The microbiological diagnosis of tuberculous meningitis of Haydarpasa-1 study

Using cerebrospinal fluid nanopore sequencing assay to diagnose tuberculous meningitis: a retrospective cohort study in China

OBJECTIVE

This study aimed to evaluate the efficiency of nanopore sequencing for the early diagnosis of tuberculous meningitis (TBM) using cerebrospinal fluid and compared it with acid-fast bacilli (AFB) smear, mycobacterial growth indicator tube culture and Xpert Mycobacterium tuberculosis (MTB)/rifampicin (RIF).

DESIGN

Single-centre retrospective study.

SETTING

The Tuberculosis Diagnosis and Treatment Center of Zhejiang Chinese and Western Medicine Integrated Hospital.

PARTICIPANTS

We enrolled 64 adult patients with presumptive TBM admitted to our hospital from August 2021 to August 2023.

METHODS

We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of AFB smear, culture, Xpert MTB/RIF and nanopore sequencing to evaluate their diagnostic efficacy compared with a composite reference standard for TBM.

RESULTS

Among these 64 patients, all tested negative for TBM by AFB smear. The sensitivity, specificity, PPV and NPV were 11.11%, 100%, 100% and 32.2% for culture, 13.33%, 100%, 100% and 2.76% for Xpert MTB/RIF, and 77.78%, 100%, 100% and 65.52% for nanopore sequencing, respectively.

CONCLUSION

The diagnostic accuracy of the nanopore sequencing test was significantly higher than that of conventional testing methods used to detect TBM.

Chronic meningitis in adults: a comparison between neurotuberculosis and neurobrucellosis

BACKGROUND

In regions endemic for tuberculosis and brucellosis, distinguishing between tuberculous meningitis (TBM) and brucella meningitis (BM) poses a substantial challenge. This study investigates the clinical and paraclinical characteristics of patients with TBM and BM.

METHODS

Adult patients diagnosed with either TBM or BM who were admitted to two referral hospitals between March 2015 and October 2022, were included, and the characteristics of the patients were analyzed.

RESULTS

Seventy patients formed the study group, 28 with TBM and 42 with BM, were included. TBM patients had a 2.06-fold (95% CI: 1.26 to 3.37, P-value: 0.003) higher risk of altered consciousness and a 4.80-fold (95% CI: 1.98 to 11.61, P-value: < 0.001) higher risk of extra-neural involvement as compared to BM patients. Cerebrospinal fluid (CSF) analysis revealed a significantly higher percentage of polymorphonuclear leukocytes (PMN) in TBM compared to BM (Standardized mean difference: 0.69, 95% CI: 0.18 to 1.20, P-value: 0.008). Neuroimaging findings indicated higher risks of hydrocephalus (P-value: 0.002), infarction (P-value: 0.029), and meningeal enhancement (P-value: 0.012) in TBM compared to BM. Moreover, TBM patients had a 67% (95% CI: 21% to 131%, P-value:0.002) longer median length of hospital stay and a significantly higher risk of unfavorable outcomes (Risk ratio: 6.96, 95% CI: 2.65 to 18.26, p < 0.001).

CONCLUSIONS

Our study emphasizes that TBM patients displayed increased frequencies of altered consciousness, PMN dominance in CSF, extra-neural involvement, hydrocephalus, meningeal enhancement, and brain infarction. The findings emphasize the diagnostic difficulties and underscore the importance of cautious differentiation between these two conditions to guide appropriate treatment strategies.

Infectious causes of fever of unknown origin in developing countries: An international ID-IRI study

Background

Fever of unknown origin (FUO) in developing countries is an important dilemma and further research is needed to elucidate the infectious causes of FUO.

Methods

A multi-center study for infectious causes of FUO in lower middle-income countries (LMIC) and low-income countries (LIC) was conducted between January 1, 2018 and January 1, 2023. In total, 15 participating centers from seven different countries provided the data, which were collected through the Infectious Diseases-International Research Initiative platform. Only adult patients with confirmed infection as the cause of FUO were included in the study. The severity parameters were quick Sequential Organ Failure Assessment (qSOFA) ≥2, intensive care unit (ICU) admission, vasopressor use, and invasive mechanical ventilation (IMV).

Results

A total of 160 patients with infectious FUO were included in the study. Overall, 148 (92.5%) patients had community-acquired infections and 12 (7.5%) had hospital-acquired infections. The most common infectious syndromes were tuberculosis (TB) (n=27, 16.9%), infective endocarditis (n=25, 15.6%), malaria (n=21, 13.1%), brucellosis (n=15, 9.4%), and typhoid fever (n=9, 5.6%). Plasmodium falciparum, Mycobacterium tuberculosis, Brucellae, Staphylococcus aureus, Salmonella typhi, and Rickettsiae were the leading infectious agents in this study. A total of 56 (35.0%) cases had invasive procedures for diagnosis. The mean qSOFA score was 0.76±0.94 {median (interquartile range [IQR]): 0 (0-1)}. ICU admission (n=26, 16.2%), vasopressor use (n=14, 8.8%), and IMV (n=10, 6.3%) were not rare. Overall, 38 (23.8%) patients had at least one of the severity parameters. The mortality rate was 15 (9.4%), and the mortality was attributable to the infection causing FUO in 12 (7.5%) patients.

Conclusions

In LMIC and LIC, tuberculosis and cardiac infections were the most severe and the leading infections causing FUO.

Development and validation of a new model for the early diagnosis of tuberculous meningitis in adults based on simple clinical and laboratory parameters

BACKGROUND

The differential diagnosis between tuberculous meningitis (TBM) and viral meningitis (VM) or bacterial meningitis (BM) remains challenging in clinical practice, particularly in resource-limited settings. This study aimed to establish a diagnostic model that can accurately and early distinguish TBM from both VM and BM in adults based on simple clinical and laboratory parameters.

METHODS

Patients diagnosed with TBM or non-TBM (VM or BM) between January 2012 and October 2021 were retrospectively enrolled from the General Hospital (derivation cohort) and Branch Hospital (validation cohort) of Ningxia Medical University. Demographic characteristics, clinical symptoms, concomitant diseases, and cerebrospinal fluid (CSF) parameters were collated. Univariable logistic analysis was performed in the derivation cohort to identify significant variables (P < 0.05). A multivariable logistic regression model was constructed using these variables. We verified the performance including discrimination, calibration, and applicability of the model in both derivation and validation cohorts.

RESULTS

A total of 222 patients (70 TBM and 152 non-TBM [75 BM and 77 VM]) and 100 patients (32 TBM and 68 non-TBM [31 BM and 37 VM]) were enrolled as derivation and validation cohorts, respectively. The multivariable logistic regression model showed that disturbance of consciousness for > 5 days, weight loss > 5% of the original weight within 6 months, CSF lymphocyte ratio > 50%, CSF glucose concentration < 2.2 mmol/L, and secondary cerebral infarction were independently correlated with the diagnosis of TBM (P < 0.05). The nomogram model showed excellent discrimination (area under the curve 0.959 vs. 0.962) and great calibration (P-value in the Hosmer-Lemeshow test 0.128 vs. 0.863) in both derivation and validation cohorts. Clinical decision curve analysis showed that the model had good applicability in clinical practice and may benefit the entire population.

CONCLUSIONS

This multivariable diagnostic model may help clinicians in the early discrimination of TBM from VM and BM in adults based on simple clinical and laboratory parameters.

Screening for Latent Tuberculosis Infection in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

Importance

Latent tuberculosis infection (LTBI) can progress to active tuberculosis disease, causing morbidity and mortality.

