Cefotaxime and ceftriaxone cerebrospinal fluid levels during treatment of bacterial meningitis in children

Ceftriaxone-Related Encephalopathy in a Patient With End-Stage Renal Disease and High Ceftriaxone Concentrations in Cerebrospinal Fluid and Plasma: A Case Report

Ceftriaxone (CTRX) does not require dose adjustment based on the renal function status and is used to treat infections. Recently, several studies reported the incidence of antibiotic-associated encephalopathy due to CTRX in patients with end-stage renal disease (ESRD). We experienced a case of CTRX-related encephalopathy in a patient on hemodialysis. When CTRX-related encephalopathy was discovered, the CTRX concentrations were measured in the blood and cerebrospinal fluid (CSF). The highest blood and CSF CTRX concentrations in this patient were 967 and 100.7 μg/mL, respectively, which were approximately 10 times higher than the CSF concentrations in a previously evaluated patient with CTRX encephalopathy. The concentration of CTRX may be increased in patients with ESRD. Hence, encephalopathy must be suspected in this patient group when CTRX is used.

Thymoquinone ameliorates amikacin induced oxidative damage in rat brain tissue

We investigated the potential neuroprotective effects of thymoquinone (TQ) on amikacin (AK) induced oxidative damage in rat brain. We used 21 male rats divided randomly into three equal groups. The control group was injected intraperitoneally (i.p.) with 0.5 ml 0.9% aqueous NaCl and given 1 ml 0.9% aqueous NaCl orally. The AK group was administered 1.2 g/kg aqueous AK i.p. as a single dose on the day 3 of the study. The AK + TQ group was given a single 1.2 g/kg dose of AK i.p. on the day 3 of the study plus 40 mg/kg/day TQ by oral gavage daily. Treatment with TQ increased serum ferritin and decreased serum calcium levels significantly. TQ also decreased NADPH oxidase-2, NADPH oxidase-4, and caspase-3 levels. Decreased malondialdehyde (MDA) levels and increased superoxide dismutase (SOD) and catalase (CAT) activities were detected in the AK + TQ group compared to the AK group. TQ administration inhibited lipid peroxide formation and blocked oxidative reactions, which reduced the MDA level and increased SOD and CAT activities induced by AK. Oxidative damage caused by AK was ameliorated by TQ treatment owing to its antioxidative and anti-apoptotic effects. TQ may be a potential therapeutic agent for reducing the severity of AK induced oxidative damage to the brain.

Dose optimisation of antibiotics used for meningitis

PURPOSE OF REVIEW

Central nervous system (CNS) infections such as ventriculitis and meningitis are associated with significant morbidity and mortality. In part, this may be due to increased difficulties in achieving a therapeutic antibiotic concentration at the site of infection due to both the pharmacokinetic (PK) changes observed during critical illness and the reduced antibiotic penetration through the blood brain barrier. This paper reviews the pharmacodynamics (PD) and CNS PKs of antibiotics used for Gram-negative bacterial CNS infections to provide clinicians with practical dosing advice.

RECENT FINDINGS

Recent PK studies have shown that currently used intravenous antibiotic dosing regimens may not achieve a therapeutic exposure within the CNS, even for reportedly 'susceptible' bacteria per the current clinical meningitis breakpoints. Limited data exist for new β-lactam antibiotic/β-lactamase inhibitor combinations, which may be required for multidrug resistant infections. Intraventricular antibiotic administration, although not a new concept, has further evidence demonstrating improved patient outcomes compared with intravenous therapy alone, despite the ongoing paucity of PK studies guiding dosing recommendations.

SUMMARY

Clinicians should obtain the bacterial minimum inhibitory concentration when treating patients with CNS Gram-negative bacterial infections and consider the underlying PK/PD principles when prescribing antibiotics. Therapeutic drug monitoring, where available, should be considered to guide dosing. Intraventricular therapy should also be considered for patients with ventricular drains to optimise clinical outcomes.

CSF concentration of cefotaxime in adult patients with pneumococcal meningitis: a multicentre retrospective study

BACKGROUND AND OBJECTIVES

Pneumococcal meningitis is a devastating disease that requires adequate meningeal antibiotic penetration to limit the mortality. Despite a large usage in this indication, data about CSF concentration of cefotaxime during pneumococcal meningitis in adults are scarce. Therefore, we aimed to describe the CSF concentration obtained after high-dose cefotaxime administration in adult patients treated for Streptococcus pneumoniae meningitis.

