Encephalitis and meningitis in Western Africa: a scoping review of pathogens.

OBJECTIVE: To give an overview of the recently reported literature on the aetiologies of meningitis and encephalitis in western sub-Saharan Africa. METHODS: We conducted a scoping review following PRISMA guidance on published meningitis and encephalitis cases in the 16 countries of the United Nations-defined western sub-Saharan African region as identified in cohort studies, case series, and case reports, published 01/01/2000-08/01/2020, and available in four databases in August 2020 with an abstract in English, French or Italian. RESULTS: There were 38 distinct pathogens identified from 91 cohort studies' data and 48 case reports or case series' data. In cohort-level data, the majority of cases were caused by Neisseria meningitidis (71.5%), Streptococcus pneumoniae (17.6%) and Haemophilus influenzae (7.3%). In case report- and case series-level data, 40.5% of patients were <18 years old, 28.6% were female, and 28.6% were known to be immunocompromised. The case fatality rate was 39.3%. The most commonly reported pathogens among immunocompetent patients were Salmonella species (13 cases) and Ebola virus (9 cases), and the most commonly reported pathogen among immunocompromised patients was Cryptococcus neoformans (18 cases). Most cohort cases (52.3%) derived from Niger followed by Burkina Faso (28.6%). Most cases from single reports or series were reported from Nigeria (21.4%), Mali (20.2%) and Burkina Faso (19.0%). CONCLUSIONS: Given the small number of pathogens reported, our findings underscore the need to better screen, diagnose and monitor populations in western sub-Saharan Africa for additional CNS pathogens, including those posing significant outbreak risks.

Atypical presentation of invasive meningococcal disease caused by serogroup W meningococci.

Neisseria meningitidis, a gram-negative diplococcus, is typically an asymptomatic coloniser of the oropharynx and nasopharynx. Passage of N. meningitidis into the bloodstream can cause invasive meningococcal disease (IMD), a potentially life-threatening illness with rapid onset that generally presents as meningitis, septicemia or both. Serogroup W IMD has been increasing in prevalence in recent years, and observations suggest that it may present with atypical signs and symptoms. Herein, a literature search was performed to identify trends in atypical serogroup W IMD presentation in order to review those that are most prevalent. Findings indicate that the most prevalent atypical presentations of serogroup W IMD include acute gastrointestinal (GI) symptoms, septic arthritis and bacteremic pneumonia or severe upper respiratory tract infection, notably epiglottitis. Atypical clinical presentation is associated with higher case fatality rates and can lead to misdiagnoses. Such risks highlight the need for clinicians to consider IMD in their differential diagnoses of patients with acute GI symptoms, septic arthritis or bacteremic pneumonia, primarily in regions where serogroup W is prevalent.

Combined therapy with ceftriaxone and doxycycline does not improve the outcome of meningococcal meningitis in mice compared to ceftriaxone monotherapy.

BACKGROUND: Meningococcal meningitis (MM) is a life-threatening disease associated with approximately 10% case fatality rates and neurological sequelae in 10-20% of the cases. Recently, we have shown that the matrix metalloproteinase (MMP) inhibitor BB-94 reduced brain injury in a mouse model of MM. The present study aimed to assess whether doxycycline (DOX), a tetracycline that showed a neuroprotective effect as adjuvant therapy in experimental pneumococcal meningitis (PM), would also exert a beneficial effect when given as adjunctive therapy to ceftriaxone (CRO) in experimental MM. METHODS: BALB/c mice were infected by the intracisternal route with a group C Neisseria meningitidis strain. Eighteen h post infection (hpi), animals were randomised for treatment with CRO [100 mg/kg subcutaneously (s.c.)], CRO plus DOX (30 mg/kg s.c.) or saline (control s.c.). Antibiotic treatment was repeated 24 and 40 hpi. Mouse survival and clinical signs, bacterial counts in cerebella, brain damage, MMP-9 and cyto/chemokine levels were assessed 48 hpi. RESULTS: Analysis of bacterial load in cerebella indicated that CRO and CRO + DOX were equally effective at controlling meningococcal replication. No differences in survival were observed between mice treated with CRO (94.4%) or CRO + DOX (95.5%), (p > 0.05). Treatment with CRO + DOX significantly diminished both the number of cerebral hemorrhages (p = 0.029) and the amount of MMP-9 in the brain (p = 0.046) compared to untreated controls, but not to CRO-treated animals (p > 0.05). Levels of inflammatory markers in the brain of mice that received CRO or CRO + DOX were not significantly different (p > 0.05). Overall, there were no significant differences in the parameters assessed between the groups treated with CRO alone or CRO + DOX. CONCLUSIONS: Treatment with CRO + DOX showed similar bactericidal activity to CRO in vivo, suggesting no antagonist effect of DOX on CRO. Combined therapy significantly improved mouse survival and disease severity compared to untreated animals, but addition of DOX to CRO did not offer significant benefits over CRO monotherapy. In contrast to experimental PM, DOX has no adjunctive activity in experimental MM.

