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.

Diagnostic Yield of Pneumococcal Antigen Detection in Cerebrospinal Fluid for Diagnosis of Pneumococcal Meningitis Among Children in China.

OBJECTIVE: To determine the diagnostic accuracy of pneumococcal antigen detection in diagnosis of pneumococcal meningitis in children. METHODS: Purulent meningitis was diagnosed according to European Society for Clinical Microbiology and Infectious Diseases (ESCMID) guideline between July 2014 and June 2016. Along with a cerebrospinal fluid (CSF) culture, pneumococcal antigen detection in cerebrospinal fluid (CSF) was performed, and further identification of pathogens was done with 16S rDNA-PCR and high-throughput sequencing. RESULTS: CSF samples collected from 184 children (median age of 1.92 mo). CSF culture was used as the gold standard. 46 (25%) had positive results for culture and 10 (5.4%) were pneumococci; 34 (18.5%) were pneumococcal antigen positive. The sensitivity and specificity of pneumococcal antigen detection were 100% (95% CI: 89.4%-100%) and 86.2% (95% CI: 96.4%-99.9%), respectively. 92.3% (12/13) were confirmed by nucleic acid detection to be pneumococci. CONCLUSIONS: Pneumococcal antigen detection in CSF has adequate sensitivity and specificity in diagnosing pneumococcal meningitis.

Rare Meningitis and Epileptic Seizure Infected with Brucella melitensis: a Case Report.

BACKGROUND: Although brucellosis is the most common zoonotic disease worldwide, human meningitis infected with Brucella melitensis is rare and difficult to diagnosis. Herein we describe the clinical aspects of a rare case of Brucella melitensis meningitis accompanied by epileptic seizure. METHODS: Bacterial culture of CSF was utilized to find the pathogen. Serum and CSF agglutination tests were used to detect the capacity of Brucella antigen. Bacterial clone was identified by the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF). Magnetic resonance imaging (MRI) was used to monitor the recovery changes for meningitis. RESULTS: The bacterial culture was positive for Brucella app. Antigen-antibody agglutination test was also positive with a titer more than 1/200. A reliable identification score of 2.8 for Brucella melitensis was obtained by MALDI-TOF. MRI showed obviously improved meningitis after therapy. CONCLUSIONS: The results of this study suggest the treatments for Brucella meningitis must be planned depending on the patient's clinical conditions and the laboratory identification of pathogen infection as early as possible.

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

BACKGROUND: There is currently no research on the diagnostic value of metagenomic next-generation sequencing (mNGS) for a single pathogens in CSF. The aim of this study was to analyse the value of mNGS for identifying Streptococcus pneumoniae (S. pneumoniae) in paediatric bacterial meningitis. METHODS: Bacterial meningitis (BM) cases from October 23, 2014, to December 31, 2016, and December 1, 2017, to July 31, 2018 at Beijing Children's Hospital were reviewed. Clinical features and pathogens were analysed. RESULTS: We diagnosed 135 patients with BM in this study. A total of 43 S. pneumoniae were identified by combination methods. 26/135 (19.3%) patients had positive results in S. pneumoniae by blood and/or cerebrospinal fluid (CSF) culture. Alere BinaxNow®Streptococcus pneumoniae Antigen test was positive in 35/135(25.9%) cases. 32/135 (23.7%) S. pneumoniae were identified by mNGS. Six CSF samples were identified as S. pneumoniae only by mNGS technology. Taking culture as the gold standard, the sensitivity and specificity of mNGS for diagnosing S. pneumoniae meningitis were 73.1 and 88.1%, respectively. The positive predictive value (PPV) and negative predictive value (NPV) of diagnosing S. pneumoniae meningitis by mNGS were 59.4 and 93.2%, respectively. When comparison between mNGS and combined tests (culture and Alere BinaxNow®Streptococcus pneumoniae Antigen test), the sensitivity and specificity of mNGS for S. pneumoniae identification were 70.3 and 93.9%, the PPV and NPV in the identification of S. pneumoniae by mNGS were 81.4 and 89.3%, respectively. The difference in number of unique reads of S. pneumoniaein from CSF sample (< 14 days onset) and CSF sample (> 14 days from onset) was statistically significant (170.5 VS. 13, P = 0.019). The difference in the collected time of CSF for culture and mNGS was statistically significant (4 days VS. 14 days, P < 0.001). CONCLUSIONS: mNGS has high sensitivity and specificity for S. pneumoniae identification. The pathogen load (number of unique reads) of S. pneumonia is related to the CSF collection time. mNGS was less affected than culture by the use of antibiotics before CSF collection.

