diagnosis and antibiotic treatment remains unknown. We retrospectively analyzed 79 patients with suspected CNS infection and undertook mNGS. The value of mNGS was investigated in terms of identification of pathogen and guidance for the adjustment of antibiotic treatment. The relationship between the time of initiating mNGS since onset and the Glasgow Outcome Scale (GOS) score after 90-day follow-up were analyzed. Fifty out of 79 cases with suspicious severe CNS infection were finally diagnosed. Despite previous routine laboratory tests, mNGS further promoted the accurate identification of pathogens in 23 cases (47.9%). The sensitivity, specificity, and accuracy of mNGS test in this study were 84.0, 79.3, and 82.3%, respectively. Furthermore, mNGS facilitated the adjustment of empirical antibiotic treatments in 38 cases (48.1%). The time of taking mNGS since onset had an insignificant weak positive correlation with GOS after 90-day follow-up (r = -0.73, P = 0.08). mNGS facilitated the accurate identification of pathogens in suspicious severe CNS infections and promoted the accurate antibiotic therapy even empirical antibiotics were administrated. It should be taken as early as possible to improve the clinical outcome of patients with suspicious severe CNS infection.

Diagnosis of Neurological Infections in Pediatric Patients from Cell-Free DNA Specimens by Using Metagenomic Next-Generation Sequencing.

Central nervous system (CNS) infections can cause significant morbidity and mortality, especially in children. Rapid and accurate pathogenic detection in suspected CNS infections is essential for disease control at the early stage of infection. To evaluate the performance of metagenomic next-generation sequencing (mNGS) of cell-free DNA (cfDNA) in cerebrospinal fluid (CSF) in pediatric patients, we retrospectively analyzed the efficiency of cfDNA mNGS in children with CNS infections (n = 257) or noninfectious neurological disorders (n = 81). The CSF samples of 124 random subjects were used to evaluate the accuracy between mNGS of cfDNA and whole-cell DNA (wcDNA). In total, cfDNA mNGS detected a wide range of microbes with a detection rate of 71.0%, and the sensitivity and total coincidence rate with clinical diagnosis reached 68.9% and 67.5%, respectively. Compared with wcDNA mNGS, cfDNA mNGS had a higher efficacy in detecting viruses (66 versus 13) and Mycobacterium (7 versus 1), with significantly higher reads per million. The dominant causative pathogens were bacteria and viruses in CNS infections, but these presented with different pathogen spectra in different age categories. The best timing for the mNGS test ranged from 1 to 6 days after the start of anti-infection therapy, and the earlier mNGS started, the better was identification of bacterial CNS infections. This study emphasized that cfDNA mNGS had overall superiority to conventional methods on causative pathogen detection in pediatric CNS infections, and it was even better than wcDNA mNGS. Furthermore, research needs to be better validated in large-scale clinical trials to improve the clinical applications of cfDNA mNGS. IMPORTANCE Our study emphasized that cfDNA mNGS had overall superiority to conventional methods on causative pathogen detection in CNS-infected children, and it was even better than wcDNA mNGS. cfDNA mNGS detected a wide range of pathogens with a high total coincidence rate (67.5%) against clinical diagnosis. The best timing for cfDNA mNGS detection ranged from 1 to 6 days, rather than 0 days, after the start of empirical anti-infection therapy. The earlier mNGS started, the better the identifications of bacterial CNS infections. To the best of our knowledge, this research is the first report evaluating the clinical utility of mNGS with different methods (cfDNA versus wcDNA) of extracting DNA from CSF specimens in diagnosing pediatric CNS infections. Meanwhile, this is the largest cohort study that has evaluated the performance of mNGS using cfDNA from CSF specimens in pediatric patients with CNS infections.