Virulence Traits of a Serogroup C Meningococcus and Isogenic cssA Mutant, Defective in Surface-Exposed Sialic Acid, in a Murine Model of Meningitis.

In serogroup C Neisseria meningitidis, the cssA (siaA) gene codes for an UDP-N-acetylglucosamine 2-epimerase that catalyzes the conversion of UDP-N-acetyl-α-d-glucosamine into N-acetyl-d-mannosamine and UDP in the first step in sialic acid biosynthesis. This enzyme is required for the biosynthesis of the (α2→9)-linked polysialic acid capsule and for lipooligosaccharide (LOS) sialylation. In this study, we have used a reference serogroup C meningococcal strain and an isogenic cssA knockout mutant to investigate the pathogenetic role of surface-exposed sialic acids in a model of meningitis based on intracisternal inoculation of BALB/c mice. Results confirmed the key role of surface-exposed sialic acids in meningococcal pathogenesis. The 50% lethal dose (LD50) of the wild-type strain 93/4286 was about four orders of magnitude lower than that of the cssA mutant. Compared to the wild-type strain, the ability of this mutant to replicate in brain and spread systemically was severely impaired. Evaluation of brain damage evidenced a significant reduction in cerebral hemorrhages in mice infected with the mutant in comparison with the levels in those challenged with the wild-type strain. Histological analysis showed the typical features of bacterial meningitis, including inflammatory cells in the subarachnoid, perivascular, and ventricular spaces especially in animals infected with the wild type. Noticeably, 80% of mice infected with the wild-type strain presented with massive bacterial localization and accompanying inflammatory infiltrate in the corpus callosum, indicating high tropism of meningococci exposing sialic acids toward this brain structure and a specific involvement of the corpus callosum in the mouse model of meningococcal meningitis.

Long-term health and socioeconomic consequences of childhood and adolescent onset of meningococcal meningitis.

We estimated the long-term socioeconomic consequences and health care costs of Neisseria meningitidis meningitis (NM). The prospective cohort study included Danish individuals with onset of NM in childhood and adolescence, diagnosed between 1980 and 2009. Health care costs and socioeconomic data were obtained from nationwide administrative and health registers. Two thousand nine hundred two patients were compared with 11,610 controls matched for age, gender, and other sociodemographic characteristics. In the follow-up analysis at the age of 30 years, 1028 patients were compared with 4452 controls. We found that (1) NM caused increased mortality at disease onset, but after adequate treatment, the mortality rate was similar to that of the general population; (2) neurological and eye diseases were more frequently observed in patients; (3) patients had significantly lower grade-point averages; (4) patients had lower income even when transfer payments were taken into account; and (5) patients' initial health care costs were elevated.Conclusion: NM has significant influence on mortality, morbidity, education, and income. We suggest that the management of patients with previous meningococcal meningitis should focus on early educational and social interventions to improve social and health outcomes. What is known: • Meningococcal meningitis is a severe infectious disease affecting children and adolescents with high rates of mortality and complications. What is new: • Meningococcal meningitis causes increased mortality at disease onset, but after adequate treatment the mortality rate is similar to that of the general population. • Meningococcal meningitis in childhood and adolescence has a major long-term effect on morbidity, health care costs, education, employment, and income.

Rapid Laboratory Identification of Neisseria meningitidis Serogroup C as the Cause of an Outbreak - Liberia, 2017.