Generation and application of DNA aptamers against HspX for accurate diagnosis of tuberculous meningitis.

Tuberculous meningitis (TBM) is the most severe manifestation of tuberculosis and its diagnosis remains a challenge even today due to the lack of an adequate test. HspX antigen of Mycobacterium tuberculosis was previously established as a reliable diagnostic biomarker for TBM in an ELISA test format using anti-HspX polyclonal antibodies. Towards overcoming the limitations of batch-to-batch variation and challenges of scalability in antibody generation, we utilized Systematic Evolution of Ligands by EXponential enrichment (SELEX) to develop high affinity DNA aptamers against HspX as an alternative diagnostic reagent. Post-SELEX optimization of the best-performing aptamer candidate, H63, established its derivative H63 SL-2 M6 to be superior to its parent. Aptamer H63 SL-2 M6 displayed a specific and high affinity interaction with HspX (Kd ∼9.0 × 10-8 M). In an Aptamer Linked Immobilized Sorbent Assay (ALISA), H63 SL-2 M6 significantly differentiated between cerebrospinal fluid specimens from TBM and non-TBM subjects (n = 87, ***p < 0.0001) with ∼100% sensitivity and ∼91% specificity. Notably, ALISA exhibited comparable performance with previously reported antibody-based ELISA and qPCR. Altogether, our findings establish the utility of HspX aptamer for the reliable diagnosis of TBM and pave the way for developing an aptamer-based point-of-care test for TBM.

Cerebrospinal fluid Lyme multiplex assay results are not diagnostic in horses with neuroborreliosis.

BACKGROUND: The accuracy of the Lyme multiplex assay for the diagnosis of neuroborreliosis in horses is unknown. HYPOTHESIS/OBJECTIVES: To describe Lyme multiplex results in horses with a postmortem diagnosis of neuroborreliosis. The hypothesis was that paired serum and cerebrospinal fluid (CSF) results and a CSF : serum ratio would allow differentiation of horses with neuroborreliosis from those with other neurologic diseases. ANIMALS: Ninety horses that had neurologic examinations, serum and CSF Lyme multiplex analyses, and postmortem examination of the nervous system performed. METHODS: Retrospective study. Data collected included signalment, ante- and postmortem diagnoses, and serum and CSF Lyme multiplex results. The CSF : serum ratio was calculated by dividing CSF median fluorescent intensity (MFI) by serum MFI for each result. RESULTS: Ten horses had a final diagnosis of neuroborreliosis, 70 were diagnosed with other neurologic diseases, and 10 had no neurologic disease. Not all horses with neuroborreliosis had positive results: 4/10 had at least 1 positive serum result, 5/10 had at least 1 positive CSF result, and 3/10 had at least 1 CSF result 4-fold higher than the corresponding serum result. Results were similar for the 70 horses with other neurologic diseases: 53% had at least 1 positive serum result, 50% had at least 1 positive CSF result, and 16% had at least 1 CSF result 4-fold higher than the corresponding serum result. CONCLUSIONS AND CLINICAL IMPORTANCE: Positive Lyme multiplex results were common in horses with neurologic diseases and did not adequately differentiate horses with neuroborreliosis from horses with other disorders.

Evaluation of a rapid antigen test for detection of Streptococcus pneumoniae in cerebrospinal fluid.