PATIENTS AND METHODS

In this multicentre, observational, retrospective study, cases of adult patients with S. pneumoniae meningitis hospitalized between January 2013 and October 2019 for whom cefotaxime concentration was measured in CSF were reviewed.

RESULTS

Cefotaxime concentration was analysed in 44 CSF samples collected among 31 patients. Median (IQR) age was 61 years (52-69). Dexamethasone was administered in 27 subjects. Median (IQR) cefotaxime daily dosage was 15 g (12-19), corresponding to 200 mg/kg (150-280). CSF samples were collected approximately 5 days after cefotaxime initiation. Median (IQR, range) cefotaxime CSF concentration was 10.3 mg/L (4.8-19.3, 1.2-43.4). Median (range) MIC for Streptococcus pneumoniae was 0.25 mg/L (0.008-1) (n = 22). The median (IQR, range) CSF/MIC ratio was 38 (12-146, 4-1844). Twenty-five CSF concentrations (81%) were above 10 times the MIC. Cefotaxime was discontinued in two patients for toxicity. In-hospital mortality rate was 29%.

CONCLUSIONS

Adult patients with pneumococcal meningitis treated with a high dose of cefotaxime (200 mg/kg/day) had elevated CSF concentrations with satisfying pharmacokinetics/pharmacodynamics parameters and tolerability profile. This study brings reassuring pharmacological data regarding the use of high-dose cefotaxime monotherapy for treating pneumococcal meningitis with susceptible strains to cefotaxime.

Evaluating Ceftriaxone 80 mg/kg Administration by Rapid Intravenous Infusion-A Clinical Service Evaluation

In pediatric ambulatory care, the speed of medication infusion can have major impact on healthcare staff workload and the number of children able to be treated by services designed to reduce inpatient length of stay. In many regions of the world, local and supraregional guidelines allow ceftriaxone infusions of ≥50 mg/kg in infants and children up to 12 years of age to be given over 10 minutes. The generic European summary of product characteristics for ceftriaxone does not state a specific infusion time for this dose range, although 1 manufacturers' summary of product characteristics in the United Kingdom states a 30-minute minimum infusion time. We conducted a formal service evaluation of a change in practice at a large UK pediatric children's hospital and demonstrated the clinical feasibility, safety, and high parent satisfaction of 10-minute ceftriaxone infusions for prescribed doses ≥50 mg/kg. This approach can improve patient flow within hospital-based ambulatory services as well as by community nursing teams administering antibiotics at home.

Cerebrospinal fluid pharmacokinetics of ceftaroline in neurosurgical patients with an external ventricular drain

BACKGROUND

Owing to its antibacterial properties, ceftaroline could be attractive for prevention or treatment of bacterial post-neurosurgical meningitis/ventriculitis. However, few data are available concerning its meningeal concentrations.

OBJECTIVES

To investigate ceftaroline CSF pharmacokinetics in ICU patients with an external ventricular drain (EVD).

METHODS

Patients received a single 600 mg dose of ceftaroline as a 1 h intravenous infusion. Blood and CSF samples were collected before and 0.5, 1, 3, 6, 12 and 24 h after the end of the infusion. Concentrations were assayed in plasma and CSF by LC-MS/MS. A two-step compartmental pharmacokinetic analysis was conducted. Ceftaroline plasma data were first analysed, and thereafter plasma parameters estimated and corrected for protein binding of 20% were fixed to fit unbound CSF concentrations. In the final model, parameters for both plasma and CSF data were simultaneously estimated.

RESULTS

Nine patients with an EVD were included. The Cmax was 18.29 ± 3.33 mg/L in plasma (total concentrations) and at 0.22 ± 0.17 mg/L in CSF (unbound concentration). The model-estimated CSF input/CSF output clearance ratio was 9.4%, attesting to extensive efflux transport at the blood-CSF barrier.

CONCLUSIONS

Ceftaroline CSF concentrations are too low to ensure prophylactic protection against most pathogens with MICs between 1 and 2 mg/L, owing to its limited central distribution.

