Pneumococcal meningitis in adults: spectrum of complications and prognostic factors in a series of 87 cases

Toll-like receptor stimulation enhances phagocytosis and intracellular killing of nonencapsulated and encapsulated Streptococcus pneumoniae by murine microglia

Toll-like receptors (TLRs) are crucial pattern recognition receptors in innate immunity that are expressed in microglia, the resident macrophages of the brain. TLR2, -4, and -9 are important in the responses against Streptococcus pneumoniae, the most common agent causing bacterial meningitis beyond the neonatal period. Murine microglial cultures were stimulated with agonists for TLR1/2 (Pam(3)CSK(4)), TLR4 (lipopolysaccharide), and TLR9 (CpG oligodeoxynucleotide) for 24 h and then exposed to either the encapsulated D39 (serotype 2) or the nonencapsulated R6 strain of S. pneumoniae. After stimulation, the levels of interleukin-6 and CCL5 (RANTES [regulated upon activation normal T-cell expressed and secreted]) were increased, confirming microglial activation. The TLR1/2, -4, and -9 agonist-stimulated microglia ingested significantly more bacteria than unstimulated cells (P < 0.05). The presence of cytochalasin D, an inhibitor of actin polymerizaton, blocked >90% of phagocytosis. Along with an increased phagocytic activity, the intracellular bacterial killing was also increased in TLR-stimulated cells compared to unstimulated cells. Together, our data suggest that microglial stimulation by these TLRs may increase the resistance of the brain against pneumococcal infections.

[Sensitivity and specificity of clinical signs in adults]

Clinical diagnosis of acute bacterial meningitis may be delayed, either because off lack of sensitivity of clinical signs, or because of a poor vital prognosis; but over diagnosing is also frequent, leading to useless, expensive, and potentially dangerous hospitalizations. We conducted a comprehensive review of English and French literature from 1997 to 2007 by searching MEDLINE to review the accuracy of clinical examination for the diagnosis of meningitis. Additional references were identified by reviewing reference lists of articles back to 1993. We used the keywords "meningitis", "meningitis and clinical features", "cerebrospinal fluid (CSF) pleocytosis", "headache and fever", "Kernig sign", "Brudzinski sign", and "neck stiffness". We excluded nosocomial meningitis. Sensitivity for clinical signs such as headache, vomiting, or fever was low, generally less than 30%, neck stiffness could reach 45%, but the absence of two signs among fever, headache, neck stiffness, and altered mental status eliminated meningitis with a negative predictive value of 95%. Given the seriousness of bacterial meningitis, clinicians perform lumbar puncture (or brain imaging) too often, especially in high-risk patients. Further prospective clinical research is needed to improve the accuracy of bacterial meningitis clinical diagnosis.

Prehospital diagnostic and therapeutic management of otogenic Streptococcus pneumoniae meningitis

Prehospital diagnostics and therapeutic management, as well as clinical and laboratory data from 57 consecutive cases with otogenic pneumococcal meningitis (OPM) in Denmark during a 2-y period (1999-2000) were studied by review of discharge and medical records including a questionnaire sent to the general practitioners responsible for the individual patient. 12 cases were <2 y of age, whereas the remaining 45 cases were >21 y of age. Fever (in 98%) and altered consciousness (in 98%), respectively, were significantly more frequent prehospital symptoms (median duration of symptoms: 2 d (1-4)) than earache (in 71%, p < 0.0001), tympanic perforation (in 38%, p < 0.0001), and back rigidity (in 25%, p < 0.0001) in OPM. Some 82% visited a physician before admission, and an otogenic focus was diagnosed in 57%, a myringotomy was performed in 12%, and antibiotic therapy was initiated in 29% of these cases. Prehospital antibiotic therapy was more likely to be initiated in patients where the physician found an otogenic focus compared to patients where an otogenic was not found (46% vs 6%, respectively, p = 0.01). However, <10% of cases with OPM were treated for otitis media with adequate dosing of antibiotics for more than 1 d based on pharmacodynamic estimates. The clinical course was more severe in adults than in children (e.g. need for assisted ventilation (61% vs 0%, respectively, p < 0.01), development of sequelae (75% vs 8%, respectively, p < 0.01) together with higher CSF WBC and CSF protein levels (3738 vs 1361 cells/microl and 3.8 vs 1.6 g/l, respectively, p < 0.01), whereas corticosteroids were more frequently given to children than to adults (55% vs 3%, p < 0.001). Prehospital antibiotic therapy was not significantly associated with a more favourable outcome of OPM (50% vs 60%, respectively, p = 0.73). In conclusion, our results suggest that an otogenic focus is as frequent in adults as in children with pneumococcal meningitis and that an otogenic examination should be performed on patients presenting with fever and altered consciousness. Moreover, OPM seems predominantly to occur in patients receiving no or inadequate antibiotic therapy for otitis media.

