Patient and strain characteristics in relation to the outcome of meningococcal disease: a multivariate analysis

Global Case Fatality of Bacterial Meningitis During an 80-Year Period: A Systematic Review and Meta-Analysis

Importance

The impact of vaccination, antibiotics, and anti-inflammatory treatment on pathogen distribution and outcome of bacterial meningitis over the past century is uncertain.

Objective

To describe worldwide pathogen distribution and case fatality ratios of community-acquired bacterial meningitis.

Data Sources

Google Scholar and MEDLINE were searched in January 2022 using the search terms bacterial meningitis and mortality.

Study Selection

Included studies reported at least 10 patients with bacterial meningitis and survival status. Studies that selected participants by a specific risk factor, had a mean observation period before 1940, or had more than 10% of patients with health care-associated meningitis, tuberculous meningitis, or missing outcome were excluded.

Data Extraction and Synthesis

Data were extracted by 1 author and verified by a second author. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Random-effects models stratified by age (ie, neonates, children, adults), Human Development Index (ie, low-income or high-income countries), and decade and meta-regression using the study period's year as an estimator variable were used.

Main Outcome and Measure

Case fatality ratios of bacterial meningitis.

Results

This review included 371 studies performed in 108 countries from January 1, 1935, to December 31, 2019, describing 157 656 episodes. Of the 33 295 episodes for which the patients' sex was reported, 13 452 (40%) occurred in females. Causative pathogens were reported in 104 598 episodes with Neisseria meningitidis in 26 344 (25%) episodes, Streptococcus pneumoniae in 26 035 (25%) episodes, Haemophilus influenzae in 22 722 (22%), other bacteria in 19 161 (18%) episodes, and unidentified pathogen in 10 336 (10%) episodes. The overall case fatality ratio was 18% (95% CI, 16%-19%), decreasing from 32% (95% CI, 24%-40%) before 1961 to 15% (95% CI, 12%-19%) after 2010. It was highest in meningitis caused by Listeria monocytogenes at 27% (95% CI, 24%-31%) and pneumococci at 24% (95% CI, 22%-26%), compared with meningitis caused by meningococci at 9% (95% CI, 8%-10%) or H influenzae at 11% (95% CI, 10%-13%). Meta-regression showed decreasing case fatality ratios overall and stratified by S pneumoniae, Escherichia coli, or Streptococcus agalactiae (P < .001).

Conclusions and Relevance

In this meta-analysis with meta-regression, declining case fatality ratios of community-acquired bacterial meningitis throughout the last century were observed, but a high burden of disease remained.

A meta-analytic evaluation of sex differences in meningococcal disease incidence rates in 10 countries

The magnitude and consistency of the sex differences in meningococcal disease incidence rates (IR) have not been systematically examined in different age groups, countries and time periods. We obtained national data on meningococcal disease IR by sex, age group and time period, from 10 countries. We used meta-analytic methods to combine the male to female incidence rate ratios (IRRs) by country and year for each age group. Meta-regression analysis was used to assess the contribution of age, country and time period to the variation in the IRRs. The pooled male to female IRRs (with 95% CI) for ages 0–1, 1–4, 5–9, 10–14 and 15–44, were 1.25 (1.19–1.32), 1.24 (1.20–1.29), 1.13 (1.07–1.20), 1.21 (1.13–1.29) and 1.15 (1.10–1.21), respectively. In the age groups 45−64 and over 65, the IR were lower in males with IRRs of 0.83 (0.78–0.88) and 0.64 (0.60–0.69), respectively. Sensitivity analysis and meta-regression confirmed that the results were robust. The excess meningococcal IR in young males and the higher rates in females at older ages were consistent in all countries, except the Czech Republic. While behavioural factors could explain some of the sex differences in the older age groups, the excess rates in very young males suggest that genetic and hormonal differences could be important.

Cost-utility analysis of a nationwide vaccination programme against serogroup B meningococcal disease in Israel

OBJECTIVES

Using cost-utility analysis, to evaluate whether or not to adopt a Neisseria meningitidis serogroup B vaccination programme for Israeli children.

METHODS

Epidemiological, demographic, health service utilisation and economic data were integrated into a spreadsheet model to calculate the cost per averted disability-adjusted life year (DALY) of the intervention.