LUMBER PUNCTURE AND ASSOCIATED FACTORS AMONG PARENTS OF CHILDREN HOSPITALIZED WITH SUSPECTED CENTRAL NERVOUS SYSTEM INFECTONS

Lumber Puncture (LP) can be performed for both diagnostic and therapeutic purposes. Failure to perform LP is associated with greater morbidity and mortality due to delayed diagnosis and improper management. This study was conducted to evaluate frequency of LP refusal and its associated factors among parents of children hospitalized with suspected Central Nervous System (CNS) infections. This cross-sectional study was conducted from October 2021 to April 2022 at National Institute of Child Health (NICH), Karachi, Pakistani. Parents/attendants of all pediatric patients hospitalized with suspected CNS infections and advised LP by the treating physicians were included in the study. A semi-structured questionnaire was used to assess the perception and attitude of patients’ towards the procedure and if they agreed for their child to undergo LP. Parents of 338 children were enrolled, out of which 203(60.1%) consented for LP. Majority refused because of fear of complications followed by those who believed LP was not required (29%). Common misconceptions regarding LP complications were risk of death (13%), epilepsy (11%) and paralysis (7%). Significantly lower refusals were observed when no other course was offered as alternate to LP (p-value &lt;0.001). There was high frequency of LP refusal among parents of pediatric patients presenting with suspected CNS infections, most important cause of refusal was fear of complications.

Cerebrospinal fluid analysis in emergency patients with suspected infection of the central nervous system.

Meningitis and encephalitis are potentially life-threatening diseases that require fast and accurate diagnostics and therapy. The value of polymerase chain reaction (PCR) multiplex testing in clinical practice is still a matter of debate. This study aims to evaluate its benefits and limitations in emergency patients. We assessed the value of a meningoencephalitis PCR array in the clinical routine of an emergency department. Of 1578 emergency patients who received a lumbar puncture, 43% received it for a clinically suspected central nervous system (CNS) infection. After initial workup for cerebrospinal fluid (CSF) cell count, protein and glucose, a CNS infection was still considered likely in 307 patients. In these patients, further microbiologic workup was performed. A total of 230 samples were examined by PCR and a pathogen was detected in 66 of these samples. In the case of a positive microbiologic result, a comparison between PCR array and standard method was available for 59 samples, which demonstrated an overcall agreement of 80% (n= 47/59). Of interest, exclusively array-positive results were observed for patients with meningitis found to be positive for Streptococcus pneumoniae; four out of five patients had been treated with antibiotics before the lumbar puncture. In samples with normal CSF cell count only two positive array results were obtained, both for human herpesvirus 6, and these were not clinically relevant. Our data suggest that the array substantially contributes to a detection of pathogens in patients with suspected CNS infection and seems of particular interest in patients with acute bacterial meningitis under empiric antibiotic treatment. In CSF samples with normal cell count, it might be dispensable.

Seizures in adults with suspected central nervous system infection

BackgroundSeizures can be part of the clinical presentation of central nervous system (CNS) infections. We describe patients suspected of a neurological infection who present with a seizure and study diagnostic accuracy of clinical and laboratory features predictive of CNS infection in this population.MethodsWe analyzed all consecutive patients presenting with a seizure from two prospective Dutch cohort studies, in which patients were included who underwent cerebrospinal fluid (CSF) examination because of the suspicion of a CNS infection.ResultsOf 900 episodes of suspected CNS infection, 124 (14%) presented with a seizure. The median age in these 124 episodes was 60 years (IQR 45–71) and 53% of patients was female. CSF examination showed a leukocyte count ≥ 5/mm3 in 41% of episodes. A CNS infection was diagnosed in 27 of 124 episodes (22%), a CNS inflammatory disorder in 8 (6%) episodes, a systemic infection in 10 (8%), other neurological disease in 77 (62%) and in 2 (2%) episodes another systemic disease was diagnosed. Diagnostic accuracy of clinical and laboratory characteristics for the diagnosis of CNS infection in this population was low. CSF leukocyte count was the best predictor for CNS infection in patients with suspected CNS infection presenting with a seizure (area under the curve 0.94, [95% CI 0.88 – 1.00]).ConclusionsClinical and laboratory features fail to distinguish CNS infections from other causes of seizures in patients with a suspected CNS infection. CSF leukocyte count is the best predictor for the diagnosis of CNS infection in this population.

