PCR of cerebrospinal fluid for diagnosis of bacterial meningitis during meningococcal epidemics; an example from Sudan

Meningococcal disease is feared due to its rapid progression and high case fatality rate, especially in the African meningitis belt, where epidemics of meningococcal meningitis appear cyclically. Culture, direct microscopy and antigen detection are the basic methods for diagnosis and species identification of bacterial meningitis. These methods are known to have limitations, especially in developing countries. The aim of the present study was to document the application of PCR technology for the diagnosis of bacterial meningitis in cerebrospinal fluid (CSF) samples (n = 52) collected during epidemics in Sudan. In the application of PCR for detection of the causative agent of bacterial meningitis (based on the 16S rRNA gene), bacterial DNA was identified in 49 samples. Common bacterial species causing bacterial meningitis could be detected in 31 of the CSF samples (27 meningococci), while 18 contained DNA, mainly from normally contaminating bacteria. A specific PCR for group A meningococci (based on the sacC gene) was positive in 27 of the CSF samples. The results show that PCR technology is a sharp-edged tool for confirmation of a diagnosis of meningococcal meningitis and for obtaining a direct genogrouping of group A meningococci in CSF. It is important to stress the use of direct and specific PCRs to avoid interference by contaminating bacteria, a great problem in samples from areas in the meningitis belt.     

Predictive Value of Serum and Cerebrospinal Fluid Procalcitonin Levels for the Diagnosis of Bacterial Meningitis

Background: The value of serum and cerebrospinal fluid (CSF) procalcitonin for differentiating between acute bacterial and viral meningitis was assessed and compared to other parameters which are usually used in clinical practice. Patients: 45 adult patients (20 with bacterial and 25 with tick-borne encephalitis, TBE) were included in this prospective study. Results: The median serum procalcitonin level in patients with bacterial meningitis was 6.45 ng/ml (range 0.25–43.76 ng/ml) and in the group with viral meningitis 0.27 ng/ml (range 0.05–0.44 ng/ml). 11 patients with bacterial meningitis had an elevated procalcitonin concentration not only in serum, but also in CSF. A serum procalcitonin level > 0.5 ng/ml had a positive predictive value for bacterial meningitis of 100% and a negative predictive value of 93%, while corresponding values for CSF procalcitonin were 100% and 74%, respectively. Conclusion: Serum and CSF procalcitonin concentrations > 0.5 ng/ml appear to be a reliable indicator of bacterial central nervous system (CNS) infection, with maximal positive predictive values and high negative predictive values. Received: October 23, 2000 · Revision accepted: June 1, 2001     

High sensitivity and specificity of serum procalcitonin levels in adults with bacterial meningitis.

It was shown in children that serum procalcitonin was the best marker to use to differentiate bacterial from viral meningitis. To evaluate procalcitonin in the diagnosis of acute bacterial and viral meningitis, we conducted a prospective study including adult patients who were suspected of having meningitis and who were admitted to an emergency department. Cerebrospinal fluid (CSF) and serum levels of procalcitonin were measured in 105 consecutive patients. The diagnosis of meningitis was based on clinical findings, gram staining, culture, and chemical analysis of CSF. Twenty-three patients had bacterial meningitis, 57 had viral meningitis, and 25 did not have meningitis. Bacteriologic and chemical analysis of CSF did not allow correct differentiation of viral from bacterial meningitis. On the other hand, a serum procalcitonin level >0.2 ng/mL had a sensitivity and specificity of up to 100% in the diagnosis of bacterial meningitis. Serum procalcitonin levels seem to be the best marker in differentiating between bacterial and viral meningitis in adults.     

