Postneurosurgical State Research Articles

Sex-based differences in bacterial meningitis in adults: Epidemiology, clinical features, and therapeutic outcomes

BackgroundTo investigate the sex-based differences in clinical features, causative pathogens, and outcomes of hospital-based culture-proven adult bacterial meningitis. ObjectiveThis retrospective study enrolled 621 patients at a tertiary medical center. To compare changes over time, the presentation of disease among the enrolled patients was divided into two equal time periods: the first study period (1986–2002) and the second study period (2003–2019). ResultsOf the 621 patients enrolled in this study, 396 were males and 225 were females. The overall case fatality rate was 30.4% with 30.1% and 31.1% in males and females, respectively. Regarding the causative pathogens, there was a rising incidence of coagulase-negative staphylococcal infections and a decreasing incidence of Klebsiella pneumoniae infection in both male and female in the second study period. The prevalence of patients with nosocomial infection in a postneurosurgical state were 41.9% (68/162) in the first study period and 58.1% (94/162) in the second study period in male group, and 34.8% (32/92) in the first study period and 65.2% (60/92) in the second study period in female group, respectively. Significant factors between the sexes difference included age (P = 0.004), traumatic brain injury (P = 0.01), alcoholism (P < 0.001), brain tumor (P < 0.001), systemic lupus erythematosus (SLE) (P = 0.004), presence of diabetic ketoacidosis/hyperglycemic hyperosmolar state (P = 0.033), brain abscess (P = 0.042), and total protein (P = 0.002) and white blood cell count (P = 0.036) of cerebrospinal fluid data. ConclusionOur study revealed an increase in the number of patients with nosocomial infection with a postneurosurgical state in both male and female in the second study period. Males were younger and frequently presented with a history of head trauma and alcoholism with concomitant brain abscesses while females presented with SLE and brain tumor. The therapeutic outcome did not show differences between the sexes.

High incidence of severe neurological manifestations and high mortality rate for adult Listeria monocytogenes meningitis in Taiwan

The clinical characteristics and therapeutic outcomes of adult Listeria monocytogenes meningitis are not commonly examined in isolation in the literature. During a study period of 19 years (2000–2018), 366 patients with culture-proven adult bacterial meningitis (ABM) were identified in the author’s hospital (264 patients in 2000–2010 and 102 patients in 2011–2018). Of the 366 ABM patients, 330 had monomicrobial infections while the other 36 had mixed infections. L. monocytogenes infection was identified in 11 of the 330 patients with monomicrobial ABM (3 in 2000–2010 and 8 in 2011–2018). These 11 patients included 5 males and 6 females, aged 47 to 76 years (median age = 61.7). None of the 11 patients had a postneurosurgical state as the underlying cause, but 3 of them contracted the infection nosocomially. Common underlying conditions included liver cirrhosis (4), systemic malignancy (3), diabetes mellitus (3), and renal disease (2). The most common clinical manifestations were fever (11), altered consciousness (8), seizure (8), bacteremia (7) and hydrocephalus (5). The therapeutic result revealed a mortality rate of 72.7% (8/11), but no significant prognostic factors were identified. The clinical features of 8 additional Taiwanese L. monocytogenes ABM patients reported in the literature, were also included for analysis. The present study revealed an increase in L. monocytogenes ABM in recent years and most patients presented with severe neurological manifestations. The current study is a preliminary overview of L. monocytogenes meningitis in adults and a further large-scale study is needed for improved delineation of this specific infectious syndrome.

High prevalence of KPC-2-producing hypervirulent Klebsiella pneumoniae causing meningitis in Eastern China.

