Nosocomial meningitis in a university hospital between 1993 and 2002

Epidemiology and antimicrobial resistance patterns of bacterial meningitis among hospitalized patients at a tertiary care hospital in Saudi Arabia: a six-year retrospective study

INTRODUCTION

Bacterial meningitis poses significant medical challenges due to its acute inflammatory nature and potential for severe neurological complications, emphasizing the need for prompt diagnosis and treatment. Limited data exists on its epidemiology and antimicrobial resistance trends among hospitalized patients in Saudi Arabia. This study aimed to investigate these factors at a tertiary care hospital over six years.

METHODS

A retrospective analysis was conducted on cerebrospinal fluid samples results from 222 bacterial meningitis cases among hospitalized patients between 2018 and 2023. Demographic, clinical, microbiological data, and antibiotic susceptibility patterns were collected and analyzed.

RESULTS

Pseudomonas aeruginosa (43%) was the predominant pathogen isolated. Neonates (16%) and children (47%) were most affected population. Nosocomial meningitis accounted for 92% of cases, mainly in the intensive care settings (50.45%). Extended-spectrum beta-lactamase was the leading resistance pattern (12.2%). Seasonal variation was observed, with a peak incidence in October-November.

CONCLUSION

The study highlights the substantial burden of bacterial meningitis among hospitalized patients, especially among high-risk groups. Emerging antimicrobial resistance emphasizes the need for optimized surveillance and stewardship. Future prospective research employing molecular techniques across multiple centers in the country is warranted to enhance understanding and guide public health strategies in Saudi Arabia.

Characteristics and outcomes of cerebrospinal fluid shunt and drain-associated infections

INTRODUCTION

Data on infections associated with cerebrospinal fluid shunt (CSF-S) or device-associated infection (CSF-SDI) are limited in adults. We performed a retrospective study to describe characteristics, management, and outcome of CSF-SDI.

METHODS

All patients with CSF-SDI and admitted to our institution from January 2013 to December 2019 were included.

RESULTS

Among 50 patients, fifty-six episodes of CSF-SDI (41 external ventricular device-associated infections (CSF-D) and 15 other shunt infections (CSF-S) were included. The incidence of CSF-SDI was 11.9 %. Fever was the most common symptom (81 %). Enterobacterales were more prevalent in CSF-S than in CSF-D (20 % vs 53 %, p = 0.02). As regards CSF-D, deceased patients (11/41, 27 %) more frequently had a Glasgow coma scale score decreasing from baseline (p < 0.01), lower glycorrhachia (p < 0.01), a higher protein level in CSF (p = 0.001) and a positive control CSF culture (p = 0.031).

CONCLUSIONS

CSF-SDIs are rare but with a high mortality rate. Mortality was more closely related to the infection than to comorbidities or underlying neurosurgical disease. A second CSF analysis significantly helped to detect patients with CSF-D with a poor prognosis.

Diagnostic Significance of Targeted Next-Generation Sequencing in Central Nervous System Infections in Neurosurgery of Pediatrics

Background

Cerebrospinal fluid (CSF) pathogen culture suffers from the drawbacks of prolonged cycle time and a low positivity rate in diagnosing intracranial infections in children. This study aims to investigate the diagnostic potential of targeted next-generation sequencing (tNGS) in pediatric neurosurgery for central nervous system (CNS) infections.

Methods

A retrospective study was conducted on children under 14 with suspected intracranial infections following craniocerebral trauma or surgery between November 2018 and August 2020. Routine, biochemical, smear, and pathogen culture tests were performed on CSF during treatment. The main parameters of CSF analysis encompassed white blood cells (WBC, ×10⁶/L) count, percentage of multinucleated cells (%), protein levels (g/L), glucose concentration (GLU, mmol/L), chloride levels (mmol/L), and pressure (mmH2O). The outcomes of tNGS were assessed through the Receiver Operating Characteristic (ROC) curve and pertinent diagnostic parameters.