联检脑脊液中LAM-IgG和TB-DNA在诊断结核性脑膜炎中的应用

目的　了解脑脊液 (CSF)中阿拉伯糖甘露糖脂IgG抗体 (LAM-IgG)和TB-DNA指标对结脑的诊断价值。方法 以CSF为标本,用酶联免疫吸附试验 (ELISA)检测LAM-IgG,用聚合酶链反应(PCR)检测TB-DNA。结果 102份结脑病人CSF标本,LAM-IgG阳性率51.0% (52102),TB-DNA阳性率81.4% (83102),LAM-IgG阳性及 或TB-DNA阳性共93例 (91.2%)。40份非结核性的中枢神经系统疾病病例的CSF标本,均未检出LAM-IgG和TB-DNA.结论 LAM-IgG和TB-DNA均是诊断结脑的较好的指标,两者联检可进一步提高检测敏感性。     

The leukocyte esterase test for detection of cerebrospinal fluid leukocytosis and bacterial meningitis

We conducted a study to assess the efficacy of the dipstick leukocyte esterase test (LET) in the detection of cerebrospinal fluid (CSF) leukocytosis as a quick screen for bacterial meningitis. Nine hundred forty-two CSF samples were collected from 800 patients. The LET was compared in a double-blinded fashion with routine cell count determinations and cultures. We reviewed the clinical courses of all patients with positive cultures to assess the significance of culture isolates. Statistical analysis revealed LET sensitivity of 84.4% and specificity of 98.1% for clinical presentations of bacterial meningitis for which initiation of therapy is currently recommended. The LET identified culture-proven cases of meningitis with sensitivity of 73% and specificity of 95%. We propose the LET as an adjunct to, but not a replacement for, CSF cell count and chemistry determination in the initial laboratory assessment of bacterial meningitis. It is a reasonable screen that allows rapid initiation of treatment and directs the laboratory technician to devote extra attention to examination of a CSF specimen with a higher likelihood of pathology.     

Bacteria and viruses induce production of interferon in the cerebrospinal fluid of children with acute meningitis: a study of 57 cases and review.

The CSF of 57 infants and children with bacterial or enterovirus meningitis was analyzed for the presence of interferon (IFN). CSF was collected when the diagnosis of meningitis was made; a bacterium or enterovirus was isolated in all cases. IFN was detectable in CSF in 24% of cases of bacterial meningitis and in 75% of cases of viral meningitis. Titers of IFN were generally lower in cases of bacterial meningitis. Neither the presence of IFN nor the level of IFN titers correlated with the patient's age or number of white blood cells or mononuclear cells in the CSF. Coxsackievirus induced production of IFN more consistently and in higher titers than did echovirus. None of 35 control patients had detectable IFN in CSF. A literature review and our data indicate that the presence of IFN in CSF suggests infection of the CNS but does not differentiate bacterial from viral infection. The finding of IFN in the CSF of children with bacterial meningitis supports evidence that bacteria and other nonviral microorganisms induce IFN production. The protective role of IFN in nonviral infections deserves further investigation.     

隐球菌性脑膜炎26例临床分析

目的 总结隐球菌性脑膜炎的资料,提高对隐球菌性脑膜炎的认识。方法 回顾性总结近20年（1981年10月至2001年9月）隐球菌性脑膜炎的一般资料,诊断及治疗情况。结果 共26例患者,其中男12例,女14例,年龄5－62岁,平均35．6岁,有基础疾病者16例,其中系统红斑狼疮（SLE）9例,人类免疫缺陷病毒感染或艾滋病（HIV／AIDS）4例,其他疾病3例;有明确鸽子接触史者12例;误诊结核性脑膜炎者5例,狼疮脑病者6例;墨汁染色找到隐球菌者23例（23／26）,乳胶凝集试验抗原阳性20例（20／20）。颅内压明显增高＞300mm H2O者15例,脑室扩大行侧脑室引流者9例;12例给予两性霉素B（AmpB) 5氟胞嘧啶,6例又同时加氟康唑治疗,5例AmpB 氟康唑,1例单纯应用AmpB治疗。AmpB最大用量：AmpB10.05g 脂质体两性霉素B20g,平均用量2.6g;治愈17例,好转4例,死亡或自动出院5例。同时发现近5年隐球菌性脑膜炎病例数明显增多。结论 近年来,隐球菌性脑膜炎发病率明显增高,可能和免疫抑制剂和糖皮质激素的应用及HIV／AIDS增多有关,减少病死的关键在于提高早期诊断率,治疗仍首选AmpB加5氟胞嘧啶,侧脑室引流可减少AmpB的用量,提高治愈率,缩短疗程。     

Positive blood cultures and diagnosis of bacterial meningitis in cases with negative culture of cerebrospinal fluid