RESULTS

Assuming 78 % vaccine efficacy with no herd immunity, vaccination will prevent 223 cases and 22 deaths over a 100-year period. Based on vaccine price of $60 per dose, total intervention costs ($315,400,000) are partially offset by a $22,700,000 reduction in treatment and sequelae costs as a result of decreased morbidity. The intervention was not cost-effective since the net cost ($292,700,000) per averted DALY gained (1249 mostly due to decreased mortality) was $234,394. Additional two dose catch-up programmes vaccinating children in cohorts aged 1-2 to 1-13 were also not cost-effective.

CONCLUSIONS

The vaccination will become cost-effective if vaccine costs fall below $19.44 per dose. However, in identified high risk areas, the vaccine would be cost-effective and could be recommended for use both with and without catch-up campaigns.

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.

The burden and impact of severe and long-term sequelae of meningococcal disease

This review describes current knowledge on the severity and long-term sequelae of meningococcal disease (MD) specifically. The literature databases Medline and Embase were used by combining search terms for MD and Neisseria meningitidis with terms for severity, mortality and sequelae. Case fatality for sufferers of MD remains high, typically 5-10%, despite the best medical care. Long-term sequelae in survivors may include physical, neurological, cognitive, behavioral and psychological consequences, such as hearing loss, amputations, skin scarring and neurodevelopmental deficits. A significantly lower quality of life is seen in survivors of MD compared with unaffected controls, with detrimental effects of childhood MD continuing into adulthood. MD carries a substantial risk of long-term sequelae and mortality. This should be recognized by physicians treating patients with this disease and lends support for the implementation of preventative measures such as vaccination.

Meningococcal serogroup A, C, W₁₃₅ and Y conjugated vaccine: a cost-effectiveness analysis in the Netherlands

Background

In 2002, vaccination with a serogroup C meningococcal conjugate vaccine (MenC) was introduced in the Netherlands for all children aged 14 months. Despite its success, herd immunity may wane over time. Recently, a serogroup A,C,W135,Y meningococcal conjugate vaccine (MenACWY) was licensed for use in subjects of 12 months of age and above.

Objectives

To evaluate the cost-effectiveness of meningococcal vaccination at 14 months and an additional vaccination at the age of 12 years, both with the MenACWY vaccine.

Methods

A decision analysis cohort model, with 185,000 Dutch newborns, was used to evaluate the cost-effectiveness of different immunization strategies. For strategies including a vaccination at 12 years of age, an additional cohort with adolescents aged 12 years was followed. The incremental cost-effectiveness ratio (ICER) was estimated for the current disease incidence and for a scenario when herd immunity is lost.

Results

Vaccination with MenACWY at 14 months is cost-saving. Vaccinating with MenACWY at 14 months and at 12 years would prevent 7 additional cases of meningococcal serogroup A,C,W135,Y disease in the birth cohort and adolescent cohort followed for 99 years compared to the current vaccine schedule of a single vaccination with MenC at 14 months. With the current incidence, this strategy resulted in an ICER of €635,334 per quality adjusted life year. When serogroup C disease incidence returns to pre-vaccination levels due to a loss of vaccine-induced herd-immunity, vaccination with MenACWY at 14 months and at 12 years would be cost-saving.

Conclusions

Routine vaccination with MenACWY is cost-saving. With the current epidemiology, a booster-dose with MenACWY is not likely cost-effective. When herd immunity is lost, a booster-dose has the potential of being cost-effective. A dynamic model should be developed for more precise estimation of the cost-effectiveness of the prevention of disappearance of herd immunity.

Dynamics of childhood invasive meningococcal disease in Israel during a 22-year period (1989-2010)

AIM

To describe the dynamics in the incidence of childhood invasive meningococcal disease (IMD) in Israel during a 22-year period (1989-2010).

METHODS

A longitudinal prospective surveillance in all 27 medical centers with pediatric services in Israel. All cases of children <15 years old with positive blood/cerebrospinal fluid (CSF) culture for Neisseria meningitidis were reported. Demographic, clinical, and bacteriological data were recorded. Meningococcal vaccine was not routinely given to Israeli children during the study period.