On April 25, 2017, a cluster of unexplained illness and deaths among persons who had attended a funeral during April 21-22 was reported in Sinoe County, Liberia (1). Using a broad initial case definition, 31 cases were identified, including 13 (42%) deaths. Twenty-seven cases were from Sinoe County (1), and two cases each were from Grand Bassa and Monsterrado counties, respectively. On May 5, 2017, initial multipathogen testing of specimens from four fatal cases using the Taqman Array Card (TAC) assay identified Neisseria meningitidis in all specimens. Subsequent testing using direct real-time polymerase chain reaction (PCR) confirmed N. meningitidis in 14 (58%) of 24 patients with available specimens and identified N. meningitidis serogroup C (NmC) in 13 (54%) patients. N. meningitidis was detected in specimens from 11 of the 13 patients who died; no specimens were available from the other two fatal cases. On May 16, 2017, the National Public Health Institute of Liberia and the Ministry of Health of Liberia issued a press release confirming serogroup C meningococcal disease as the cause of this outbreak in Liberia.

Pre-admission antibiotics for suspected cases of meningococcal disease.

BACKGROUND: Meningococcal disease can lead to death or disability within hours after onset. Pre-admission antibiotics aim to reduce the risk of serious disease and death by preventing delays in starting therapy before confirmation of the diagnosis. OBJECTIVES: To study the effectiveness and safety of pre-admission antibiotics versus no pre-admission antibiotics or placebo, and different pre-admission antibiotic regimens in decreasing mortality, clinical failure, and morbidity in people suspected of meningococcal disease. SEARCH METHODS: We searched CENTRAL (6 January 2017), MEDLINE (1966 to 6 January 2017), Embase (1980 to 6 January 2017), Web of Science (1985 to 6 January 2017), LILACS (1982 to 6 January 2017), and prospective trial registries to January 2017. We previously searched CAB Abstracts from 1985 to June 2015, but did not update this search in January 2017. SELECTION CRITERIA: Randomised controlled trials (RCTs) or quasi-RCTs comparing antibiotics versus placebo or no intervention, in people with suspected meningococcal infection, or different antibiotics administered before admission to hospital or confirmation of the diagnosis. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted data from the search results. We calculated the risk ratio (RR) and 95% confidence interval (CI) for dichotomous data. We included only one trial and so did not perform data synthesis. We assessed the overall quality of the evidence using the GRADE approach. MAIN RESULTS: We found no RCTs comparing pre-admission antibiotics versus no pre-admission antibiotics or placebo. We included one open-label, non-inferiority RCT with 510 participants, conducted during an epidemic in Niger, evaluating a single dose of intramuscular ceftriaxone versus a single dose of intramuscular long-acting (oily) chloramphenicol. Ceftriaxone was not inferior to chloramphenicol in reducing mortality (RR 1.21, 95% CI 0.57 to 2.56; N = 503; 308 confirmed meningococcal meningitis; 26 deaths; moderate-quality evidence), clinical failures (RR 0.83, 95% CI 0.32 to 2.15; N = 477; 18 clinical failures; moderate-quality evidence), or neurological sequelae (RR 1.29, 95% CI 0.63 to 2.62; N = 477; 29 with sequelae; low-quality evidence). No adverse effects of treatment were reported. Estimated treatment costs were similar. No data were available on disease burden due to sequelae. AUTHORS' CONCLUSIONS: We found no reliable evidence to support the use pre-admission antibiotics for suspected cases of non-severe meningococcal disease. Moderate-quality evidence from one RCT indicated that single intramuscular injections of ceftriaxone and long-acting chloramphenicol were equally effective, safe, and economical in reducing serious outcomes. The choice between these antibiotics should be based on affordability, availability, and patterns of antibiotic resistance.Further RCTs comparing different pre-admission antibiotics, accompanied by intensive supportive measures, are ethically justified in people with less severe illness, and are needed to provide reliable evidence in different clinical settings.

Case-Fatality Rates and Sequelae Resulting from Neisseria meningitidis Serogroup C Epidemic, Niger, 2015.

We describe clinical symptoms, case-fatality rates, and prevalence of sequelae during an outbreak of Neisseria meningitidis serogroup C infection in a rural district of Niger. During home visits, we established that household contacts of reported case-patients were at higher risk for developing meningitis than the general population.