The diagnosis of bacterial meningitis may be established through positive blood cultures in cases with negative culture of cerebrospinal fluid (CSF). However, information is sparse regarding how often the aetiological diagnosis is determined by blood culture alone. Therefore, we undertook a retrospective study of patients with meningitis and a blood culture-based bacterial diagnosis in North Jutland County, Denmark in 1997-2005. Patients were included if they had 1) a microscopy- and culture-negative CSF specimen with a leukocyte count > or =100x10(6)/l and an erythrocyte count < or =10,000x10(6)/l and 2) a positive blood culture within an interval of 3 d. A total of 20 patients fulfilled these criteria: 7 with Streptococcus pneumoniae, 4 with Neisseria meningitidis, 4 with Staphylococcus aureus, and 5 with miscellaneous bacteria. Suitable antibiotic therapy was delayed up to 48 h after lumbar puncture, and in-hospital mortality was 25%. A discharge diagnosis of bacterial meningitis was missing in 6/20 cases, and 12/20 cases had not been reported to Danish health authorities. Thus, patients with CSF-culture negative bacterial meningitis are at risk of delayed therapy, a poor outcome, and incomplete notification to health authorities.     

Usefulness of rapid antigen detection for the diagnosis of systemic infections due to Haemophilus influenzae]

Twenty-eight cases of systemic infections due to Haemophilus influenzae diagnosed from October 1988 to December 1998 were analyzed retrospectively. The clinical manifestations were 13 meningitis (15 episodes), 9 septic arthritis, 4 acute epiglottitis, 1 septicemia and 1 lung abscess. In the 15 meningitis episodes, 13 had positive CSF culture results, and the other 2 episodes of pretreated with antibiotics were diagnosed by H. influenzae type b (Hib) antigen detection by using concentrated urine specimens. In the 9 septic arthritis cases, 6 had positive synovial fluid culture results. Of the 3 cases with negative results on Gram stain and on synovial fluid and blood cultures, etiological diagnosis was established by Hib antigen detection in synovial fluid. Results of Hib antigen detection were positive in all 8 cases (100%). In 6 of these 8 cases, antimicrobial therapy was started by the results of antigen detection. In the 4 acute epiglottitis, 2 had positive blood culture results, and the other 1 case was diagnosed by Hib antigen detection by using concentrated urine specimen. In 3 of these 4 cases, H. influenzae strains isolated from nasopharyngeal swab or aspirated sputum were serotyped as type b. In this study, rapid antigen detection has several advantages in the rapid laboratory diagnosis of systemic infections due to Haemophilus influenzae. 1. The detection of Hib antigen is the only way to diagnose bacterial etiology of infection in patients who had received partially treatment with antimicrobials. Urine is as an appropriate specimen for antigen testing as CSF in patients with suspected Hib meningitis. Moreover, to detect Hib antigen in synovial fluid is clinically useful in septic arthritis. 2. Both the antigen detection and Gram stain made the rapid presumptive identifications and effected therapeutic decision making. 3. Antigen detection methods have also been used in serotyping of clinical isolates. We conclude that rapid antigen detection is a very useful tool for the rapid etiological diagnosis and guideline for the choice of antimicrobials in systemic infections due to Hib. It is necessary to diagnose bacterial etiology as a routine procedure using not only Gram stain and culture but also rapid antigen detection technique in patients with suspected Hib systemic infection.     

Primary and opportunistic pathogens associated with meningitis in adults in Bangui, Central African Republic, in relation to human immunodeficiency virus serostatus.