Results

Among the 35 included pediatric patients, 22 were clinically diagnosed with CNS infection in neurosurgery, tNGS was confirmed in 18 cases. The sensitivity and specificity of tNGS were 81.8% and 76.9%, respectively, while the traditional method of CSF cultures and smears exhibited a sensitivity of 13.6% and a specificity of 100%. ROC curve analysis indicated an area under the curve (AUC) of 0.794 for tNGS and 0.568 for the CSF cultures and smears. CSF analysis indicated that the two groups exhibited statistically significant differences in terms of WBC count [330.0 (110.00-2639.75) vs 14.00 (4.50-26.50), P<0.001] and percentage of multinuclear cells (%) [87.50 (39.75-90.00) vs 0 (0-10.00), P<0.001]. However, the remaining parameters did not statistically significant differences between the groups (all P>0.05).

Conclusion

tNGS demonstrates a high degree of diagnostic accuracy when detecting infections within the CNS of pediatric neurosurgery patients. tNGS can effectively establish for diagnosing CNS infections by detecting pathogenic microorganisms and their corresponding virulence and/or resistance genes within the test samples.

Intrathecal Colistin Induced Chemical Meningitis in a Case of Multi-Drug Resistant Acinetobacter baumannii Meningitis

The possibility of encountering multi-drug resistant Gram-negative bacteria is higher in nosocomial meningitis. These bacteria are clinically important because of their higher mortality rate, and colistin is almost the only treatment option in resistant strains. However, intrathecal administration of colistin can result in chemical meningitis. We reported a case with chemical meningitis during the intravenous sulbactam plus colistin and intrathecal colistin therapy for multi-drug resistant Acinetobacter baumannii meningitis. Cerebrospinal fluid findings of the patient improved after discontinuation of intrathecal colistin therapy. This reversible complication may occur during intrathecal therapy. Discontinuation of intrathecal therapy or reducing the antibiotic dose will be the most appropriate approach to manage such cases.

Nosocomial meningitis in intensive care: a 10-year retrospective study and literature review

Background

Nosocomial meningitis is a medical emergency that requires early diagnosis, prompt initiation of therapy, and frequent admission to the intensive care unit (ICU).

Methods

A retrospective study was conducted in adult patients diagnosed with nosocomial meningitis who required admission to the ICU between April 2010 and March 2020. Meningitis/ventriculitis and intracranial infection were defined according to Centers for Disease Control and Prevention guidelines.

Results

An incidence of 0.75% of nosocomial meningitis was observed among 70 patients. The mean patient age was 59 years and 34% were ≥65 years. Twenty-two percent of patients were in an immunocompromised state. A clear predisposing factor for nosocomial meningitis (traumatic brain injury, basal skull fracture, brain hemorrhage, central nervous system [CNS] invasive procedure or device) was present in 93% of patients. Fever was the most frequent clinical feature. A microbiological agent was identified in 30% of cases, of which 27% were bacteria, with a predominance of Gram-negative over Gram-positive. Complications developed in 47% of cases, 24% of patients were discharged with a Glasgow coma scale <14, and 37% died. There were no clear clinical predictors of complications. Advanced age (≥65 years old) and the presence of complications were associated with higher hospital mortality.

Conclusions

Nosocomial meningitis in critical care has a low incidence rate but high mortality and morbidity. In critical care patients with CNS-related risk factors, a high level of suspicion for meningitis is warranted, but diagnosis can be hindered by several confounding factors.