RESULTS

The mean age ± standard deviation (SD) among the 743 cases was 40.7 ± 40.2 months. The mean yearly incidence/100,000 was 2.0 ± 0.8. Age-specific incidences were 8.7 ± 2.8, 2.9 ± 1.5, and 0.8 ± 0.5 for children <1, 1-4, and >4 years old, respectively. The overall incidence decreased significantly from 3.7 in 1989 to 1.5 in 2010. Meningitis constituted 69.2 % of all cases. The most common serogroups were: B (76.9 %), C (10.9 %), Y (8.0 %), and W(135) (2.9 %). 78.6 % of all serogroup B isolates were from children <5 years old (p < 0.01). Serogroup C was found mainly in children ≥5 years old (63.4 %). The case fatality rates (CFRs) for children <1, 1-4, >4 years old, and the total study population were 9.2, 12.3, 7.7, and 9.9 %, respectively. CFRs were higher for children without meningitis (14.9 %) compared to children with meningitis (7.9 %) (p < 0.01).

CONCLUSIONS

Overall, and for serogroups B and W135, childhood IMD rates decreased significantly in Israel during the study period, without routine vaccine usage. The most common serogroup in all age groups was B, which was most prevalent in children <5 years old. No change in the trend of the overall CFR was noted during the study period.

Cost-effectiveness of vaccination against meningococcal B among Dutch infants: Crucial impact of changes in incidence

OBJECTIVE

Recently, a vaccine with the capacity to protect against serogroup B meningococcal (MenB) disease received a positive opinion of the European Medicines Agency. Previously, such a vaccine was estimated to be cost-effective. However, since then, the MenB disease incidence has declined drastically in the Netherlands. Therefore, we re-assessed the potential incremental cost-effectiveness ratio (ICER) of vaccinating infants in the Netherlands with a MenB vaccine.

RESULTS

Routine infant vaccination (2, 3, 4+11 mo) could prevent 39 cases of MenB disease in a single birth cohort, corresponding to a total gain of 133 quality-adjusted life years (QALYs). However, this strategy is unlikely to be cost-effective if the vaccine costs €40 per dose (€243,778 per QALY). At a disease incidence of 5.7 per 100,000 person-years or a vaccine price of €10 per dose including administration costs, the ICER becomes more acceptable and remains below a threshold of €50,000 per QALY.

METHODS

A cohort of 185,000 Dutch newborns was followed in a Markov model to compare routine vaccination against MenB disease with no vaccination. The ICER was estimated for different disease incidences. The study was performed from a societal perspective.

CONCLUSIONS

At the current low level of disease incidence, introduction of routine infant vaccination, following a 2, 3, 4+11 mo schedule, against MenB disease is unlikely cost-effective in the Netherlands. If the MenB disease incidence increases or the vaccine price is substantially lower than €40, routine infant vaccination has the potential to be cost-effective.

Increased incidence of meningococcal disease in HIV-infected individuals associated with higher case-fatality ratios in South Africa

OBJECTIVES

We aimed to compare the incidence of meningococcal disease amongst HIV-infected and uninfected individuals and to evaluate whether HIV is a risk factor for mortality and bacteremia amongst patients with meningococcal disease.

DESIGN

Cohort surveillance study.

METHODS

We conducted laboratory-based surveillance for meningococcal disease in Gauteng Province, South Africa. HIV status and outcome data were obtained at sentinel sites. Incidence in HIV-infected and uninfected persons was calculated assuming a similar age-specific HIV prevalence in tested and untested individuals. Risk factors for death and bacteremia (as compared with meningitis) were evaluated using multivariable logistic regression.

RESULTS

From 2003 to 2007, 1336 meningococcal cases were reported. Of 504 patients at sentinel sites with known outcome, 308 (61%) had HIV serostatus data. HIV prevalence amongst cases of meningococcal disease was higher than the population HIV prevalence in all age groups. The incidence of meningococcal disease in HIV-infected individuals was elevated in all age groups with an age-adjusted relative risk of 11.3 [95% confidence interval (CI) 8.9-14.3, P < 0.001]. The case-fatality ratio (CFR) was 20% (27/138) amongst HIV-infected and 11% (18/170) amongst HIV-uninfected individuals [odds ratio (OR) 2.1, 95% CI 1.1-3.9]. On multivariable analysis, CFR was greater amongst patients with bacteremia (35%, 29/82) compared with meningitis (7%, 16/226) (OR 7.8, 95% CI 3.4-17.7). HIV infection was associated with increased odds of bacteremia (OR 2.7, 95% CI 1.5-5.0).