Aetiologies and clinical presentation of central nervous system infections in Vietnamese patients: a prospective study

Knowledge of the clinical presentation of central nervous system (CNS) infections and the causative pathogens is crucial for appropriate diagnosis and rapid initiation of appropriate treatment to prevent severe neurological sequelae. The aim of this study is to understand the aetiology of CNS infections based on the clinical presentation of Vietnamese patients. A prospective hospital-based cohort study was conducted between May 2014 and May 2017. We screened 137 patients with clinically suspected CNS infection for fungal, bacterial and viral pathogens using their cerebrospinal fluid (CSF) and blood cultures. In addition, DNA or RNA extracted from CSF samples were subjected to nucleic acid testing (NAT) with a selective panel of bacterial, viral and fungal pathogens. At least one pathogen could be detected in 41% (n = 56) of the patients. The main pathogens causing CNS infections were Streptococcus suis (n = 16; 12%) and Neisseria meningitidis (n = 9; 7%), followed by Herpes simplex virus 1/2 (n = 4; 3%) and Klebsiella pneumoniae (n = 4; 3%). Other pathogens were only identified in a few cases. Patients with bacterial CNS infections were significantly older, had a worse outcome, a lower Glasgow Coma Scale (GCS), a higher rate of speech impairment and neck stiffness than patients with viral or tuberculous CNS infections. In northern Vietnam, adults are mostly affected by bacterial CNS infections, which have a severe clinical course and worse outcomes compared to viral or tuberculous CNS infections. Clinicians should be aware of the regional occurrence of pathogens to initiate rapid and appropriate diagnosis and treatment.

Inconsistency analysis between metagenomic next-generation sequencing results of cerebrospinal fluid and clinical diagnosis with suspected central nervous system infection

BackgroundRecently, with the rapid progress of metagenomic next-generation sequencing (mNGS), inconsistency between mNGS results and clinical diagnoses has become more common. There is currently no reasonable explanation for this, and the interpretation of mNGS reports still needs to be standardised.MethodsA retrospective analysis was conducted on 47 inpatients with suspected central nervous system (CNS) infections, and clinical data were recorded. The final diagnosis was determined by an expert group based on the patient’s clinical manifestation, laboratory examination, and response to treatment. mNGS results were compared with the final diagnosis, and any inconsistencies that occurred were investigated. Finally, the credibility of mNGS results was evaluated using the integral approach, which consists of three parts: typical clinical features, positive results with the traditional method, and cerebrospinal fluid cells ≥ 100 (× 106/L) or protein ≥ 500 mg/L, with one point for each item.ResultsForty-one patients with suspected CNS infection were assigned to infected (ID, 31/41, 75.61%) and non-infected groups (NID, 10/41, 24.39%) after assessment by a panel of experts according to the composite diagnostic criteria. For mNGS-positive results, 20 of the 24 pathogens were regarded as contaminants when the final score was ≤ 1. The remaining 11 pathogens detected by mNGS were all true positives, which was consistent with the clinical diagnosis when the score was ≥ 2. For mNGS negative results, when the score was ≥ 2, the likelihood of infection may be greater than when the score is ≤ 1.ConclusionThe integral method is effective for evaluating mNGS results. Regardless of whether the mNGS result was positive or negative, the possibility of infection was greater when the score was ≥ 2. A negative mNGS result does not necessarily indicate that the patient was not clinically infected, and, therefore, clinical features are more important.

Human herpes virus type-6 is associated with central nervous system infections in children in Sudan.

