Prognostic Factors in meningococcal disease

Progress and Challenges in Bacterial Meningitis: A Review

IMPORTANCE

Bacterial meningitis is a worldwide health problem, with incidence rates ranging from approximately 0.9 per 100 000 individuals per year in high-income countries to 80 per 100 000 individuals per year in low-income countries. In low-income countries, bacterial meningitis has a mortality rate of up to 54%. Up to 24% of those who survive develop chronic neurological sequelae, such as hearing loss or focal neurological deficits.

OBSERVATIONS

Streptococcus pneumoniae causes about 72% and Neisseria meningitidis causes about 11% of cases of bacterial meningitis in people older than 16 years. Escherichia coli and Streptococcus agalactiae cause about 35% of cases of early-onset neonatal meningitis. In adults, risk factors for bacterial meningitis include older age and immunosuppressive conditions. The most common symptoms are headache (84%), fever (74%), stiff neck (74%), altered mental status (median [IQR] Glasgow Coma Scale score of 11 [9-14] on a scale ranging from 3-15), and nausea (62%). Brain imaging should be performed before lumbar puncture if patients present with altered mental status, focal neurological deficits, papilledema, or history of immunocompromising conditions or central nervous system disease. Bacterial meningitis should be suspected if any of the following are present on admission: serum leukocytes greater than 10.0 ×109/L, cerebrospinal fluid (CSF) leukocytes greater than 2000/μL, CSF granulocytes greater than 1180/μL, CSF protein greater than 2.2 g/L, CSF glucose less than 34.23 mg/dL, or fever. A positive Gram stain result for bacteria is diagnostic, but the sensitivity of a positive Gram stain result for bacterial meningitis ranges from 50% to 90%. In countries in which the prevalence of ceftriaxone-resistant Streptococcus pneumoniae exceeds 1%, vancomycin and ceftriaxone are the empirical antibiotics of choice, with the addition of ampicillin in neonates, older patients, and immunocompromised patients. Adjunctive dexamethasone should be used in patients with bacterial meningitis but stopped if Listeria monocytogenes is confirmed.

CONCLUSIONS AND RELEVANCE

Bacterial meningitis affects approximately 0.9 per 100 000 individuals to 80 per 100 000 individuals per year and has a mortality rate as high as 54%. First-line therapy is prompt empirical intravenous antibiotic therapy and adjunctive dexamethasone.

Risk scores for outcome in bacterial meningitis: Systematic review and external validation study

OBJECTIVES

To perform an external validation study of risk scores, identified through a systematic review, predicting outcome in community-acquired bacterial meningitis.

METHODS

MEDLINE and EMBASE were searched for articles published between January 1960 and August 2014. Performance was evaluated in 2108 episodes of adult community-acquired bacterial meningitis from two nationwide prospective cohort studies by the area under the receiver operating characteristic curve (AUC), the calibration curve, calibration slope or Hosmer-Lemeshow test, and the distribution of calculated risks.

FINDINGS

Nine risk scores were identified predicting death, neurological deficit or death, or unfavorable outcome at discharge in bacterial meningitis, pneumococcal meningitis and invasive meningococcal disease. Most studies had shortcomings in design, analyses, and reporting. Evaluation showed AUCs of 0.59 (0.57-0.61) and 0.74 (0.71-0.76) in bacterial meningitis, 0.67 (0.64-0.70) in pneumococcal meningitis, and 0.81 (0.73-0.90), 0.82 (0.74-0.91), 0.84 (0.75-0.93), 0.84 (0.76-0.93), 0.85 (0.75-0.95), and 0.90 (0.83-0.98) in meningococcal meningitis. Calibration curves showed adequate agreement between predicted and observed outcomes for four scores, but statistical tests indicated poor calibration of all risk scores.

INTERPRETATION

One score could be recommended for the interpretation and design of bacterial meningitis studies. None of the existing scores performed well enough to recommend routine use in individual patient management.

Disseminated intravascular coagulation, antithrombin III, and complement in meningococcal infections

Serial assessments of some blood coagulation factors, antithrombin III (AT III), and complement were made in 18 patients with meningococcal (mgc) infection. All patients displayed laboratory evidence of activation of the blood clotting system. Two patients showed clinical signs of disseminated intravascular coagulation. Only AT III differed significantly between patients with and without complications. There was no correlation between changes in blood clotting, activation of the complement system and the course or duration of the disease. These results do not enable one t identify patients who need specific prophylactic therapy. Controlled clinical trials, including administration of heparin, dextran, aprotinin, and others, are still required to ensure optimal treatment in fulminant mgc infections.

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.

Severity of illness and organ dysfunction scoring in children

OBJECTIVE

To describe predictive and descriptive general scores that can be used to estimate the severity of illness in critically ill children.

DESIGN

Review of the medical literature.

SETTING

Pediatric intensive care units (PICUs).

PATIENTS

Critically ill children.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two predictive scores are frequently used in PICUs: the Pediatric Risk of Mortality III score and the Pediatric Index of Mortality 2. The data considered in these scores are collected at baseline. Predictive scores can be used to compare expected and observed mortality in PICUs or to estimate the balance in the baseline severity of illness of patients included in the different arms of a randomized clinical trial. Only one descriptive score is validated to estimate the severity of cases of multiple organ dysfunction syndrome in PICUs, namely, the Pediatric Logistic Organ Dysfunction score. The data required to calculate this score are collected from baseline to discharge from the PICU or up to 2 hrs before death in the PICU. The Pediatric Logistic Organ Dysfunction score can be used to describe the clinical outcome of patients during their stay in a PICU.

CONCLUSION

Pediatric Risk of Mortality III, Pediatric Index of Mortality 2, and Pediatric Logistic Organ Dysfunction scores are the best available tools to estimate the severity of illness in critically ill children.