Short-term rifampicin pretreatment reduces inflammation and neuronal cell death in a rabbit model of bacterial meningitis

OBJECTIVE

In bacterial meningitis, severe systemic and local inflammation causes long-term impairment and death of affected patients. The current antibiotic therapy relies on cell wall-active beta-lactam antibiotics, which rapidly sterilize the cerebrospinal fluid (CSF). However, beta-lactams inhibit cell wall synthesis, induce bacteriolysis, and thereby evoke a sudden release of high amounts of toxic and proinflammatory bacterial products. Because tissue damage in bacterial meningitis is the result of bacterial toxins and the inflammatory host response, any reduction of free bacterial compounds promises to prevent neuronal damage.

DESIGN

In vitro experiments and randomized prospective animal study.

SETTING

University research laboratories.

SUBJECTS

Streptococcus pneumoniae broth cultures and New Zealand White rabbits.

INTERVENTIONS

We evaluated a concept to improve bacterial meningitis therapy in which a short-term pretreatment with the protein synthesis-inhibiting antibiotic rifampicin precedes the standard antibiotic therapy with ceftriaxone. First, logarithmically growing pneumococcal cultures were subdivided and exposed to different antibiotics. Then, rabbits suffering from pneumococcal meningitis were randomized to receive rifampicin pretreatment or ceftriaxone alone.

MEASUREMENTS AND MAIN RESULTS

In pneumococcal cultures, quantitative immunoblotting and real-time polymerase chain reaction revealed a reduced release of pneumolysin and bacterial DNA by rifampicin pretreatment for 30 minutes in comparison with ceftriaxone treatment alone. In vivo, a 1-hour rifampicin pretreatment reduced the release of bacterial products and attenuated the inflammatory host response, as demonstrated by decreased CSF levels of prostaglandin E2 and total protein and increased glucose CSF/plasma ratios. Rifampicin pretreatment reduced infection-associated neuronal apoptotic cell loss compared with ceftriaxone-treated controls.

CONCLUSIONS

A short-term pretreatment with rifampicin reduced the beta-lactam-induced release of deleterious bacterial products, attenuated inflammation, and thereby decreased neuronal cell loss in experimental bacterial meningitis. This concept has the potential to reduce inflammation-associated neuronal injury in bacterial meningitis and should be evaluated in a clinical trial.

[Managing adult patients with acute community-acquired meningitis presumed of bacterial origin]

Early clinical data must lead to suspect bacterial meningitis if fever, the most frequent sign, is present and if it is associated with more or less constant neurological and meningeal signs (consciousness impairment, headache, neck stiffness, focal neurological deficit, seizure, etc.). A skin rash is frequent in case of meningococcal meningitis whereas cranial nerve palsy is more in favor of tuberculous or Listeria meningitis. Presence of otitis, sinusitis, pneumonia, or a recent head trauma strongly suggests a pneumococcal involvement. Tuberculous meningitis is generally characterized by a slow evolution of meningeal signs together with aspecific signs. The main prognostic factors are consciousness impairment, circulatory instability, focal neurological signs, and advanced age. Morbidity and mortality are increased in case of pneumococcal compared to meningococcal meningitis. Cranial tomodensitometry gives further information about intracranial complications of meningitis. In some cases, particularly if focal neurological or intracranial hypertension signs are present, it must be performed before a lumbar puncture. The risk factors of meningitis must be investigated and treated if possible according to the bacterium. The management of patient after hospital discharge depends on evolution after treatment. The presence of neurological sequels imposes a specialized ambulatory follow-up. Neuropsychological sequels (cognitive dysfunction, memory impairment) can also persist for years even in absence of other neurological disorders.

[Antibiotic management of presumptive bacterial meningitis in adults (rational, methods, course, and follow-up)]

The annual incidence of community acquired meningitis ranges between 0.6 and four per 100,000 adults in industrialized countries. The most common causative bacteria are Streptococcus pneumoniae, Neisseria meningitidis, Listeria monocytogenes. The emergence of resistance to antibiotics, especially for S. pneumoniae, could explain the clinical failure of third generation cephalosporins used to treat adults with S. pneumoniae meningitis. The present therapeutic suggestions are more based on the extrapolation of an experimental model than on relevant clinical trials.

Hospital-based study of the prognostic factors in adult patients with acute community-acquired bacterial meningitis in Tokyo, Japan

BACKGROUND

Prognostic factors related to community-acquired bacterial meningitis (BM) in adult patients have been evaluated using multivariate analysis in The Netherlands, where the rate of antibiotic resistance was low. However, an evaluation of these factors in countries with a high rate of antibiotic resistance has not yet been done. Thus, we studied the prognostic factors in adults with community-acquired BM in our hospitals, which are located in Tokyo, Japan, where the rate of antibiotic resistance is high.