Disease Burden of Invasive Meningococcal Disease in the Netherlands Between June 1999 and June 2011: A Subjective Role for Serogroup and Clonal Complex.

BACKGROUND: Several countries consider the implementation of a meningococcal serogroup B vaccine for young children and/or serogroup C or ACWY conjugate vaccine for adolescents. Representative information on clinical course of invasive meningococcal disease (IMD) is useful to evaluate cost-effectiveness of vaccination. Information on the relation between infecting meningococcal clonal complex (CC), disease course and outcome of IMD is scarce. METHODS: A retrospective study using Dutch surveillance data on IMD from June 1999 to June 2011. Clinical information was retrieved from hospital records. The effect of age, comorbidity, clinical manifestation, serogroup, and CC on disease course and outcome was assessed in multivariable analyses. Meningococcal CCs were assessed by multilocus sequence typing. RESULTS: Clinical information was retrieved for 879 IMD cases: 48% of patients presented with meningitis, 17% with septic shock, and 22% with septic shock plus meningitis. Development of septic shock was not related to CC or serogroup. Median (interquartile range) duration of hospital admission was 10 (8-13) days. Intensive care unit admittance (38%) was higher for patients aged ≥10 years and patients with septic shock (P-values ≤.001). Case-fatality rate (8%) and development of sequelae (29%) was dependent on age and clinical manifestation (P-values ≤.001) and not affected by comorbidity, CC, or serogroup. CONCLUSIONS: IMD still coincides with a considerable disease burden and mortality. Disease course and outcome depend mainly on age and clinical manifestation and less on meningococcal CC or serogroup.

Outcomes of invasive meningococcal disease in adults and children in Canada between 2002 and 2011: a prospective cohort study.

BACKGROUND: Neisseria meningitidis causes 500 000 cases of septicemia and meningitis worldwide annually, with approximately 200 cases in Canada each year. Previous studies describe a case-fatality rate of 5%-15% and up to 20% of survivors suffering from long-term disability. METHODS: This study was performed in Canada between 2002 and 2011; the study area included >50% of the country's population. We identified risk factors associated with death and the development of complications in children and adults admitted to hospital with confirmed invasive meningococcal disease (IMD). Clinical information was obtained from hospital records. Risk factors for death and complications were analyzed by univariate and multivariable analyses. RESULTS: Of 868 individuals hospitalized with IMD, there were 73 deaths (8.4%) and 157 (18%) developed complications. The most common complications were hearing loss (5.4%), skin scarring (5.4%), amputation (3.4%), renal dysfunction (2.6%), and seizures (2.5%). Mortality was independently associated with shock (adjusted odds ratio [aOR], 23.30; P<.0001), age (aOR, 1.02 per 1-year increased age; P<.0001), symptom onset within 24 hours of admission (aOR, 1.80; P=.0471), and admission to the intensive care unit (aOR, 0.41; P=.0196). Development of complications was independently associated with seizures (aOR, 4.55; P<.0001), shock (aOR, 3.10; P<.0001), abnormal platelet count (aOR, 2.14; P=.0002), bruising (aOR, 3.17; P=.0059), abnormal white blood cell count (aOR, 0.52; P=.0100), and prior antibiotic exposure (aOR, 0.27; P=.0273). CONCLUSIONS: Outcomes following IMD remain poor in this resource-rich setting in the 21st century. These data identify priorities for clinical management of adults and children with IMD, and provide prognostic information for affected patients and their families and cost-effectiveness analyses for meningococcal vaccine programs.

Rifampin use in acute community-acquired meningitis in intensive care units: the French retrospective cohort ACAM-ICU study.