BackgroundHuman herpes virus type-6 (HHV-6) is increasingly recognised as a febrile agent in children. However, less is known in sub-Saharan African countries, including Sudan.ObjectiveWe investigated the involvement of HHV-6 in paediatric central nervous system (CNS) infections in Khartoum, Sudan.MethodsFebrile patients aged up to 15 years with suspected CNS infections at Omdurman Hospital for Children from 01 December 2009 to 01 August 2010 were included. Viral DNA was extracted from leftover cerebrospinal fluid (CSF) specimens and quantitatively amplified by real-time polymerase chain reaction (PCR) at Umeå University in Sweden.ResultsOf 503 CSF specimens, 13 (2.6%) were positive for HHV-6 (33.0% [13/40 of cases with proven infectious meningitis]). The median thermal cycle threshold for all HHV-6-positive specimens was 38 (range: 31.9–40.8). The median number of virus copies was 281.3/PCR run (1 × 105 copies/mL CSF; range: 30–44 × 103 copies/PCR run [12 × 103 – 18 × 106 copies/mL CSF]). All positive patients presented with fever and vomiting; 86.0% had seizures. The male-to-female ratio was 1:1; 50.0% were toddlers, 42.0% infants and 8.0% teenagers. Most (83.0%) were admitted in the dry season and 17.0% in the rainy season. Cerebrospinal fluid leukocytosis was seen in 33.0%, CSF glucose levels were normal in 86.0% and low in 14.0%, and CSF protein levels were low in 14.0% and high in 43.0%.ConclusionAmong children in Sudan with CNS infections, HHV-6 is common. Studies on the existence and spread of HHV-6 chromosomal integration in this population are needed.

Neurofilament light chain in central nervous system infections: a prospective study of diagnostic accuracy

Diagnosing central nervous system (CNS) infections quickly is often difficult. Neurofilament light chain (NfL) is a component of the axonal cytoskeleton and identified as marker of neuronal damage in several CNS diseases. We evaluated the diagnostic accuracy of NfL for diagnosing CNS infections. We included patients from a prospective cohort of consecutive patients in whom a lumbar puncture was performed for suspected CNS infection in an academic hospital in The Netherlands. The index test was NfL in cerebrospinal fluid (CSF) and reference standard the final clinical diagnosis. Diagnostic accuracy was determined using the area-under-the-curve (AUC) with 95% confidence intervals (CI). The association of CSF NfL with clinical characteristics, diagnosis and outcome was evaluated. Between 2012 and 2015, 273 episodes in adults of which sufficient CSF was available were included. CNS infection was diagnosed in 26%(n = 70), CNS inflammatory disease in 7%(n = 20), systemic infection in 32%(n = 87), and other neurological disorders in 33%(n = 90). Median CSF NfL level was 593 pg/ml (IQR 249–1569) and did not discriminate between diagnostic categories or CNS infection subcategories. AUC for diagnosing any CNS infection compared to patients without CNS infections was 0.50 (95% CI 0.42–0.59). Patients presenting with an altered mental status had higher NfL levels compared to other patients. We concluded that NfL cannot discriminate between causes in patients suspected of CNS infections. High concentrations of NfL are associated with severe neurological disease and the prognostic value of NfL in patients with CNS infections should be investigated in future research.

Application of metagenomic next-generation sequencing in the diagnosis of infectious diseases of the central nervous system after empirical treatment.

BACKGROUNDThe diagnostic value of metagenomic next-generation sequencing (mNGS) in central nervous system (CNS) infectious diseases after empirical treatment has not been reported.AIMTo investigate the diagnostic value of mNGS of cerebrospinal fluid (CSF) in the empirically treated CNS infectious diseases.METHODSA total of 262 CSF samples from patients with suspected CNS infections were collected between August 2020 and December 2021. Both mNGS and conventional methods were used for testing. The conventional methods included microbial culture, smear, polymerase chain reaction, etc.RESULTSAmong 262 suspected cases, 183 cases (69.84%) were diagnosed as CNS infection, including 86 cases of virus infection (47.00%), 70 cases of bacterial infection (38.25%) and 27 cases of fungal infection (14.76%). The sensitivity and specificity of mNGS were 65.6% (95%CI: 58.2%-72.3%) and 89.6% (95%CI: 79.1%-95.3%), respectively. The PPV of mNGS was 94.5% (95%CI: 88.6%-97.6%), and the NPV was 48.8% (95%CI: 39.7%–57.9%). The pathogen detective sensitivity and accuracy of mNGS were higher than those of conventional methods (Sensitivity: 65.6% vs 37.2%; P < 0.001; Accuracy: 72.0% vs 50%, P < 0.001). The results showed that compared with conventional methods, mNGS technology was a more sensitive method for the diagnosis of CNS infection after empirical treatment.CONCLUSIONmNGS can be a better method applied in the diagnosis of CNS infection after empirical treatment.