CONCLUSION

HIV-infected individuals may be at increased risk of meningococcal disease. The increased CFR in HIV-infected patients may be explained by their increased odds of bacteremia compared to meningitis.

Global and regional risk of disabling sequelae from bacterial meningitis: a systematic review and meta-analysis

Few data sources are available to assess the global and regional risk of sequelae from bacterial meningitis. We aimed to estimate the risks of major and minor sequelae caused by bacterial meningitis, estimate the distribution of the different types of sequelae, and compare risk by region and income. We systematically reviewed published papers from 1980 to 2008. Standard global burden of disease categories (cognitive deficit, bilateral hearing loss, motor deficit, seizures, visual impairment, hydrocephalus) were labelled as major sequelae. Less severe, minor sequelae (behavioural problems, learning difficulties, unilateral hearing loss, hypotonia, diplopia), and multiple impairments were also included. 132 papers were selected for inclusion. The median (IQR) risk of at least one major or minor sequela after hospital discharge was 19.9% (12.3-35.3%). The risk of at least one major sequela was 12.8% (7.2-21.1%) and of at least one minor sequela was 8.6% (4.4-15.3%). The median (IQR) risk of at least one major sequela was 24.7% (16.2-35.3%) in pneumococcal meningitis; 9.5% (7.1-15.3%) in Haemophilus influenzae type b (Hib), and 7.2% (4.3-11.2%) in meningococcal meningitis. The most common major sequela was hearing loss (33.9%), and 19.7% had multiple impairments. In the random-effects meta-analysis, all-cause risk of a major sequela was twice as high in the African (pooled risk estimate 25.1% [95% CI 18.9-32.0%]) and southeast Asian regions (21.6% [95% CI 13.1-31.5%]) as in the European region (9.4% [95% CI 7.0-12.3%]; overall I(2)=89.5%, p<0.0001). Risks of long-term disabling sequelae were highest in low-income countries, where the burden of bacterial meningitis is greatest. Most reported sequelae could have been averted by vaccination with Hib, pneumococcal, and meningococcal vaccines.

A surveillance network for meningococcal disease in Europe

Between 1999 and 2004, the European Union Invasive Bacterial Infections Surveillance Network (EU-IBIS) received c. 50,000 reports of meningococcal disease from 27 participating countries. Analysis has demonstrated a major decline in the incidence of invasive disease in those countries that have introduced routine vaccination against serogroup C infection. The establishment of rapid reporting of W135 and B2a/B2b strains has been able to provide early reassurance that these strains are not emerging as major public health problems in Europe. Between September 2001 and February 2005, the EU-MenNet project offered further opportunities for enhancing this data resource. Collaborative projects included: improving the EU-IBIS website; reviewing case ascertainment in Europe; reviewing cost-effectiveness studies for meningococcal serogroup C conjugate (MCC) vaccination; international comparisons of MCC vaccine efficacy; and mathematical modelling studies. In addition, linking of data from the European Meningococcal Multi-locus Sequence Type Centre to epidemiological data was performed. Particular clonal complexes were found to be preferentially associated with certain serogroups. Case fatality was also found to vary with clonal complex, suggesting that genotype can be a marker for hypervirulence. The importance of close collaboration between networks of epidemiologists, microbiologists, and the wider scientific and public health community is demonstrated.

High case-fatality rates of meningococcal disease in Western Norway caused by serogroup C strains belonging to both sequence type (ST)-32 and ST-11 complexes, 1985-2002

A total of 293 meningococcal disease (McD) patients from Western Norway hospitalized during 1985-2002 were examined for risk factors related to death. The case-fatality rate (CFR) increased from 4% during 1985-1993 to 17% during 1994-2002. We analysed the phenotypic and genotypic characteristics of the meningococcal patient isolates, with the aim of identifying whether highly virulent meningococcal strains contributed to the increased CFR. The Norwegian epidemic strain B:15:P1.7,16/ST-32 complex was overall the most common phenotype/genotype (n=75) and caused most deaths (n=9; CFR 12.0%). However, fatality was significantly associated with disease caused by serogroup C meningococcal strains; C:15:P1.7,16/ST-32 and C:2a/ST-11 complex strains, which had the highest CFRs of 21.1% and 18.2% respectively. Serogroup B strains of the ST-32 complex differing by serotype and/or serosubtype from the epidemic strain had a CFR of 5.1%, while the CFR of disease caused by other strains (all phenotypes and genotypes pooled) was 2.2%. The distribution of phenotypes/clonal complexes varied significantly between 1985-1993 and 1994-2002 (P<0.001); B:15/ST-32 complex strains decreased whereas both C:15:P1.7,16/ST-32 complex strains and strains with other phenotypes/clonal complexes increased. Our results indicate that C:15:P1.7,16/ST-32 and C:2a/ST-11 complex strains were highly virulent strains and contributed to the high CFR of McD in patients from Western Norway. To reduce fatality, rapid identification of such virulent strains is necessary. In addition, early and specific measures should include public information, vaccination of populations at risk of disease and carriage eradication, when clustering of patients occurs.