Short course intravenous benzylpenicillin treatment of adults with meningococcal disease

BACKGROUND

Short-course treatment of meningococcal disease (including meningitis) with 4-5 days of an i.v. beta-lactam is of proven efficacy. Since April 1998, all adult patients with meningococcal disease admitted to Auckland Hospital were prospectively treated with 3 days of i.v. benzylpenicillin.

AIMS

To assess the clinical features, laboratory findings, disease complications and outcome of patients with meningococcal disease prospectively treated with 3 days of i.v. benzylpenicillin.

METHODS

A retrospective chart review of all adult patients with meningococcal disease admitted to Auckland Hospital from April 1998 to December 2002 was conducted.

RESULTS

Ninety patients with definite (n = 72) or -probable (n = 16) meningococcal disease were admitted during the study period. Two were excluded on the basis of treatment duration. The remaining 88 patients received a mean +/- standard deviation duration of treatment of 3.1 +/- 0.5 days (excluding those who died while receiving treatment). Six patients (7%) died, four of whom while on treatment. There were no relapses.

CONCLUSION

Three days of i.v. benzylpenicillin for the treatment of adults with meningococcal disease is effective.

Comparison of prediction models for adverse outcome in pediatric meningococcal disease using artificial neural network and logistic regression analyses

The objective of this study was to compare artificial neural network (ANN) and multivariable logistic regression analyses for prediction modeling of adverse outcome in pediatric meningococcal disease. We analyzed a previously constructed database of children younger than 20 years of age with meningococcal disease at four pediatric referral hospitals from 1985-1996. Patients were randomly divided into derivation and validation datasets. Adverse outcome was defined as death or limb amputation. ANN and multivariable logistic regression models were developed using the derivation set, and were tested on the validation set. Eight variables associated with adverse outcome in previous studies of meningococcal disease were considered in both the ANN and logistic regression analyses. Accuracies of these models were then compared. There were 381 patients with meningococcal disease in the database, of whom 50 had adverse outcomes. When applied to the validation data set, the sensitivities for both the ANN and logistic regressions models were 75% and the specificities were both 91%. There were no significant differences in any of the performance parameters between the two models. ANN analysis is an effective tool for developing prediction models for adverse outcome of meningococcal disease in children, and has similar accuracy as logistic regression modeling. With larger, more complete databases, and with advanced ANN algorithms, this technology may become increasingly useful for real-time prediction of patient outcome.

Meningococcal disease: how to prevent and how to manage

Meningococcal disease is a significant problem in the paediatric population. The diagnosis of meningococcal disease can be problematic and progression of the disease can rapidly lead to a life-threatening illness. Despite the success of antibiotic treatment, mortality rates remain high. The development of protein-polysaccharide conjugate vaccines has significantly improved the success of vaccination in reducing the incidence of meningococcal disease. However, a comprehensive vaccine conferring protection against disease-associated serogroups remains elusive. The aim of this review is to highlight recent significant improvements in the prevention and management of meningococcal disease.

Mortality in severe meningococcal disease

AIM

To evaluate mortality of critically ill children admitted with meningococcal disease.

METHODS

Prospective study of all children admitted to a regional paediatric intensive care unit (PICU) between January 1995 and March 1998 with meningococcal disease. Outcome measures were actual overall mortality, predicted mortality (by PRISM), and standardised mortality ratio.

RESULTS

A total of 123 children were admitted with meningococcal disease. There was an overall PICU mortality of 11 children (8.9%). The total mortality predicted by PRISM was 24.9. The standardised mortality ratio (SMR) was 0.44. Results were compared with those from four previously published meningococcal PICU studies (USA, Australia, UK, Netherlands) in which PRISM scores were calculated. The overall PICU mortality and SMR were lower than those in the previously published studies.

CONCLUSION

Compared with older studies and calibrating for disease severity, this study found a decrease in the mortality of critically ill children with meningococcal disease.

Can generic scores (Pediatric Risk of Mortality and Pediatric Index of Mortality) replace specific scores in predicting the outcome of presumed meningococcal septic shock in children?

OBJECTIVE

To compare, in children with septic shock and purpura, the accuracy in predicting death of two specific scores (the MenOPP bedside clinical [MOC] score of Gedde Dahl and the score of Groupe Francophone de Réanimation Pédiatrique [GFRP]), the C-reactive protein (CRP) level, and the two pediatric generic scores (the Pediatric Risk of Mortality [PRISM] and Pediatric Index of Mortality [PIM] scores).

DESIGN

Prospective, population-based study with analysis of previous comparative studies.

SETTING

A 14-bed pediatric intensive care unit in a university hospital.

PATIENTS

All children admitted consecutively to the pediatric intensive care unit with septic shock and purpura (n = 58, with 16 deaths [27.6%]) from January 1993 to May 2000.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The MOC and GFRP scores and the CRP level were prospectively determined at admission. The PRISM score was prospectively calculated within 24 hrs of admission or at the time of death, and the PIM score was calculated retrospectively between 1993 and 1997 and then prospectively from admission data. The nonparametric estimate of the area under the receiver operating characteristic curves (AUC) was calculated from the raw data using the Wilcoxon-Mann-Whitney two-sample statistic, and the standard error of the AUCs was calculated with DeLong's method. All the scores had an AUC >0.80, the PRISM probability of death having the best one (0.96 +/- 0.02). The PRISM value, which is easier to calculate, had an AUC of 0.95 +/- 0.02. The PRISM score performed significantly better than the PIM score (AUC, 0.83 +/- 0.06; p <.01) and the CRP level (AUC, 0.80 +/- 0.06; p <.01); however, there was no significant difference between the MOC (AUC, 0.91 +/- 0.04) and GFRP scores (AUC, 0.87 +/- 0.05). Analyzing literature and calculating AUCs from original data of previous studies, we observed that the superiority of the PRISM score had never been demonstrated in meningococcal diseases.