OBJECTIVE: To determine the causative organisms and characteristics of patients presenting with meningitis in Bangui in order to provide guidance to physicians for case management. METHODS: Adults with proven or suspected meningitis were enrolled in this prospective study. LABORATORY TESTS: Full blood count, blood chemistry, and HIV tests were performed. Cerebrospinal fluid (CSF) was submitted for routine microbiology, chemistry (glucose, protein), and hematology testing. When classical microbiology analyses were negative, a broad-range bacterial polymerase chain reaction (BRBPCR) was used. RESULTS AND CONCLUSIONS: Of the 276 patients enrolled, 215 (77.9%) were HIV positive. In HIV-positive patients cryptococcal meningitis (CM) was the most common cause of meningitis (39.1%) followed by pyogenic meningitis (PM) (30.7%), mononuclear meningitis (MM) (28.8%), and tuberculous meningitis (TM) (1.4%). In HIV-negative patients, PM was the most common cause (60.7%) followed by MM (37.7%) and CM (1.6%, one case). In-hospital mortality was higher in HIV-positive patients (73/128 = 57%) compared to those HIV negative (3/18 = 16.7%) (p = 0.001). Streptococcus pneumoniae (n = 26) was the most common bacterial diagnosis, mainly in HIV-positive patients (n = 22, 10.2%). Meningococcal meningitis (14 Neisseria meningitidis of group A and one W135) was diagnosed in nine (4.2%) HIV-positive and six (9.8%) HIV-negative patients. Gram-negative rods were isolated from five HIV-positive and two HIV-negative patients, respectively. The bacteria and fungi involved in meningitis did not display high levels of in vitro resistance. Conventional microbiology techniques failed to detect the causative agent in 55 (53.4%) PM cases. Broad-range bacterial PCR detected DNA from S. pneumoniae in three samples, N. meningitidis in two, Escherichia coli in one, Listeria monocytogenes in two and Staphylococcus aureus in one sample. In the CSF of five (three HIV negative and two HIV positive), PCR products were not identified with the oligonucleotide probes specific for the usual species of bacteria found in CSF, or genera commonly considered potential contaminants of clinical samples. Among the MM cases, 77 (90.5%) probable viral meningitis (54 HIV positive and 23 HIV negative) and eight TM (HIV positive) were suspected.     

Lack of sensitivity of the latex agglutination test to detect bacterial antigen in the cerebrospinal fluid of patients with culture-negative meningitis.

For culture-negative meningitis, use of the latex agglutination test for detection of bacterial antigen in the CSF has a sensitivity of only 7%. Routine use of the latex agglutination test may not contribute to the management of suspected acute bacterial meningitis, since patients are treated on the basis of their clinical presentations and CSF findings.     

Detection of Cysticercus antigens and antibodies in cerebrospinal fluid of patients with chronic meningitis

Chronic meningitism is a less frequent manifestation of neurocysticercosis caused by Taenia solium cysticerci. In the present study we used Co-agglutination (Co-A), a simple and rapid slide agglutination test to detect specific Cysticercus antigen in the 67 cerebrospinal fluid (CSF) samples from patients with chronic meningitis of unknown etiology. The results were compared with that of ELISA for detection of antibodies. Among these samples four (5.97%) were positive for Cysticercus antigen by Co-A test and six (8.95%) were positive for antibodies by ELISA. Two samples were positive by both Co-A and ELISA, two were positive only by Co-A and four were positive only by ELISA. In the present study, although Cysticercus antigen and antibodies were present in CSF samples from eight (11.94%) patients, we cannot affirm that all the cases of chronic meningitis are due to cysticercosis, but for any case of chronic meningitis of unknown origin, it would be useful to consider the possibility of cysticercal meningitis.     

脑脊液维生素D结合蛋白在脑膜炎中的水平及对临床治疗效果的影响

目的研究脑脊液维生素D结合蛋白水平在脑膜炎中的表达特征及其对治疗效果的影响。 方法选择2016年6月至2019年6月期间收治的107例脑膜炎患者作为研究对象,其中病毒性脑膜炎26例、细菌性脑膜炎63例、结核性脑膜炎18例,检测所有患者脑脊液维生素D结合蛋白的水平,然后根据脑脊液维生素D结合蛋白的表达水平分为高水平组和低水平组,比较高水平组和低水平组患者对治疗的敏感性、临床治疗效果及预后。 结果细菌性脑膜炎患者脑脊液VDBP平均水平（3.23±0.98）μg/mL低于病毒性脑膜炎（3.87±1.19）μg/mL、结核性脑膜炎（4.02±1.40）μg/mL,差异有统计学意义（P<0.05）。VDBP高水平组患者平均起效时间（4.82±1.46）d长于VDBP低水平组（3.75±1.19）d,临床疗效的平均秩次（60.33）低于VDBP低水平组（88.50）,不良事件发生率（64.29%）、并发症发生率（57.14%）均高于VDBP低水平组（24.14%、24.14%）,差异均有统计学意义（P<0.05）。 结论脑膜炎患者中脑脊液VDBP含量越高,患者治疗起效时间越长,疗效越差,且出现不良事件和并发症的概率更高,可以作为一个指导临床治疗和不良事件预防的参考指标。     