Clinical Features of Post-Operative Nosocomial Meningitis in Adults and Evaluation of Efficiency of Intrathecal Treatment

Background: Post-operative nosocomial meningitis is a critical complication that develops in patients after neurosurgical interventions and operations. Patients and Methods: Data were collected for 65 patients who were diagnosed as having nosocomial meningitis after neurosurgery. The agent profile, clinical and biochemical differences in gram-negative and gram-positive meningitis, and the effectiveness of intrathecal antibiotic administration in cases with carbapenem-resistant gram-negative agents were evaluated. Results: Gram-negative bacteria were isolated in 52.3% of patients. In gram-negative cases of post-operative nosocomial meningitis, white blood cell count (p = 0.015), C-reactive protein (p = 0.001), cerebrospinal fluid leukocyte count (p = 0.0001), and protein (p = 0.0001) were higher, and glucose (p = 0.002) was lower. Concurrent bacteremia (p = 0.041), 14-day mortality (p = 0.022), and 30-day mortality (p = 0.023) were higher in gram-negative cases. Empirical treatment was appropriate in 78.5% of the patients. Seventeen patients (26.2%) received intrathecal antibiotic agents in addition to intravenous antibiotic treatment because of carbapenem-resistant gram-negative bacteria. Nine (53%) of the patients receiving intrathecal therapy had Acinetobacter baumannii as the agent, six had Klebsiella pneumoniae (35.4%), one had Pseudomonas aeruginosa (5.8%), and one had Providencia rettgeri (5.8%). The mean intravenous treatment duration was 21.4 ± 10.6 (4-60) days, and the mean intrathecal treatment duration was 17.6 ± 14.0 (1-51) days. Eleven patients received colistimethate sodium intrathecally (1 × 10 mg/d), three patients received amikacin intrathecally (1 × 10 mg/d), and three patients received gentamicin intrathecally (1 × 10 mg/d). Clinical and microbiologic treatment success was achieved in nine patients (53%). Conclusions: In cases of meningitis caused by carbapenem-resistant agents, intrathecal administration of antibiotic agents such as gentamicin, amikacin, and colistin with limited blood-brain barrier transition in intravenous administration will increase survival. Therefore, intrathecal antibiotic administration should be considered as a part of routine of nosocomial meningitis.

2017 Infectious Diseases Society of America's Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis

The Infectious Diseases Society of America (IDSA) Standards and Practice Guidelines Committee collaborated with partner organizations to convene a panel of 10 experts on healthcare-associated ventriculitis and meningitis. The panel represented pediatric and adult specialists in the field of infectious diseases and represented other organizations whose members care for patients with healthcare-associated ventriculitis and meningitis (American Academy of Neurology, American Association of Neurological Surgeons, and Neurocritical Care Society). The panel reviewed articles based on literature reviews, review articles and book chapters, evaluated the evidence and drafted recommendations. Questions were reviewed and approved by panel members. Subcategories were included for some questions based on specific populations of patients who may develop healthcare-associated ventriculitis and meningitis after the following procedures or situations: cerebrospinal fluid shunts, cerebrospinal fluid drains, implantation of intrathecal infusion pumps, implantation of deep brain stimulation hardware, and general neurosurgery and head trauma. Recommendations were followed by the strength of the recommendation and the quality of the evidence supporting the recommendation. Many recommendations, however, were based on expert opinion because rigorous clinical data are not available. These guidelines represent a practical and useful approach to assist practicing clinicians in the management of these challenging infections.

Epidemiologic and microbiologic evaluation of nosocomial infections associated with Candida spp in children: A multicenter study from Istanbul, Turkey

BACKGROUND

The purpose of this study was to establish species distribution of Candida isolates from pediatric patients in Istanbul, Turkey, and to determine risk factors associated with nosocomial Candida infections.

METHODS

This study was conducted between June 2013 and June 2014 by participation of 7 medical centers in Istanbul. Candida spp strains isolated from the clinical specimens of pediatric patients were included. Clinical features were recorded on a standardized data collection sheet.