CONCLUSIONS

The PRISM score performed better than the PIM score, and was not surpassed by specific scores. Thus, we propose its use for outcome prediction in children with septic shock and purpura. However, if the PRISM score is to be used as inclusion criterion for clinical trials, it should be evaluated within a few hours after admission.

Comparison of the performance of two general and three specific scoring systems for meningococcal septic shock in children

OBJECTIVE

To evaluate the performance at admission to the pediatric intensive care unit (PICU) of five severity scores, two general (the Pediatric Risk of Mortality [PRISM] II and III scores) and three specific for meningococcal septic shock (Leclerc, Glasgow Meningococcal Septicemia Prognostic Score [GMSPS], and Gedde-Dahl's MOC score) in children with this condition.

DESIGN

Multicenter, retrospective, cohort study.

SETTING

The PICUs from four tertiary centers.

PATIENTS

Patients were 192 children ranging in age from 1 month to 14 yrs consecutively admitted to the participating PICUs during a period of 12 yrs and 6 months (January 1983 to June 1995), who were diagnosed with presumed or confirmed meningococcal septic shock. Patients with a length of stay <2 hrs were excluded from the study.

INTERVENTIONS

Clinical and laboratory data gathered during the first 2 hrs after admission were used to compute the scoring systems tested.

MEASUREMENTS AND MAIN RESULTS

There were 66 deaths (34%). Neisseria meningitidis was cultured from 142 (74%) children. GMSPS and PRISM II provided the best discriminative capability, as measured by the area under the receiver operating characteristic curve (SEM): 0.816 (0.036) and 0.803 (0.041), respectively. The other three scores gave lower receiver operating characteristic areas: PRISM III = 0.777 (0.043), MOC = 0.775 (0.037), and Leclerc = 0.661 (0.045). There was a statistically significant difference between the areas under the receiver operating characteristic curve of GMSPS and Leclerc (p < .01) but not between the GMSPS and the remaining three scores. All five scores presented good calibration with no significant differences between observed and predicted mortality (Hosmer-Lemeshow goodness-of-fit test).

CONCLUSIONS

The specific GMSPS and the general pediatric severity system PRISM II performed better than the other three scores, being appropriate tools to assess severity of illness at admission to the PICU in children with presumed meningococcal septic shock.

Waterhouse-Friderichsen syndrome and bilateral renal cortical necrosis in meningococcal sepsis

Waterhouse-Friderichsen syndrome and bilateral renal cortical necrosis (BRCN) are rare complications of meningococcal sepsis associated with high mortality rates. We describe a 20-year-old man who presented with a 1-day history of fever, chills, malaise, and vomiting. He collapsed in the emergency room, requiring mechanical ventilation and intravenous vasopressors for resuscitation. He was noted to be anuric, and computed tomography showed adrenal hemorrhage and BRCN. Blood cultures later confirmed Neisseria meningitidis sepsis, and a biopsy confirmed renal cortical infarction. The patient was treated aggressively with intravenous antibiotics, corticosteroids, and immunoglobulins, in addition to plasmapheresis, dialysis, and supportive measures. He recovered his adrenal function and was discharged from the hospital, but he remains dialysis dependent. To our knowledge, this is the first reported case of concomitant Waterhouse-Friderichsen syndrome and BRCN in a patient with meningococcal sepsis.

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.

Clinical features, laboratory findings and management of meningococcal meningitis in England and Wales: report of a 1997 survey. Meningococcal meningitis: 1997 survey report

OBJECTIVES

To describe the epidemiological, clinical and laboratory features of meningococcal meningitis and the effects of antibiotics on laboratory investigations under current clinical practices in England and Wales.

METHODS

Using a telephone questionnaire, information was gathered on 103 cases with a clinical diagnosis of meningococcal meningitis. Included were cases with samples submitted to the Public Health Laboratory Service (PHLS), Meningococcal Reference Unit (MRU) over a 5-month period in 1997. Tests included microscopic examination, latex agglutination and culture for Neisseria meningitidis, and at MRU confirmation of identification and characterization of isolates and meningococcal polymerase chain reaction (PCR) analysis on blood and cerebrospinal fluids (CSF).

RESULTS

Clinically 45% of the cases had predominantly meningitis and 55% had septicaemia and meningitis. Only 29% of the cases received pre-admission benzylpenicillin, and 66% were given antibiotics within an hour of hospital attendance. Microbiological confirmation was achieved in 97 cases, 46 (44%) by traditional tests and 92 (89%) by PCR assay, including some with both. The blood culture positive rate was 23 (22%), but in predominant meningitis the rate was only 10% (5/46). PCR was the sole method of confirmation in 48 cases. Seventy percent of the plasma samples referred were reactive by PCR assay, but all samples taken more than 24 h after hospital antibiotics were non-reactive. PCR-based techniques increased the overall number of cases with a serogroup identified by 44%. Lumbar punctures were performed in 73 of the cases and microbiological confirmation was achieved in 67 (92%) of these cases, compared to 26/30 without lumbar puncture (LP). Eighty-nine percent of the CSF samples referred were reactive by PCR; 50% of the CSF samples taken more than 24 h after hospital antibiotics were reactive, whilst none were positive by culture or microscopy.

CONCLUSION

Due to variable clinical manifestations, early diagnosis and treatment was difficult. Laboratory confirmation has been improved by the introduction of PCR-based techniques. Meningococcal DNA was detected by molecular methods in CSF samples taken up to 72 h after commencement of antibiotics. During this period patients could be stabilized and the chances of complications attendant upon early LP reduced. In addition to providing accurate epidemiological information, confirming the diagnosis may alter the extent and length of follow-up.

Cerebrospinal fluid pleocytosis and prognosis in invasive meningococcal disease in children

BACKGROUND

The absence of cerebrospinal fluid (CSF) pleocytosis in invasive meningococcal disease (IMD) has been associated with an increased risk of death. It is unknown whether patients who lack a cellular response to central nervous system (CNS) infection are at the same risk of adverse outcome as patients who lack CNS infection.