Objective

To review the evidence on benefits and harms of screening for and treatment of LTBI in adults to inform the US Preventive Services Task Force (USPSTF).

Data Sources

PubMed/MEDLINE, Cochrane Library, and trial registries through December 3, 2021; references; experts; literature surveillance through January 20, 2023.

Study Selection

English-language studies of LTBI screening, LTBI treatment, or accuracy of the tuberculin skin test (TST) or interferon-gamma release assays (IGRAs). Studies of LTBI screening and treatment for public health surveillance or disease management were excluded.

Data Extraction and Synthesis

Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings; meta-analyses conducted when a sufficient number of similar studies were available.

Main Outcomes and Measures

Screening test accuracy; development of active tuberculosis disease, transmission, quality of life, mortality, and harms.

Results

A total of 113 publications were included (112 studies; N = 69 009). No studies directly evaluated the benefits and harms of screening. Pooled estimates for sensitivity of the TST were 0.80 (95% CI, 0.74-0.87) at the 5-mm induration threshold, 0.81 (95% CI, 0.76-0.87) at the 10-mm threshold, and 0.60 (95% CI, 0.46-0.74) at the 15-mm threshold. Pooled estimates for sensitivity of IGRA tests ranged from 0.81 (95% CI, 0.79-0.84) to 0.90 (95% CI, 0.87-0.92). Pooled estimates for specificity of screening tests ranged from 0.95 to 0.99. For treatment of LTBI, a large (n = 27 830), good-quality randomized clinical trial found a relative risk (RR) for progression to active tuberculosis at 5 years of 0.35 (95% CI, 0.24-0.52) for 24 weeks of isoniazid compared with placebo (number needed to treat, 112) and an increase in hepatotoxicity (RR, 4.59 [95% CI, 2.03-10.39]; number needed to harm, 279). A previously published meta-analysis reported that multiple regimens were efficacious compared with placebo or no treatment. Meta-analysis found greater risk for hepatotoxicity with isoniazid than with rifampin (pooled RR, 4.22 [95% CI, 2.21-8.06]; n = 7339).

Conclusions and Relevance

No studies directly evaluated the benefits and harms of screening for LTBI compared with no screening. TST and IGRAs were moderately sensitive and highly specific. Treatment of LTBI with recommended regimens reduced the risk of progression to active tuberculosis. Isoniazid was associated with higher rates of hepatotoxicity than placebo or rifampin.

Microbiological diagnosis and mortality of tuberculosis meningitis: Systematic review and meta-analysis

BACKGROUND

Tuberculosis (TB) which is caused by Mycobacterium tuberculosis poses a significant public health global treat. Tuberculosis meningitis (TBM) accounts for approximately 1% of all active TB cases. The diagnosis of Tuberculosis meningitis is notably difficult due to its rapid onset, nonspecific symptoms, and the difficulty of detecting Mycobacterium tuberculosis in cerebrospinal fluid (CSF). In 2019, 78,200 adults died of TB meningitis. This study aimed to assess the microbiological diagnosis TB meningitis using CSF and estimated the risk of death from TBM.

METHODS

Relevant electronic databases and gray literature sources were searched for studies that reported presumed TBM patients. The quality of included studies was assessed using the Joanna Briggs Institute Critical Appraisal tools designed for prevalence studies. Data were summarized using Microsoft excel ver 16. The proportion of culture confirmed TBM, prevalence of drug resistance and risk of death were calculated using the random-effect model. Stata version 16.0 was used perform the statistical analysis. Moreover, subgroup analysis was conducted.

RESULTS

After systematic searching and quality assessment, 31 studies were included in the final analysis. Ninety percent of the included studies were retrospective studies in design. The overall pooled estimates of CSF culture positive TBM was 29.72% (95% CI; 21.42-38.02). The pooled prevalence of MDR-TB among culture positive TBM cases was 5.19% (95% CI; 3.12-7.25). While, the proportion of INH mono-resistance was 9.37% (95% CI; 7.03-11.71). The pooled estimate of case fatality rate among confirmed TBM cases was 20.42% (95%CI; 14.81-26.03). Based on sub group analysis, the pooled case fatality rate among HIV positive and HIV negative TBM individuals was 53.39% (95%CI; 40.55-66.24) and 21.65% (95%CI;4.27-39.03) respectively.

CONCLUSION

Definite diagnosis of TBM still remains global treat. Microbiological confirmation of TBM is not always achievable. Early microbiological confirmation of TBM has great importance to reduce mortality. There was high rate of MDR-TB among confirmed TBM patients. All TB meningitis isolates should be cultured and drug susceptibility tested using standard techniques.

Diagnostic Model for Discrimination Between Tuberculous Meningitis and Bacterial Meningitis

Background

The differential diagnosis between tuberculous meningitis (TBM) and bacterial meningitis (BM) remains challenging in clinical practice. This study aimed to establish a diagnostic model that could accurately distinguish TBM from BM.

Methods

Patients with TBM or BM were recruited between January 2017 and January 2021 at Tongji Hospital (Qiaokou cohort) and Sino-French New City Hospital (Caidian cohort). The detection for indicators involved in cerebrospinal fluid (CSF) and T-SPOT assay were performed simultaneously. Multivariate logistic regression was used to create a diagnostic model.

Results

A total of 174 patients (76 TBM and 98 BM) and another 105 cases (39 TBM and 66 BM) were enrolled from Qiaokou cohort and Caidian cohort, respectively. Significantly higher level of CSF lymphocyte proportion while significantly lower levels of CSF chlorine, nucleated cell count, and neutrophil proportion were observed in TBM group when comparing with those in BM group. However, receiver operating characteristic (ROC) curve analysis showed that the areas under the ROC curve (AUCs) produced by these indicators were all under 0.8. Meanwhile, tuberculosis-specific antigen/phytohemagglutinin (TBAg/PHA) ratio yielded an AUC of 0.889 (95% CI, 0.840–0.938) in distinguishing TBM from BM, with a sensitivity of 68.42% (95% CI, 57.30%–77.77%) and a specificity of 92.86% (95% CI, 85.98%–96.50%) when a cutoff value of 0.163 was used. Consequently, we successfully established a diagnostic model based on the combination of TBAg/PHA ratio, CSF chlorine, CSF nucleated cell count, and CSF lymphocyte proportion for discrimination between TBM and BM. The established model showed good performance in differentiating TBM from BM (AUC: 0.949; 95% CI, 0.921–0.978), with 81.58% (95% CI, 71.42%–88.70%) sensitivity and 91.84% (95% CI, 84.71%–95.81%) specificity. The performance of the diagnostic model obtained in Qiaokou cohort was further validated in Caidian cohort. The diagnostic model in Caidian cohort produced an AUC of 0.923 (95% CI, 0.867–0.980) with 79.49% (95% CI, 64.47%–89.22%) sensitivity and 90.91% (95% CI, 81.55%–95.77%) specificity.

Conclusions

The diagnostic model established based on the combination of four indicators had excellent utility in the discrimination between TBM and BM.

Characteristics and biomarkers of patients with central nervous system infection admitted to a referral hospital in Northern Vietnam

Background

Laboratory facilities for etiological diagnosis of central nervous system (CNS) infection are limited in developing countries; therefore, patients are treated empirically, and the epidemiology of the pathogens is not well-known. Tubercular meningitis is one of the common causes of meningitis, which has high morbidity and mortality, but lacks sensitive diagnostic assays. The objectives of this study were to determine the causes of meningitis in adult patients by using molecular assays, to assess the risk factors associated with them, and to explore whether biomarkers can differentiate tubercular meningitis from bacterial meningitis.