Detection of Streptococcus pneumoniae antigen in cerebrospinal fluid (CSF) using lateral flow immunochromatography tests (ICTs) is an effective, rapid and low-cost method to diagnose pneumococcal meningitis. This study evaluated the diagnostic accuracy of the Uni-Gold ICT to detect pneumococcal antigen in CSF specimens, compared with gold standard bacteriology and quantitative real-time PCR (qPCR) testing. CSF specimens (n=69) from patients with suspected bacterial meningitis were included in the study. 13/69 (19%) were positive and 56/69 (81%) were negative for pneumococcus by the gold standard tests. The ICT had sensitivity of 85% (55%-98%), specificity of 96% (88%-100%), positive likelihood ratio of 23.7 (6-94) and negative likelihood ratio of 0.16 (0.04-0.57). Overall, a strong correlation between the ICT and qPCR results was seen (κ=0.81). In contrast, CSF microscopy and culture were exceptionally insensitive. The ICT method is sufficiently robust and accurate for use in algorithms to diagnose bacterial meningitis.

Evaluation of host Hsp(s) as potential biomarkers for the diagnosis of tuberculous meningitis.

OBJECTIVES: Diagnosis of tuberculosis meningitis (TBM) remains challenging in tuberculosis (TB) endemic countries. The need for TB biomarkers arises, in part, from the difficulty of accurately diagnosing TBM with the available methods. PATIENTS AND METHODS: To explore the potential of host Hsps (Hsp 25, Hsp 60, Hsp 70 and Hsp 90) as an alternative marker in TBM diagnosis, we evaluated cerebrospinal fluid (CSF) sample of TBM (n=49), Pyogenic Meningitis (PM) (n=20), Viral Meningitis (VM) (n=09), Fungal Meningitis (FM) (n=04) and non infectious control (n=79) patients using indirect ELISA. RESULTS: Out of four Hsps, Hsp 70 and Hsp 90 yields 89% & 88% sensitivity and 82% & 89% specificity, respectively. The positive (PPV) and negative (NPV) predictive values yielded in TBM group for Hsp 70 was 86.27% (73.74-94.27) and 93.51% (85.48-97.83), respectively. For Hsp 90 the obtained PPV was 89.36% (76.88-96.41) and NPV was 91.36% (82.99-96.44). In 86% of TBM patients all the four Hsps were found to be positive and none of the patient was found to be negative for all Hsps in the same group. CONCLUSIONS: The data presented in the study indicate that host Hsp 70 and Hsp 90 shows good sensitivity and specificity and have potential in the diagnosis of TBM disease. The combined use of all Hsps (Hsp 25, Hsp 60, Hsp 70 and Hsp 90) effectively distinguishes patients with TBM from other disease controls.

Epidemiology and emm types of invasive group A streptococcal infections in Finland, 2008-2013.

Invasive Streptococcus pyogenes (group A streptococcus, GAS) infections are a major global cause of morbidity and mortality. We analysed the surveillance data on invasive GAS and the microbiological characteristics of corresponding isolates to assess the incidence and emm type distribution of invasive GAS infections in Finland. Cases defined as patients with isolations of blood and cerebrospinal fluid S. pyogenes are mandatorily notified to the National Infectious Disease Registry and sent to the national reference laboratory for emm typing. Antimicrobial data were collected through the network including all clinical microbiology laboratories. Pulsed-field gel electrophoresis (PFGE) analysis was performed to assess clonality. In total, 1165 cases of invasive GAS were reported in Finland during 2008-2013; the median age was 52 years (range, 0-100) and 54% were male. The overall day 7 case fatality rate was 5.1% (59 cases). The average annual incidence was 3.6 cases per 100,000 population. A total of 1122 invasive GAS isolates (96%) were analysed by emm typing; 72 different emm types were identified, of which emm28 (297 isolates, 26%), emm89 (193 isolates, 12%) and emm1 (132 isolates, 12%) were the most common types. During 2008-2013, an increase of erythromycin resistance (1.9% to 8.7%) and clindamycin (0.9% to 9.2%) was observed. This resistance increase was in parallel with the introduction of a novel clone emm33 into Finland. The overall incidence of invasive GAS infections remained stable over the study period in Finland. We identified clonal spread of macrolide-resistant invasive emm33 GAS type, highlighting the importance of molecular surveillance.