OBJECTIVES

To determine the frequency of presentation and outcome of three groups of children with IMD: Group 1, children with CSF pleocytosis; Group 2, children without CSF pleocytosis and with negative CSF cultures (bacteremia alone); and Group 3, children without CSF pleocytosis but with positive CSF cultures (CNS infection without CSF pleocytosis).

METHODS

We reviewed the medical records of children with IMD at four pediatric referral hospitals between 1985 and 1996. Clinical and laboratory indices and severe adverse outcomes (defined as death or limb loss) were compared in the three groups. Multivariable logistic regression analysis was performed to determine whether CNS infection without CSF pleocytosis was independently associated with adverse outcome in IMD.

RESULTS

Three hundred seventy-seven children with IMD were identified. Eighty-six patients were excluded because their CSF analysis either was not done or was unevaluable; of these patients 22 (25.6%) had an adverse outcome. Of the 291 evaluable patients 204 (70.1%) had CSF pleocytosis, 52 (17.9%) had bacteremia alone and 35 (12.0%) had CNS infection without CSF pleocytosis. Patients with CNS infection without CSF pleocytosis had significantly lower white blood cell and platelet counts and more coagulopathy than patients with bacteremia alone (P < or = 0.05) or patients with CSF pleocytosis (P < or = 0.01). The frequency of adverse outcome was 40% for patients with CNS infection without CSF pleocytosis compared with 9.6% for patients with bacteremia alone (P = 0.001) and 3.4% for patients with CSF pleocytosis (P < 0.001). CNS infection without CSF pleocytosis was independently associated with adverse outcome by multivariable logistic regression analysis (P = 0.003).

CONCLUSIONS

Approximately 30% of all children with IMD present without CSF pleocytosis. Of these patients those with CNS infection without pleocytosis are at higher risk of adverse outcome than either patients with CSF pleocytosis or patients with bacteremia alone.

A normal platelet count at admission in acute meningococcal disease does not exclude a fulminant course

OBJECTIVE

To determine the value of the platelet count at admission for the assessment of the severity of disease in acute meningococcal infections.

DESIGN

Retrospective and prospective, descriptive patient study.

SETTING

University Hospital Intensive Care Unit (ICU).

PATIENTS

All patients (n = 92) with acute meningococcal disease from 1985 to 1997, who arrived at the ICU within 12 h after hospital admission and had more than one platelet count during the first 12 h.

MEASUREMENTS AND RESULTS

After admission, platelets dropped in 95% of the patients. At admission, 2/41 (5%) of the non-hypotensive patients and 13/51 (25%) of the hypotensive patients had platelets fewer than 100 x 10(9)/l. During the following 12 h, these percentages increased to 15% and 71%, respectively. Fatalities had, at admission, a median platelet count of 111 x 10(9)/l (range, 19-302 x 10(9)/l), whereas the nadir, occurring at median 7.0 h (range, 1.3-12 h), was 31 x 10(9)/l (range, 12-67 x 10(9)/l). Plasma TNF, measured shortly after admission, correlated better with the platelet nadir (r = -0.65, p < 0.0001) than with the platelet count at admission. Similarly, serum lactate correlated better with the platelet nadir.

CONCLUSIONS

As platelets drop after admission, the use of the platelet count at admission for the assessment of the prognosis in acute meningococcal disease may be misleading. Frequently repeated platelet counts are a better tool for evaluating the severity of 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: a comparison of eight severity scores in 125 children

OBJECTIVE

To investigate the accuracy of eight different prognostic scores (Stiehm, Niklasson, Leclerc, Garlund, the MOC score, Tesero, the Glasgow Meningococcal Septicaemia Prognostic Score (GMSPS) and Tüyzüs) in the prediction of fatal outcome in meningococcal disease.

DESIGN

Combined prospective and retrospective study.

SETTING

A 175-bed pediatric department of a university hospital providing secondary care to +/- 180,000 inhabitants and serving as a referral center. The Pediatric Intensive Care (14 beds) is one of the six PICUs in the Netherlands and provides tertiary care for children under 18 years.

PATIENTS

During an 8-year period (1986-1994) 125 children (mean age 4 years, 10 months) with culture-proven meningococcal disease were studied: 34 patients presenting with meningitis, 33 patients with septic shock and 58 patients with meningitis and septic shock.

MAIN RESULTS

All eight scores discriminated above average between survivors and non-survivors, as expressed by the corresponding Receiver Operator Characteristic (ROC) curves. The area under the ROC curve (AUC) ranged from 0.74 for the Garlund score to 0.93 for the GMSPS. The GMSPS performed significantly better than its competitors, even after exclusion of the base deficit as one of the score components (AUC = 0.92). It showed above average calibration when logistically transformed into a probability of mortality, and accurately identified a subgroup of patients with no mortality. None of the scores correctly identified non-survivors.

CONCLUSION

The GMSPS is a simple score that can be reliably used for risk classification and the identification of low-risk patients.

Multivariable predictive models for adverse outcome of invasive meningococcal disease in children

For prediction of adverse outcome (AO, defined as death or limb amputation) of invasive meningococcal disease (IMD) in children, two multivariable models were derived and validated by reviewing the data in the medical records of patients with IMD, who ranged from birth to 19 years of age, at three pediatric referral hospitals between 1985 and 1990 (derivation set, n = 153, 19 AO) and between 1991 and 1994 (validation set, n = 92, 11 AO). Variables in the derivation set significantly associated with AO (p < 0.05) were entered into a logistic regression analysis. Because coagulation studies (prothrombin time, partial thromboplastin time, and serum fibrinogen concentration) were available for only 50% of patients, two analyses were performed, either excluding (model 1) or including (model 2) coagulation studies. These analyses identified an absolute neutrophil count less than 3000/mm3, poor perfusion, and a platelet count less than 150,000/mm3 (model 1), and a serum fibrinogen concentration less than 2.5 gm/L (250 mg/dl) and an absolute neutrophil count less than 3000/mm3 (model 2), as independent predictors of AO (p < 0.05). When the models were tested on the validation set, the presence of at least two of the three predictors in model 1 had a sensitivity of 82% and a specificity of 97% in predicting AO; the presence of both predictors in model 2 had a sensitivity of 89% and a specificity of 97%. These models can reliably identify patients with IMD at high risk of AO for whom consideration of novel therapies is justified.