Variations in case fatality and fatality risk factors of meningococcal disease in Western Norway, 1985-2002

In a retrospective epidemiological study, 293 meningococcal disease patients hospitalized during 1985-2002, were examined for fatality and risk factors related to death. The overall case fatality rate (CFR) was 8.2%, but increased from 4% during 1985-1993 to 17% during 1994-2002. The latter 9-year period was characterized by more serogroup C infections and more patients with thrombocytopenia on admission to hospital. All patients categorized as meningitis on admission survived. Of the 24 patients who died, 21 had meningococcal skin rash on admission, 23 had an onset to admission time of < or =24 h, and 16 had severe septicaemia with hypotension and/or ecchymoses without meningitis on admission. By multivariate analyses, a short onset to admission time, >50 petechiae, thrombocytopenia and severe septicaemia on admission were associated with fatality. More lives could be saved through earlier admission to hospital. This can be achieved through more information to the public about the early signs of meningococcal septicaemia, with the recommendation to look for skin rash in patients with acute fever during the first day and night.

Bacterial Meningitis in Children

Acute bacterial meningitis is still an important cause of morbidity and mortality in children worldwide. Recently, Haemophilus influenzae type b (Hib), once a common cause of meningitis, has virtually disappeared in developed nations, reflecting the overwhelming success of Hib vaccination. Unfortunately, Hib remains a significant pathogen in resource-poor countries. The introduction of the conjugated pneumococcal vaccine in 2000 may lead to similar future trends as witnessed with Hib. As the resistance of Streptococcus pneumoniae to penicillin and cephalosporins continues to evolve, vancomycin has become an important antibacterial in the treatment of bacterial meningitis. The unreliable penetration of this agent into cerebrospinal fluid is of concern, which is compounded by the controversial use of corticosteroids in paediatric meningitis. Some data suggest that in certain situations the addition of rifampicin (rifampin) to ceftriaxone may be a better choice. While dexamethasone is now considered the standard adjunctive therapy in the treatment of pneumococcal meningitis in adult patients, the benefit in children is not so clear and remains controversial; thus, there is no definitive paediatric recommendation. Several anti-inflammatory agents currently under investigation may be used in the future as adjunctive therapy for bacterial meningitis. It is clear that the current concepts in the treatment of childhood bacterial meningitis are evolving, and other antibacterial options and possible alternatives such as carbapenems and fluoroquinolones should be considered. Fluid restriction because of the Syndrome of Inappropriate Antidiuretic Hormone Secretion is widely advocated and used. Yet, this practice was recently challenged. It seems that most patients with meningitis do not need fluid restriction. The overwhelming success of the conjugated Hib vaccine and the encouraging results of the new conjugated pneumococcal and meningococcal vaccines suggest that the ideal management of bacterial meningitis is prevention and vaccines development against the most common bacterial agents are the best solution.