Neonatal purulent meningitis in southern Tunisia: Epidemiology, bacteriology, risk factors and prognosis.

OBJECTIVES: To study the epidemiological, clinical and bacteriological aspects and outcome of purulent neonatal meningitis (PNM). METHODOLOGY: Retrospective analysis of 55 cases of PNM hospitalized in the pediatric ward of Hedi Chaker Hospital from 1990 to 2012. Infants less than 29 days of age were included. The diagnosis was made on either the presence of bacteria in the cerebrospinal fluid (CSF) or the combination of pleocytosis >30 cells/mm(3), protein level >1.3 g/l and glucose level <2.2 mmol/l or CSF/blood glucose ratio <0.4. RESULTS: The male:female sex ratio was 1.75. One or more maternal risk factors for infection were found in 24 cases. The main symptoms were fever and poor feeding. Soluble antigen was positive in four cases and cultures had isolated the bacteria in 28 cases. The mortality rate was 40%. The sequelae rate in the survivors was 16.4%. CONCLUSION: This study emphasizes the severity of PNM with high rates of mortality and neurological sequelae.

Immunoconfirmation of central nervous system tuberculosis by blotting: A study of 300 cases.

Tuberculous meningitis (TBM) is a serious form of disease of the central nervous system. Early and accurate diagnosis of the disease and effective treatment are key important factors to contain the disease. The disease presents as chronic meningitis where other partners such as fungal meningitis, neurosyphilis, cysticercal meningitis, carcinomatous meningitis and partially treated pyogenic meningitis share a similar clinical picture making the diagnosis complicated. Culturing of the pathogen Mycobacterium tuberculosis (MTB) from the cerebrospinal fluid (CSF) sample has shown a poor response. The main immunological method for the immunodiagnosis of TBM is the detection of an antibody response in the CSF. In the present study, total MTB sonicated extract antigen was used for ELISA and Western blot. ELISA shows overall immune response of the test sample, whereas Western blotting reveals the specific reactivity to a particular molecular weight antigen. This would also reveal the immunodominant antigen. A total of 300 CSF samples were analyzed by both ELISA and Western blotting. Of the 240 clinically suspected TBM cases, 111 samples were positive by ELISA and 81 samples by Western blot. A total of 76 CSF samples were positive by both ELISA and Western blot. None of the control samples showed positivity either by ELISA or by Western blot. TBM patients revealed major antibody reactivity to 30-40 kD region, followed by 14 kD region. ELISA is sensitive with mild non-specific binding, but Western blot is specific in detecting the immune response. The findings will be useful in definitive immunodiagnosis of TBM.

Diagnostic accuracy of intracellular mycobacterium tuberculosis detection for tuberculous meningitis.