Meningococcal disease in urban south western Sydney, 1990-1994

BACKGROUND

There has been a sustained increase in incidence of meningococcal disease throughout Australia since 1987. In south western Sydney the incidence is higher than the national rate and a cluster of cases occurred in 1991 resulting in a widespread vaccination programme.

AIMS

To investigate the clinical demographics of patients with meningococcal disease treated in south western Sydney, and to differentiate meningococcal strains to understand better the epidemiology in this urban setting. In addition, to investigate whether delays in diagnosis of meningococcal disease and institution of appropriate treatment were occurring.

METHODS

Retrospective classification of notified cases as meningitis, septicaemia, meningitis/septicaemia, and other syndromes. Clinical information recorded to establish patterns of disease, delays in diagnosis and appropriate treatment, and outcome. Microbiological classification of organisms isolated by serogroup, serotype and subtype.

RESULTS

Meningococcal disease primarily affects young children in winter months in south western Sydney, with a secondary peak of incidence in the 15-20 year old age group. 20.7% presented with meningitis only, 22.4% with septicaemia only, and 53.4% with meningitis/septicaemia. There was a delay in diagnosis and institution of appropriate treatment of more than two hours in 21/58 (36.2%) patients including three of the six who died. No patient had received a parenteral antibiotic prior to coming to hospital -18.9% had received an oral antibiotic. The use of antibiotics before diagnostic lumbar puncture decreased the number of positive CSF cultures. However, in all but one patient with negative cultures there was other microbiological evidence of meningococcal disease. The mortality rate was highest (30.8%) in patients with septicaemia only, 6.5% in patients with meningitis/septicaemia and 0% in patients with meningitis only. Serogroup C was the predominant organism in all age groups. The predominant serotype was 2b (80% of serogroup C isolates). Subtypes were more variable but P1.2 occurred in 66.7% of serogroup C strains.

CONCLUSIONS

There is a need for more education in our Health Area to improve the time taken to diagnose and institute appropriate treatment. The predominance of serogroup C is unusual in urban Australia where national data show serogroup B organisms predominate. Meningococci of phenotype C:2b:P1.2 have continued to cause disease in our Health Area for the past five years. This phenotype is uncommon in other areas of Australia.

The outcome of children admitted to intensive care with meningococcal septicaemia

OBJECTIVE

To review our experience of children with meningococcal septicaemia, and to validate, in our group, severity scores used in different populations to predict outcome.

DESIGN

Retrospective review of case notes and charts.

PATIENTS

A total of 35 children were admitted to the paediatric intensive care unit (ICU) in the Royal Children's Hospital (RCH) in the 8 years between January 1985 and December 1992 with proven meningococcal septicaemia.

RESULTS

Ages ranged from 4 months to 16 years, with a median age of 20 months. The median meningococcal score was 4 and the median PRISM score was 20, with scores above these being significantly associated with death (P < 0.0001). Thirty-two children (91%) received infusions of colloid for hypovolaemia and twenty-nine (83%) received one or more inotropic drugs. Twenty-one children (60%) required mechanical ventilation for a median of 16.5 h (range 7-574). Seven children (20%) underwent plasmapheresis. Six children (17%) underwent haemofiltration and two (6%), peritoneal dialysis. One patient received extracorporeal membrane oxygenation (ECMO) because of circulatory failure. Twenty-one children (60%) developed disseminated intravascular coagulation, renal failure and/or skin or limb necrosis. The overall survival was 66%, and all survivors are functionally normal.

CONCLUSION

The mortality from the disease remains at 34% despite the technological advances in intensive care. The PRISM and meningococcal scores are useful in predicting outcome. Novel methods of treatment (e.g., plasmapheresis or ECMO) may be valuable.

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.

Epidemiology of meningococcal infections in children in mid-southern part of Turkey

59 patients were treated for meningococcal infections in Cukurova University Faculty of Medicine, Division of Pediatric Infectious Diseases. 50.8% of patients were male, 33.9% were under two years of age and 61% were under five. 78% of patients were admitted to hospital in winter and spring time. Meningococcal meningitis (MM) was present in 39% of patients on admission, however, meningococcemia in 27.1% and meningococcemia and meningococcic meningitis (Meningococcemia + MM) in 33.9%. Fatality rate was 18.6% and no association was found between mortality and clinical type of disease (p > 0.05), but mortality ratio decreased with an increasing age (p < 0.01). No deaths occurred among the 12 patients who received i.v. penicillin treatment shortly before admitting to hospital, on the other hand 11 of 47 patients (23.4%) without such a previous treatment died.

Prognostic factors in childhood bacterial meningitis

The purpose of this study was to identify possible risk factors associated with a poor prognosis in childhood bacterial meningitis. We also analysed the influence of duration of symptoms and prehospital antibiotic therapy on outcome. Ninety-two children aged 1 month to 13.8 years were included, of whom 4 died (4.3%) and 14 (15.2%) experienced permanent neurological sequelae. Hearing impairment was the most frequent sequela and was strongly associated with the length of history. Multiple logistic regression revealed duration of symptoms > 48 h, pre-hospital seizures, peripheral vasoconstriction, < 1000 x 10(6)/l leucocytes in cerebrospinal fluid and temperature < or = 38.0 degrees C on admission as risk factors independently associated with later death or sequelae. There was no association between pre-hospital oral or parenteral antibiotic therapy and outcome. These risk factors may be of value in selecting patients for more intensive therapy and in identifying possible candidates for new treatment strategies.