The case-fatality rate of meningococcal disease in Catalonia, 1990-1997

The objective was to analyse the case-fatality rate (CFR) of meningococcal disease (MD) in Catalonia, Spain. A retrospective study was carried out. Clinical histories of cases of MD reported for the period 1990-1997 in Catalonia were reviewed. For all cases, the variables gender, age, clinical type, y of presentation, province, phenotype and death by meningococcal disease were collected. The association between death and the other variables was studied by bivariate and unconditional logistic regression analysis. In the 2343 cases studied there were 146 deaths (6.2%) due to meningococcal disease. The CFR was higher in females (OR: 1.5, 95%CI: 1.1-2.1), in the 20 to 49 y (OR: 2.4, 95%CI: 1.2-4.9) and > or = 50 y (OR: 5.3, 95%CI: 2.8-10.1) age groups, in cases with septicaemia (OR: 2.4, 95%CI: 1.6-3.5), in the cases produced by serogroup A (OR: 4.7, 95%CI: 1.0-23.4) and in cases occurring during 1993 (OR: 2.1, 95%CI: 1.1-4.1) or in the province of Lleida (OR: 2.9, 95%CI: 1.2-7.2). In the multivariate analysis, death was associated with the 20-49 y age group (OR: 3.9, 95%CI: 1.8-8.4), the > or = 50 y age group (OR: 7.3, 95%CI: 3.6-14.7), septicaemia (OR: 3.1; 95%CI: 2.0-4.7) and residing in the province of Lleida (OR: 3.2; 95%CI: 1.2-8.5). The CFR of meningococcal disease in Catalonia was not associated with the emergent phenotype C:2b:P1.2,5 strain, which caused an outbreak in other regions of Spain.

Epidemiology of meningococcal disease in Switzerland, 1999-2002

In Switzerland, immunisation against serogroup C meningococcal disease is recommended for persons at increased risk but is not included in the national vaccination programme. The aim of this study was to present the nationwide surveillance data on invasive meningococcal disease collected from 1999 to 2002, emphasising the evolution in the absence of extended vaccination. The number of reported cases of meningococcal disease peaked at 178 cases in 2000 (incidence rate of 2.5/100,000 person-years), with 61% of all cases attributed to serogroup C meningococci (incidence rate, 1.5/100,000 person-years). Since 2001, a spontaneous decrease in the reported cases was observed, resulting in an overall incidence rate of 1.4/100,000 person-years in 2002 (serogroup C cases, 0.8/100,000 person-years). On the other hand, the case-fatality rate of serogroup C cases increased to 18% in 2002, leading to an increase in the overall case-fatality rate from 8% to 14% (P>0.05). The small sample size reduces the interpretability of this observation. However, when the introduction of a generalised vaccination against serogroup C meningococcal disease is discussed, the fluctuations in the number of vaccine-preventable deaths should receive greater attention.

The immunopathogenesis of meningococcal disease

This review describes the mechanisms of the immune response to meningococcal disease, examining the extent to which individual variation of the immune response can determine susceptibility. It concludes by summarising the difficulties encountered by recent efforts to develop new immunomodulatory treatments.

Fatal outcome from meningococcal disease--an association with meningococcal phenotype but not with reduced susceptibility to benzylpenicillin

Penicillin has been the mainstay of treatment for meningococcal disease. Isolates of Neisseria meningitidis that are less susceptible to penicillin have been reported in several countries and in recent years have become more common. The clinical significance of this reduced susceptibility has not been investigated on a large scale. Hence, N. meningitidis isolates from culture-confirmed cases of meningococcal disease in England and Wales, between 1993 and 2000, were routinely serogrouped, serotyped and tested for susceptibility to penicillin. These data were linked to death registrations and analysed retrospectively. The changing trends in susceptibility were described and multivariate logistic regression was used to examine associations between strain characteristics and fatal outcome. The frequency of N. meningitidis isolates less susceptible to penicillin increased from < 6% in 1993 to > 18% in 2000. In particular, isolates expressing serogroup C with serotype 2b and serogroup W135 had a higher frequency of reduced penicillin susceptibility (49% and 55%, respectively). There was no evidence of an association between fatal outcome and infection with a less penicillin-susceptible isolate. Fatal outcome was associated with serogroup and serotype, with the odds of death for cases infected with C:2a and B:2a strains three-fold higher when compared with the baseline. For this large dataset the serogroup and serotype of the infecting strain influenced mortality from meningococcal disease and may be markers for hypervirulence. No association was found between reduced penicillin susceptibility and fatal outcome, but the increasing frequency of isolates less susceptible to penicillin highlights the need for continued surveillance.

[Epidemiological characterization of meningococcal disease in a metropolitan area in Southeastern Brazil, 1976-1994]

INTRODUCTION

Meningococcal disease continues to warrant assessment as to its endemic and epidemic multicausality and temporal trends in various locations.