BackgroundKlebsiella pneumoniae has been the leading causative pathogen for adult bacterial meningitis in several Asian countries. The clinical and microbiological characteristics of K. pneumoniae meningitis in mainland China are still unknown.Materials and methodsThe clinical data of patients with K. pneumoniae meningitis from January 2011 to July 2017 in a tertiary hospital were retrospectively evaluated. The isolates were tested for antibiotic-resistance genes, virulence-associated genes, and molecular subtypes. Hyper-virulent K. pneumoniae (hvKP) was defined as the presence of pLVPK-like virulence plasmid.ResultsDuring the study period, a total of 48 patients with meningitis caused by K. pneumoniae were identified, accounting for 21.2% (48/226) of Gram-negative bacilli meningitis. Of the 44 available isolates, 65.9% (29/44) were carbapenem resistant, and all except one har-bored blaKPC-2. K64 was the most common serotype (n=13), followed by K47 (n=11) and K1 (n=5). The pLVPK-related genetic loci were found in about half of isolates (iutA: 56.8%, iucA: 56.8%, rmpA2:50.0%, rmpA: 43.2%, and iroN: 40.9%). Twenty-two strains carrying pLVPK-derived virulence plasmid were defined as hvKP. Notably, the coexistence of blaKPC-2-encoding plasmid and the pLVPK-derived virulence plasmid was detected in 15 strains (34.1%, 15/44), suggesting K. pneumoniae carbapenemase-2 (KPC-2)-producing hvKP. The proportion of KPC-2-producing hvKP by year increased remarkably from 0% (2011) to 71.4% (2017). Of the 15 KPC-2-producing hvKP strains, 80.0% (12/15) were assigned to sequence type 11 and 2 strains (13.3%) belonged to clonal complex 23. Most of the patients infected with KPC-2-producing hvKP had preceding postneurosurgical state (93.3%, 14/15) and severe pneumonia (73.3%, 11/15). All the cases (100%, 15/15) had fatal outcome.ConclusionThe high prevalence and mortality of K. pneumoniae, especially KPC-2-producing hvKP meningitis, in China should be of concern. The implementation of epidemiological surveillance and identification of an effective clinical treatment are paramount.

Clinical characteristics of Citrobacter meningitis in adults: High incidence in patients with a postneurosurgical state and strains not susceptible to third-generation cephalosporins

Adult bacterial meningitis (ABM) caused by Citrobacter (C.) infection is very uncommon and the clinical characteristics of this specific infectious syndrome have not been analyzed in the literature. The clinical characteristics of six Citrobacter ABM patients collected during a study period of 30 years (1986–2015) were enrolled, and they accounted for 1.1% (6/540) of our ABM patients. In this study, a total of 14 patients with Citrobacter ABM (six collected from our hospital and eight from the literature) were included for analysis. The 14 patients were nine men, three women and two with unknown gender, aged 31–84 years (median: 64 years), of whom 78.6% (11/14) had an underlying postneurosurgical condition and 21.4% (3/14) belonged to mixed infections. The most common clinical manifestations were fever (50%, 7/14), altered consciousness (50%, 7/14), and headache (28.6%, 4/14). These clinical presentations were neither specific nor unique; therefore, cerebrospinal fluid studies including cultures were important for the diagnostic confirmation. Of the implicated Citrobacter strains, C, koseri was the most common (57.1%, 8/14), followed by C. freundii (21.4%, 3/14) and C. farmeri (7.1%, 1/14). Of the Citrobacter strains collected from CSF specimens of our six Citrobacter ABM patients, 33.3% (2/6) and 66.7% (4/6) were not susceptible to ceftazidime or ceftriaxone, respectively, but they were all susceptible to carbapenem. The therapeutic results showed a mortality rate of 21.4% (3/14).

Anaerobic bacterial meningitis in adults

Anaerobic infection is a very uncommon condition in adult bacterial meningitis (ABM), and its clinical characteristics have yet to be clarified. We enrolled 540 patients with culture-proven bacterial meningitis during a study period of 30 years (1986–2015), of whom 13 (2.4%) had anaerobic infections. These 13 patients were eight men and five women, aged 22–77 years. Among them, 53.8% (7/13) had a postneurosurgical state as the preceding event, and 79.6% (10/13) had underlying medical conditions including diabetes mellitus, malignancy, liver cirrhosis, cerebral infarct and alcoholism. Nosocomial and mixed infections were found in 15.5% (2/13) and 46.1% (6/13) of the patients, respectively. A total of 14 anaerobic strains were isolated from cerebrospinal fluid specimens, including nine Gram-negative (G(−)) strains: Fusobacterium nucleatum (3), Prevotella species (3) and Bacteroides fragilis (3), and five Gram-positive (G(+)) strains: Propionibacterium acnes (3) and Peptostreptococcus micros (also known as Parvimonas micra) (2). All of the implicated G(+) anaerobic bacteria were susceptible to penicillin, and no multiple drug-resistant strains were found among the implicated G(−) anaerobic bacteria. Despite treatment, 30.8% (4/13) of the patients died. Of the nine survivors, 22.2% (2/9) had a full recovery, while the other 77.8% (7/9) had varying degrees of neurological deficits. Compared with the good outcome group (n = 6, modified Rankin scale (mRS) scores: 0–2), the poor outcome group (n = 7, mRS scores ≧3) had higher incidence of seizure. These results may offer a preliminary view of the clinical characteristics of anaerobic ABM.