RATIONALE: Early diagnosis and treatment of tuberculous meningitis saves lives, but current laboratory diagnostic tests lack sensitivity. OBJECTIVES: We investigated whether the detection of intracellular bacteria by a modified Ziehl-Neelsen stain and early secretory antigen target (ESAT)-6 in cerebrospinal fluid leukocytes improves tuberculous meningitis diagnosis. METHODS: Cerebrospinal fluid specimens from patients with suspected tuberculous meningitis were stained by conventional Ziehl-Neelsen stain, a modified Ziehl-Neelsen stain involving cytospin slides with Triton processing, and an ESAT-6 immunocytochemical stain. Acid-fast bacteria and ESAT-6-expressing leukocytes were detected by microscopy. All tests were performed prospectively in a central laboratory by experienced technicians masked to the patients' final diagnosis. MEASUREMENTS AND MAIN RESULTS: Two hundred and eighty patients with suspected tuberculous meningitis were enrolled. Thirty-seven had Mycobacterium tuberculosis cultured from cerebrospinal fluid; 40 had a microbiologically confirmed alternative diagnosis; the rest had probable or possible tuberculous meningitis according to published criteria. Against a clinical diagnostic gold standard the sensitivity of conventional Ziehl-Neelsen stain was 3.3% (95% confidence interval, 1.6-6.7%), compared with 82.9% (95% confidence interval, 77.4-87.3%) for modified Ziehl-Neelsen stain and 75.1% (95% confidence interval, 68.8-80.6%) for ESAT-6 immunostain. Intracellular bacteria were seen in 87.8% of the slides positive by the modified Ziehl-Neelsen stain. The specificity of modified Ziehl-Neelsen and ESAT-6 stain was 85.0% (95% confidence interval, 69.4-93.8%) and 90.0% (95% confidence interval, 75.4-96.7%), respectively. CONCLUSIONS: Enhanced bacterial detection by simple modification of the Ziehl-Neelsen stain and an ESAT-6 intracellular stain improve the laboratory diagnosis of tuberculous meningitis.

Early diagnosis of tuberculous meningitis by an indirect ELISA protocol based on the detection of the antigen ESAT-6 in cerebrospinal fluid.

BACKGROUND: Early diagnosis of tuberculous meningitis (TBM) is still a challenge; the present study aimed to establish a method of detecting the antigen early secreted antigenic target 6 (ESAT-6) in cerebrospinal fluid (CSF) by an indirect enzyme-linked immunosorbance assay (ELISA) protocol and to study the value of detecting ESAT-6 in CSF in the early diagnosis of TBM. METHODS: An indirect ELISA protocol was used, employing a monoclonal antibody (mAb) against ESAT-6, which was used to demonstrate ESAT-6 in the CSF from TBM patients and non-TBM controls. CSF was obtained from 100 patients: confirmed TBM, clinically diagnosed TBM, disease controls, and healthy controls (n = 10). Pure recombinant ESAT-6 (standard product) was used in serial dilutions to detect the absorbance and to establish a standard curve from the data; the concentration was on the X axis vs. absorbance on the Y axis, and the standard curve was used to interpolate the concentration of ESAT-6 in samples. RESULTS: The indirect ELISA method provided 88 % sensitivity and 92 % specificity for the diagnosis of TBM using a mAb to ESAT-6. The mean concentration of ESAT-6 in TBM patients was significantly higher than that of the non-TBM groups. There was also a significant difference in the mean ESAT-6 expression between the confirmed TBM patients and the clinically diagnosed TBM patients (p < 0.01). CONCLUSIONS: Detection of ESAT-6 in the CSF of TBM patients by indirect ELISA protocol gives a reliable early diagnosis and can be used to develop an immunodiagnostic assay with increased sensitivity and specificity.

A five-year field assessment of rapid diagnostic tests for meningococcal meningitis in Niger by using the combination of conventional and real-time PCR assays as a gold standard.

BACKGROUND: Meningococcocal meningitis represents an important cause of mortality and morbidity in sub-Saharan countries. Confirmatory bacteriological or molecular diagnosis is essential for patient management/treatment and meningitis surveillance, but many laboratory tests are expensive and rarely available for low-income countries. A rapid diagnostic test (RDT) represents a valuable alternative to improve case management and surveillance. METHODS: A dipstick RDT developed in early 2000s that detects Neisseria meningitidis serogroups A, C, W and Y but for which a new conjugated antibody (L4-8) for the detection of serogroup A replaced the original K15-2 was assessed in the field by trained staff from health centres and district hospitals in Niger. The results were compared to those obtained in the reference laboratory and the sensitivity and specificity of RDTs were determined using conventional and real-time PCR assays as a gold standard. RESULTS: RDT results from field staff and the reference laboratory obtained for 2095 cerebrospinal fluid (CSF) specimens presented a strong concordance of 94% with Cohen's κ coefficient of 0.88. The observed concordance between RDTs operated by staff from the reference laboratory vs combination of conventional and real-time PCR assays was 89% with Cohen's κ coefficient of 0.76 indicating very good agreement. The theoretical overall sensitivity for RDT was 91.5% and the specificity 84.6%. CONCLUSIONS: RDT has proven to be relatively sensitive and specific for the detection of meningococcal serogroups A/C/Y/W. We confirmed that these RDTs can be reliably operated by trained but non-specialised staff in basic health facilities.