Methods

We conducted a cross-sectional study in the Department of Infectious Diseases, Bach Mai Hospital, Hanoi, Vietnam, from June 2012 to May 2014. All patients who were 16 years old and who had meningoencephalitis suggested by abnormal cerebrospinal fluid (CSF) findings (CSF total cell >5/mm3 or CSF protein 40 mg/dL) were included in the study. In addition to culture, CSF samples were tested for common bacterial and viral pathogens by polymerase chain reaction (PCR) and for biomarkers: C-reactive protein and adenosine deaminase (ADA).

Results

Total number of patients admitted to the department was 7506; among them, 679 were suspected to have CNS infection, and they underwent lumbar puncture. Five hundred eighty-three patients had abnormal CSF findings (meningoencephalitis); median age was 45 (IQR 3158), 62.6% were male, and 60.9% were tested for HIV infection. Among 408 CSF samples tested by PCR, out of them, 358 were also tested by culture; an etiology was identified in 27.5% (n=112). S. suis (8.8%), N. meningitis (3.2%), and S. pneumoniae (2.7%) were common bacterial and HSV (2.2%), Echovirus 6 (0.7%), and Echovirus 30 (0.7%) were common viral pathogens detected. M. tuberculosis was found in 3.2%. Mixed pathogens were detected in 1.8% of the CSF samples. Rural residence (aOR 4.1, 95% CI 1.214.4) and raised CSF ADA (10 IU/L) (aOR 25.5, 95% CI 3.1212) were associated with bacterial meningitis when compared with viral meningitis; similarly, raised CSF ADA (10 IU/L) (aOR 42.2, 95% CI 2.0882) was associated with tubercular meningitis.

Conclusions

Addition of molecular method to the conventional culture had enhanced the identification of etiologies of CNS infection. Raised CSF ADA (10 IU/L) was strongly associated with bacterial and tubercular meningitis. This biomarker might be helpful to diagnose tubercular meningitis once bacterial meningitis is ruled out by other methods.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41182-021-00322-2.

Development and validation of a new scoring system for the early diagnosis of tuberculous meningitis in adults

We developed and validated a new diagnostic scoring system by simultaneously comparing 28 factors (including clinical, laboratory, and imaging) of HIV uninfected adult tuberculous meningitis (TBM) with viral meningitis (VM), bacterial meningitis (BM), and cryptococcal meningitis (CM). Predictors of TBM diagnosis obtained by logistic regression. A total of 382 patients with intracranial infection participated, and eight factors were independently associated with TBM diagnosis: symptom duration, evidence of extracranial tuberculosis, cerebrospinal fluid (CSF) leukocyte, CSF neutrophil, CSF protein, low serum sodium, meningeal enhancement, and tuberculomas. Factors are assigned according to weight, a score of ≥ 5 was suggestive of TBM with a sensitivity of 85.8% and a specificity of 87.7%, and the area under the receiver operating characteristic curve was 0.923. When applied to a prospective validation cohort, this scoring model showed robust performance. Our study suggests that the application of this score can help diagnose TBM more efficiently.

Xpert MTB/RIF Ultra and Xpert MTB/RIF assays for extrapulmonary tuberculosis and rifampicin resistance in adults

BACKGROUND

Xpert MTB/RIF Ultra (Xpert Ultra) and Xpert MTB/RIF are World Health Organization (WHO)-recommended rapid nucleic acid amplification tests (NAATs) widely used for simultaneous detection of Mycobacterium tuberculosis complex and rifampicin resistance in sputum. To extend our previous review on extrapulmonary tuberculosis (Kohli 2018), we performed this update to inform updated WHO policy (WHO Consolidated Guidelines (Module 3) 2020).

OBJECTIVES

To estimate diagnostic accuracy of Xpert Ultra and Xpert MTB/RIF for extrapulmonary tuberculosis and rifampicin resistance in adults with presumptive extrapulmonary tuberculosis.

SEARCH METHODS

Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, Science Citation Index, Web of Science, Latin American Caribbean Health Sciences Literature, Scopus, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform, the International Standard Randomized Controlled Trial Number Registry, and ProQuest, 2 August 2019 and 28 January 2020 (Xpert Ultra studies), without language restriction.

SELECTION CRITERIA

Cross-sectional and cohort studies using non-respiratory specimens. Forms of extrapulmonary tuberculosis: tuberculous meningitis and pleural, lymph node, bone or joint, genitourinary, peritoneal, pericardial, disseminated tuberculosis. Reference standards were culture and a study-defined composite reference standard (tuberculosis detection); phenotypic drug susceptibility testing and line probe assays (rifampicin resistance detection).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias and applicability using QUADAS-2. For tuberculosis detection, we performed separate analyses by specimen type and reference standard using the bivariate model to estimate pooled sensitivity and specificity with 95% credible intervals (CrIs). We applied a latent class meta-analysis model to three forms of extrapulmonary tuberculosis. We assessed certainty of evidence using GRADE.

MAIN RESULTS

69 studies: 67 evaluated Xpert MTB/RIF and 11 evaluated Xpert Ultra, of which nine evaluated both tests. Most studies were conducted in China, India, South Africa, and Uganda. Overall, risk of bias was low for patient selection, index test, and flow and timing domains, and low (49%) or unclear (43%) for the reference standard domain. Applicability for the patient selection domain was unclear for most studies because we were unsure of the clinical settings. Cerebrospinal fluid Xpert Ultra (6 studies) Xpert Ultra pooled sensitivity and specificity (95% CrI) against culture were 89.4% (79.1 to 95.6) (89 participants; low-certainty evidence) and 91.2% (83.2 to 95.7) (386 participants; moderate-certainty evidence). Of 1000 people where 100 have tuberculous meningitis, 168 would be Xpert Ultra-positive: of these, 79 (47%) would not have tuberculosis (false-positives) and 832 would be Xpert Ultra-negative: of these, 11 (1%) would have tuberculosis (false-negatives). Xpert MTB/RIF (30 studies) Xpert MTB/RIF pooled sensitivity and specificity against culture were 71.1% (62.8 to 79.1) (571 participants; moderate-certainty evidence) and 96.9% (95.4 to 98.0) (2824 participants; high-certainty evidence). Of 1000 people where 100 have tuberculous meningitis, 99 would be Xpert MTB/RIF-positive: of these, 28 (28%) would not have tuberculosis; and 901 would be Xpert MTB/RIF-negative: of these, 29 (3%) would have tuberculosis. Pleural fluid Xpert Ultra (4 studies) Xpert Ultra pooled sensitivity and specificity against culture were 75.0% (58.0 to 86.4) (158 participants; very low-certainty evidence) and 87.0% (63.1 to 97.9) (240 participants; very low-certainty evidence). Of 1000 people where 100 have pleural tuberculosis, 192 would be Xpert Ultra-positive: of these, 117 (61%) would not have tuberculosis; and 808 would be Xpert Ultra-negative: of these, 25 (3%) would have tuberculosis. Xpert MTB/RIF (25 studies) Xpert MTB/RIF pooled sensitivity and specificity against culture were 49.5% (39.8 to 59.9) (644 participants; low-certainty evidence) and 98.9% (97.6 to 99.7) (2421 participants; high-certainty evidence). Of 1000 people where 100 have pleural tuberculosis, 60 would be Xpert MTB/RIF-positive: of these, 10 (17%) would not have tuberculosis; and 940 would be Xpert MTB/RIF-negative: of these, 50 (5%) would have tuberculosis. Lymph node aspirate Xpert Ultra (1 study) Xpert Ultra sensitivity and specificity (95% confidence interval) against composite reference standard were 70% (51 to 85) (30 participants; very low-certainty evidence) and 100% (92 to 100) (43 participants; low-certainty evidence). Of 1000 people where 100 have lymph node tuberculosis, 70 would be Xpert Ultra-positive and 0 (0%) would not have tuberculosis; 930 would be Xpert Ultra-negative and 30 (3%) would have tuberculosis. Xpert MTB/RIF (4 studies) Xpert MTB/RIF pooled sensitivity and specificity against composite reference standard were 81.6% (61.9 to 93.3) (377 participants; low-certainty evidence) and 96.4% (91.3 to 98.6) (302 participants; low-certainty evidence). Of 1000 people where 100 have lymph node tuberculosis, 118 would be Xpert MTB/RIF-positive and 37 (31%) would not have tuberculosis; 882 would be Xpert MTB/RIF-negative and 19 (2%) would have tuberculosis. In lymph node aspirate, Xpert MTB/RIF pooled specificity against culture was 86.2% (78.0 to 92.3), lower than that against a composite reference standard. Using the latent class model, Xpert MTB/RIF pooled specificity was 99.5% (99.1 to 99.7), similar to that observed with a composite reference standard. Rifampicin resistance Xpert Ultra (4 studies) Xpert Ultra pooled sensitivity and specificity were 100.0% (95.1 to 100.0), (24 participants; low-certainty evidence) and 100.0% (99.0 to 100.0) (105 participants; moderate-certainty evidence). Of 1000 people where 100 have rifampicin resistance, 100 would be Xpert Ultra-positive (resistant): of these, zero (0%) would not have rifampicin resistance; and 900 would be Xpert Ultra-negative (susceptible): of these, zero (0%) would have rifampicin resistance. Xpert MTB/RIF (19 studies) Xpert MTB/RIF pooled sensitivity and specificity were 96.5% (91.9 to 98.8) (148 participants; high-certainty evidence) and 99.1% (98.0 to 99.7) (822 participants; high-certainty evidence). Of 1000 people where 100 have rifampicin resistance, 105 would be Xpert MTB/RIF-positive (resistant): of these, 8 (8%) would not have rifampicin resistance; and 895 would be Xpert MTB/RIF-negative (susceptible): of these, 3 (0.3%) would have rifampicin resistance.