The clinical characteristics of adult bacterial meningitis caused by non-Pseudomonas (Ps.) aeruginosa Pseudomonas species: A clinical comparison with Ps. aeruginosa meningitis

Adult bacterial meningitis (ABM) caused by non-Pseudomonas (Ps.) aeruginosa Pseudomonas (NPAP) species infection has rarely been reported. The clinical characteristics of 52 cases of Pseudomonas ABM (11 NPAP- and 41 Ps. aeruginosa-related meningitis) collected during a 30-year study period (1986–2015) were included. Eleven cases of NPAP ABM were identified in the literature, and their clinical data were also collected. Therefore, a total of 22 NPAP ABM cases were enrolled. The clinical characteristics of the NPAP ABM and Ps. aeruginosa ABM groups were compared. Of the implicated NPAP strains, Ps. putida and Ps. stutzeri were the most common (7 cases each), followed by Ps. mendocina in 4, Ps. fluorescens in 1, Ps. fulva in 1, Ps. alcaligenes in 1, and Ps. mosselii in 1. Of the 22 cases, 50% (11/22) had an underlying postneurosurgical state. Fever (77.3%, 17/22) and altered consciousness (45.5%, 10/22) were the most common clinical presentations. Antibiotic non-susceptibility was found in 3 strains of Ps. putida and 1 Ps. mosselii strain. Compared to the patients with Ps. aeruginosa ABM, those with NPAP ABM had a higher incidence of spontaneous infections and a better survival rate. In conclusion, although Ps. putida, Ps. stutzeri and Ps. mendocina were the major implicated strains of NPAP ABM, the clinical characteristics of this specific group of ABM demonstrated marked heterogeneity. Even though the cases with NPAP ABM had better therapeutic results than those with Ps. aeruginosa ABM, further large-scale studies are needed to better delineate this specific group of ABM.

Epidemiologic trend of adult bacterial meningitis in southern Taiwan (2006–2015)

The purpose of this study is to analyze recent epidemiologic trend of adult bacterial meningitis (ABM) in Taiwan. The clinical features, laboratory data and therapeutic outcomes of 157 patients with ABM from 2006–2015 were analyzed. The results were compared with those of our previous two epidemiologic studies of ABM (1st study: 202 cases, January 1986–June 1999; 2nd study: 181 cases, July 1999–December 2005). Of the 157 patients with ABM, 96 were men and 61 women, and 68.2% (107/157) of them had a postneurosurgical state as the underlying condition. Monomicrobial infections and mixed infections were found in 92.4% (145/157) and 7.6% (12/145) of the cases, respectively. Of the implicated pathogens of monomicrobial infections, staphylococcal species were the most common, accounting for 27.6% (40/145) of them and Klebsiella species were the second common accounting for 13.8% (20/145) of them. The other common Gram-negative pathogens were Pseudomonas species and Acinetobacter species, accounting for 10.3% (15/145) and 7.6% (11/145), respectively. The overall mortality rate was 25.5% (40/157), and septic shock and liver cirrhosis were significant prognostic factors. This study revealed a change in the epidemiologic trend of ABM and the study results may offer important information for clinicians managing patients with ABM.

Clinical characteristics of Stenotrophomonas maltophilia meningitis in adults: A high incidence in patients with a postneurosurgical state, long hospital staying and antibiotic use