Combination therapy with ciprofloxacin and third-generation cephalosporin versus third-generation cephalosporin monotherapy in Escherichia coli meningitis in infants: a multicentre propensity score-matched observational study

OBJECTIVES

Escherichiacoli is the second cause of bacterial meningitis in neonates. Despite the use for 35 years of third-generation cephalosporins (3GCs), high morbidity and mortality rates with E. coli meningitis continue to occur. Because ciprofloxacin has good microbiologic activity against E. coli and good penetration in cerebrospinal fluid and brain, some authors have suggested adding ciprofloxacin to a 3GC regimen. The objective of this study was to assess combining 3GCs with ciprofloxacin versus 3GCs alone in a cohort of infants with E. coli meningitis.

METHODS

We included all cases of E. coli meningitis diagnosed in infants <12 months of age that were prospectively collected through the French paediatric meningitis surveillance network between 2001 and 2016. The main outcome was the proportion of short-term neurologic complications with versus without ciprofloxacin. The analysis was conducted retrospectively by multivariable regression and propensity score (PS) analysis.

RESULTS

Among the 367 infants enrolled, 201 (54.8%) of 367 had ciprofloxacin and 3GC cotreatment and 166 (45.2%) of 367 only a 3GC. Median age and weight were 15 days (range, 1-318 days) and 3.42 kg (range, 0.66-9.4 kg). A total of 86 (23.4%) of 367 infants presented neurologic complications (seizures, strokes, empyema, abscesses, hydrocephalus, arachnoiditis); 57 received ciprofloxacin cotreatment. Complications were associated with ciprofloxacin cotreatment on multivariable analysis (odds ratio (OR) = 1.9; 95% confidence interval (CI), 1.1-3.4) and PS analysis (OR = 1.9; 95% CI, 1.1-3.3). Mortality rate did not differ with and without ciprofloxacin: 22 (10.9%) of 201 versus 16 (9.6%) of 166 deaths (OR = 0.7; 95% CI, 0.3-1.6; PS analysis).

CONCLUSIONS

Ciprofloxacin added to 3GCs at least offers no advantage for neurologic outcome and mortality in infants with E. coli meningitis.

Pharmacokinetics-pharmacodynamics issues relevant for the clinical use of beta-lactam antibiotics in critically ill patients

Antimicrobials are among the most important and commonly prescribed drugs in the management of critically ill patients and beta-lactams are the most common antibiotic class used. Critically ill patient's pathophysiological factors lead to altered pharmacokinetics and pharmacodynamics of beta-lactams.A comprehensive bibliographic search in PubMed database of all English language articles published from January 2000 to December 2017 was performed, allowing the selection of articles addressing the pharmacokinetics or pharmacodynamics of beta-lactam antibiotics in critically ill patients.In critically ill patients, several factors may increase volume of distribution and enhance renal clearance, inducing high intra- and inter-patient variability in beta-lactam concentration and promoting the risk of antibiotic underdosing. The duration of infusion of beta-lactams has been shown to influence the fT > minimal inhibitory concentration and an improved beta-lactam pharmacodynamics profile may be obtained by longer exposure with more frequent dosing, extended infusions, or continuous infusions.The use of extracorporeal support techniques in the critically ill may further contribute to this problem and we recommend not reducing standard antibiotic dosage since no drug accumulation was found in the available literature and to maintain continuous or prolonged infusion, especially for the treatment of infections caused by multidrug-resistant bacteria.Prediction of outcome based on concentrations in plasma results in overestimation of antimicrobial activity at the site of infection, namely in cerebrospinal fluid and the lung. Therefore, although no studies have assessed clinical outcome, we recommend using higher than standard dosing, preferably with continuous or prolonged infusions, especially when treating less susceptible bacterial strains at these sites, as the pharmacodynamics profile may improve with no apparent increase in toxicity.A therapeutic drug monitoring-guided approach could be particularly useful in critically ill patients in whom achieving target concentrations is more difficult, such as obese patients, immunocompromised patients, those infected by highly resistant bacterial strains, patients with augmented renal clearance, and those undergoing extracorporeal support techniques.