AUTHORS' CONCLUSIONS

Xpert Ultra and Xpert MTB/RIF may be helpful in diagnosing extrapulmonary tuberculosis. Sensitivity varies across different extrapulmonary specimens: while for most specimens specificity is high, the tests rarely yield a positive result for people without tuberculosis. For tuberculous meningitis, Xpert Ultra had higher sensitivity and lower specificity than Xpert MTB/RIF against culture. Xpert Ultra and Xpert MTB/RIF had similar sensitivity and specificity for rifampicin resistance. Future research should acknowledge the concern associated with culture as a reference standard in paucibacillary specimens and consider ways to address this limitation.

Neurobrucellosis associated with feral swine hunting in the southern United States

Although uncommon, Brucella infection can occur outside the areas of high endemicity, such as the USA. In the southern USA, hunters of wild swine are at risk for brucellosis. We present a case of a patient with fever, headache and constitutional symptoms that were ongoing for 11 months. He was diagnosed with neurobrucellosis. The patient was treated successfully with intravenous ceftriaxone, oral doxycycline and oral rifampin therapy. He had persistent neurological sequelae after completing treatment. This case illustrates the high index of suspicion needed to diagnose neurobrucellosis in a non-endemic country because initial symptoms can be subtle. The disease can be treated successfully, but long-lasting neurological sequelae are common.

Machine-Learning-Based Approach to Differential Diagnosis in Tuberculous and Viral Meningitis

Background

Tuberculous meningitis (TBM) is the most severe form of tuberculosis, but differentiating between the diagnosis of TBM and viral meningitis (VM) is difficult. Thus, we have developed machine-learning modules for differentiating TBM from VM.

Material and Methods

For the training data, confirmed or probable TBM and confirmed VM cases were retrospectively collected from five teaching hospitals in Korea between January 2000 - July 2018. Various machine-learning algorithms were used for training. The machine-learning algorithms were tested by the leave-one-out cross-validation. Four residents and two infectious disease specialists were tested using the summarized medical information.

Results

The training study comprised data from 60 patients with confirmed or probable TBM and 143 patients with confirmed VM. Older age, longer symptom duration before the visit, lower serum sodium, lower cerebrospinal fluid (CSF) glucose, higher CSF protein, and CSF adenosine deaminase were found in the TBM patients. Among the various machine-learning algorithms, the area under the curve (AUC) of the receiver operating characteristics of artificial neural network (ANN) with ImperativeImputer for matrix completion (0.85; 95% confidence interval 0.79 - 0.89) was found to be the highest. The AUC of the ANN model was statistically higher than those of all the residents (range 0.67 - 0.72, P <0.001) and an infectious disease specialist (AUC 0.76; P = 0.03).

Conclusion

The machine-learning techniques may play a role in differentiating between TBM and VM. Specifically, the ANN model seems to have better diagnostic performance than the non-expert clinician.

Advances in tuberculous meningitis diagnosis

Introduction: Tuberculous meningitis (TBM) is the most devastating form of central nervous system tuberculosis (TB) and causes high mortality worldwide. Nonspecific clinical manifestations and limited sensitivity of existing laboratory methods make the diagnosis elusive due to the paucibacillary nature of the infection. Areas Covered: We reviewed current literature on the adequacy and limitations of globally existing laboratory methods for diagnosing TBM. Expert opinion: TBM is deadliest among all TB forms, as the outcome may lead to death in 50% of cases, and survivors undergo irreversible neurological disorders. Therefore, early diagnosis and prompt treatment are cornerstones of effective disease management. Conventional microscopy and culture are widely used modalities but remain inadequate in most TBM cases. Although expanded use of rapid molecular tests such as real-time PCR and Xpert Ultra, even in resource-limited settings, hold promising results for TB diagnosis but need optimization for early detection of TBM. Moreover, CSF IGRA is also used but unable to differentiate between active and latent TB. Overall no single test for diagnosing TBM has adequate accuracy so, there is an urgent need to devise a point-of-care test.

The diagnostic utility of the "Thwaites' system" and "lancet consensus scoring system" in tuberculous vs. non-tuberculous subacute and chronic meningitis: multicenter analysis of 395 adult patients

BACKGROUND

Tuberculous meningitis (TBM) represents a diagnostic and management challenge to clinicians. The "Thwaites' system" and "Lancet consensus scoring system" are utilized to differentiate TBM from bacterial meningitis but their utility in subacute and chronic meningitis where TBM is an important consideration is unknown.

METHODS

A multicenter retrospective study of adults with subacute and chronic meningitis, defined by symptoms greater than 5 days and less than 30 days for subacute meningitis (SAM) and greater than 30 days for chronic meningitis (CM). The "Thwaites' system" and "Lancet consensus scoring system" scores and the diagnostic accuracy by sensitivity, specificity, and area under the curve of receiver operating curve (AUC-ROC) were calculated. The "Thwaites' system" and "Lancet consensus scoring system" suggest a high probability of TBM with scores ≤4, and with scores of ≥12, respectively.