ObjectiveStenotrophomonas (S.) maltophilia is an uncommon pathogen of adult bacterial meningitis (ABM). MethodsThe clinical characteristics of six S. maltophilia ABM cases, collected during a study period of nine years (2001–2009) were included. In the related literature, 13 S. maltophilia ABM cases were reported, and their clinical data were also collected. ResultsThe 19 S. maltophilia ABM cases included 11 men and 8 women, aged 28–70 years. Of these 19 cases, 89.5% (17/19) had underlying neurosurgical (NS) conditions as the preceding event. Before the development of S. maltophilia ABM, 52.6% (10/19) of them had long stays in hospital and 63.2% (12/19) had undergone antibiotic treatment. Among the implicated S. maltophilia cases, three strains were found to have a resistance to sulfamethoxazole–trimethoprim (SMZ–TMP). Two of our five cases had resistant strains to levofloxacin. Among the antibiotics chosen for treatment, SMZ–TMP was the most common followed by quinolone (ciprofloxacin, levofloxacin, moxifloxacin). The therapeutic results showed 2 cases expired while the other 17 cases survived. ConclusionsS. maltophilia ABM usually develops in patients with a preceding neurosurgical condition, a long hospital stay and antibiotic use. SMZ–TMP and quinolones, especially the ciprofloxacin, are the major antibiotic used. This study also shows the emergence of clinical S. maltophilia strains which are not susceptible to SMZ–TMP and quinolones and this development may pose a more serious threat in the near future because treatment options may become depleted and limited despite the mortality rate of this specific group of ABM not being high at this time.

Clinical characteristics and therapeutic outcomes of nosocomial super-infection in adult bacterial meningitis

BackgroundSuper-infection in adult bacterial meningitis (ABM) is a condition wherein the cerebrospinal fluid (CSF) grows new pathogen(s) during the therapeutic course of meningitis. It is an uncommon but clinically important condition rarely examined in literature.MethodsTwenty-seven episodes of super-infection states in 21 ABM patients collected in a 9.5-year study period (January 2001 to June 2010) were evaluated. The clinical characteristics, implicated pathogens, results of antimicrobial susceptibility tests, and therapeutic outcomes were analyzed.ResultsTwenty-one patients (13 men, 8 women) aged 25-73 years (median, 45 years) had post-neurosurgical state as the preceding event and nosocomial infection. The post-neurosurgical states included spontaneous intracranial hemorrhage (ICH) with craniectomy or craniotomy with extra-ventricular drainage (EVD) or ventriculo-peritoneal shunt (VPS) in 10 patients, traumatic ICH with craniectomy or craniotomy with EVD or VPS in 6 patients, hydrocephalus s/p VPS in 2 patients, and one patient each with cerebral infarct s/p craniectomy with EVD, meningeal metastasis s/p Omaya implant, and head injury. All 21 patients had EVD and/or VP shunt and/or Omaya implant during the whole course of ABM. Recurrent fever was the most common presentation and the implicated bacterial pathogens were protean, many of which were antibiotic resistant. Most patients required adjustment of antibiotics after the pathogens were identified but even with antimicrobial therapy, 33.3% (7/21) died. Morbidity was also high among survivors.ConclusionsSuper-infection in ABM is usually seen in patients with preceding neurosurgical event, especially insertion of an external drainage device. Repeat CSF culture is mandatory for diagnostic confirmation because most of the implicated bacterial strains are non-susceptible to common antibiotics used. Unusual pathogens like anaerobic bacteria and fungi may also appear. Despite antimicrobial therapy, prognosis remains poor.

Changing Epidemiology of Adult Bacterial Meningitis in Southern Taiwan: A Hospital-Based Study

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. 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). 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. 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.

Postneurosurgical Nosocomial Bacterial Brain Abscess in Adults

Bacterial brain abscess after a neurosurgical procedure has become an important occurrence in the hospital setting. However, no information about the frequency, clinical relevance, and the outcome has been reported. Over a period of 19 years (1986- 2004), a total of 31 patients were retrospectively identified as having brain abscesses after neurosurgical procedures and were enrolled in this study. Those included in this study accounted for 0.17% (31/18600) of all neurosurgical procedures in the same period. There was an increased percentage of adult postneurological nosocomial brain abscess compared to all adult bacterial brain abscesses in recent years. The majority of cases were due to Gram-negative bacilli and polymicrobial infections, including both Gram-negative bacilli and Staphylococcus species. Furthermore, the appearance of multi-antibiotic resistant strains was also noted during the study period. The overall fatality rate was 16%. Post-neurosurgical states have become important predisposing factor for bacterial brain abscess. In patients that undergo neurosurgical procedures and develop smoldering fever, progressively disturbed consciousness, headache, and new onset focal neurologic signs, immediate neuro-imaging studies should be undertaken to determine whether bacterial brain abscess is present. Although mortality may be related to the primary brain pathology, early diagnosis and timely use of appropriate antibiotics based on antimicrobial susceptibility testing are also essential for survival.