Comparación de adenosina deaminasa y detección de anticuerpos anti-antígeno A60 para el diagnóstico de meningitis tuberculosa / A comparative study for adenosine deaminase and anti-antigen A-60 antibodies detection for the diagnosis of tuberculous meningitis

Background: Diagnosis of tuberculous meningitis (TBM) is hampered by the lack of rapid and accurate diagnostic tools. We evaluated the immunological response to Mycobacterium tuberculosis anti-A60 antibodies in cerebrospinal fluid (CSF) in comparison to adenosine deaminase (ADA) determination, for the diagnosis of TBM. Methods: A total of 63 CSF samples were analyzed by indirect ELISA for the detection of anti- A60 IgG, IgM and IgA. These include samples from 17 patients with confirmed TBM and 46 control patients with other infections. Results: The mean individual anti-A60 IgM, IgG and IgA CSF antibody titers were significantly higher in TBM in comparison with control groups (p < 0.01). The best discriminatory CSF antibody for confirming TBM diagnosis was IgM, with an area under the receiver operating characteristic curve of 0.928 (95%CI 0.834-0.978), compared to 0.863 (95% CI: 0.752-0.936) for ADA testing (p = NS). The sensitivity of anti- A60 IgM CSF antibody titers (cutoff > 0.06 U/ml) was 94.1% compared to 88.2% for ADA (cutoff > 6.2 U/ml), p = NS. Both anti A60 IgM and ADA showed the same moderate specificity (80.4%). Two cases of TBM were correctly identified by anti-A60 IgM but missed by ADA. Conclusion: The ELISA test for anti-antigen A60 antibodies (IgM) is a rapid and sensitive tool for the rapid diagnosis of TBM that can be a complement to ALDA determination. The specificity of both tests is still a limitation in TBM diagnosis.

Antecedentes: El diagnóstico de meningitis tuberculosa (MTBC) se ve limitado por la ausencia de técnicas diagnósticas rápidas y precisas en líquido cefalorraquídeo (LCR). En este estudio evaluamos la respuesta inmunoló-gica de anticuerpos anti-antígeno A60 de Mycobacterium tuberculosis en LCR en comparación a la determinación de adenosina deaminasa (ADA). Métodos: Un total de 63 muestras de LCR fueron estudiadas mediante ELISA indirecto para detección de IgG, IgM e IgA anti-A60. Estas muestras incluyeron 17 casos de MTBC confirmada y 46 controles con otras infecciones. Resultados: Los títulos de IgG, IgM e IgA anti A-60 resultaron significativamente superiores en casos de MTBC versus controles (p > 0,01). El anticuerpo con mej or poder discriminatorio resultó IgM, con un área bajo la curva ROC de 0,928 (95%IC 0,8340,978), comparado a 0,863 (95% IC: 0,752-0,936) para ADA (p = NS). La sensibilidad de IgM anti-A60 (nivel de corte > 0,06 U/ml) fue de 94,1% versus 88,2% para ADA (nivel de corte > 6,2 U/ml), p = NS. Ambos IgM anti-A60 y ADA presentaron la misma especificidad baja-moderada (80,4%). Dos casos de MMTBC fueron correctamente identificados por IgM anti-A60 pero no por ALDA. Conclusión: La detección de anticuerpos anti-A60 (IgM) puede ser de ayuda en el diagnostico de MTBC en forma complementaria a la determinación de ALDA. La baja especificidad de ambos tests constituye su principal limitante.

