Meningococcal disease in Wales: clinical features, outcome and public health management

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.

Effectiveness of antibiotics given before admission in reducing mortality from meningococcal disease: systematic review

OBJECTIVE

To review the evidence for effectiveness of treatment with antibiotics before admission in reducing case fatality from meningococcal disease.

DESIGN

Systematic review.

DATA SOURCES

Cochrane register of trials and systematic reviews, database of abstracts of reviews of effectiveness, health technology assessment, and national research register in England and Wales, Medline, Embase, and CAB Health.

INCLUDED STUDIES

Studies describing vital outcome of at least 10 cases of meningococcal disease classified by whether or not antibiotics were given before admission to hospital.

RESULTS

14 observational studies met the review criteria. Oral antibiotic treatment given before admission was associated with reduced mortality among cases (combined risk ratio 0.17, 95% confidence interval 0.07 to 0.44). In seven studies in which all included patients were seen in primary care, the association between parenteral antibiotics before admission and outcome was inconsistent (chi2 for heterogeneity 11.02, P = 0.09). After adjustment for the proportion given parenteral antibiotics before admission, there was no residual heterogeneity. A higher proportion of patients given parenteral antibiotics before admission was associated with reduced mortality after such treatment and vice versa (P = 0.04).

CONCLUSION

Confounding by severity is the most likely explanation both for the beneficial effect of oral antibiotics and the harmful effect observed in some studies of parenteral antibiotics. We cannot conclude whether or not antibiotics given before admission have an effect on case fatality. The data are consistent with benefit when a substantial proportion of cases are treated.

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.

Update on meningococcal disease with emphasis on pathogenesis and clinical management

The only natural reservoir of Neisseria meningitidis is the human nasopharyngeal mucosa. Depending on age, climate, country, socioeconomic status, and other factors, approximately 10% of the human population harbors meningococci in the nose. However, invasive disease is relatively rare, as it occurs only when the following conditions are fulfilled: (i) contact with a virulent strain, (ii) colonization by that strain, (iii) penetration of the bacterium through the mucosa, and (iv) survival and eventually outgrowth of the meningococcus in the bloodstream. When the meningococcus has reached the bloodstream and specific antibodies are absent, as is the case for young children or after introduction of a new strain in a population, the ultimate outgrowth depends on the efficacy of the innate immune response. Massive outgrowth leads within 12 h to fulminant meningococcal sepsis (FMS), characterized by high intravascular concentrations of endotoxin that set free high concentrations of proinflammatory mediators. These mediators belonging to the complement system, the contact system, the fibrinolytic system, and the cytokine system induce shock and diffuse intravascular coagulation. FMS can be fatal within 24 h, often before signs of meningitis have developed. In spite of the increasing possibilities for treatment in intensive care units, the mortality rate of FMS is still 30%. When the outgrowth of meningococci in the bloodstream is impeded, seeding of bacteria in the subarachnoidal compartment may lead to overt meningitis within 24 to 36 h. With appropriate antibiotics and good clinical surveillance, the mortality rate of this form of invasive disease is 1 to 2%. The overall mortality rate of meningococcal disease can only be reduced when patients without meningitis, i.e., those who may develop FMS, are recognized early. This means that the fundamental nature of the disease as a meningococcus septicemia deserves more attention.

Update on meningococcal disease with emphasis on pathogenesis and clinical management

The only natural reservoir of Neisseria meningitidis is the human nasopharyngeal mucosa. Depending on age, climate, country, socioeconomic status, and other factors, approximately 10% of the human population harbors meningococci in the nose. However, invasive disease is relatively rare, as it occurs only when the following conditions are fulfilled: (i) contact with a virulent strain, (ii) colonization by that strain, (iii) penetration of the bacterium through the mucosa, and (iv) survival and eventually outgrowth of the meningococcus in the bloodstream. When the meningococcus has reached the bloodstream and specific antibodies are absent, as is the case for young children or after introduction of a new strain in a population, the ultimate outgrowth depends on the efficacy of the innate immune response. Massive outgrowth leads within 12 h to fulminant meningococcal sepsis (FMS), characterized by high intravascular concentrations of endotoxin that set free high concentrations of proinflammatory mediators. These mediators belonging to the complement system, the contact system, the fibrinolytic system, and the cytokine system induce shock and diffuse intravascular coagulation. FMS can be fatal within 24 h, often before signs of meningitis have developed. In spite of the increasing possibilities for treatment in intensive care units, the mortality rate of FMS is still 30%. When the outgrowth of meningococci in the bloodstream is impeded, seeding of bacteria in the subarachnoidal compartment may lead to overt meningitis within 24 to 36 h. With appropriate antibiotics and good clinical surveillance, the mortality rate of this form of invasive disease is 1 to 2%. The overall mortality rate of meningococcal disease can only be reduced when patients without meningitis, i.e., those who may develop FMS, are recognized early. This means that the fundamental nature of the disease as a meningococcus septicemia deserves more attention.