Culture-proven bacterial meningitis in elderly patients in southern Taiwan: clinical characteristics and prognostic factors.

The epidemiologic landscape of causative pathogens and clinical characteristics of bacterial meningitis varies with several clinical factors including preceding/pre-existent medical and/or surgical conditions, modes of contraction, geographic distributions, status of vaccinations, the study time periods and differences among age groups. In order to delineate the epidemiology of bacterial meningitis in senior adults (ages > or =60 y/o) in southern Taiwan, we analyzed the clinical characteristics and therapeutic outcomes of 64 senior adults (42 men and 22 women, aged 60-80 years) with bacterial meningitis collected over a period of 13 years at our hospital. The prognostic factors between fatal and non-fatal groups of patients were compared. Twenty-seven of the 64 patients belonged to a nosocomial infection group, and the other 37 comprised a community-acquired infection group. Sixty percent (39/64) of the patients had a post-neurosurgical state as the most preceding event prior to infection. Liver disease (13) and diabetes mellitus (6) were the most common underlying conditions of the other 25 patients with spontaneous meningitis. Of these 64 patients, Klebsiella (K.) pneumoniae (18), Acinetobacter baumannii (5), Escherichia coli (5), and Enterobacter species (5) were the most commonly implicated Gram-negative pathogens. Staphylococcus (S.) aureus infection was increasing during the study period. The therapeutic results of this group of patients showed a mortality rate of 38% (24/64). The presence of septic shock was the most significant prognostic factor. In conclusion, for this study group, a post-neurosurgical state was the single most important preceding event for senior adults developing bacterial meningitis. Of the implicated pathogens, K. pneumoniae and S. aureus were the most common gram-negative and gram-positive pathogens, respectively. The therapeutic result of this specific group of patients showed a high mortality rate; however, the small case number and possible bias of case selection have limited the analytical conclusions of this study.

Bacterial Meningitis in Young Adults in Southern Taiwan: Clinical Characteristics and Therapeutic Outcomes

To delineate the epidemiologic trend, clinical characteristics and therapeutic outcomes of bacterial meningitis in young adults in Southern Taiwan. Over a period of 18 years, 329 cases of culture-proven adult bacterial meningitis were identified at our hospital. Among these 329 cases, 62 were identified as young adults (< or = 40 years) and their clinical features, laboratory data and therapeutic outcomes were reviewed. The prognostic factors between fatal and non-fatal groups were compared. The 62 young adults were 48 men and 14 women, aged 17-40 years. Thirty of the 62 patients belonged to nosocomial infection, and the other 32 belonged to community-acquired infection. A total of 74% (46/62) of the patients had a post-neurosurgical state as the underlying condition. Alcoholism (n = 8) was the most common underlying condition of the other 16 patients with spontaneous meningitis. Of these 62 patients, Klebsiella pneumoniae and Pseudomonas aeruginosa were the most common implicated gram-negative pathogens. During the late study period, there was an increase in coagulase-negative staphylococcus and Staphylococcus aureus infections. The therapeutic results of this group of patients are as follows: 13 patients died, 18 had full recovery and 31 had varying degrees of neurologic deficits. Impaired consciousness and thrombocytopenia were significant prognostic factors. A post-neurosurgical state is an important preceding event for young adults to develop bacterial meningitis. Of the implicated gram-negative pathogens, K. pneumoniae and P. aeruginosa are common; however, there has been an increase in staphylococcal infection in recent years. Therapeutic results of this specific group of patients showed that 20% (13/62) of the patients died, and 50% (31/61) of the patients in this study had neurologic deficits. However, the small case number and possible bias of case selection has limited the analytical conclusions of this study. Further large-scale studies are needed to delineate the clinical characteristics and therapeutic outcomes of bacterial meningitis in this specific group of patients.