METHODS

We selected 71 consecutive adult patients with community-acquired BM in which the pathogens were identified and then classified the patients into two groups based on the Glasgow Outcome Scale: a favorable outcome group (n=48), and an unfavorable outcome group (n=23). Their clinical and laboratory variables were analyzed using single logistic regression analysis followed by multiple logistic regression analysis.

RESULTS

The overall mortality rate was 23%. The rate of antibiotic resistance was 54.9%. The most common resistant bacteria were penicillin-resistant Streptococcus pneumoniae, followed by methicillin-resistant Staphylococcus aureus. The Glasgow Coma Scale score (GCS) at the initiation of antibiotic therapy and a low thrombocyte count were identified as significant unfavorable prognostic factors (GCS: p=0.020, odds ratio=0.528, 95%CI=0.309-0.902; thrombocyte count: p=0.037, odds ratio=0.802, 95%CI=0.652-0.987). The presence of antibiotic-resistant bacteria was not identified as a prognostic factor.

CONCLUSION

Patients with a low GCS at the initiation of antibiotic therapy and low thrombocyte counts had unfavorable outcomes. With appropriate antibiotic administration, the antibiotic-resistant bacteria were not identified as an unfavorable prognostic factor, even in an area with a high rate of antibiotic resistance.

Toll-like receptors in bacterial meningitis

Bacterial meningitis is still an important infectious disease with a high morbidity and mortality rate. Bacterial infection of the cerebrospinal fluid (CSF) space causes a powerful inflammatory reaction that is largely responsibly for meningitis-induced tissue damage and adverse outcome of the disease. In a landmark series of experiments in the mid-1980s, cell wall components including lipooligosaccharides and lipoteichoic acid were indicated to be the key bacterial elements that can trigger the host inflammatory response in the CSF. Ten years ago, the discovery of Toll-like receptor proteins (TLRs) that allow the detection of microbial components and initiate the host immune response opened up new horizons in research on the pathophysiology of meningitis. Cell culture approaches provided the first evidence for a crucial role of TLRs in sensing meningeal pathogens including Streptococcus pneumoniae, Neisseria meningitidis, Streptococcus agalactiae, and Listeria monocytogenes. Subsequently, studies in mice with single or combined deficiencies in TLRs demonstrated that TLR activation is a key event in meningeal inflammation and, even more interestingly, a pivotal factor for meningitis-associated tissue damage. A detailed understanding of the mechanisms of host-pathogen interactions in the CSF space may generate new opportunities for specific treatment strategies for bacterial meningitis.

Serial magnetic resonance imagings of multiple brain abscesses in a patient with pneumococcal meningoencephalitis

We report a 43-yr-old man manifesting bacterial meningoencephalitis and multiple abscesses by Streptococcus pneumoniae. Serial magnetic resonance (MR) imagings and MR spectroscopy showed the evolution of multiple brain abscesses over 4 weeks: the enhanced rings became thicker and the dimension of whole lesions larger despite shrinkage of the ring-enhanced regions. These findings may be evidence of active inflammation working to sequestrate the lesion and protect the surrounding normal brain parenchyma from additional damage, even in the final stage of the brain abscess.

Innate immunity to pneumococcal infection of the central nervous system depends on toll-like receptor (TLR) 2 and TLR4

BACKGROUND

Recent studies have suggested that, in addition to Toll-like receptor (TLR) 2, other pattern recognition receptors mediate activation of the immune response after infection of the central nervous system (CNS) with Streptococcus pneumoniae (SP).

METHODS

Using a mouse meningitis model, we investigated the influence of TLR4 single deficiency (TLR4(-/-)), TLR2/TLR4 double deficiency (TLR2/4(-/-)), and TLR2/TLR4/TLR9 triple deficiency (TLR2/4/9(-/-)) on the immune response of the CNS to SP infection. To identify the cell populations that mediate the responses to SP, we generated TLR2/4(-/-)-wild-type (wt) bone marrow (BM) chimeras.

RESULTS

Compared with infected wt mice, infected TLR2/4(-/-) and TLR2/4/9(-/-) mice had similar reductions in brain cytokine levels, pleocytosis, and cerebral pathologic findings, whereas no such effect was noted in infected TLR4(-/-) mice. The attenuated immune response was paralleled by an impaired host defense that resulted in worsening of disease. Analysis of the chimeric mice after infection showed that mere TLR2/4 deficiency, either of radioresistant cells or of transplanted BM-derived cells, was sufficient to mount a substantial cerebral immune response, such as that noted in wt mice.

CONCLUSION

In murine SP meningitis, TLR2 and TLR4 expressed on radioresistant and transplanted BM-derived cells were major cellular sensors of invading SP inducing inflammatory responses.