RESULTS

A total of 395 patients were identified; 313 (79.2%) had subacute and 82 (20.8%) with chronic meningitis. Patients with chronic meningitis were more likely caused by tuberculosis and had higher rates of HIV infection (P < 0.001). A total of 162 patients with TBM and 233 patients with non-TBM had unknown (140, 60.1%), fungal (41, 17.6%), viral (29, 12.4%), miscellaneous (16, 6.7%), and bacterial (7, 3.0%) etiologies. TMB patients were older and presented with lower Glasgow coma scores, lower CSF glucose and higher CSF protein (P < 0.001). Both criteria were able to distinguish TBM from bacterial meningitis; only the Lancet score was able to differentiate TBM from fungal, viral, and unknown etiologies even though significant overlap occurred between the etiologies (P < .001). Both criteria showed poor diagnostic accuracy to distinguish TBM from non-TBM etiologies (AUC-ROC was <. 5), but Lancet consensus scoring system was fair in diagnosing TBM (AUC-ROC was .738), sensitivity of 50%, and specificity of 89.3%.

CONCLUSION

Both criteria can be helpful in distinguishing TBM from bacterial meningitis, but only the Lancet consensus scoring system can help differentiate TBM from meningitis caused by fungal, viral and unknown etiologies even though significant overlap occurs and the overall diagnostic accuracy of both criteria were either poor or fair.

Factors associated with false negative interferon-γ release assay results in patients with tuberculosis: A systematic review with meta-analysis

Which factors are related to false negative results of the interferon-γ release assay (IGRA) is unclear. This systematic review described the risk factors associated with false negative IGRA results. Two authors independently identified studies designed to evaluate risk factors for false negative IGRA results from PubMed, the Cochrane Register of Control Trial database, and EMBASE, accessed on October 22, 2018. Meta-analyses were conducted with random-effect models, and heterogeneity was calculated with the I² method. Of 1,377 titles and abstracts screened, 47 full texts were selected for review, and we finally included 17 studies in this systematic review. The most commonly studied risk factor (14 studies) was advanced age, followed by low peripheral lymphocyte counts (7 studies), and these factors were associated with false negative results even with different tuberculosis incidences (pooled odds ratio 2.06; 95% CI, 1.68–2.52 in advanced age and 2.68; 95% CI, 2.00–3.61 in low peripheral lymphocyte counts). Advanced age and low peripheral lymphocyte counts may be common risk factors for false negative IGRA results, suggesting that people with these factors need to be carefully followed, even if they have negative IGRA results.

Diagnostic Testing in Central Nervous System Infection

Patients with central nervous system (CNS) infection experience very high levels of morbidity and mortality, in part because of the many challenges inherent to the diagnosis of CNS infection and identification of a causative pathogen. The clinical presentation of CNS infection is nonspecific, so clinicians must often order and interpret many diagnostic tests in parallel. This can be a daunting task given the large number of potential pathogens and the availability of different testing modalities. Here, we review traditional diagnostic techniques including Gram stain and culture, serology, and polymerase chain reaction (PCR). We highlight which of these are recommended for the pathogens most commonly tested among U.S. patients with suspected CNS infection. Finally, we describe the newer broad-range diagnostic approaches, multiplex PCR and metagenomic sequencing, which are increasingly used in clinical practice.

Meningitis in adults: diagnosis and management

Bacterial meningitis is a medical emergency. All clinicians who provide acute medical care require a sound understanding of the priorities of managing a patient with suspected meningitis during the first hour. These include obtaining blood cultures, performing lumbar puncture and initiating appropriate therapy, while avoiding harmful delays such as those that result from not administering treatment until neuroimaging has been performed. Despite the increasing availability of newer diagnostic techniques, the interpretation of cerebrospinal fluid parameters remains a vital skill for clinicians. International and local guidelines differ with regard to initial empirical therapy of bacterial meningitis in adults; the North American guideline recommends ceftriaxone and vancomycin for all patients, while the Australian, UK and European guidelines recommend that vancomycin only be added for patients who are more likely to have pneumococcal meningitis or who have a higher likelihood of being infected with a strain of Streptococcus pneumoniae with reduced susceptibility to ceftriaxone. Patients with risk factors for Listeria meningitis also require an anti-Listeria agent, such as benzylpenicillin, to be added to this treatment regimen. Dexamethasone should be a routine component of empirical therapy due to its proven role in reducing morbidity and mortality from pneumococcal meningitis.

Predictors for false-negative QuantiFERON-TB Gold assay results in patients with extrapulmonary tuberculosis

BACKGROUNDS

Extrapulmonary tuberculosis (EPTB) is a heterogeneous disease, and diagnosis is sometimes difficult. We investigated the diagnostic performance of the QuantiFERON-TB Gold assay (QFT-GIT) according to sites of EPTB and predictors for false-negative QFT-GIT results.

METHODS

A total of 2176 patients were registered with active TB from January 2012 to December 2016 in Seoul St. Mary's Hospital, a 1200-bed tertiary teaching hospital in Seoul, Korea. We retrospectively reviewed the medical records of 163 EPTB patients who underwent QFT-GIT.

RESULTS

False negative QFT-GIT results were found in 28.8% (95% CI 0.22-0.36) of patients with EPTB. In the proven TB group, negative QFT-GIT results were found in 28.6% (95% CI 0.04-0.71) of pleural, 8.3% 0.002-0.38of lymph node, 8.3% (95% CI 0.002-0.38) of skeletal and 5.8% (95% CI 0.001-0.28) of gastrointestinal TB cases. Among probable TB cases, QFT-GIT negative results were identified in 46.2% (95% CI 0.19-0.75) of skeletal, 33.3% (95% CI 10-0.65) of pericardial, 30.8% (95% CI 0.09-0.61) of pleural and 17.2% (95% CI 0.10-0.56) of gastrointestinal TB cases. In the possible TB cases, central nervous system TB (n = 21) was most frequent, and 66.7% (95% CI 0.43-0.85) of those showed QFT-GIT negative results. By multivariate analysis, possible TB was independently associated with false-negative QFT-GIT results (OR 4.92, 95% CI 1.51-16.06, p = 0.008).

CONCLUSIONS

Prudent interpretation of QFT-GIT results might be needed according to anatomic site of involvement and diagnostic criteria in patients with high suspicion of EPTB.

Xpert® MTB/RIF assay for extrapulmonary tuberculosis and rifampicin resistance

BACKGROUND

Tuberculosis (TB) is the world's leading infectious cause of death. Extrapulmonary TB accounts for 15% of TB cases, but the proportion is increasing, and over half a million people were newly diagnosed with rifampicin-resistant TB in 2016. Xpert^® MTB/RIF (Xpert) is a World Health Organization (WHO)-recommended, rapid, automated, nucleic acid amplification assay that is used widely for simultaneous detection of Mycobacterium tuberculosis complex and rifampicin resistance in sputum specimens. This Cochrane Review assessed the accuracy of Xpert in extrapulmonary specimens.

OBJECTIVES

To determine the diagnostic accuracy of Xpert a) for extrapulmonary TB by site of disease in people presumed to have extrapulmonary TB; and b) for rifampicin resistance in people presumed to have extrapulmonary TB.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, Science Citation Index, Web of Science, Latin American Caribbean Health Sciences Literature (LILACS), Scopus, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform, the International Standard Randomized Controlled Trial Number (ISRCTN) Registry, and ProQuest up to 7 August 2017 without language restriction.