不典型表现的结核性脑膜炎62例临床分析

目的　总结不典表现的结核性脑膜炎 (结脑)的诊断与治疗。方法 回顾性分析 62例不典型结脑患者的临床资料。结果 本组病例在临床上没有典型的结脑症状，表现意识障碍 17例(27.4%)、头晕、低热 47例 (75.8%)、乏力、精神萎靡 13例 (21.0%)；肢体麻木 21例 (33.9%)、瘫痪5例 (8.1%)、颅神经损害 18例 (29.0%)和尿潴留 10例；(16.1%)、癫痫样发作 4例 (6.5%)。胸部影像学检查阳性 37例 (59.7%)、头颅CT阳性 13例 (21%)。脑脊液检查 :糖降低 30例 (48.4%)、氯化物降低 32例 (51.6%)、蛋白升高 36例 (58.1%)、腺苷酸脱氨酶 (ADA)阳性 58例 (93.5%)、结核抗体 (PPD IgG)阳性 48例 (77.4%)、涂片抗酸杆菌阳性 2例 (3.2%)。 61例经抗结核治疗痊愈，1例死亡。结论 不典型结脑临床表现缺乏特异性，脑脊液改变不典型，但脑脊液中结核抗体阳性对于诊断中枢神经系统结核病有参考意义，且腺苷酸脱氨酶是一个敏感及特异性强的指标，实验实及影像学检查对确诊该病有重要意义。规范抗结核治疗配合鞘内注射效果佳。     

Cerebrospinal fluid adenosine deaminase activity for the diagnosis of tuberculous meningitis in adults

We studied adenosine deaminase (ADA) activity in cerebrospinal fluid (CSF) of 16 cases of tuberculous meningitis, 4 cases of cryptococcal meningitis, 5 cases of bacterial meningitis, 12 cases of eosinophilic meningitis, 26 cases of aseptic meningitis, 6 cases of carcinomatous meningitis and 108 cases with normal CSF. The mean CSF ADA values for the different groups were: 39.44 +/- 41.46, 13.00 +/- 7.43, 34.20 +/- 40.81, 3.17 +/- 4.82, 10.03 +/- 9.23, 8.67 +/- 13.60, and 2.58 +/- 2.90 U/I, respectively. Comparing the ADA activity between patients with tuberculous meningitis and non-tuberculous meningitis, the receiver-operating characteristic (ROC) curve identified a CSF ADA level of 15.5 U/I as the best cut-off value to differentiate between the two, with a sensitivity of 75% and a specificity of 93%, with an area under the curve of 0.92. When tuberculous meningitis was compared with aseptic and carcinomatous meningitis, the ROC curve identified a CSF ADA level of 19.0 U/I as the best cut-off value for differentiation, with a sensitivity of 69% and a specificity of 94%, with an area under the curve of 0.83. The level of CSF ADA may be useful as a complementary tool in the early diagnosis of tuberculous meningitis.     

Meningitis without a petechial rash in children in the Hib vaccine era

AIMS: (1) To determine the causes of meningitis in children immunized with Hib vaccine, presenting without a non-blanching rash; (2) to review the use of dexamethasone in this group. METHOD: Retrospective review of all children with more then 10 white cells/mm(3) in their cerebrospinal fluid (CSF), admitted between January 1998 and August 2002. Children were excluded if they had a non-blanching rash on admission or if their discharge diagnosis was not meningitis. Local guidelines recommended dexamethasone to be given before antibiotics for children with meningitis and no rash. RESULTS: One hundred and eight children were identified. Causes of proven meningitis were: viral 41 (enterovirus 40), bacterial 22. CSF culture or PCR was the only diagnostic test in 31 children. Dexamethasone was given to 16 children. Length of admission was shorter in children with viral compared with bacterial meningitis (4 vs 8 days; P < 0.0001). SUMMARY: Viral meningitis is the commonest cause of meningitis without rash. Enteroviral PCR was the most useful test and needs to be widely available. Confirmation of enteroviral meningitis allowed early discharge. Few children were given dexamethasone, but only 5/108 may have benefited. CONCLUSIONS: The most common cause of meningitis without a rash in British children is enterovirus. The use of dexamethasone in children with meningitis without a rash should be reconsidered or, at least, individualised.     