[A case of elderly onset loss of consciousness due to bacterial meningitis and subsequent vasculitis]

We reported an 83-year-old woman, who suffered from bacterial meningitis and subsequent vasculitis. She experienced episodes of loss of consciousness several times in July, 2006. She also had recurrent fever and was admitted to a local hospital. Routine examinations, including brain MRI and electroencephalogram, were negative and urinary tract infection was diagnosed. After successful antibiotic therapy, she was transferred to a rehabilitation hospital. After transfer, she had no headache, but presented fever again, and a reduced level of consciousness. Cerebrospinal fluid test showed that cell counts were high with a predominance of neutrophils, and her glucose level was low. She received antibiotic therapy on her suspicion of bacterial meningitis. Bacterial cultures of CSF and blood were negative, probably due to the previous antibiotic therapy. Repeated CSF analysis showed a decrease in cell counts, but her lower consciousness did not improve. Moreover, neurological symptoms such as left pyramidal tract sign appeared. She was transferred to our hospital on the suspicion of vasculitis. Diffusion MRI showed high intensity in the right middle cerebral artery (MCA) area and CT angiography showed the stenosis of the right MCA at the M3 portion. Two courses of steroid pulse therapy were performed. Her consciousness gradually improved and eventually could talk although cognitive decline remained as a residual deficit. Our patient failed to be diagnosed early because of atypical symptoms of meningitis. Caution seems necessary for elderly cases presenting with atypical initial symptoms of meningitis. Steroid pulse therapy was effective for the subsequent vasculitis, as reported previously.

EFNS guideline on the management of community-acquired bacterial meningitis: report of an EFNS Task Force on acute bacterial meningitis in older children and adults

Acute bacterial meningitis (ABM) is a potentially life-threatening neurological emergency. An agreed protocol for early, evidence-based and effective management of community-acquired ABM is essential for best possible outcome. A literature search of peer-reviewed articles on ABM was used to collect data on the management of ABM in older children and adults. Based on the strength of published evidence, a consensus guideline was developed for initial management, investigations, antibiotics and supportive therapy of community-acquired ABM. Patients with ABM should be rapidly hospitalized and assessed for consideration of lumbar puncture (LP) if clinically safe. Ideally, patients should have fast-track brain imaging before LP, but initiation of antibiotic therapy should not be delayed beyond 3 h after first contact of patient with health service. In every case, blood sample must be sent for culture before initiating antibiotic therapy. Laboratory examination of cerebrospinal fluid is the most definitive investigation for ABM and whenever possible, the choice of antibiotics, and the duration of therapy, should be guided by the microbiological diagnosis. Parenteral therapy with a third-generation cephalosporin is the initial antibiotics of choice in the absence of penicillin allergy and bacterial resistance; amoxicillin should be used in addition if meningitis because of Listeria monocytogenes is suspected. Vancomycin is the preferred antibiotic for penicillin-resistant pneumococcal meningitis. Dexamethasone should be administered both in adults and in children with or shortly before the first dose of antibiotic in suspected cases of Streptococcus pneumoniae and H. Influenzae meningitis. In patients presenting with rapidly evolving petechial skin rash, antibiotic therapy must be initiated immediately on suspicion of Neisseria meningitidis infection with parenteral benzyl penicillin in the absence of known history of penicillin allergy.

Changing epidemiology of pneumococcal meningitis after the introduction of pneumococcal conjugate vaccine in the United States

BACKGROUND

Although hospitalizations due to invasive pneumococcal disease decreased after routine vaccination of young children with a 7-valent pneumococcal conjugate vaccine (PCV7) began in 2000, information on the trends in pneumococcal meningitis is limited.

METHODS

We estimated national trends in rates of hospitalization for pneumococcal meningitis, using data from the Nationwide Inpatient Sample, 1994-2004. Pneumococcal meningitis cases and deaths were identified on the basis of the International Classification of Diseases, Ninth Edition, Clinical Modification coded primary discharge diagnosis, and rates were calculated using US Census data as denominators. The year 2000 was considered to be a transition year, and the average annualized rate after PCV7 introduction (2001-2004) was compared with that during the baseline years (1994-1999).

RESULTS

During 1994-2004, there were 21,396 hospitalizations and 2684 deaths (12.5%) due to pneumococcal meningitis in the United States. In children aged < 2 years, the average annualized rates of pneumococcal meningitis hospitalizations per 100,000 population decreased from 7.7 in 1994-1999 to 2.6 in 2001-2004 (change, -66.0%; 95% confidence interval [CI], -73.5% to -56.3%). Among children aged 2-4 years, the hospitalization rate decreased from 0.9 to 0.5 per 100,000 (change, -51.5%; 95% CI, -66.9% to -28.9%). Average rates also decreased by 33.0% (95% CI, -43.4% to -20.9%) among adults aged > or = 65 years. After PCV7 introduction (2001-2004), an estimated 1822 and 573 pneumococcal meningitis hospitalizations were prevented in persons aged < 5 years and > or = 65 years, respectively. Overall, an estimated 3330 pneumococcal meningitis hospitalizations and 394 deaths were prevented in persons of all ages during 2001-2004 in the United States.