Intensive blood and plasma exchange for treatment of coagulopathy in meningococcemia

Eight pediatric patients with fulminant meningococcemia, purpura, and disseminated intravascular cogulation who by multiple prognostic scoring systems were anticipated to have a poor outcome underwent intensive plasma exchange (IPE) or whole blood exchange (WBE) in addition to standard medical therapy. IPE/WBE was initiated shortly after admission with a mixture of both fresh frozen plasma and cryoprecipitate as the replacement solution. All IPE procedures were performed using a continuous flow system and a red cell prime. The mean fibrinogen level increased from 62 to 192 mg/dl, the prothrombin time (PT) decreased from a mean of 32.4 seconds to 15.1 seconds, and the mean activated partial thromboplastin time (APTT) decreased from 89.5 seconds to 40.1 seconds following completion of the initial IPE/WBE. There was a corresponding improvement in all coagulation factor levels but only slight improvement in antithrombin III (ATIII) and protein C levels. Seven of eight patients survived (87.5%) their initial presentation with the sole early death attributed to meningitis with cerebral edema. Mean fluid balance after the procedure was +10.8 +/- 5.87 cc/kg. There were no significant bleeding or cardiovascular complications during the procedure. There was no clinical or radiographic evidence of fluid overload after the procedure. This experience demonstrates that IPE/WBE may be conducted safely in critically ill, unstable pediatric patients and is effective in rapidly improving coagulopathy without fluid overload.

Prognostic factors in meningococcal disease and a new scoring system

One-hundred-and-forty patients diagnosed as having meningococcal disease have been investigated retrospectively with respect to prognostic factors. The overall mortality was 8.6%, the mortality rate of the infants under 6 months of age being higher than that of the other groups. In cases where there was no meningitis or leucocytosis, the presence of hypotension, disturbed consciousness and diffuse petechiae increased the mortality rate significantly. High fever did not have any effect on mortality. We propose a new practical and reliable scoring system for meningococcal disease for determining the influence of prognostic factors on mortality.

Rapid diagnosis of acute meningococcal infections by needle aspiration or biopsy of skin lesions

OBJECTIVES

To evaluate the usefulness of Gram staining and culture of skin lesions in patients with acute meningococcal infections.

DESIGN

Retrospective study.

SETTING

Community hospital and intensive care unit of a teaching hospital.

SUBJECTS

51 patients admitted from 1989 to 1993 with proved meningococcal infections and microbiological examination of specimens from skin lesions.

INTERVENTIONS

Needle aspiration of a skin lesion before start of antibiotic treatment in 26 patients in the community hospital; punch biopsy of skin lesion after start of antibiotic treatment in 25 patients in the teaching hospital.

MAIN OUTCOME MEASURES

Detection of meningococci by Gram staining of specimens from skin lesions according to category of infection (meningococcaemia, meningitis, meningitis with shock, or septic shock without meningitis).

RESULTS

Bacteria were detected in the specimen from haemorrhagic skin lesions by culture or Gram staining, or both in 32 (63%) patients. The sensitivity of the Gram stain was 51% and did not differ significantly from its sensitivity in detecting bacteria in cerebrospinal fluid. In meningococcal sepsis, however, a Gram stained skin lesion was significantly more sensitive (72%) than Gram stained cerebrospinal fluid (22%). In patients with meningitis skin lesions gave positive results on staining more often if shock was present. The results for punch biopsy specimens were not affected by antibiotics as Gram staining gave positive results up to 45 hours after the start of treatment and culture gave positive results up to 13 hours.

CONCLUSION

Microbiological examination of skin lesions is informative, especially in patients with sepsis and inconclusive results from cerebrospinal fluid, and may provide a diagnosis in such patients within 45 minutes. It differentiates well between meningitis with and without haemodynamic complications, and the result is not affected by previous antibiotic treatment.

Early treatment with parenteral penicillin in meningococcal disease

OBJECTIVE

To measure the effect of parenteral antibiotics given before admission to hospital on mortality and on bacteriological investigations in meningococcal disease.

DESIGN

Retrospective review of hospital notes and laboratory and public health medicine department records.

SETTING

Three health districts in south west England.

SUBJECTS

Patients with meningococcal disease in Gloucester district presenting between 1 January 1982 and 31 December 1991 (n = 190); patients with meningococcal disease in Plymouth (n = 118) and Bath (n = 73) districts presenting between 1 January 1988 and 31 December 1991 (total = 381).

MAIN OUTCOME MEASURE

Number of deaths from meningococcal disease.

RESULTS

Parenteral antibiotic given by general practitioners was associated with a substantial reduction in mortality (from 9% to 5%; relative risk 0.6, 95% confidence interval 0.2 to 1.5); patients with a rash were more likely to be given parenteral antibiotics, and mortality was further reduced (from 12% to 5%; 0.5, 0.2 to 1.4). In a district where such treatment was regularly encouraged its use increased from 5% to 40% of cases over 10 years (p = 0.00001). Treatment with parenteral antibiotics before admission made isolation of meningococci from blood and cerebrospinal fluid less likely but did not affect nasopharyngeal cultures.

CONCLUSIONS

General practitioners should carry benzylpenicillin in their emergency bags at all times and should administer it promptly, preferably intravenously, whenever meningococcal disease is suspected, unless the patient has had an anaphylactic reaction to penicillin. Specimens for culture should include a nasopharyngeal swab.