Acute abdomen as an atypical presentation of meningococcal septicaemia

The clinical manifestations and course of meningococcal disease have been well described, but atypical presentations may, if unrecognized, lead to a delay in treatment. We describe here an unusual case of this disease in a 21-y-old woman who presented with an acute rigid abdomen, clinical and laboratory features of sepsis, shock and early DIC with no indication of meningococcal infection. She developed a rapidly spreading purpuric rash, conjunctival haemorrhages, hypotension and tachycardia and a low urine output. Laboratory investigations showed a low platelet count, low haemoglobin and normal WBC. A presumptive diagnosis of meningococcal septicaemia was made and recovery followed treatment with cefotaxime, fluids and inotropes. A fully sensitive Neisseria meningitis Group C, type 2a, subtype NT was isolated from blood cultures, but not from CSF obtained after antibiotic treatment.

Polyarticular septic arthritis caused by non-encapsulated haemophilus influenzae biotype I in a rheumatic adult

Haemophilus influenzae causes less than 1% of all septic arthritis cases in adults. Most often serotype b is responsible. Here we describe a rare case of non-encapsulated H. influenzae-induced polyarticular septic arthritis in a rheumatic patient with no other infectious focus.

How long is too long? Determining the early management of meningococcal disease in Birmingham

OBJECTIVE

To determine the length of time cases of meningococcal disease wait before receiving parenteral antibiotic therapy in hospital.

METHOD

The hospital case notes of residents of Birmingham who were admitted to local hospitals in 1993 and discharged with a diagnosis of meningitis or meningococcal disease were reviewed. This information was combined with that held by the West Midlands Ambulance Service.

RESULTS

Forty out of the 82 patients (49%) who met the case definition had meningococcal infection. Twenty one patients (26%) were admitted by ambulance, 11 of whom had meningococcal infection. The mean time from a request for an ambulance to the patient reaching hospital was 52 min for those with meningococcal infection compared to 55 min for those without. Nineteen patients (47.5%) with meningococcal infection waited more than one hour after admission for antibiotic treatment. Seven had an initial diagnosis of meningitis or meningococcal infection. Ten out of 27 patients with a meningococcal rash (37%), 13 out of 22 patients aged under five years (59%) and 13 out of 24 patients with microbiologically confirmed meningococcal infection (54%) waited more than one hour for treatment. Seven patients with meningococcal infection received benzyl penicillin before admission. Six received hospital antibiotic treatment within the hour.

CONCLUSION

The assumption that patients suspected of having meningitis or meningococcal disease are treated promptly once in hospital is not always correct. The results of this study reinforce the need for all doctors to give benzyl penicillin promptly to patients they suspect have meningococcal disease.

Meningococcal antibody titres in infants of women immunised with meningococcal polysaccharide vaccine during pregnancy

Seventy five Gambian women were immunised with a single dose of a group A+group C meningococcal polysaccharide vaccine during the last trimester of pregnancy. IgG antibody titres were measured in mothers and in their infants by an enzyme-linked immunosorbent assay (ELISA). All women had a good response to vaccination and maternal antibodies were high at the time of delivery (23.2 micrograms/ml for group A antibodies and 14.3 micrograms/ml for group C antibodies). However, only a proportion of this antibody crossed the placenta; cord blood:maternal antibody ratios were 30% for group A antibody and 44% for group C antibody, respectively. Considerable variability in cord blood:maternal blood ratios was seen between individuals. This could not be related to age, parity, or ethnic group. Mean group A and group C cord blood:maternal blood ratios were lower in women with serological evidence of syphilis than in seronegative women, and diminished transfer of group A antibody was noted in women with active malarial infection of the placenta. Antibody titres declined rapidly in infants and by the age of 3-4 months these had reached control values. Maternal immunisation may give infants some protection against group A and group C meningococcal disease but only during the first few months of life.

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.

Mortality from group C meningococcal disease: a case for a conjugate vaccine?

This 17-year retrospective review of children with meningococcal disease (MCD) has determined the mortality due to serogroup C, in order to assess the potential impact of a group C conjugate vaccine. Four hundred and forty-nine cases of MCD were admitted to our hospitals during 1977-1993; 78 due to group C, 11 of whom died. There was a significant increase in the proportion of cases due to group C from 1986 onwards (10% vs 21%), and an increase in the total number of cases of MCD (151 vs 298). The currently available group C polysaccharide vaccine has low efficacy below 2 years of age and could not have prevented 54 cases of group C disease. A conjugate group C vaccine administered between 2 and 4 months of age could have prevented 68 cases, including all fatal cases. The recent increase in MCD is partly due to an increase in group C disease. A meningococcal group C conjugate vaccine could prevent most cases of infection due to group C, and decrease the mortality from MCD by up to 30%.

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

To investigate the joint association of patient and strain characteristics with the outcome of meningococcal disease (MD), data were collected on 563 consecutive cases of MD reported between 1989 and 1990 in The Netherlands. The meningococcal isolates were characterized with regard to their surface characteristics. Sequelae occurred in 8.5% of the patients, and were only associated with the presence of bacteraemia. The case-fatality rate was 7.7%. Infants aged < or = 5 months and patients in the age-groups of 10-19 years and > or = 50 years had an increased risk for a fatal outcome compared with children from 6 months to 9 years old (Odds Ratios [ORs]: 5.1, 3.4 and 9.8, respectively). The OR for females versus males was 2.3. The ORs for patients with bacteraemia, or a combination of bacteraemia and meningitis, compared with meningitic patients, were 2.3 and 3.1. Meningococcal strain characteristics did not influence the case-fatality rate substantially. In conclusion, host factors were found to be determinants for a fatal outcome of MD in The Netherlands from 1989 to 1990.