CONCLUSION

After implementation of routine childhood vaccination with PCV7, hospitalizations for pneumococcal meningitis decreased significantly for both children and adults. Most pneumococcal meningitis cases now occur among adults.

Myeloid Src kinases regulate phagocytosis and oxidative burst in pneumococcal meningitis by activating NADPH oxidase

Myeloid cells, including neutrophils and macrophages, play important roles in innate immune defense against acute bacterial infections. Myeloid Src family kinases (SFKs) p59/61(hck) (Hck), p58(c-fgr) (Fgr), and p53/56(lyn) (Lyn) are known to control integrin beta(2) signal transduction and FcgammaR-mediated phagocytosis in leukocytes. In this study, we show that leukocyte recruitment into the cerebrospinal fluid space and bacterial clearance is hampered in mice deficient in all three myeloid SFKs (hck(-/-)fgr(-/-)lyn(-/-)) during pneumococcal meningitis. As a result, the hck(-/-)fgr(-/-)lyn(-/-) mice developed increased intracranial pressure and a worse clinical outcome (increased neurologic deficits and mortality) compared with wild-type mice. Impaired bacterial killing was associated with a lack of phagocytosis and superoxide production in triple knockout neutrophils. Moreover, in hck(-/-)fgr(-/-)lyn(-/-) neutrophils, phosphorylation of p40(phox) was absent in response to pneumococcal stimulation, indicating a defect in NAPDH oxidase activation. Mice lacking the complement receptor 3 (CR3; CD11b/CD18), which belongs to the beta(2)-integrin family, also displayed impaired host defense against pneumococci, along with defective neutrophil superoxide production, but cerebrospinal fluid pleocytosis was normal. Cerebral expression of cytokines and chemokines was not decreased in both mouse strains, indicating that CR3 and myeloid SFKs are dispensable for the production of inflammatory mediators. Thus, our study demonstrates the pivotal role of myeloid SFKs and CR3 in mounting an effective defense against CNS infection with Streptococcus pneumonia by regulating phagocytosis and NADPH oxidase-dependent superoxide production. These data support the role of SFKs as critical mediators of CR3 signal transduction in host defense.

Streptococcus pneumoniae meningoencephalitis with unusual and widespread white matter lesions

Streptococcus pneumoniae is a common cause of bacterial meningitis, frequently leading to death or severe neurological impairment. We report an exceptional case of a 7-month-old child with meningoencephalitis caused by S. pneumoniae. Peculiar, widespread and unique signal abnormalities were found on magnetic resonance imaging (MRI) with extensive central nervous white matter injury as well as evidence of thrombosis of the lateral transverse sinus. These changes were observed very early in the course of the illness, presumably reflecting widespread cytotoxic edema, vasculitis and acute demyelination. These lesions occurred despite appropriate antibiotic and anti-inflammatory (glucocorticoid) therapy started very early in the course of the disease. Such diffuse white matter lesions in the early course of (pediatric) cases of S. pneumoniae meningoencephalitis have not been reported previously.

Meningitis in the athlete

Infectious diseases among athletic teams commonly present challenges for team physicians and primary care doctors. There is some evidence to suggest that athletes are more susceptible to infection during an outbreak of the general population. The frequent physical contact and close travel arrangements associated with many team sports may put athletes at even greater risk. Viral meningitis is the most commonly reported central nervous system infection in the literature, and transmission seems to be increased among U.S. high school football teams. Septic meningitis is a life-threatening emergency that can occur in outbreaks affecting populations frequently involved in organized athletics (adolescents and young adults). The purpose of this review is to identify current medical literature on the epidemiology, diagnosis, treatment, and prevention of meningitis in the athletic population.

A risk score for unfavorable outcome in adults with bacterial meningitis

OBJECTIVE

To derive and validate a bedside risk score for adverse outcome in adults with bacterial meningitis.

METHODS

We derived a score for the risk for an unfavorable outcome (Glasgow Outcome Scale score 1-4) by performing logistic regression analyses of data from a prospective cohort study (Dutch Meningitis Cohort; N = 696). A key set of independent prognostic variables was selected from 22 potential predictors. A nomogram based on these key variables was constructed to facilitate use in clinical practice. To validate this nomogram, we used data from our randomized controlled trial on adjunctive dexamethasone therapy in adults with bacterial meningitis (European Dexamethasone Study; N = 301).