RESULTS

A total of 134 systemic Candida infections were identified in 134 patients. The patients were admitted in pediatric and neonatal intensive care units (41.8% and 9.7%, respectively) and in pediatric wards (48.5%). Candida albicans was the most prevalent species (47%), followed by Candida parapsilosis (13.4%), Candida tropicalis (8.2%), Candida glabrata (4.5%), Candida lusitaniae (3.7%), Candida kefyr (2.2%), Candida guilliermondii (1.5%), Candida dubliniensis (0.7%), and Candida krusei (0.7%). Types of Candida infections were candidemia (50.7%), urinary tract infection (33.6%), surgical site infection (4.5%), central nervous system infection (3.7%), catheter infection (3.7%), and intra-abdominal infection (3.7%). In multivariate analysis, younger age (1-24 months) and detection of non-albicans Candida spp was found to be risk factors associated with candidemia (P = 0.040; odds ratio [OR], 4.1; 95% confidence interval [CI], 1.06-15.86; and P = 0.02; OR, 2.4; 95% CI, 1.10-5.53, respectively).

CONCLUSIONS

This study provides an update for the epidemiology of nosocomial Candida infections in Istanbul, which is important for the management of patients and implementation of appropriate infection control measures.

Clinical Characteristics and Predictors of Adverse Outcome in Adult and Pediatric Patients With Healthcare-Associated Ventriculitis and Meningitis

Background. Healthcare-associated meningitis or ventriculitis is a serious and life-threatening complication of invasive neurosurgical procedures or penetrating head trauma.

Methods. We performed a retrospective study of adults and children with the diagnosis of healthcare-associated meningitis or ventriculitis, as defined by the 2015 Centers of Disease Control and Prevention case definition, at 2 large tertiary care hospitals in Houston, Texas from July 2003 to November 2014. Patients were identified by infection control practitioners and by screening cerebrospinal fluid samples sent to the central laboratory. We collected data on demographics, clinical presentations, laboratory results, imaging studies, treatments, and outcomes.

Results. A total of 215 patients were included (166 adults and 49 children). A positive cerebrospinal fluid culture was seen in 106 (49%) patients, with the majority of the etiologies being Staphylococcus and Gram-negative rods. An adverse clinical outcome was seen in 167 patients (77.7%) and was defined as death in 20 patients (9.3%), persistent vegetative state in 31 patients (14.4%), severe disability in 77 patients (35.8%), or moderate disability in 39 patients (18.1%). On logistic regression analysis, age >45 years (adjusted odds ratio [OR], 6.47; 95% confidence interval [CI], 2.31–18.11; P ≤ .001), abnormal neurological exam (adjusted OR, 3.04; 95% CI, 1.27–7.29; P = .013), and mechanical ventilation (adjusted OR, 5.34; 95% CI, 1.51–18.92; P = .01) were associated with an adverse outcome.

Conclusions. Healthcare-associated meningitis or ventriculitis is associated with significant morbidity and mortality.

Pseudomonas aeruginosa meningitis/ventriculitis in a UK tertiary referral hospital

BACKGROUND

Pseudomonas aeruginosa is a rare cause of meningitis and ventriculitis but is generally associated with significant morbidity and mortality.

AIM

We sought to determine the epidemiology, risk factors and outcome of meningitis and ventriculitis due to P. aeruginosa at our institution in order to inform preventive strategies and treatment guidelines.

METHODS

Retrospective study of all patients with a positive cerebrospinal fluid (CSF) culture admitted to a tertiary care hospital over 18 years. Clinical details, demographic, microbiological and antibiotic data were obtained from laboratory and medical records.

RESULTS

Twenty-four episodes occurred in 21 patients over 18 years. Pyrexia (75%), fluctuating mental status (50%) and headache (41%) were the most frequent presenting symptoms. Nineteen of the 21 patients had previously undergone a neurosurgical procedure and seven had extra-ventricular devices in situ. Twelve (57%) patients had P. aeruginosa isolated from another site prior to their episode. Most (89%) CSF samples demonstrated a neutrophilia; the CSF protein, when measured, was raised in all cases. Gram-negative bacilli were visible on CSF microscopy in only three isolates. There were relatively low rates of resistance to most antimicrobials tested and combination treatment of intravenous with intrathecal antibiotics was often used. No patients died within 28 days.