SELECTION CRITERIA

We included diagnostic accuracy studies of Xpert in people presumed to have extrapulmonary TB. We included TB meningitis and pleural, lymph node, bone or joint, genitourinary, peritoneal, pericardial, and disseminated TB. We used culture as the reference standard. For pleural TB, we also included a composite reference standard, which defined a positive result as the presence of granulomatous inflammation or a positive culture result. For rifampicin resistance, we used culture-based drug susceptibility testing or MTBDRplus as the reference standard.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data, assessed risk of bias and applicability using the QUADAS-2 tool. We determined pooled predicted sensitivity and specificity for TB, grouped by type of extrapulmonary specimen, and for rifampicin resistance. For TB detection, we used a bivariate random-effects model. Recognizing that use of culture may lead to misclassification of cases of extrapulmonary TB as 'not TB' owing to the paucibacillary nature of the disease, we adjusted accuracy estimates by applying a latent class meta-analysis model. For rifampicin resistance detection, we performed univariate meta-analyses for sensitivity and specificity separately to include studies in which no rifampicin resistance was detected. We used theoretical populations with an assumed prevalence to provide illustrative numbers of patients with false positive and false negative results.

MAIN RESULTS

We included 66 unique studies that evaluated 16,213 specimens for detection of extrapulmonary TB and rifampicin resistance. We identified only one study that evaluated the newest test version, Xpert MTB/RIF Ultra (Ultra), for TB meningitis. Fifty studies (76%) took place in low- or middle-income countries. Risk of bias was low for patient selection, index test, and flow and timing domains and was high or unclear for the reference standard domain (most of these studies decontaminated sterile specimens before culture inoculation). Regarding applicability, in the patient selection domain, we scored high or unclear concern for most studies because either patients were evaluated exclusively as inpatients at tertiary care centres, or we were not sure about the clinical settings.Pooled Xpert sensitivity (defined by culture) varied across different types of specimens (31% in pleural tissue to 97% in bone or joint fluid); Xpert sensitivity was > 80% in urine and bone or joint fluid and tissue. Pooled Xpert specificity (defined by culture) varied less than sensitivity (82% in bone or joint tissue to 99% in pleural fluid and urine). Xpert specificity was ≥ 98% in cerebrospinal fluid, pleural fluid, urine, and peritoneal fluid.Xpert testing in cerebrospinal fluidXpert pooled sensitivity and specificity (95% credible interval (CrI)) against culture were 71.1% (60.9% to 80.4%) and 98.0% (97.0% to 98.8%), respectively (29 studies, 3774 specimens; moderate-certainty evidence).For a population of 1000 people where 100 have TB meningitis on culture, 89 would be Xpert-positive: of these, 18 (20%) would not have TB (false-positives); and 911 would be Xpert-negative: of these, 29 (3%) would have TB (false-negatives).For TB meningitis, ultra sensitivity and specificity against culture (95% confidence interval (CI)) were 90% (55% to 100%) and 90% (83% to 95%), respectively (one study, 129 participants).Xpert testing in pleural fluidXpert pooled sensitivity and specificity (95% CrI) against culture were 50.9% (39.7% to 62.8%) and 99.2% (98.2% to 99.7%), respectively (27 studies, 4006 specimens; low-certainty evidence).For a population of 1000 people where 150 have pleural TB on culture, 83 would be Xpert-positive: of these, seven (8%) would not have TB (false-positives); and 917 would be Xpert-negative: of these, 74 (8%) would have TB (false-negatives).Xpert testing in urineXpert pooled sensitivity and specificity (95% CrI) against culture were 82.7% (69.6% to 91.1%) and 98.7% (94.8% to 99.7%), respectively (13 studies, 1199 specimens; moderate-certainty evidence).For a population of 1000 people where 70 have genitourinary TB on culture, 70 would be Xpert-positive: of these, 12 (17%) would not have TB (false-positives); and 930 would be Xpert-negative: of these, 12 (1%) would have TB (false-negatives).Xpert testing for rifampicin resistanceXpert pooled sensitivity (20 studies, 148 specimens) and specificity (39 studies, 1088 specimens) were 95.0% (89.7% to 97.9%) and 98.7% (97.8% to 99.4%), respectively (high-certainty evidence).For a population of 1000 people where 120 have rifampicin-resistant TB, 125 would be positive for rifampicin-resistant TB: of these, 11 (9%) would not have rifampicin resistance (false-positives); and 875 would be negative for rifampicin-resistant TB: of these, 6 (1%) would have rifampicin resistance (false-negatives).For lymph node TB, the accuracy of culture, the reference standard used, presented a greater concern for bias than in other forms of extrapulmonary TB.

AUTHORS' CONCLUSIONS

In people presumed to have extrapulmonary TB, Xpert may be helpful in confirming the diagnosis. Xpert sensitivity varies across different extrapulmonary specimens, while for most specimens, specificity is high, the test rarely yielding a positive result for people without TB (defined by culture). Xpert is accurate for detection of rifampicin resistance. For people with presumed TB meningitis, treatment should be based on clinical judgement, and not withheld solely on an Xpert result, as is common practice when culture results are negative.

Pleocytosis in a patient with relapsing polychondritis accompanied by meningoencephalitis: a case report

Background

Relapsing polychondritis (RP) is an uncommon immune-related disease with unknown causes. It is characterized by inflammation of cartilaginous or non-cartilaginous structures, such as the ears, nose, respiratory tract, eyes, and joints. Neurological involvement is rare in RP.

Case presentation

We report a case of pleocytosis in a 64-year-old man diagnosed as having RP with meningoencephalitis. The patient’s condition markedly improved following methylprednisolone treatment.

Conclusions

To our knowledge, this is the first report of recurrent pleocytosis in a patient with RP accompanied by meningoencephalitis. Steroid pulse therapy is effective in most cases, and early diagnosis is of importance.

Progress on Diagnosis of Tuberculous Meningitis

Central nervous system (CNS) disease caused by Mycobacterium tuberculosis (MTB) is highly devastating. Tuberculous meningitis (TBM) is the most common form of CNS tuberculosis (TB). Rapid, sensitive, and affordable diagnostic tests are not available. Ziehl-Neelsen (ZN) stain has a very low sensitivity in cases of TBM, the sensitivity rates is of about 10-20%.The detection rate can be improved by taking large volume CSF samples (>6 ml) and prolonged slide examination (30 min). Culture of MTB from the CSF is slow and insufficiently sensitive. The sensitivity is different, which varies from 36% to 81.8%. The microscopic observation drug susceptibility (MODS) assay was recommended by the World Health Organization in 2011. The sensitivity is 65%, which is more sensitive and faster than CSF smear. Commercial PCR assays were found to be insensitive at detecting MTB in CSF samples. Many research provided the value of ADA on the TBM diagnosis. Interferon-gamma release assays (IGRAs) are not recommended for diagnosis of active TB disease. Imaging is essential in diagnosis and showing complications of CNS TB. Thwaites criteria and the Lancet consensus scoring system (LCSS) were developed to improve the diagnosis of TBM. Clinicians will continue to make judgment based on clinical examination, inflammatory CSF examinations, imaging studies, and scoring systems.

Central nervous system infections in the absence of cerebrospinal fluid pleocytosis

Previous multicenter/multinational studies were evaluated to determine the frequency of the absence of cerebrospinal fluid pleocytosis in patients with central nervous system infections, as well as the clinical impact of this condition. It was found that 18% of neurosyphilis, 7.9% of herpetic meningoencephalitis, 3% of tuberculous meningitis, 1.7% of Brucella meningitis, and 0.2% of pneumococcal meningitis cases did not display cerebrospinal fluid pleocytosis. Most patients were not immunosuppressed. Patients without pleocytosis had a high rate of unfavorable outcomes and thus this condition should not be underestimated.

Prior treatment with non anti-TB antibiotics, and the duration of symptoms have no effect on diagnostics of tuberculous meningitis

PURPOSE

Our objective was to investigate whether diagnosis of tuberculous meningitis (TBM) with microbiological and molecular analysis was affected by prior empirical non anti tuberculosis antibiotics or by duration of symptoms before lumbar puncture.