Features and outcome in meningococcal disease presenting with maculopapular rash

Sixty nine patients with meningococcal disease some of whom presented with a maculopapular rash were entered in a prospective multicentre study. The clinical and laboratory features of children presenting with maculopapular rashes were compared with those of children presenting with typical haemorrhagic rashes. Of the 69 children 26 (38%) developed maculopapular rashes; nine (13%) had a maculopapular rash only, and the remaining 17 had a mixed maculopapular-purpuric rash. Twelve of the 17 (7%) had less than 12 petechiae. Children with maculopapular rashes had significantly higher platelet counts (median 294 compared with 243 x 10(9)/l), and plasma total haemolytic complement activity (80.5 compared with 65.0 U/ml) and significantly lower Glasgow meningococcal septicaemia prognostic scores (2.5 compared with 5.5) than those with purpuric rashes on admission. There were no significant differences between the groups in mortality, white cell count or absolute neutrophil count on admission, or C reactive protein concentration. Meningococcal disease can present with a maculopapular rash alone but this does not necessarily mean that the disease is less severe.

Clinical features and complications of epidemic group A meningococcal disease in Sudanese children

The clinical presentation and laboratory features in relation to short-term outcome in 118 prospectively studied Sudanese children who were admitted with meningococcal (MC) meningitis and/or septicaemia during the 1988 group A MC epidemic in Greater Khartoum are described. Their ages ranged from 25 days to 15 years (mean: 78 months) and 42% were less than 5 years old. The male:female ratio was 1.6:1. Forty (34%) came from one of the peri-urban shanty towns encircling Greater Khartoum. A history of MC immunization (A and C vaccine) was obtained in 22%, but only five children (4.8%) had the vaccine between 4 weeks and 1 year before their illness. The commonest symptoms on admission were vomiting, neck rigidity and diarrhoea. Convulsions were significantly more frequent in children under 5 years old (p = 0.0005). Fifty-six (47%) had evidence of malnutrition. In descending order, fever, neck stiffness and Kernig's sign were the most commonly observed signs, the latter two being significantly more often detected in children older than 1 year. Twenty-four patients 20%) had disturbed consciousness. The case fatality rate was 6.3% and this was significantly higher in those presenting with meningococcal septicaemia (p = 0.0006). Other significant associations with mortality were short duration (less than 1 day) of symptoms (p = 0.0006) and clinical shock detected on admission p = 0.003). Transient complications were infrequent and permanent neurological sequelae were confined to bilateral profound sensorineural hearing loss in three children (2.9%) and hemiplegia in two 1.9%.(ABSTRACT TRUNCATED AT 250 WORDS)

Features of a large epidemic of group A meningococcal meningitis in Khartoum, Sudan in 1988

A large epidemic (February-August 1988) of group A sulphonamide resistant, clone III-1 meningococcal meningitis in Khartoum, Sudan is described. A total of 10,099 cases were admitted to treatment centers with 8,397 cases during March and April, corresponding to an annual incidence of 1,679/100,000 inhabitants during this period. The age profile showed a high morbidity in adults (31% of the cases greater than or equal to 20 years). The male dominance was marked especially in the adult cases with a proportion of 3.2:1. The epidemic started during the hot and dry season and declined when the clouds came, humidity rose, temperature fell and a mass vaccination campaign had been implemented together with other epidemic precautions. Vaccination with a combined group A/C polysaccharide vaccine had been given 4 weeks-1 year before hospitalization to 11% of the children, 80% of whom were greater than 18 months of age. The estimated case fatality rate was 6.3%. Since 47% of the cases came from periurban and rural areas, the actual mortality during the epidemic might have been higher when considering those who may have died before reaching any of the treatment centres. Fatal cases had a short history of acute illness and a septic condition. Septicaemia was rare and seen in only 3.7% of the cases, the rest had acute purulent meningitis. Hearing loss/impairment and hemiplegia was diagnosed in 2-3% of the cases. The epidemiology, based on detailed typing/subtyping and restriction enzyme patterns of meningococcal strains, was apparently associated with the Mecca outbreak in August 1987.

Antibodies to meningococci in children with meningococcal disease

Sera from 33 children with and 84 without meningococcal disease were examined for antimeningococcal IgG and IgM antibodies using an ELISA test. The meningococcal patients had a significantly higher prevalence of specific IgG antibodies (p = 0.0014), and also higher prevalence of IgM antibodies (p = 0.08; NS) than other children. These results indicate that the patients had been immunologically stimulated for some time before admission. The meningococcal patients who died had lower prevalence of specific IgM antibodies than the surviving patients, but the difference was not significant (p = 0.16). A significant increase of or high level of antimeningococcal antibodies was found in 11/12 patients examined, the last one had high levels already at admission. This type of ELISA test should therefore be helpful in the diagnosis of meningococcal disease when blood or CSF cultures are negative.

Childhood acute bacterial meningitis in the Sudan: an epidemiological, clinical and laboratory study