INTRODUCTION: Bacterial meningitis among critically ill adult patients remains associated with both high mortality and frequent, persistent disability. Vancomycin was added to treatment with a third-generation cephalosporin as recommended by French national guidelines. Because animal model studies had suggested interest in the use of rifampin for treatment of bacterial meningitis, and after the introduction of early corticosteroid therapy (in 2002), there was a trend toward increasing rifampin use for intensive care unit (ICU) patients. The aim of this article is to report on this practice. METHODS: Five ICUs participated in the study. Baseline characteristics and treatment data were retrospectively collected from charts of patients admitted with a diagnosis of acute bacterial meningitis during a 5-year period (2004-2008). The ICU mortality was the main outcome measure; Glasgow Outcome Scale and 3-month mortality were also assessed. RESULTS: One hundred fifty-seven patients were included. Streptococcus pneumoniae and Neisseria meningitidis were the most prevalent causative microorganisms. The ICU mortality rate was 15%. High doses of a cephalosporin were the most prevalent initial antimicrobial treatment. The delay between admission and administration of the first antibiotic dose was correlated with ICU mortality. Rifampin was used with a cephalosporin for 32 patients (ranging from 8% of the cohort for 2004 to 30% in 2008). Administration of rifampin within the first 24 h of hospitalization could be associated with a lower ICU survival. Statistical association between such an early rifampin treatment and ICU mortality reached significance only for patients with pneumococcal meningitis (p=0.031) in univariate analysis, but not in the logistic model. CONCLUSIONS: We report on the role of rifampin use for patients with community-acquired meningitis, and the results of this study suggest that this practice may be associated with lower mortality in the ICU. Nevertheless, the only independent predictors of ICU mortality were organ failure and pneumococcal infection. Further studies are required to confirm these results and to explain how rifampin use would reduce mortality.

A functional microsatellite of the macrophage migration inhibitory factor gene associated with meningococcal disease.

Macrophage migration inhibitory factor (MIF) is an abundantly expressed proinflammatory cytokine playing a critical role in innate immunity and sepsis and other inflammatory diseases. We examined whether functional MIF gene polymorphisms (-794 CATT(5-8) microsatellite and -173 G/C SNP) were associated with the occurrence and outcome of meningococcal disease in children. The CATT(5) allele was associated with the probability of death predicted by the Pediatric Index of Mortality 2 (P=0.001), which increased in correlation with the CATT(5) copy number (P=0.04). The CATT(5) allele, but not the -173 G/C alleles, was also associated with the actual mortality from meningoccal sepsis [OR 2.72 (1.2-6.4), P=0.02]. A family-based association test (i.e., transmission disequilibrium test) performed in 240 trios with 1 afflicted offspring indicated that CATT(5) was a protective allele (P=0.02) for the occurrence of meningococcal disease. At baseline and after stimulation with Neisseria meningitidis in THP-1 monocytic cells or in a whole-blood assay, CATT(5) was found to be a low-expression MIF allele (P=0.005 and P=0.04 for transcriptional activity; P=0.09 and P=0.09 for MIF production). Taken together, these data suggest that polymorphisms of the MIF gene affecting MIF expression are associated with the occurrence, severity, and outcome of meningococcal disease in children.

Surveillance of bacterial meningitis in the country of Georgia, 2006-2010.

Bacterial meningitis remains important cause of morbidity and mortality worldwide, particularly in developing countries. This study analyzed the data from sentinel surveillance for bacterial meningitis among children <5 years of age hospitalized in largest children's hospital in Tbilisi, capital of Georgia and adult patients hospitalized in infectious diseases hospital during 2006-2010 with suspected bacterial meningitis. The surveillance is conducted by National Center for Disease Control and Public Health (NCDCPH). The number of patients with identified organism was 127 (19 %). In the subsample of patients with laboratory confirmed bacterial meningitis Streptococcus pneumoniae was the most frequently isolated organism (67 cases, 52.8 %), followed by. influenza (17 cases, 13.4 %) and Neisseria meningitidis (16 cases, 12.6 %). The number of patients with suspected TB meningitis was 27 (21.3 %). The overall case fatality rate in the subgroup of patients with identified organism was 12.3 %. The highest mortality was observed among TB patients (22.2 %) with 14.3 % mortality for N. meningitidis and 10.3 % for S. pneumoniae. No lethal outcome was observed among patients with Haemophilus influenzae.

Elevated soluble urokinase receptor values in CSF, age and bacterial meningitis infection are independent and additive risk factors of fatal outcome.