Streptococcus pneumoniae serotype-2 childhood meningitis in Bangladesh: a newly recognized pneumococcal infection threat.

BACKGROUND: Streptococcus pneumoniae is a leading cause of meningitis in countries where pneumococcal conjugate vaccines (PCV) targeting commonly occurring serotypes are not routinely used. However, effectiveness of PCV would be jeopardized by emergence of invasive pneumococcal diseases (IPD) caused by serotypes which are not included in PCV. Systematic hospital based surveillance in Bangladesh was established and progressively improved to determine the pathogens causing childhood sepsis and meningitis. This also provided the foundation for determining the spectrum of serotypes causing IPD. This article reports an unprecedented upsurge of serotype 2, an uncommon pneumococcal serotype, without any known intervention. METHODS AND FINDINGS: Cases with suspected IPD had blood or cerebrospinal fluid (CSF) collected from the beginning of 2001 till 2009. Pneumococcal serotypes were determined by capsular swelling of isolates or PCR of culture-negative CSF specimens. Multicenter national surveillance, expanded from 2004, identified 45,437 patients with suspected bacteremia who were blood cultured and 10,618 suspected meningitis cases who had a lumber puncture. Pneumococcus accounted for 230 culture positive cases of meningitis in children <5 years. Serotype-2 was the leading cause of pneumococcal meningitis, accounting for 20.4% (45/221; 95% CI 15%-26%) of cases. Ninety eight percent (45/46) of these serotype-2 strains were isolated from meningitis cases, yielding the highest serotype-specific odds ratio for meningitis (29.6; 95% CI 3.4-256.3). The serotype-2 strains had three closely related pulsed field gel electrophoresis types. CONCLUSIONS: S. pneumoniae serotype-2 was found to possess an unusually high potential for causing meningitis and was the leading serotype-specific cause of childhood meningitis in Bangladesh over the past decade. Persisting disease occurrence or progressive spread would represent a major potential infection threat since serotype-2 is not included in PCVs currently licensed or under development.

[A comparative study for adenosine deaminase and anti-antigen A-60 antibodies detection for the diagnosis of tuberculous meningitis]. / Comparación de adenosina deaminasa y detección de anticuerpos anti-antígeno A60 para el diagnóstico de meningitis tuberculosa.

BACKGROUND: Diagnosis of tuberculous meningitis (TBM) is hampered by the lack of rapid and accurate diagnostic tools. We evaluated the immunological response to Mycobacterium tuberculosis anti-A60 antibodies in cerebrospinal fluid (CSF) in comparison to adenosine deaminase (ADA) determination, for the diagnosis of TBM. METHODS: A total of 63 CSF samples were analyzed by indirect ELISA for the detection of anti- A60 IgG, IgM and IgA. These include samples from 17 patients with confirmed TBM and 46 control patients with other infections. RESULTS: The mean individual anti-A60 IgM, IgG and IgA CSF antibody titers were significantly higher in TBM in comparison with control groups (p < 0.01). The best discriminatory CSF antibody for confirming TBM diagnosis was IgM, with an area under the receiver operating characteristic curve of 0.928 (95%CI 0.834-0.978), compared to 0.863 (95% CI: 0.752-0.936) for ADA testing (p = NS). The sensitivity of anti- A60 IgM CSF antibody titers (cutoff > 0.06 U/ml) was 94.1% compared to 88.2% for ADA (cutoff > 6.2 U/ml), p = NS. Both anti A60 IgM and ADA showed the same moderate specificity (80.4%). Two cases of TBM were correctly identified by anti-A60 IgM but missed by ADA. CONCLUSION: The ELISA test for anti-antigen A60 antibodies (IgM) is a rapid and sensitive tool for the rapid diagnosis of TBM that can be a complement to ALDA determination. The specificity of both tests is still a limitation in TBM diagnosis.