Coagulase-Negative Staphylococcal Meningitis in Adults: Clinical Characteristics and Therapeutic Outcomes

We wanted to analyze the clinical characteristics and therapeutic outcomes of adult meningitis caused by coagulase-negative staphylococci (CoNS). Over a period of 5 years (January 1999 to December 2003), 127 cases were identified as having adult culture-proven bacterial meningitis caused by a single pathogen. Of them, 14 cases with CoNS meningitis were enrolled, and their clinical characteristics and therapeutic outcomes were analyzed. The 14 cases (median age 37.5; range 24-77 years old) included nine men and five women. With polynerase chain reaction sequencing of bacterial 16S r-RNA, 10 of the 14 CoNS strains were identified as Staphylococcus epidermidis infection, and the other four belonged to Staphylococcus haemolyticus. All 14 cases were in a postneurosurgical state with insertion of a ventriculoperitoneal shunt, external ventricular device or intrathecal port A as their underlying conditions, and 12 of the 14 patients contracted the infection nosocomially. Fever (86%), leukocytosis (79%), hydrocephalus (50%), consciousness disturbance (36%), and seizure (7%) were the major clinical manifestations. All the involved CoNS strains showed resistance to oxacillin but retained their susceptibility to vancomycin and linezolid. All 14 CoNS strains had positive mecA gene detection. With the removal of neurosurgical devices and intravenous vancomycin therapy, 86% (12/14) of the patients survived. CoNS meningitis accounted for 11% (14/127) of our adult bacterial meningitis. All adult CoNS meningitis patients had a disrupted barrier of the central nervous system as the underlying condition. S. epidermidis was the most common CoNS subtype involved. All involved CoNS strains were oxacillin resistant. The therapeutic result showed that adult CoNS meningitis had a mortality rate of 14% (2/14).

A Case of Spontaneous Methicillin‐Resistant Staphylococcus aureus Meningitis in a Health Care Worker

Meningitis caused by Staphylococcus aureus is an unusual illness that is often associated with bacteremia, contiguous infection and/or a post-neurosurgical state. Until recently, most cases were caused by methicillin-susceptible strains, but there are a few reports of methicillinresistant S aureus strains causing meningitis. A new case of meningitis caused by methicillin-resistant S aureus in a neonatal intensive care nurse who did not have bacteremia or neurosurgery is reported. The patient made a full recovery after treatment with vancomycin and rifampin.

Commentary

BACKGROUND We compared the clinical features and therapeutic outcomes of intracranial suppurations (IEs) caused by subdural empyema (SDEs) and epidural abscesses (EAs). METHODS Twenty-four patients with IE were retrospectively identified at our institution over a period of 14 years. Therapeutic outcomes at 6 months were determined using the Glasgow Outcome Scale. RESULTS Among them, 15 had SDE and nine had EA with or without SDE. The three most frequently encountered clinical features included fever (79%), disturbed consciousness (58%), and seizures (54%). Postneurosurgical or posttraumatic states (42%) and complication after meningitis (38%) were the two most common modes of infection. The overall mortality rate was 8% (2/24). However, if mortality and severe neurologic sequelae were included in the poor outcome group, then 29% (7/24) of our patients would be considered treatment failures. CONCLUSION In this study, SDE commonly arose following bacterial meningitis with a more fulminant course, but no deaths occurred. In contrast, EA commonly has a more indolent course and is postoperatively or post-traumatically related, and therefore may have a higher mortality rate based on primary brain pathophysiology alone. In patients with meningitis or who undergo postneurosurgical procedures and develop fever, progressive disturbed consciousness, seizures, and focal neurologic signs, immediate neuroimaging studies should be performed to determine whether IE is present. Early surgical drainage and aggressive antimicrobial therapy are necessary.

Bacterial brain abscess: microbiological features, epidemiological trends and therapeutic outcomes.

Despite the advent of modern neurosurgical techniques, new antibiotics, and powerful imaging technologies, brain abscess remains a potentially fatal central nervous system infection. To determine the epidemiological trends, prognostic factors, and outcomes of bacterial brain abscess, to improve the therapeutic strategy for this disease. Retrospective hospital-based epidemiology study. Over a period of 15 years (1986-2000), 123 patients were retrospectively identified as having brain abscesses at Kaohsiung Chang Gung Memorial Hospital. To compare changes over time, the appearance of disease among our patients was divided into two time periods: 1986-1993 and 1994-2000. The prevalence rate of brain abscesses caused by Gram-negative organisms significantly increased in the second study period. Viridans streptococci and Klebsiella pneumoniae were the two prevalent pathogens associated with haematogenous spread. Metastatic septic abscess, a devastating complication of K. pneumoniae septicaemia, frequently occurs in diabetic patients, with a high mortality rate. Viridans streptococci were the most prevalent pathogens from infection in paranasal sinusitis, but no fatality occurred. In recent years, head trauma and/or post-neurosurgical states have become important predisposing factors, and nosocomial infections also play an important role. Despite the availability of new antibiotics and the development of better neurosurgical techniques, therapeutic outcomes of brain abscess showed no significant change when comparing the two study periods, and only the presence of septic shock influenced outcome.