The aim of the present study was to evaluate the potential role of cerebrospinal fluid soluble urokinase receptor (suPAR) level, infection and age as risk factors for fatal outcome in patients suspected of having meningitis and/or bacteraemia on admission to hospital. A total of 545 cerebrospinal fluid samples from patients with clinically suspected meningitis were sent to the Hellenic National Meningitis Reference Laboratory. Ten of 545 (1.83%) patients died. Analysis by receiver operating characteristics (ROC) curve revealed that both suPAR and age were significant for prediction of fatal outcome. Patients with levels of suPAR above the cut-off values and age ≥ 51 years, or patients in which either Neisseria meningitis or Streptococcus pneumoniae were detected were categorized as high risk patients. The combination of the above three predictors (suPAR, age and infectious agent) in a logistic regression model with outcome of infection as the dependent variable yielded an overall odds ratio (OR = 85.7, 95% CI 10.6-690.2) with both sensitivity and specificity being equal to the value of 0.9. In conclusion, suPAR, age and type of infection have an additive effect in predicting mortality among patients suspected of meningitis.

Emergence of serogroup C meningococcal disease associated with a high mortality rate in Hefei, China.

BACKGROUND: Neisseria meningitidis serogroup C has emerged as a cause of epidemic disease in Hefei. The establishment of serogroup C as the predominant cause of endemic disease has not been described. METHODS: We conducted national laboratory-based surveillance for invasive meningococcal disease during 2000-2010. Isolates were characterized by pulsed-field gel electrophoresis and multilocus sequence typing. RESULTS: A total of 845 cases of invasive meningococcal disease were reported. The incidence increased from 1.25 cases per 100,000 population in 2000 to 3.14 cases per 100,000 in 2003 (p < 0.001), and peaked at 8.43 cases per 100,000 in 2005. The increase was mainly the result of an increase in the incidence of serogroup C disease. Serogroup C disease increased from 2/23 (9%) meningococcal cases and 0.11 cases per 100,000 in 2000 to 33/58 (57%) cases and 1.76 cases per 100,000 in 2003 (p < 0.01). Patients infected with serogroup C had serious complications more frequently than those infected with other serogroups. Specifically, 161/493 (32.7%) cases infected with serogroup C had at least one complication. The case-fatality rate of serogroup C meningitis was 11.4%, significantly higher than for serogroup A meningitis (5.3%, p = 0.021). Among patients with meningococcal disease, factors associated with death in univariate analysis were age of 15-24 years, infection with serogroup C, and meningococcemia. CONCLUSIONS: The incidence of meningococcal disease has substantially increased and serogroup C has become endemic in Hefei. The serogroup C strain has caused more severe disease than the previously predominant serogroup A strain.

An evaluation of emerging vaccines for childhood meningococcal disease.

BACKGROUND: Meningococcal meningitis is a major cause of disease worldwide, with frequent epidemics particularly affecting an area of sub-Saharan Africa known as the "meningitis belt". Neisseria meningitidis group A (MenA) is responsible for major epidemics in Africa. Recently W-135 has emerged as an important pathogen. Currently, the strategy for control of such outbreaks is emergency use of meningococcal (MC) polysaccharide vaccines, but these have a limited ability to induce herd immunity and elicit an adequate immune response in infant and young children. In recent times initiatives have been taken to introduce meningococcal conjugate vaccine in these African countries. Currently there are two different types of MC conjugate vaccines at late stages of development covering serogroup A and W-135: a multivalent MC conjugate vaccine against serogroup A,C,Y and W-135; and a monovalent conjugate vaccine against serogroup A. We aimed to perform a structured assessment of these emerging meningococcal vaccines as a means of reducing global meningococcal disease burden among children under 5 years of age. METHODS: We used a modified CHNRI methodology for setting priorities in health research investments. This was done in two stages. In the first stage we systematically reviewed the literature related to emerging MC vaccines relevant to 12 criteria of interest. In Stage II, we conducted an expert opinion exercise by inviting 20 experts (leading basic scientists, international public health researchers, international policy makers and representatives of pharmaceutical companies). They answered questions from CHNRI framework and their "collective optimism" towards each criterion was documented on a scale from 0 to 100%. RESULTS: For MenA conjugate vaccine the experts showed very high level of optimism (~ 90% or more) for 7 out of the 12 criteria. The experts felt that the likelihood of efficacy on meningitis was very high (~ 90%). Deliverability, acceptability to health workers, end users and the effect on equity were all seen as highly likely (~ 90%). In terms of the maximum potential impact on meningitis disease burden, the median potential effectiveness of the vaccines in reduction of overall meningitis mortality was estimated to be 20%; (interquartile range 20-40% and min. 8%, max 50 %). For the multivalent meningococcal vaccines the experts had similar optimism for most of the 12 CHNRI criteria with slightly lower optimism in answerability and low development cost criteria. The main concern was expressed over the cost of product, its affordability and cost of implementation. CONCLUSIONS: With increasing recognition of the burden of meningococcal meningitis, especially during epidemics in Africa, it is vitally important that strategies are taken to reduce the morbidity and mortality attributable to this disease. Improved MC vaccines are a promising investment that could substantially contribute to reduction of child meningitis mortality world-wide.