Microdialysis study of cefotaxime cerebral distribution in patients with acute brain injury

Central nervous system (CNS) antibiotic distribution was described mainly from cerebrospinal fluid data, and only few data exist on brain extracellular fluid concentrations. The aim of this study was to describe brain distribution of cefotaxime (2 g/8 h) by microdialysis in patients with acute brain injury who were treated for a lung infection. Microdialysis probes were inserted into healthy brain tissue of five critical care patients. Plasma and unbound brain concentrations were determined at steady state by high-performance liquid chromatography. In vivo recoveries were determined individually using retrodialysis by drug. Noncompartmental and compartmental pharmacokinetic analyses were performed. Unbound cefotaxime brain concentrations were much lower than corresponding plasma concentrations, with a mean cefotaxime unbound brain-to-plasma area under the curve ratio equal to 26.1 ± 12.1%. This result was in accordance with the brain input-to-brain output clearances ratio (CL(in,brain)/CL(out,brain)). Unbound brain concentrations were then simulated at two dosing regimens (4 g every 6 h or 8 h), and the time over the MICs (T>MIC) was estimated for breakpoints of susceptible and resistant Streptococcus pneumoniae strains. T>MIC was higher than 90% of the dosing interval for both dosing regimens for susceptible strains and only for 4 g every 6 h for resistant ones. In conclusion, brain distribution of cefotaxime was well described by microdialysis in patients and was limited.

Pharmacokinetics of antibacterial agents in the CSF of children and adolescents

The adequate management of central nervous system (CNS) infections requires that antimicrobial agents penetrate the blood-brain barrier (BBB) and achieve concentrations in the CNS adequate for eradication of the infecting pathogen. This review details the currently available literature on the pharmacokinetics (PK) of antibacterials in the CNS of children. Clinical trials affirm that the physicochemical properties of a drug remain one of the most important factors dictating penetration of antimicrobial agents into the CNS, irrespective of the population being treated (i.e. small, lipophilic drugs with low protein binding exhibit the best translocation across the BBB). These same physicochemical characteristics determine the primary disposition pathways of the drug, and by extension the magnitude and duration of circulating drug concentrations in the plasma, a second major driving force behind achievable CNS drug concentrations. Notably, these disposition pathways can be expected to change during the normal process of growth and development. Finally, CNS drug penetration is influenced by the nature and extent of the infection (i.e. the presence of meningeal inflammation). Aminoglycosides have poor CNS penetration when administered intravenously. Intrathecal gentamicin has been studied in children with more promising results, often exceeding the minimum inhibitory concentration. There are very limited data with intrathecal tobramycin in children. However, in the few patients that have been studied, the CSF concentrations were highly variable. Penicillins generally have good CNS penetration. Aqueous penicillin G reaches greater concentrations than procaine or benzathine penicillin. Concentrations remain detectable for ≥ 12 h. Of the aminopenicillins, both ampicillin and parenteral amoxicillin reach adequate CNS concentrations; however, orally administered amoxicillin resulted in much lower concentrations. Nafcillin and piperacillin are the final two penicillins with pediatric data: their penetration is erratic at best. Cephalosporins vary greatly in regard to their CSF penetration. Few first- and second-generation cephalosporins are able to reach higher CSF concentrations. Cefuroxime is the only exception and is usually avoided due to its adverse effects and slower sterilization of the CSF than third-generation agents. Ceftriaxone, cefotaxime, ceftazidime, cefixime and cefepime have been studied in children and are all able to adequately penetrate the CSF. As with penicillins, concentrations are greatest in the presence of meningeal inflammation. Meropenem and imipenem are the only carbapenems with pediatric data. Imipenem reaches higher CSF concentrations; however, meropenem is preferred due to its lower incidence of seizures. Aztreonam has also demonstrated favorable penetration but only one study has been completed in children. Both chloramphenicol and sulfamethoxazole/trimethoprim (cotrimoxazole) penetrate into the CNS well; however, significant toxicities limit their use. The small size and minimal protein binding of fosfomycin contribute to its favorable CNS PK. Although rarely used, it achieves higher concentrations in the presence of inflammation and accumulation is possible. Linezolid reaches high CSF concentrations; however, more frequent dosing might be required in infants due to their increased elimination. Metronidazole also has very limited information but it demonstrated favorable results similar to adult data; CSF concentrations even exceeded plasma concentrations at certain time points. Rifampin (rifampicin) demonstrated good CNS penetration after oral administration. Vancomycin demonstrates poor CNS penetration after intravenous administration. When combined with intraventricular therapy, CNS concentrations are much greater. Of the antituberculosis agents, isoniazid, pyrazinamide and streptomycin have been studied in children. Isoniazid and pyrazinamide have favorable CSF penetration. Streptomycin appears to produce unpredictable CSF levels. No pediatric-specific data are available for clindamycin, daptomycin, macrolides, tetracyclines, and fluoroquinolones. Daptomycin, fluoroquinolones, and tetracyclines have demonstrated favorable CNS penetration in adults; however, data are limited due to their potential pediatric-specific toxicities and newness within the marketplace. Macrolides and clindamycin have demonstrated poor CNS penetration in adults and thus have not been studied in pediatrics.