MATERIALS AND METHODS

We retrospectively evaluated medical records of patients with TBM confirmed by positive culture, nucleic acid amplification techniques (NAATs) or Ehrlich-Ziehl-Neelsen staining (EZNs) from the cerebrospinal fluid (CSF) or by characteristic results of biochemical analysis of CSF combined with a typical clinical manifestation.

RESULTS

68 adult patients were analyzed. The isolation rates for NAATs, Lowenstein-Jensen (LJ) culture, BACTEC and EZNs were 70.6%, 69.1%, 67.6% and 26.5%, respectively. Biochemical analysis of CSF samples revealed: pleocytosis (median 224 [range 78-380]cells/mm³) with lymphocyte predominance (76 [45-90]%), elevated levels of protein (2.43 [1.50-3.84]g/l) and lactic acid (5.0 [3.9-7.2]mmol/l). Forty (65%) patients received no anti-tuberculosis antibiotic treatment before the diagnostic lumbar puncture. The were no significant differences in the microbiological and biochemical CSF analyses, between the patients who received and those who did not receive non anti-TB empirical antibiotic treatment. The median duration of symptoms before the diagnostic lumbar puncture was 24 (range 11-61) days. No significant differences in microbiological and biochemical analysis of CSF where found when comparing patients with duration of symptoms lasting above and less than the median time.

CONCLUSIONS

Neither prior non anti-TB antibiotic therapy, nor the duration of symptoms before diagnostic lumbar puncture have any effect on confirmation of TBM by microbiological and biochemical CSF analysis.

Central Nervous System Infections

This chapter provides an overview of infectious syndromes, pathogens, and diagnostic testing modalities for central nervous system infections in the immunocompromised host.

The burden and epidemiology of community-acquired central nervous system infections: a multinational study

Risk assessment of central nervous system (CNS) infection patients is of key importance in predicting likely pathogens. However, data are lacking on the epidemiology globally. We performed a multicenter study to understand the burden of community-acquired CNS (CA-CNS) infections between 2012 and 2014. A total of 2583 patients with CA-CNS infections were included from 37 referral centers in 20 countries. Of these, 477 (18.5%) patients survived with sequelae and 227 (8.8%) died, and 1879 (72.7%) patients were discharged with complete cure. The most frequent infecting pathogens in this study were Streptococcus pneumoniae (n = 206, 8%) and Mycobacterium tuberculosis (n = 152, 5.9%). Varicella zoster virus and Listeria were other common pathogens in the elderly. Although staphylococci and Listeria resulted in frequent infections in immunocompromised patients, cryptococci were leading pathogens in human immunodeficiency virus (HIV)-positive individuals. Among the patients with any proven etiology, 96 (8.9%) patients presented with clinical features of a chronic CNS disease. Neurosyphilis, neurobrucellosis, neuroborreliosis, and CNS tuberculosis had a predilection to present chronic courses. Listeria monocytogenes, Staphylococcus aureus, M. tuberculosis, and S. pneumoniae were the most fatal forms, while sequelae were significantly higher for herpes simplex virus type 1 (p < 0.05 for all). Tackling the high burden of CNS infections globally can only be achieved with effective pneumococcal immunization and strategies to eliminate tuberculosis, and more must be done to improve diagnostic capacity.

Infectious encephalitis: Management without etiological diagnosis 48hours after onset

Introduction

The etiological diagnosis of infectious encephalitis is often not established 48 hours after onset. We aimed to review existing literature data before providing management guidelines.

Method

We performed a literature search on PubMed using filters such as “since 01/01/2000”, “human”, “adults”, “English or French”, and “clinical trial/review/guidelines”. We also used the Mesh search terms “encephalitis/therapy” and “encephalitis/diagnosis”.

Results

With Mesh search terms “encephalitis/therapy” and “encephalitis/diagnosis”, we retrieved 223 and 258 articles, respectively. With search terms “encephalitis and corticosteroid”, we identified 38 articles, and with “encephalitis and doxycycline” without the above-mentioned filters we identified 85 articles. A total of 210 articles were included in the analysis.

Discussion

Etiological investigations must focus on recent travels, animal exposures, age, immunodeficiency, neurological damage characteristics, and potential extra-neurological signs. The interest of a diagnosis of encephalitis for which there is no specific treatment is also to discontinue any empirical treatments initially prescribed. Physicians must consider and search for autoimmune encephalitis.

Neurosurgery and human immunodeficiency virus in the era of combination antiretroviral therapy: a review

Human immunodeficiency virus (HIV) is a global health problem. It renders the central nervous system susceptible to infectious and noninfectious diseases. HIV-positive individuals may present to neurosurgical services with brain lesions of unknown etiology. The differential diagnosis in these cases is broad, including opportunistic infections and malignancies, and investigation should be tailored accordingly. Opportunistic infections of the central nervous system can be complicated by hydrocephalus, and the management is pathogen dependent. Patients may also present to a neurosurgical service with conditions unrelated to their HIV status. This review outlines important conditions that cause brain lesions and hydrocephalus. It addresses the issues of diagnosis and intervention in HIV-positive patients in the era of combination antiretroviral therapy, while not ignoring the potential for opportunistic central nervous system infection in undiagnosed patients. The care of HIV-positive patients presenting to neurosurgical services requires a multidisciplinary approach, which is reflected in the authorship of this review, as well as in the guidance given.

Clinical features, Outcomes and Molecular Profiles of Drug Resistance in Tuberculous Meningitis in non-HIV Patients

Tuberculous meningitis continues to be a serious problem for physicians because it is difficult to make an early diagnosis and the consequences of delaying treatment are severe. The objective of this study is to provide data for the optimization of diagnostic and timely treatment of tuberculous meningitis. Of the 401 human immunodeficiency virus (HIV)-negative tuberculous meningitis patients in our study, 332 were found to have an impaired blood brain barrier (82.8%). Nearly 17.0% of patients failed to be timely diagnosed. Headache (53.6%) and fever (48.6%) were the most common features, and Computed Tomography/Magnetic Resonance Imaging (CT/MRI) detected 96 patients (23.9%) with abnormal meningeal imaging. Cerebrospinal fluid real-time polymerase chain reaction was positive in 73.8% of the tuberculous meningitis patients, whereas, smears and cultures detected only 6.7% and 5.2%, respectively. Further analysis identified striking differences between drug-resistant and drug-susceptible tuberculous meningitis. Patients with drug resistance correlated with grave prognosis. Tuberculous meningitis diagnosis should overall embody clinical symptoms, laboratory and cerebral imaging findings, and more sensitive diagnostic approaches are still warranted. Our data suggest cerebrospinal fluid polymerase chain reaction for mycobacterial DNA and molecular drug susceptibility testing as routine assays for suspected tuberculous meningitis patients, and observation of the blood brain barrier function could be performed for individual management.

Antituberculosis drug resistance patterns in adults with tuberculous meningitis: results of haydarpasa-iv study

Background

Tuberculous meningitis (TBM) caused by Mycobacterium tuberculosis resistant to antituberculosis drugs is an increasingly common clinical problem. This study aimed to evaluate drug resistance profiles of TBM isolates in adult patients in nine European countries involving 32 centers to provide insight into the empiric treatment of TBM.

Methods

Mycobacterium tuberculosis was cultured from the cerebrospinal fluid (CSF) of 142 patients and was tested for susceptibility to first-line antituberculosis drugs, streptomycin (SM), isoniazid (INH), rifampicin (RIF) and ethambutol (EMB).