Genetic characterisation of the emerging invasive Neisseria meningitidis serogroup Y in Sweden, 2000 to 2010.

Neisseria meningitidis serogroups B and C have been responsible for the majority of invasive meningococcal disease in Europe. Recently, an increase of N. meningitidis disease due to serogroup Y has been noted in Sweden (in 2010, the proportion was 39%, with an incidence of 0.23 per 100,000 population), as well as in other northern European countries. We aimed to investigate the clonal pattern of the emerging serogroup Y in Sweden during 2000 to 2010. The serogroup Y isolates identified during this time (n=85) were characterised by multilocus sequence typing and sequencing of the fetA, fHbp, penA, porA and porB genes. The most frequent clone (comprising 28 isolates) with identical allele combinations of the investigated genes, was partly responsible for the observed increased number of N. meningitidis serogroup Y isolates. It was sulfadiazine resistant, with genosubtype P1.5-2,10-1,36-2, sequence type 23, clonal complex 23, porB allele 3-36, fetA allele F4-1, fHbp allele 25 and penA allele 22. The first case with disease due to this clone was identified in 2002: there was a further case in 2004, six during 2006 to 2007, eight during 2008 to 2009, with a peak of 12 cases in 2010. An unusual increase of invasive disease in young adults (aged 20­29 years) caused by this clone was shown, but no increase in mortality rate was observed.

U.S. military fatalities due to Neisseria meningitidis: case reports and historical perspective.

Meningococcal disease has historically been associated with military populations, particularly during periods of mobilization. Although the U.S. military has now been engaged in conflicts for nearly a decade, the incidence of meningococcal disease in the U.S. population as a whole has reached historic lows. Despite vaccination of all service members in basic military training, the risk of meningococcal disease appears to be equal to or greater than that of the civilian population. These 3 case reports of recent fatalities in the U.S. military and their historic contexts illustrate the circumstances under which meningococcus can strike and highlight the need for continued vigilance in military populations.

[Hospital admissions for meningococcal infections in Madrid, Spain (1997-2005)]. / Ingresos hospitalarios por infecciones meningocócicas en la Comunidad de Madrid (1997-2005).

BACKGROUND AND OBJECTIVES: Neisseria meningitidis infection causes an important morbidity and mortality in Spain. Our study aims to estimate the burden of hospital admissions for meningococcal infection in Spain during a nine-year period (1997-2005) by analyzing the Spanish hospital surveillance system. METHODS: An epidemiological retrospective study was conducted. Data were obtained from the national surveillance system for hospital data (Conjunto Mínimo Básico de Datos) maintained by the Ministry of Health. Information about hospitalizations, age, length of stay in hospital, mortality and cost per patient was obtained. RESULTS: There were 1137 hospital discharges for meningococcal disease (International Classification of Diseases 9th Clinical Modification: ICD 9 CM code 036 in any listed diagnosis) during the study period. Annual incidence was 2.41 cases per 100,000 individuals. Mortality rate and case-fatality rate were 0.19 cases per 100,000 population and 7.7%, respectively. The average length of hospitalization was 12 days. The youngest age group showed the highest hospitalizations incidence (24.42 hospitalizations per 100,000 population in those under 4 years of age) but the case-fatality rate was higher in the oldest group (11% in patients over 30 years). These hospitalizations imply an annual cost of 592,980 euro to the Madrid Health System. CONCLUSIONS: Our study shows that meningococcal infection is still an important cause of hospital admissions and mortality in Madrid, resulting in a high cost to the Health Care System.