RESULTS

Unfavorable outcome occurred in 237 of 696 episodes (34%) in the Dutch Meningitis Cohort; 143 patients (21%) died. In the analysis, 6 of 22 variables that are routinely available within 1 hour after admission were robust enough for inclusion in the final risk score: age, heart rate, Glasgow Coma Scale score, cranial nerve palsies, a cerebrospinal fluid leukocyte count less than 1,000 cells/mm3, and gram-positive cocci in cerebrospinal fluid Gram's stain. The concordance index for the risk score was 0.84 (95% confidence interval, 0.80-0.87) in the original cohort and 0.81 (95% confidence interval, 0.74-0.87) in the external validation cohort (European Dexamethasone Study).

INTERPRETATION

This bedside risk score can be used to identify patients with a high risk for unfavorable outcome in adults with bacterial meningitis within 1 hour after the initial presentation.

Infektionen

Trotz Weiterentwicklung moderner Antibiotika in den letzten Jahren sind die Letalitätszahlen der bakteriellen (eitrigen) Meningitis weiterhin hoch; Überlebende haben häufig neurologische Residuen. Die ungünstigen klinischen Verläufe der bakteriellen Meningitis sind meist Folge intrakranieller Komplikationen, wie z. B. eines generalisierten Hirnödems, einer zerebrovaskulären arteriellen oder venösen Beteiligung oder eines Hydrozephalus. Als Folge dieser Komplikationen kommt es häufig zu einem Anstieg des intrakraniellen Drucks. Bei schweren, komplizierten klinischen Verläufen der bakteriellen Meningitis kommen oft adjuvante Therapiemaßnahmen (z. B. intravenöse Gabe von hyperosmolaren Substanzen, externe Ventrikeldrainage) zum Einsatz. Bei Nachweis einer meningitisassoziierten septischen Sinus-/Venenthrombose erfolgt die dosisadaptierte intravenöse Heparintherapie.

Long-term functional outcome and performance status after intensive care unit re-admission: a prospective survey

BACKGROUND

Intensive care unit (ICU) re-admission identifies a high-risk group in terms of hospital mortality, length of stay, and resource utilization. Only hospital and ICU mortality are well described in the literature on critically ill patients needing re-admission.

METHODS

With ethical committee approval, from a prospectively collected database of all admissions to a combined medical and surgical ICU from January 1 to December 31, 2004, we identified all ICU re-admissions from within the hospital and analysed the factors associated with increased incidence of re-admission. At 2-3 yr after discharge, we evaluated the functional outcome of the surviving re-admitted patients as Glasgow Outcome Score (GOS) and Karnofsky index and identified determinants of both mortality and good functional outcome.

RESULTS

Seventy-three (7.4%) of the 1061 patients who survived their first ICU stay were re-admitted during the study period. Of the 73 re-admitted patients, 14 died in ICU, 17 died later in the same hospital stay, and 10 died in the interim. Thus, 32 (43.8%) were alive 2-3 yr after discharge. The median [IQR] GOS of the survivors was 4 (see Mackle and colleagues in One year outcome of intensive care patients with decompensated alcoholic liver disease.

CONCLUSIONS

Although the ICU, hospital, and subsequent mortalities are high in patients after ICU re-admission, most survivors at 2-3 yr had by then made a good functional recovery and were independent.

Nitrogen and oxygen molecules in meningitis-associated labyrinthitis and hearing impairment

Pneumococcal meningitis remains a serious disease with a case fatality rate of 15%-25%. Furthermore, long-term residues affect up to 50% of survivors. One of the most frequent sequelae is sensorineural hearing loss, which occurs in 26% of survivors of pneumococcal meningitis. Unfortunately, sufficient treatment regimens are still missing. New insights into the pathology and pathophysiology of meningitis-associated hearing loss have come from animal models of bacterial meningitis. Most likely, bacteria reach the cochlea through the cochlear aquaeduct. Once arrived in the perilymphatic spaces, they induce a severe suppurative labyrinthitis. The blood-labyrinth barrier breaks, hair cells are damaged, and neurons in the spiral ganglion undergo cell death, leading to meningitis-associated hearing loss. Reactive oxygen and nitrogen species, in particular peroxynitrite, seem to be among the crucial mediators of cochlear damage and hearing loss during meningitis. In our rat model of pneumococcal meningitis, adjunctive therapy with the antioxidants and peroxynitrite scavengers Mn(III)tetrakis(4-bencoic acid)-porphyrin (MnTBAP) and N-Acetyl-L-Cystein (NAC) significantly attenuated acute and long-term hearing loss. In several other animal studies of pneumococcal meningitis, adjunctive antioxidant therapy also protected infected animals from intracranial complications. Therefore, the use of antioxidants seems to be a promising future treatment option in pneumococcal meningitis.