Choice and duration of antimicrobial therapy for neonatal sepsis and meningitis

Neonatal sepsis is associated with increased mortality and morbidity including neurodevelopmental impairment and prolonged hospital stay. Signs and symptoms of sepsis are nonspecific, and empiric antimicrobial therapy is promptly initiated after obtaining appropriate cultures. However, many preterm and low birth weight infants who do not have infection receive antimicrobial agents during hospital stay. Prolonged and unnecessary use of antimicrobial agents is associated with deleterious effects on the host and the environment. Traditionally, the choice of antimicrobial agents is based on the local policy, and the duration of therapy is decided by the treating physician based on clinical symptoms and blood culture results. In this paper, we discuss briefly the causative organism of neonatal sepsis in both the developed and developing countries. We review the evidence for appropriate choice of empiric antimicrobial agents and optimal duration of therapy in neonates with suspected sepsis, culture-proven sepsis, and meningitis. Moreover, there is significant similarity between the causative organisms for early- and late-onset sepsis in developing countries. The choice of antibiotic described in this paper may be more applicable in developed countries.

Therapeutic management of bacterial meningitis in children: a systematic review and comparison of published guidelines from a European perspective

Bacterial meningitis is an infectious disease emergency that can cause substantial morbidity and mortality. We compared the most recent international guidelines and recommendations on bacterial meningitis management in infants and children in developed countries, in terms of initial management approach, empirical antimicrobial therapy, timing, dosages, and duration of antimicrobial therapy, and possible adjunctive treatment with dexamethasone. Secondly, epidemiological data on bacterial resistance in several european countries were analyzed and discussed in relation to the therapies currently recommended for bacterial meningitis. The comparative analysis of the selected guidelines highlighted significant differences in the therapeutic management of bacterial meningitis. Differences among guidelines have important consequences for daily practice. An agreed protocol for early, evidence-based, and effective therapeutic management of bacterial meningitis is essential for the best outcome. further studies and expert consensus are required to establish the best management of bacterial meningitis in the european setting based on the most recent epidemiological data on resistance rates.

Clinical behavior of Streptococcus pneumoniae meningoencephalitis

OBJECTIVE

There was an increased number of cases of meningoencephalitis caused by Streptococcus pneumoniae, after the successful vaccination campaigns against Neisseria meningitidis and Haemophilus influenzae. This paper aims at describing the clinical characteristics, the laboratory findings, the complications, and the therapeutic management of these patients, who have been suffering from this disease since 1993 to 2006.

METHOD

Twelve children with Streptococcus pneumoniae meningoencephalitis admitted to the pediatric hospital of San Miguel del Padron, City of Havana in this period were assessed.

RESULTS

Children under one year are the most frequently affected. Septic shock and brain edema were the most severe complications. Three patients died, implying that this disease has a serious course. Early treatment of brain edema is very important to reduce mortality. The elective drugs for treatment of these cases of Streptococcus pneumoniae meningoencephalitis were vancomycin combined with cephalosporin, cefotaxime or ceftriaxone type.

CONCLUSION

Patients with Streptococcus pneumoniae meningoencephalitis show clinical characteristics, complications, and sequels that are different to other bacterial meningoencephalitis, meaning that they could be helpful for physicians considering the differential diagnosis of meningoencephalitis.

[Treatment of community acquired bacterial meningitis, after microbiological identification]

INTRODUCTION

Are the 1996 SPILF consensus conference recommendations on bacterial meningitis (BM) still adequate?

OBJECTIVE

The literature published after 1996 was analyzed and the reviewers summarized the available data on antibiotic treatment once BM microbiological diagnosis made or strongly suspected.

METHOD

A review was made using PubMed, 10,015 references were examined. Only articles published after 1997 were analyzed.

RESULTS

No study allowed to recommend other regimens than those previously recommended in 1996, in case of meningococcal or pneumococcal infection: 3rd generation cephalosporin or amoxicillin, combined with vancomycin in case of penicillin-intermediate or resistant pneumococcus. In some cases, alternatives are possible, in case of pneumococcal infection: meropenem or antipneumococcal fluoroquinolone were recommended by US guidelines. New antibiotics available on the market were tested using experimental pneumococcal meningitis models: daptomycin and ertapenem seemed to be useful but linezolid was not. Among the antibiotic combinations tested, ceftriaxone+rifampicine demonstrated a better efficacy than ceftriaxone+vancomycin. There was not contributive published data on the length of treatment for bacterial meningitis.