CONCLUSION

Pseudomonas aeruginosa meningitis and ventriculitis are predominantly nosocomial and related to prior neurosurgery. It can be difficult to diagnose as CSF Gram-film and meningism are insensitive markers. Appropriate empirical treatment, neurosurgical prophylaxis and surveillance can aid in managing this infection.

An updated approach to healthcare-associated meningitis

Among hospital-associated infections, healthcare-associated central nervous system infections are quite important because of high morbidity and mortality rates. The causative agents of healthcare-associated meningitis differ according to the status of immune systems and underlying diseases. The most frequent agents are Gram-negative bacilli (Pseudomonas spp., Acinetobacter spp., Escherichia coli and Klebsiella pneumoniae) and Gram-positive cocci (Staphylococcus aureus and coagulase-negative staphylococci). There are currently several problems in the treatment strategies of healthcare-associated meningitis due to a globally increasing resistance problem. Strategies targeting multidrug-resistant pathogens are especially limited. This review focuses on healthcare-associated meningitis and the current treatment strategies with a particular focus on methicillin-resistant Staphylococcus aureus (MRSA) meningitis.

Is posttraumatic cerebrospinal fluid fistula a predictor of posttraumatic meningitis? A US Nationwide Inpatient Sample database study

Object

Various factors have been reported in literature to be associated with the development of posttraumatic meningitis. There is a paucity of data regarding skull fractures and facial fractures leading to CSF leaks and their association with the development of meningitis. The primary objective of this study was to analyze the US Nationwide Inpatient Sample (NIS) database to elucidate the factors associated with the development of posttraumatic meningitis. A secondary goal was to analyze the overall hospitalization cost related to posttraumatic meningitis and factors associated with that cost.

Methods

The NIS database was analyzed to identify patients admitted to hospitals with a diagnosis of head injury from 2005 through 2009. This data set was analyzed to assess the relationship of various clinical parameters that may affect the development of posttraumatic meningitis using binary logistic regression models. Additionally, the overall hospitalization cost for the head injury patients who did not undergo any neurosurgical intervention was further categorized into quartile groups, and a regression model was created to analyze various factors responsible for escalating the overall cost of the hospital stay.

Results

A total of 382,267 inpatient admissions for head injury were analyzed for the 2005–2009 period. Meningitis was reported in 0.2% of these cases (708 cases). Closed skull base fractures, open skull base fractures, cranial vault fractures, and maxillofacial fractures were reported in 20,524 (5.4%), 1089 (0.3%), 5064 (1.3%), and 88,649 (23.2%) patients, respectively. Among these patients with fractures, meningitis was noted in 0.17%, 0.18%, 0.05%, and 0.10% admissions, respectively. Cerebrospinal fluid rhinorrhea was reported in 453 head injury patients (0.1%) and CSF otorrhea in 582 (0.2%). Of the patients reported to have CSF rhinorrhea, 35 (7.7%) developed meningitis, whereas in the cohort with CSF otorrhea, 15 patients (2.6%) developed meningitis. Cerebrospinal fluid rhinorrhea (p < 0.001, OR 22.8, 95% CI 15.6–33.3), CSF otorrhea (p < 0.001, OR 9.2, 95% CI 5.2–16.09), and major neurosurgical procedures (p < 0.001, OR 5.6, 95% CI 4.8–6.5) were independent predictors of meningitis. Further, CSF rhinorrhea (p < 0.001, OR 2.0, 95% CI 1.6–2.7), CSF otorrhea (p < 0.001, OR 2.3, 95% CI 1.9–2.7), and posttraumatic meningitis (p < 0.001, OR 3.1, 95% CI 2.5–3.8) were independent factors responsible for escalating the cost of head injury in cases not requiring any major neurosurgical intervention.

Conclusions

Cerebrospinal fluid rhinorrhea and CSF otorrhea are independent predictors of posttraumatic meningitis. Furthermore, meningitis and CSF fistulas may independently lead to significantly increased cost of hospitalization in head injury patients not undergoing any major neurosurgical intervention.