An infant mouse model of brain damage in pneumococcal meningitis

Bacterial meningitis due to Streptococcus pneumoniae is associated with an significant mortality rate and persisting neurologic sequelae including sensory-motor deficits, seizures, and impairments of learning and memory. The histomorphological correlate of these sequelae is a pattern of brain damage characterized by necrotic tissue damage in the cerebral cortex and apoptosis of neurons in the hippocampal dentate gyrus. Different animal models of pneumococcal meningitis have been developed to study the pathogenesis of the disease. To date, the infant rat model is unique in mimicking both forms of brain damage documented in the human disease. In the present study, we established an infant mouse model of pneumococcal meningitis. Eleven-days-old C57BL/6 (n = 299), CD1 (n = 42) and BALB/c (n = 14) mice were infected by intracisternal injection of live Streptococcus pneumoniae. Sixteen hours after infection, all mice developed meningitis as documented by positive bacterial cultures of the cerebrospinal fluid. Sixty percent of infected C57BL/6 mice survived more than 40 h after infection (50% of CD1, 0% of BALB/c). Histological evaluations of brain sections revealed apoptosis in the dentate gyrus of the hippocampus in 27% of infected C57BL/6 and in 5% of infected CD1 mice. Apoptosis was confirmed by immunoassaying for active caspase-3 and by TUNEL staining. Other forms of brain damage were found exclusively in C57BL/6, i.e. caspase-3 independent (pyknotic) cell death in the dentate gyrus in 2% and cortical damage in 11% of infected mice. This model may prove useful for studies on the pathogenesis of brain injury in childhood bacterial meningitis.

Infectious disease and the collegiate athlete

Collegiate athletes are common reservoirs for infectious disease agents. Specific training regimens, living arrangements, and high-risk behaviors may influence the athlete's risk of contracting a variety of infectious diseases. The sports medicine physician plays an important role in recognizing, appropriately treating, designing prevention strategies for, and making return-to-activity decisions for athletes who have infectious diseases.

Pneumococcal meningitis in childhood: a longitudinal prospective study

After implementation of programmes for active immunization against Haemophilus influenzae b, Streptococcus pneumoniae and Neisseria meningitidis became the most common agents of bacterial meningitis in childhood. Over a 9-year period, children showing clinical and laboratory findings of meningitis on the basis of their positive cultures of blood or cerebro-spinal fluid (CSF) for S. pneumoniae were enrolled. Predisposing conditions, clinical and laboratory findings, and microbiological and imaging studies were considered. Meningitis-related death or neurological sequelae defined an unfavourable outcome. Sixty-four patients met the inclusion criteria. Thirty-one (48%) children had predisposing conditions to pneumococcal meningitis. Fever and neck stiffness were the main symptoms; 14 patients (22%) reported seizures before admission. Twenty-one patients required treatment in the intensive care unit (ICU). Streptococcus pneumoniae strains were penicillin susceptible in 54 cases (84%). Forty-eight children (75%) showed complete recovery. Two patients (3%) died, and 14 (22%) had sequelae. Patients with a low CSF cell count, low neutrophils, early admission to ICU or infection by penicillin-nonsusceptible strains of S. pneumoniae had an unfavourable outcome more frequently. Low blood neutrophils, low CSF cell count, early admission to ICU and infection by penicillin-nonsusceptible strains are the main factors predicting an unfavourable outcome in children with pneumococcal meningitis.

Bacterial meningitis: a review of effective pharmacotherapy

Acute bacterial meningitis is a serious and life-threatening neurological infectious disease. Despite the availability of effective antibiotics, supportive care facilities and recent advances in adjunctive strategies, for example, adjunctive dexamethasone, mortality and morbidity rates associated with bacterial meningitis remain unacceptably high. The review presents a brief overview of key clinical and epidemiological aspects of the disease and focuses on advances in pharmacotherapeutic strategies in adult patients with bacterial meningitis in the developed world.

Prognostic factors in adult community-acquired bacterial meningitis: a 4-year retrospective study

The aim of this 4-year, observational, single-center study was to identify prognostic factors and evaluate the need for intensive care in cases of bacterial meningitis. During the study period, 60 cases of adult bacterial meningitis were identified. Fifty-one patients were transferred to the intensive care unit at various times during their hospital stay. In the multivariate analysis, factors significantly associated with the need for mechanical ventilation and/or vasopressive drugs included comorbidity and a Glasgow coma score of less than 12 at hour 6 following presentation. The results indicate patients with a decreased level of consciousness, neurological deficit or comorbidity should be admitted to the intensive care unit at an early stage of illness. When patients lack these criteria 6 h following presentation, admission to the medical ward is reasonable.

Bacterial meningitis: the role of transforming growth factor-Beta in innate immunity and secondary brain damage

Project 6 of the NCCR 'Neural Plasticity and Repair' focuses on mechanisms of immunity and tissue damage in autoimmune and infectious diseases of the central nervous system (CNS). In one of the subprojects, the influence of transforming growth factor-beta (TGF-beta) on the immune reactivity of the CNS was investigated. In mice with Streptococcus pneumoniae-induced meningitis, a deletion of TGF-beta receptor II on leukocytes is found to enhance recruitment of neutrophils to the site of infection and to promote bacterial clearance. The improved host defense against S. pneumoniae was associated with an almost complete prevention of meningitis-induced vasculitis, a major intracranial complication leading to brain damage. The data show that endogenous TGF-beta suppresses host defense against bacterial infection in the CNS. This contrasts with findings from other body compartments that suggested that TGF-beta is a powerful chemotactic cytokine and increases microbial clearance.