MATERIAL AND METHOD

Based on a standardization of epidemiological investigation of meningococcal disease in the municipality of Rio de Janeiro county, Southeastern Brazil, as from epidemic of the 1970s a study to characterized the epidemiological characteristics of the disease, was realized. The total of 4,155 cases reported between 1976 and 1994 were analyzed in a retrospective, descriptive, and analytical study, using the epidemiological investigation forms issued by the Municipal Health Secretariat. Statistical analysis was performed using the chi 2, Wilcoxon-Mann-Whitney, and Kruskal-Wallis tests.

RESULTS

The study resulted in the definition of three periods, classified as post-epidemic (1976-79), endemic (1980-86), and epidemic (1987-94), differentiated by the incidence rates and the predominant meningococcal serogroup. The mean incidence rates per period in the municipality were 3.51, 1.67, and 6.53 cases/ 100,000 inhabitants, respectively. Serogroups A and C predominated during the post-epidemic period, B and A in the endemic, and B in the epidemic.

CONCLUSION

The mean case fatality rate remained virtually unchanged over time, but it varied by hospital, and during all three periods was lower in the State government reference hospital than in the other hospitals, whether public or private. The highest incidence and case fatality rates were associated with patients under one year of age, and the risk of acquiring the disease was greater among males. The highest incidence coefficients tended to occur in the same areas of the county during the three epidemiological periods, and the shanty-town population was at twice the risk of acquiring the disease.

Acute meningococcal meningitis: analysis of features of the disease according to the age of 255 patients. Copenhagen Meningitis Study Group

Clinical and laboratory features of acute meningococcal meningitis according to age were studied in 255 patients. Whereas males accounted for three out of five patients aged 0-4 years, females accounted for three out of four patients older than 50 years of age. All patients had clinical signs of nuchal rigidity and fever. Patients older than 30 years of age had less frequent petechiae (62%) than younger patients (81%). Furthermore, elderly patients above 50 years of age were prone to an obtunded mental state and a prolonged disease course with fever. Without relation to age, 2/3 had purulent meningitis and 2/3 had marked peripheral leucocytosis (> 15 x 10(9) cells/l); 90% of patients had at least one of these findings. The cellular inflammatory response in peripheral blood indicated a bacterial aetiology in > 95% of the cases. More than 80% of children and adults had abnormal CSF biochemical findings, but the level of protein and the glucose ratio (CSF/serum) were positively and negatively correlated to increasing age of the patient, respectively: thus, in children these biochemical markers may be unreliable in the differentiation between a bacterial and non-bacterial aetiology. Thrombocytopenia (< 100.000 x 10(9)/I) was not associated with age, though the lowest platelet count was found in elderly patients. The case fatality rate was 7.5%, but neither age, sex nor sign of septicaemia was associated with fatality. Thrombocytopenia, a lowered coagulation index (< 0.5, factors II, VII, X), a moderate anaemia (haemoglobin < 11 g/dl), an obtunded mental state and a history of convulsions were poor prognostic factors; only anaemia was independently correlated to fatality so this should be considered as an important prognostic marker in the acute phase of meningococcal meningitis.

Meningococcal disease in Norway 1992-1995. Epidemiology and fatality

We analysed data on all cases of meningococcal disease (MCD) reported to the Norwegian Notification System for Infectious Diseases during the period 1992-1995. For 1994, additional information on fatalities was gathered. Notifications were received from laboratories and clinicians. A total of 586 patients were included. The incidence decreased from 4.6 per 100000 in 1992 to 2.4 in 1994, and then rose to 3.7 in 1995. The initial decrease, a trend also observed in previous years, was seen in both main serogroups B and C. This decline was broken with the increase of serogroup B in 1995. MCD predominantly affects children below 5 years and teenagers. In 1994, 17/105 (16%) patients died. Main risk factors for fatal outcome were age above 30 years (adjusted odds ratio (OR) 19.8; 95% confidence interval (CI) 2.4-164), septicaemia (adjusted OR 9.5; 95% CI 2.2-41) and disease caused by strains B:15 (adjusted OR 6.4; 95% CI 1.2-35) or C:2a (adjusted OR 10.1; 95% CI 1.6-62). We conclude that the incidence of MCD in Norway is unpredictable and that the case fatality rate is substantially higher than previously believed.