The causes and treatment outcomes of 91 patients with adult nosocomial meningitis

BACKGROUND/AIMS

Frequent pathogens of nosocomial meningitis were investigated and the adequacy of empiric antibiotic therapy was assessed. Outcomes of nosocomial meningitis were also evaluated.

METHODS

Ninety-one patients, who were diagnosed and treated for nosocomial meningitis at a single tertiary hospital in Daegu, Korea for 10 years, were included. Medical record and electronic laboratory data on the causative pathogens, antibiotics used, and outcomes were retrospectively investigated.

RESULTS

Coagulase-negative Staphylococcus (40.9%) was the most common pathogen, followed by Acinetobacter (32.5%). Both were cultured as a single organism in cerebrospinal fluid (CSF). Seventy-eight patients (85.7%) had infections related to external ventricular drains (EVD). The most common empirical antibiotics were extended-spectrum beta-lactam antibiotics plus vancomycin (35/91, 38.6%). Of the 27 patients who had cultured Acinetobacter in CSF, 10 (37%) were given the wrong empirical antibiotic treatment. Seven of the 27 patients (26.9%) with cultured Acinetobacter died, and overall mortality of the 91 patients was 16.5%. In the multivariate analysis, the presence of combined septic shock (p < 0.001) and a persistent EVD state (p = 0.021) were associated with a poor prognosis.

CONCLUSIONS

Acinetobacter is one of the leading pathogens of nosocomial meningitis and may lead to inadequate coverage of empiric antibiotic therapy due to increasing resistance. An EVD should be removed early in cases of suspected nosocomial meningitis, and carbapenem might be required for the poor treatment response.

Meningitis caused by Filobasidium uniguttulatum: case report and overview of the literature

Cryptococcal meningitis is mainly caused by Cryptococcus neoformans and Cryptococcus gattii, but occasionally other Cryptococcus species and phylogenetically related species are involved. Herein, we present a case of cryptococcal meningitis from China, which was caused by an azole and flucytosine resistant Filobasidium uniguttulatum. In addition, we present an overview of the literature of meningitis caused by Cryptococcus species other than C. neoformans and C. gattii. Eight cases were related to infections of the central nervous system. Leukaemia and cancer were important risk factors in HIV-negative patients. Molecular identification and susceptibility testing are important for proper management of patients because the species involved may differ in susceptibility to antifungal drugs.

Quorum sensing in Acinetobacter: an emerging pathogen

Acinetobacter is emerging as one of the major nosocomial infectious pathogens, facilitated by tolerance to desiccation and multidrug resistance. Quorum sensing (autoinducer-receptor mechanism) plays role in biofilm formation in Acinetobacter, though its role in regulation of other virulence factors is yet to be established. Phylogenetic studies indicate that Acinetobacter baumannii is closely related to Burkholderia ambifaria but its quorum sensing genes (abaI and abaR) were acquired horizontally from Halothiobacillus neapolitanus. The prospects of quorum quenching to control the infections caused by Acinetobacter have also been discussed.

Acinetobacter baumannii: emergence of a successful pathogen

Acinetobacter baumannii has emerged as a highly troublesome pathogen for many institutions globally. As a consequence of its immense ability to acquire or upregulate antibiotic drug resistance determinants, it has justifiably been propelled to the forefront of scientific attention. Apart from its predilection for the seriously ill within intensive care units, A. baumannii has more recently caused a range of infectious syndromes in military personnel injured in the Iraq and Afghanistan conflicts. This review details the significant advances that have been made in our understanding of this remarkable organism over the last 10 years, including current taxonomy and species identification, issues with susceptibility testing, mechanisms of antibiotic resistance, global epidemiology, clinical impact of infection, host-pathogen interactions, and infection control and therapeutic considerations.

Changing epidemiology of adult bacterial meningitis in southern taiwan: a hospital-based study

BACKGROUND

Many factors may influence the epidemiologic trend of adult bacterial meningitis (ABM). The objective of this study was to analyze recent epidemiologic trends of ABM in order to provide a better therapeutic strategy.