Results

Twenty of 142 isolates (14.1 %) were resistant to at least one antituberculosis drug, and five (3.5 %) were resistant to at least INH and RIF, [multidrug resistant (MDR)]. The resistance rate was 12, 4.9, 4.2 and 3.5 % for INH, SM, EMB and RIF, respectively. The monoresistance rate was 6.3, 1.4 and 0.7 % for INH, SM and EMB respectively. There was no monoresistance to RIF. The mortality rate was 23.8 % in fully susceptible cases while it was 33.3 % for those exhibiting monoresistance to INH, and 40 % in cases with MDR-TBM. In compared to patients without resistance to any first-line drug, the relative risk of death for INH-monoresistance and MDR-TBM was 1.60 (95 % CI, 0.38–6.82) and 2.14 (95 % CI, 0:34–13:42), respectively.

Conclusion

INH-resistance and MDR rates seemed not to be worrisome in our study. However, considering their adverse effects on treatment, rapid detection of resistance to at least INH and RIF would be most beneficial for designing anti-TB therapy. Still, empiric TBM treatment should be started immediately without waiting the drug susceptibility testing.

Rational application of adenosine deaminase activity in cerebrospinal fluid for the diagnosis of tuberculous meningitis

PURPOSE

Tuberculous meningitis (TBM) is one of the most serious and difficult to diagnose manifestations of TB. An ADA value >9.5 IU/L has great sensitivity and specificity. However, all available studies have been conducted in areas of high endemicity, so we sought to determine the accuracy of ADA in a low endemicity area.

METHODS

This retrospective study included 190 patients (105 men) who had ADA tested in CSF for some reason. Patients were classified as probable/certain TBM or non-TBM based on clinical and Thwaite's criteria. Optimal ADA cutoff was established by ROC curves and a predictive algorithm based on ADA and other CSF biochemical parameters was generated.

RESULTS

Eleven patients were classified as probable/certain TBM. In a low endemicity area, the best ADA cutoff was 11.5 IU/L with 91 % sensitivity and 77.7 % specificity. We also developed a predictive algorithm based on the combination of ADA (>11.5 IU/L), glucose (<65 mg/dL) and leukocytes (≥13.5 cell/mm(3)) with increased accuracy (Se: 91 % Sp: 88 %).

CONCLUSIONS

Optimal ADA cutoff value in areas of low TB endemicity is higher than previously reported. Our algorithm is more accurate than ADA activity alone with better sensitivity and specificity than previously reported algorithms.

Tuberculous and brucellosis meningitis differential diagnosis

BACKGROUND

The Thwaites and Lancet scoring systems have been used in the rapid diagnosis of tuberculous meningitis (TBM). However, brucellar meningoencephalitis (BME) has similar characteristics with TBM. The ultimate aim of this study is to infer data to see if BME should be included in the differential diagnosis of TBM when these two systems suggest the presence of TBM.

METHOD

BME and TBM patients from 35 tertiary hospitals were included in this study. Overall 294 adult patients with BME and 190 patients with TBM were enrolled. All patients involved in the study had microbiological confirmation for either TBM or BME. Finally, the Thwaites and Lancet scoring systems were assessed in both groups.

RESULTS

The Thwaites scoring system more frequently predicted BME cases (n = 292, 99.3%) compared to the TBM group (n = 182, 95.8%) (P = 0.017). According to the Lancet scoring system, the mean scores for BME and TBM were 9.43 ± 1.71 and 11.45 ± 3.01, respectively (P < 0.001). In addition, TBM cases were classified into "probable" category more significantly compared to BME cases, and BME cases were categorized into the "possible" category more frequently.

CONCLUSIONS

When the Thwaites or Lancet scoring systems indicate TBM, brucellar etiology should also be taken into consideration particularly in endemic countries.

Tuberculous meningitis: advances in diagnosis and treatment

INTRODUCTION

Tuberculous meningitis (TBM) is the most severe form of infection caused by Mycobacterium tuberculosis, causing death or disability in more than half of those affected. The aim of this review is to examine recent advances in our understanding of TBM, focussing on the diagnosis and treatment of this devastating condition.

SOURCES OF DATA

Papers on TBM published between 1891 and 2014 and indexed in the NCBI Pubmed. The following search terms were used: TBM, diagnosis, treatment and outcome.

AREAS OF AGREEMENT

The diagnosis of TBM remains difficult as its presentation is non-specific and may mimic other causes of chronic meningoencephalitis. Rapid recognition of TBM is crucial, however, as delays in initiating treatment are associated with poor outcome. The laboratory diagnosis of TBM is hampered by the low sensitivity of cerebrospinal fluid microscopy and the slow growth of M. tuberculosis in conventional culture systems. The current therapy of TBM is based on the treatment of pulmonary tuberculosis, which may not be ideal. The combination of TBM and HIV infection poses additional management challenges because of the need to treat both infections and the complications associated with them.

AREAS OF CONTROVERSY

The pathogenesis of TBM remains incompletely understood limiting the development of interventions to improve outcome. The optimal therapy of TBM has not been established in clinical trials, and increasing antimicrobial resistance threatens successful treatment of this condition. The use of adjunctive anti-inflammatory agents remains controversial, and their mechanism of action remains incompletely understood. The role of surgical intervention is uncertain and may not be available in areas where TBM is common.

GROWING POINTS

Laboratory methods to improve the rapid diagnosis of TBM are urgently required. Clinical trials of examining the use of high-dose rifampicin and/or fluoroquinolones are likely to report in the near future.

AREAS TIMELY FOR DEVELOPING RESEARCH

The use of biomarkers to improve the rapid diagnosis of TBM warrants further investigation. The role of novel antituberculosis drugs, such as bedaquiline and PA-824, in the treatment of TBM remains to be explored. Human genetic polymorphisms may explain the heterogeneity of response to anti-inflammatory therapies and could potentially be used to tailor therapy.

Hamsi scoring in the prediction of unfavorable outcomes from tuberculous meningitis: results of Haydarpasa-II study

Predicting unfavorable outcome is of paramount importance in clinical decision making. Accordingly, we designed this multinational study, which provided the largest case series of tuberculous meningitis (TBM). 43 centers from 14 countries (Albania, Croatia, Denmark, Egypt, France, Hungary, Iraq, Italy, Macedonia, Romania, Serbia, Slovenia, Syria, Turkey) submitted data of microbiologically confirmed TBM patients hospitalized between 2000 and 2012. Unfavorable outcome was defined as survival with significant sequela or death. In developing our index, binary logistic regression models were constructed via 200 replicates of database by bootstrap resampling methodology. The final model was built according to the selection frequencies of variables. The severity scale included variables with arbitrary scores proportional to predictive powers of terms in the final model. The final model was internally validated by bootstrap resampling. A total of 507 patients' data were submitted among which 165 had unfavorable outcome. Eighty-six patients died while 119 had different neurological sequelae in 79 (16%) patients. The full model included 13 variables. Age, nausea, vomiting, altered consciousness, hydrocephalus, vasculitis, immunosuppression, diabetes mellitus and neurological deficit remained in the final model. Scores 1-3 were assigned to the variables in the severity scale, which included scores of 1-6. The distribution of mortality for the scores 1-6 was 3.4, 8.2, 20.6, 31, 30 and 40.1%, respectively. Altered consciousness, diabetes mellitus, immunosuppression, neurological deficits, hydrocephalus, and vasculitis predicted the unfavorable outcome in the scoring and the cumulative score provided a linear estimation of prognosis.