CONCLUSION

No assessed arguments could be found to modify previous guidelines. In case of problem with penicillin-resistant pneumococci, penem or a combination using ceftriaxone and rifampicin may be used.

Cerebrospinal fluid compartmental pharmacokinetics of amikacin in neonates

To describe and investigate the covariate effects of cerebrospinal fluid (CSF) amikacin pharmacokinetics in neonates, CSF samples were prospectively collected from neonates in whom amikacin had been initiated before a diagnostic lumbar puncture was performed. CSF analysis (amikacin concentration, white blood count [WBC], glucose content, and protein concentration) and amikacin therapeutic drug monitoring results (peak and trough concentrations) in serum were recorded. Correlations (Spearman rank) between the CSF amikacin concentration and the CSF WBC and glucose and protein concentration were investigated. There were 44 CSF amikacin concentrations and 83 serum samples available from 43 neonates (mean postmenstrual age, 36 weeks [range, 26 to 41 weeks]; mean weight, 2.43 kg [range, 0.87 to 3.86 kg]). The median time interval between initiation of amikacin administration and CSF sampling was 25 h (range, 2.5 to 93.7 h). The median amikacin concentration in the CSF was 1.08 mg/liter (range, 0.34 to 2.65 mg/liter), and the mean trough and peak amikacin concentrations in serum were 3.8 +/- 2.5 mg/liter and 35.7 +/- 5.9 mg/liter, respectively. A correlation between CSF amikacin and CSF protein contents (P < 0.01, r = 0.41, 95% confidence interval = 0.13 to 0.63) but not between CSF WBC and CSF glucose was documented. A two-compartment (central and CSF) linear disposition model was used to estimate population pharmacokinetics. The half time for equilibration (T(eq)) between serum and CSF compartments was used as a measure of blood-brain barrier permeability. The T(eq) was 7.58 h (coefficient of variation [CV] = 49.1%) with a partition coefficient of 0.103 (CV = 26.4%). There was no relationship between the T(eq) and CSF WBC, CSF glucose content, or CSF protein content.

Activité in vitro de la moxifloxacine (8-méthoxyquinolone) seule ou en association avec le céfotaxime sur les streptocoques du groupe B

AIM OF THE STUDY

Our objective is to determine in vitro efficiency of moxifloxacin (MXF) alone or in combination with cefotaxime (CTX) on Group B streptococcus (GBS).

MATERIALS AND METHODS

For 21 strains of GBS isolated from newborn invasive infections (6 meningitis and 15 bacteraemia), the bacterial growth in Mueller Hinton broth with MXF and/or CTX leaded to the determination of MIC and MBC, the determination of tolerance for CTX and the evaluation of the bacteriostatic action of these antibiotics combination by calculating the FIC index. Time-kill studies were conducted for MXF and CTX alone or in combination for the first four hours, with concentrations likely reached in CSF.

RESULTS

Study of GBS growth with crossed concentrations of MXF and CTX showed no resistant strains, no tolerant strains, and no antagonism between MXF and CTX. Killing curves demonstrated that MXF is ten-fold more active than CTX in the first four hours.

DISCUSSION

MXF is an interesting antibiotic for its good activity on the GBS, suggesting that MXF is a good candidate for further evaluation in GBS meningitis in animal model.

Epidemic meningitis, meningococcaemia, and Neisseria meningitidis

Meningococcus, an obligate human bacterial pathogen, remains a worldwide and devastating cause of epidemic meningitis and sepsis. However, advances have been made in our understanding of meningococcal biology and pathogenesis, global epidemiology, transmission and carriage, host susceptibility, pathophysiology, and clinical presentations. Approaches to diagnosis, treatment, and chemoprophylaxis are now in use on the basis of these advances. Importantly, the next generation of meningococcal conjugate vaccines for serogroups A, C, Y, W-135, and broadly effective serogroup B vaccines are on the horizon, which could eliminate the organism as a major threat to human health in industrialised countries in the next decade. The crucial challenge will be effective introduction of new meningococcal vaccines into developing countries, especially in sub-Saharan Africa, where they are urgently needed.