Vascular and Parameningeal Infections of the Head and Neck

Vascular and parameningeal infections of the head and neck are rare but frequently life threatening. These infections include intracranial and extracranial septic venous thrombophlebitis, arterial mycotic aneurysms and erosions, subdural empyema, and epidural abscesses. They usually arise as complications of otogenic, oropharyngeal, or paranasal sinus infections, and management involves an aggressive combined medical-surgical approach.

Intracerebroventricular antisense knockdown of G alpha i2 results in ciliary stasis and ventricular dilatation in the rat

BACKGROUND

In the CNS, the heterotrimeric G protein Galphai2 is a minor Galpha subunit with restricted localization in the ventricular regions including the ependymal cilia. The localization of Galphai2 is conserved in cilia of different tissues, suggesting a particular role in ciliary function. Although studies with Galphai2-knockout mice have provided information on the role of this Galpha subunit in peripheral tissues, its role in the CNS is largely unknown. We used intracerebroventricular (icv) antisense administration to clarify the physiological role of Galphai2 in the ventricular system.

RESULTS

High resolution MRI studies revealed that continuous icv-infusion of Galphai2-specific antisense oligonucleotide caused unilateral ventricular dilatation that was restricted to the antisense-receiving ventricle. Microscopic analysis demonstrated ependymal cell damage and loss of ependymal cilia. Attenuation of Galphai2 in ependymal cells was confirmed by immunohistochemistry. Ciliary beat frequency measurements on cultured ependymal cells indicated that antisense administration resulted in ciliary stasis.

CONCLUSION

Our results establish that Galphai2 has an essential regulatory role in ciliary function and CSF homeostasis.

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.

Coagulation, coma, and outcome in bacterial meningitis--an observational study of 38 adult cases

OBJECTIVES

The purpose of this study was to evaluate the epidemiology of intravascular coagulation in bacterial meningitis and to recognise the associations with disease severity and outcome.

METHODS

Thirty-eight consecutively admitted adult patients with microbiologically proven bacterial meningitis were observed prospectively for platelets count (PLT), platelets-decline (dPLT), prothrombin ratio (PTr), INR, and D-dimer levels during the first three days in relation to disease severity (Glasgow Coma Scale--GCS, APACHE-III) and outcome (Glasgow Outcome Scale--GOS).

RESULTS

The prevalence of activated coagulation measured by abnormal laboratory results varied respectively: PTr--30%, INR--36%, PLT--38%, dPLT--50%, and D-dimer--88%. Patients with GCS <9 at admission presented with laboratory results suggesting triggered coagulation: dPLT 48 vs. 15%/day (p=0.0246), INR 1.6 vs. 1.12 (p=0.0014), PTr 76 vs. 93% (p=0.0020). An unfavourable outcome (GOS 1-4) was observed in 42% of patients and was associated with: PLT <170 or >265 G/L (OR--24.4; p=0.0006), PTr <82% (OR--5.00; p=0.0388), INR >1.1 (OR--5.04; 0.0336), and D-dimer >850 ng/ml (OR--24.0; p=0.0033).

CONCLUSIONS

Coagulation was activated in a majority of patients with bacterial meningitis and related to coma and unfavourable outcome.

Prognostic factors and determinants of fatal outcome due to bacterial meningitis in the Lazio region of Italy, 1996–2000

OBJECTIVES

To estimate case fatality rates (CFR) of bacterial meningitis and analyze factors associated with mortality due to bacterial meningitis in the Italian region of Lazio.

METHODS

Patients reported with bacterial meningitis during the period 1996-2000, who died within 30 days from hospitalization (cases), were compared with survivors (controls) for factors related to healthcare. Age, gender, residence, bacterial agent, co-morbidities, and signs of disease severity were also analyzed in the final model. Healthcare factors were analyzed using current surveillance databases.

RESULTS

Disease severity (OR=8.84; 95% CI=3.35-23.34) and age >44 years (OR=4.59; 95% CI=2.01-10.48) were the risk factors most strongly associated with death, while treatment in an infectious diseases ward was a protective factor, although modified by patient residence and by co-morbidities.

CONCLUSIONS

This protective effect was possibly due to differences in treatment protocols between the infectious diseases ward and other wards. The protective effect was found to be stronger for residents of Rome, suggesting delayed access to infectious diseases wards for non-residents. The difference in risk of dying from meningitis at younger ages than that found in other studies should be further evaluated, using information on bacteria serogroups and antibiotic susceptibility.