General principles of therapy of pyogenic meningitis

In bacterial meningitis, several pharmacodynamic factors determine therapeutic success-when defined as sterilization of the CSF: (1) Local host defense deficits in the CNS require the use of bactericidal antibiotics to sterilize the CSF. (2) CSF antibiotic concentrations that are at least 10-fold above the MBC are necessary for maximal bactericidal activity. Protein binding, low pH, and slow bacterial growth rates are among the factors that may explain the high antibiotic concentrations necessary in vivo. (3) High CSF peak concentrations that lead to rapid bacterial killing appear more important than prolonged suprainhibitory concentrations, probably because very low residual levels in the CSF prevent bacterial regrowth, even during relatively long dosing intervals. (4) Penetration of antibiotics into the CSF is significantly impaired by the blood-brain barrier and thus, very high serum levels are necessary to achieve the CSF concentrations required for optimal bactericidal activity. Beyond these principles, recent data suggests that rapid lytic killing of bacteria in the CSF may have harmful effects on the brain because of the release of biologically active products from the lysed bacteria. Since rapid CSF sterilization remains a key therapeutic goal, the harmful consequences of bacterial lysis present a major challenge in the therapy of bacterial meningitis. Currently, dexamethasone represents that only clinically beneficial approach to reduce the harmful effects of bacterial lysis, and novel approaches are required to improve the outcome of this serious infection.     

Handheld Point-of-Care Cerebrospinal Fluid Lactate Testing Predicts Bacterial Meningitis in Uganda

We validated a handheld point-of-care lactate (POCL) monitor''s ability to measure lactate in cerebrospinal fluid (CSF) and diagnose bacterial meningitis in Uganda. There was a strong linear correspondence between POCL and standard laboratory lactate test results (R² = 0.86; P < 0.001). For 145 patients with clinical meningitis, the area under the receiver operating characteristic curve for the prediction of bacterial meningitis by CSF POCL was 0.92 (95% confidence interval = 0.85–0.99, P < 0.001). A CSF POCL concentration of 7.7 mmol/L provided 88% sensitivity and 90% specificity for the diagnosis of bacterial meningitis. CSF POCL testing had excellent use in the diagnosis of bacterial meningitis, and it may be useful where CSF analyses are delayed or laboratory infrastructure is limited.     

Staphylococcus aureus meningitis: experience with cefuroxime treatment during a 16 year period in a Danish region

Staphylococcus aureus is a rare cause of bacterial meningitis and there is no consensus on antibiotic treatment. Nafcillin is a common choice in countries where it is approved and marketed. High-dose cefuroxime has been the systemic treatment used in the study region, and a retrospective record review was conducted to determine its clinical efficacy. Cases of bacterial meningitis during 1984-1999 in the County of North Jutland, Denmark (approx. 490000 inhabitants), were identified in a regional bacteriology register. Inclusion of a case required either growth of S. aureus from > or = 2 specimens of cerebrospinal fluid (CSF), 1 positive CSF specimen with a CSF leucocyte count > 10(8)/l or 1 positive CSF specimen with a concurrent positive blood culture. A diagnosis of brain abscess required growth of S. aureus from aspirated pus. Staphylococcus aureus meningitis was confirmed in 45 patients, and 5 additional patients had a brain abscess. 44 cases were nosocomial (mortality 16%) and 6 were community acquired (mortality 83%). None of the isolates was methicillin resistant and 6 were penicillin susceptible. Intraventricular antibiotic treatment was given to 28 patients, systemic therapy included cefuroxime in 32 patients (64%) as either a primary or secondary choice, 6 (12%) were treated with penicillin G, 10 (20%) with penicillinase-resistant penicillin and 2 (4%) with cephalothin. Among 31 nosocomial cases treated systemically with cefuroxime the mortality was 10% (95% exact confidence limits 2-26%). In conclusion, cefuroxime seems to be a valid choice for S. aureus meningitis in the nosocomial setting.