Protean infectious types and frequent association with neurosurgical procedures in adult Serratia marcescens CNS infections: report of two cases and review of the literature

Serratia marcescens is a rare pathogen of adult central nervous system (CNS) infection. We report on the clinical features and therapeutic outcomes of two adult patients with such infections. The clinical characteristics of 13 other reported adult cases are also included for analysis. The 15 cases were nine males and six females, aged 19–83 years, in whom, underlying post-neurosurgical states and ear operation were noted in 93% (14/15). Fever and conscious disturbance were the most common clinical manifestations of these 15 cases, followed by hydrocephalus, seizures, and wound infections. The manifestation types were protean, including meningitis and focal suppurations such as brain abscess, cranial and spinal epidural abscess, cranial subdural abscess, and infected lumbar pseudomeningocele. One case of S. marcescens CNS infection was diagnosed postmortem; the other 14 were diagnosed by the positive culture from CSF or pus. Antibiotic therapy with or without neurosurgical intervention was the management strategy in 14/15 cases. The therapeutic results showed a high mortality rate.

Adult Enterobacter meningitis: a high incidence of coinfection with other pathogens and frequent association with neurosurgical procedures.

The clinical characteristics of Enterobacter infection in adult bacterial meningitis were defined. The clinical manifestations and therapeutic outcomes of ten adult patients with Enterobacter infections in acute bacterial meningitis were analyzed. Enterobacter infection was found in 4.5% (10/223) of our adult patients with culture-proven bacterial meningitis. The ten patients comprised seven men and three women aged between 16-69 years (mean 47 years). Coinfections with other pathogens were found in 50% of the cases, the most common pathogen being Klebsiella pneumoniae. Nine of the ten patients had a history of neurosurgery, and seven patients contracted the infection nosocomially. Multiple antibiotic-resistant strains, including resistance to third-generation cephalosporins, were found in three patients with polymicrobial infections. These three patients received iv imipenem/cilastin therapy. The therapeutic results showed that two of the ten patients died; five of the eight surviving patients had neurological sequelae. The predominant coinfection with Enterobacteriaceae in adult Enterobacter meningitis may reflect the fact that most of the cases of polymicrobial Enterobacter infections have a potential gastrointestinal source. A postneurosurgical state was the most important predisposing factor for the development of Enterobacter infection in adult bacterial meningitis in our patients. The strains of the Enterobacter species in adult polymicrobial Enterobacter meningitis were commonly resistant to multiple antibiotics, including third-generation cephalosporins. In light of the high incidence of multiple antibiotic-resistant Enterobacter strains in adult polymicrobial Enterobacter meningitis, the choice of initial empiric antibiotics may include carbapenem (imipenem/cilastin or meropenem). Although the mortality rate was not high in this group of patients, most survivors suffered neurological sequelae.

Adults with meningitis caused by oxacillin-resistant Staphylococcus aureus.

Since 1995, 11 adult patients with oxacillin-resistant Staphylococcus aureus (ORSA) meningitis have been identified at Chang Gung Memorial Hospital-Kaohsiung, in Kaohsiung, Taiwan. The 11 patients were 8 men and 3 women, aged 17-78 years. A postneurosurgical state was an underlying condition for all, and fever and disturbances in consciousness were the most common clinical manifestations. Infection with S. aureus only was found in 8 patients, and mixed infection was found in the other 3. The 8 patients with meningitis caused by S. aureus only were mainly treated with intravenous vancomycin, 2-4 g/day; 4 of these patients died. Although ORSA meningitis is uncommon among adults with culture-proven bacterial meningitis, its incidence has been increasing in recent years. The diagnosis of adult ORSA meningitis can be confirmed only with a positive culture of cerebrospinal fluid, and the choice of initial empirical antibiotics must be guided by the accumulated data concerning the relative frequency of the implicated pathogens found at each institution. Despite the high rate of mortality associated with ORSA meningitis, intravenous vancomycin therapy seems to be one of the best choices for management of this condition in adults.