The aims of the present study were to document the epidemiology, clinical features and complications of childhood acute bacterial meningitis (ABM) in The Sudan during both an inter-epidemic (endemic) period (1985-1986), and the 1988 serogroup A epidemic; and to examine the phenotypic and genetic similarities and differences of Neisseria meningitidis strains isolated in The Sudan and Sweden. A new enzyme immunoassay test (Pharmacia Meningitis EIA-Test) was evaluated as a potential rapid diagnostic method for the detection of Haemophilus influenzae (HI) type b, Neisseria meningitidis (MC) and Streptococcus pneumoniae (PNC). The test was found to have good sensitivity (0.86) and specificity (0.95) in the inter-epidemic period; and to be adaptable to the field work in The Sudan during the 1988 MC epidemic. During inter-epidemic (endemic) situations in The Sudan, greater than 90% of childhood ABM was caused by one of the three organisms, HI type b, MC and PNC. HI accounted for 57% of the cases. The peak incidence (76%) of HI cases was in infants (less than 12 months) similar to the situation in other African countries. The overall case fatality ratio was 18.6%. Prospective follow-up of survivors for 3-4 years revealed that an additional 43% either died or had permanent neurological complications, the most prevalent and persistent of which was sensorineural hearing loss recorded in 22% of long term survivors. Post-meningitic children were found to have significantly lower intelligence quotients (92.3 +/- 13.9) than their sibling controls (100.7 +/- 10.2, P = 0.029). Features of the large serogroup A sulphonamide resistant MC epidemic (February-August 1988) in Khartoum are described. An estimated annual incidence of 1,679/100,000 was recorded at the peak of the epidemic. The highest attack rate was in young children less than 5 years, as in many other African countries; nevertheless, a high morbidity was observed in adults (31% of the cases greater than or equal to 20 years). The clinical features, mortality (6.3%) and short term sequelae in Sudanese children were generally within the framework described for MC disease elsewhere. Detailed analysis of MC isolates from Sudan and Sweden by characterizing their electrophoretic enzyme types, DNA restriction endonuclease pattern and outer membrane proteins, revealed that serogroup A MC clone III-1 was responsible of The Sudan epidemic in 1988 and has been the dominant serogroup A organism in Sweden since 1973. The Sudanese strains isolated prior to the epidemic (1985) were clone IV-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Endotoxin release from neisseria meningitidis. Relationship between key bacterial characteristics and meningococcal disease

A method was established in order to measure total and filtrable (CF) endotoxin in cultures of Neisseria meningitidis strains. The Limulus lysate (LAL) test gave results which paralleled those of the standard rabbit pyrogen test and of gas chromatography (GLC), concerning detection of different CF endotoxin levels. Meningococci varied in their ability to produce CF endotoxin. Cultures of similar bacterial densities, whether with a high (E+) or a low (E-) release of endotoxin in CF, had both high yields of endotoxin in sonicated culture suspensions determined by the LAL test. GLC demonstrated only small differences in total LPS contents between E+ and E- strains. This suggests that strains with similar cell wall endotoxin contents may vary in CF endotoxin. Electron microscopy revealed that E+ strains presented a high number of free, outer cell wall fragments (blebs, tubuli, membranes and aggregates of such structures) in surroundings. Few such free, small structures were found around E- strains. The amount of CF endotoxin of E+ strains was in part a function of the number of colony forming units (CFU/ml), and generally followed the growth curve. Because of its moment of appearance, and also based on electron microscopy findings, CF endotoxin appeared mainly to be released from living bacteria. The CF level of endotoxin was low or not detected at all in cultures of E- strains although their cultures reached higher mean CFU-levels than the niveaus required for the detection of CF endotoxin in the E+ strains. The E+ property was strain dependent. Meningococci isolated from CSF or blood had a significantly higher proportion of E+ strains (88.2%) and a higher CF endotoxin titre (greater than or equal to 10(3); 34.5%), than isolates from carriers (32.3% and 10.8%, respectively) (p less than 0.001 and p less than 0.001, respectively). A high mean CFU/ml in cultures seemed to be more often associated with isolates from patients than from carriers, more often with the presence than abscence of capsular polysaccharide (p less than 0.05), and more often with the presence than absence of the E+ property (p = 0.002). E+ strains were mostly serogroupable (i.e. encapsulated), regardless of source of the isolate (99% case and 80% carrier isolates). In contrast, serogroupable bacteria were not necessarily E+ when isolated from carriers (54.8%). The serogroup most apt to cause disease tended to have the highest proportion of E+ strains and the highest level of CF endotoxin.(ABSTRACT TRUNCATED AT 400 WORDS)

Serum opsonins to serogroup B meningococci in meningococcal disease

The opsonic activity to serogroup B meningococci (B:15:P1.16) was measured in sera from 101 patients with meningococcal disease using a chemiluminescence method. On admission to hospital the opsonic activity was lower in 12 patients who died than in survivors (p = 0.0007). A close association was observed between the opsonic activity and the duration of symptoms before admission, the severity of the disease, and the levels of IgG antibodies to the outer membrane complex (15:P1.16). The opsonic activity was low in 2 premorbid sera compared to healthy controls. The mean opsonic activity peaked 2 weeks after admission and was still high 3-5 years later. Meningococcal strains of different serogroups, serotypes and subtypes induced a similar increase in opsonic activity to B:15:P1.16 meningococci. No increase in activity was observed in sera from patients with meningitis and septicemia caused by other bacteria. Serum opsonins seem to be of significant importance in the host defence against serogroup B meningococci.

Group B meningococcal infection in children during an epidemic in Cape Town, South Africa

One hundred and thirteen children with meningococcal infection were studied during an epidemic caused by N. meningitidis group B. Fifteen per cent presented with only meningeal symptoms, the remainder showed signs of septicaemia or combined septicaemia and meningitis. Sixteen per cent of the children were in shock and 18% required admission to the Intensive Care Unit (ICU). The mortality was 4.4%. More than half the children were younger than 2 years old. There was no statistical association between the age or nutritional state of the children and any of our measures of severity. A short history of symptoms was more common in children who presented with septicaemia and severe illness, who needed admission to the ICU, or who died. Diagnosis was confirmed by routine bacteriological methods and counter-immuno-electrophoresis (CIE) in 104 children. Eighty-six per cent of the isolates were group B type 2. A history of recent antibiotic treatment was associated with fewer positive cultures, but detection of meningococcal antigen by CIE was not affected by this. CIE antigen detection was not reliable because of the high incidence of false-negative results.

Association between tumour necrosis factor in serum and fatal outcome in patients with meningococcal disease

Serum samples taken on admission from 79 patients with meningococcal meningitis, septicaemia, or both, were examined in a highly sensitive bioassay for tumour necrosis factor (TNF). TNF was detected in samples from 10 of 11 patients who died but from only 8 of 68 survivors. All 5 patients with serum TNF levels over 440 units/ml (corresponding to 0.1 ng/ml recombinant TNF) died.