Clinical manifestations and course of meningococcal disease in 562 patients

To describe the clinical manifestations and course of meningococcal disease (MD) data were collected on patients with culture-proven MD, reported in the Netherlands between April 1, 1989 and April 30, 1990 by means of a questionnaire completed by the specialist in attendance. During the study period, 562 patients (295 males, 267 females) were reported. The age of the patients ranged from 2 weeks to 88 years. Of the patients, 57.8% were classified as meningitic, 20.3% as bacteraemic and 21.9% as both meningitic and bacteraemic. In 4.6% of the patients a predisposing factor was present, and in 1.4% a previous episode of meningitis had occurred. A positive family history of meningitis was reported in 12.9% of the patients. On admission, 65.2% of the patients had haemorrhagic skin lesions, 7.9% coma and 4.2% seizures. During admission, 17.8% of the patients developed serious complications. The fatality rate was 7.7%. In 73.2% of the deceased, death occurred within 2 days after admission. Of the survivors, 8.5% recovered with serious sequelae. In conclusion, 16% of the patients with meningococcal disease either died or became severely disabled. Prevention of this putative life-threatening disease seems to be the only means of circumventing the problems caused by this serious condition.

Factors associated with fatal outcome in childhood meningococcal disease

The purpose of this study was to identify factors associated with a fatal outcome in children with meningococcal disease and to design a new clinical scoring system. We reviewed the charts of all 137 children with meningococcal disease admitted alive to the University Hospital, Tromsø, during the years 1977-92. Twelve of the children died (8.7%). On admission the following clinical signs were significantly associated with poor outcome: peripheral vasoconstriction, cyanosis, extensive petechiae, hypotension, altered consciousness, hyperventilation and absence of neck rigidity. The laboratory parameters low pH, low base excess, thrombocytopenia, low Trombotest and leukopenia were also associated with later death. Multiple logistic regression was performed to examine the independent effect of each variable. Cyanosis, peripheral vasoconstriction and base excess < -10 mmol/l or pH < 7.35 were significantly associated with a fatal outcome. A clinical scoring system based on the extent of petechiae, the presence of peripheral vasoconstriction, hyperventilation and/or cyanosis, the absence of neck rigidity and impairment of consciousness is proposed. Twenty-nine patients received > or = 3.5 points, of whom 12 died and 12 survived. None of the patients who died had less than 3.5 points. The clinical scoring system is based solely on clinical signs. It can be done rapidly and performs well in identifying children who might benefit from early intensive care.

Antibody responses to the capsular polysaccharide of Neisseria meningitidis serogroup B in patients with meningococcal disease

We measured antibody responses to meningococcal serogroup B (MenB) polysaccharide (PS) by enzyme-linked immunosorbent assay (ELISA) in sera from 94 patients from The Netherlands with disease caused by Neisseria meningitidis group B. The patients ranged in age from 3 to 73 years (mean age, 18.8 years). In initial studies we showed that the binding of a panel of MenB PS-reactive human immunoglobulin M (IgM) paraproteins to biotinylated MenB PS bound to avidin-coated microtiter wells was inhibited > 90% by the addition of soluble MenB PS or encapsulated group B meningococci. In contrast, inhibition of IgM anti-MenB PS antibody-binding activity in many of the patient sera was less than 50% (range, 20 to 94%). These data suggested a high frequency of nonspecific binding in the patient sera. Therefore, all serum samples were assayed in replicate in the presence or absence of soluble MenB PS, and only the inhibitable fraction of the binding signal was used to calculate the anti-MenB PS antibody concentrations. In 17 control patients with meningococcal disease caused by serogroup A or C strains, there was no significant difference in the respective IgM or IgG anti-MenB PS antibody concentrations in paired acute- and convalescent-phase sera. In contrast, in patients with MenB disease, the geometric mean IgM anti-MenB PS antibody concentration increased from 3.9 units/ml in acute-phase serum to 10.5 units/ml in convalescent-phase serum (P < 0.001). The corresponding geometric mean IgG anti-MenB PS antibody titers were 1:27 and 1:36 (P < 0.05). There was only a weak relationship between age and the magnitude of the logarithm of the antibody concentrations in convalescent-phase sera (for IgM, r2 = 0.06 and P < 0.05; for IgG, r2 = 0.08 and P < 0.01). Our data indicate that precautions are needed to avoid nonspecificity in measuring serum antibody responses to MenB PS by ELISA. Furthermore, although this PS is thought to be a poor immunogen, patients as young as 3 years of age recovering from MenB disease demonstrate both ImG and IgG antibody responses in serum.