MATERIALS AND METHODS

The clinical features, laboratory data, and therapeutic outcomes of 181 ABM cases collected in the last 6.5 years (July 1999-December 2005) were analyzed. The results were compared with those of our previous study (202 cases, January 1986-June 1999).

RESULTS

The 181 cases consisted of 130 men (age range: 18-82 years) and 51 women (age range: 18-78 years). Monomicrobial infection and mixed infection were found in 165 cases and 16 cases, respectively. A preceding postneurosurgical state was noted in 56.9% (103/181) of cases. Despite a decrease in incidence, Klebsiella pneumoniae (25.5%, 42/165) was still the most common pathogen. A marked increase of Acinetobacter meningitis (11.5%, 19/165) was noted, which replaced Pseudomonas meningitis as the second most common Gram-negative pathogen in ABM. A marked increase in staphylococcal infection, accounting for 23% (38/165) of all cases, was also noted, of which 76% (29/38) were methicillin-resistant strains. The therapeutic result showed a mortality rate of 30.3% (55/181). Significant prognostic factors included septic shock and age at infection.

CONCLUSIONS

This study revealed a change in the epidemiologic trend of ABM, with an increase in the number of patients with a postneurosurgical state and a rising incidence of Acinetobacter and staphylococcal infections. Clinicians should pay greater attention to these changes, which may affect their management of ABM.

Efficacy of Prophylactic Antibiotics Against Meningitis after Craniotomy: A Meta-Analysis

OBJECTIVE

Although prophylactic antibiotics have been shown by randomized clinical trials (RCTs) to help prevent deep infection after craniotomies, recent reports have suggested that antibiotics are not effective in preventing postcraniotomy meningitis.

METHODS

Data on meningitis as an end point from RCTs on prophylactic antibiotics for craniotomies were pooled in a random-effects meta-analysis.

RESULTS

Six prospective randomized trials or trial subgroups enrolling 1729 patients or operations were identified. Antibiotics reduced postoperative infection rates in five of the six RCTs; no trial individually showed a statistically significant benefit from antibiotics. The pooled odds ratio for meningitis with antibiotic treatment in the six RCTs was 0.43 (95% confidence interval, 0.20–0.92; P = 0.03). Subgroup analyses showed no detectable difference in antibiotic efficacy if antibiotics, with or without gram- negative coverage, were used or if the trial was single or double blinded. A sensitivity analysis showed modest dependence of the results of the analysis on the specific definition of postoperative meningitis used in interpreting trial results.

CONCLUSION

Prophylactic antibiotics administered before craniotomy reduce rates of postoperative meningitis by approximately one-half, a statistically and clinically significant benefit.

Nosocomial bacterial meningitis in adults: a prospective series of 50 cases

In order to evaluate characteristics of nosocomial meningitis in adults, we performed a prospective cohort study of 50 episodes of nosocomial bacterial meningitis. These cases were confirmed by culture of cerebrospinal fluid (CSF) in patients aged >16 years. Classic symptoms of bacterial meningitis (headache, neck stiffness and fever) were present in >70% of the episodes, although only a minority (41%) presented with impairment of consciousness. Underlying conditions, such as a history of neurosurgery, recent head injury, CSF leakage or a distant focus of infection, were present in 94% of the episodes. Staphylococcus aureus was the most common pathogen in patients with a history of neurosurgery, causing 10 of 32 episodes (31%). Patients with a distant focus of infection, such as otitis, sinusitis or pneumonia were more likely to have meningitis due to Streptococcus pneumoniae than patients without [six of nine episodes (67%) vs seven of 41 (17%); P=0.01]. Complications occurred in 50% of the episodes and 16% of the patients died. Our study confirms that adults with nosocomial meningitis are a distinct patient group with specific bacterial pathogens, as compared to those with community-acquired bacterial meningitis. Underlying conditions, especially a history of neurosurgery or a distant focus of infection, were present in the large majority of patients, and mortality and morbidity rates were high.