Pneumococcal meningitis in children: relationship of antibiotic resistance to clinical characteristics and outcomes

Treatment and prevention strategies to combat pediatric pneumococcal meningitis

Pneumococcal meningitis is a severe, life-threatening infection of the nervous system affecting infants, children and adults alike. The incidence of pneumococcal meningitis in infants and children less than 2 years of age in Europe is approximately 10 out of 100,000 per year, rising to approximately 148 out of 100,000 per year in Gambian infants. The use of highly sensitive tests such as PCR may increase the likelihood of detecting the infection by 20% or more. Epidemics of serotype 1 pneumococcal meningitis in northern Ghana, have had many of the characteristics of meningococcal meningitis epidemics. Neurologic sequelae may occur in 28-63% of cases, and serotype 3 is associated with a 2.54 relative risk of death. The pathogenic process can be divided into invasion, inflammatory pathways, bacterial toxicity and damage; pneumolysin being particularly associated with apoptosis. In the future, neuroprotection may be achieved, targeting this process at all these levels. Therapeutic guidelines have been published by the Infectious Diseases Society of America. Standard empiric therapy, in those aged greater than or equal to 1 month, is a third-generation cephalosporin plus vancomycin. There is insufficient evidence relating to the use or otherwise of corticosteroids in pneumococcal meningitis to make a firm recommendation. The advent of a pneumococcal conjugate vaccine is the most powerful tool available for the prevention of pneumococcal meningitis in all parts of the world.

Clinical observation of meningitis caused by penicillin-susceptible and -non-susceptibleStreptococcus pneumoniaein Taiwanese children

AIM

To compare differences between clinical features and outcome in bacterial meningitis caused by penicillin-susceptible Streptococcus pneumoniae (PSSP) with that caused by penicillin-non-susceptible Streptococcus pneumoniae (PNSP).

METHODS

All patients <18 yrs hospitalised with pneumococcal meningitis between January 1984 and December 2002 at Chang Gung Children's Hospital, Taipei were reviewed retrospectively.

RESULTS

There were 28 PNSP (63.6%) and 16 PSSP cases of meningitis eligible for the study. The incidence of PNSP meningitis increased significantly over the 8-yr period (p = 0.007). Age <4 yrs (78.6% vs 50%), a lower initial white blood count (mean 11.7 vs 19.9 x10(9)/L), admission to the intensive care unit (70.4% vs 50%) and mortality (28.6% vs 6.3%) were more common in the PNSP group. However, the only significant finding was a lower proportion of polymorphic neutrophils in the CSF of the PNSP meningitis group (p = 0.04).

CONCLUSIONS

There was an increase in PNSP isolates from patients with meningitis over the 8-yr study period. No major differences were observed in clinical or laboratory features or outcome between the PSSP and PNSP groups.

Adjunctive daptomycin attenuates brain damage and hearing loss more efficiently than rifampin in infant rat pneumococcal meningitis

Exacerbation of cerebrospinal fluid (CSF) inflammation in response to bacteriolysis by beta-lactam antibiotics contributes to brain damage and neurological sequelae in bacterial meningitis. Daptomycin, a nonlytic antibiotic acting on Gram-positive bacteria, lessens inflammation and brain injury compared to ceftriaxone. With a view to a clinical application for pediatric bacterial meningitis, we investigated the effect of combining daptomycin or rifampin with ceftriaxone in an infant rat pneumococcal meningitis model. Eleven-day-old Wistar rats with pneumococcal meningitis were randomized to treatment starting at 18 h after infection with (i) ceftriaxone (100 mg/kg of body weight, subcutaneously [s.c.], twice a day [b.i.d.]), (ii) daptomycin (10 mg/kg, s.c., daily) followed 15 min later by ceftriaxone, or (iii) rifampin (20 mg/kg, intraperitoneally [i.p.], b.i.d.) followed 15 min later by ceftriaxone. CSF was sampled at 6 and 22 h after the initiation of therapy and was assessed for concentrations of defined chemokines and cytokines. Brain damage was quantified by histomorphometry at 40 h after infection and hearing loss was assessed at 3 weeks after infection. Daptomycin plus ceftriaxone versus ceftriaxone significantly (P < 0.04) lowered CSF concentrations of monocyte chemoattractant protein 1 (MCP-1), MIP-1α, and interleukin 6 (IL-6) at 6 h and MIP-1α, IL-6, and IL-10 at 22 h after initiation of therapy, led to significantly (P < 0.01) less apoptosis, and significantly (P < 0.01) improved hearing capacity. While rifampin plus ceftriaxone versus ceftriaxone also led to lower CSF inflammation (P < 0.02 for IL-6 at 6 h), it had no significant effect on apoptosis and hearing capacity. Adjuvant daptomycin could therefore offer added benefits for the treatment of pediatric pneumococcal meningitis.

Clinical outcome of pneumococcal meningitis during the emergence of pencillin-resistant Streptococcus pneumoniae: an observational study

Background

Prior to the availability of generic third-generation cephalosporins, penicillins were widely used for treatment of pneumococcal meningitis in developing countries despite concerns about rising levels of penicillin resistance among pneumococcal isolates. We examined the impact of penicillin resistance on outcomes of pneumococcal meningitis over a ten year period in an infectious diseases hospital in Brazil.

Methods

Clinical presentation, antimicrobial therapy and outcomes were reviewed for 548 patients with culture-confirmed pneumococcal meningitis from December, 1995, to November, 2005. Pneumococcal isolates from meningitis patients were defined as penicillin-resistant if Minimum Inhibitory Concentrations for penicillin were greater than 0.06 μg/ml. Proportional hazards regression was used to identify risk factors for fatal outcomes.

Results

During the ten-year period, ceftriaxone replaced ampicillin as first-line therapy for suspected bacterial meningitis. In hospital case-fatality for pneumococcal meningitis was 37%. Of 548 pneumococcal isolates from meningitis cases, 92 (17%) were resistant to penicillin. After controlling for age and severity of disease at admission, penicillin resistance was associated with higher case-fatality (Hazard Ratio [HR], 1.62; 95% Confidence Interval [CI], 1.08-2.43). Penicillin-resistance remained associated with higher case-fatality when initial therapy included ceftriaxone (HR, 1.68; 95% CI 1.02-2.76).

Conclusions

Findings support the use of third generation cephalosporin antibiotics for treatment of suspected pneumococcal meningitis even at low prevalence of pneumococcal resistance to penicillins.

[First and second line antibiotic therapy for bacterial meningitis in infants and children]

The potential severity of meningitis in infants and children requires an optimized initial empirical therapy, mainly based on direct cerebro spinal fluid (CSF) examination, and rapid therapeutic adaptation according to bacterial identification and susceptibility. Combination treatment including cefotaxim (300 mg/kg per day) or ceftriaxone (100mg/kg per day) and vancomycine (60 mg/kg per day) remains the standard first line if pneumococcal meningitis cannot be ruled out. A simple treatment with third generation cephalosporin can be used for Neisseria meningitidis or Haemophilus influenzae meningitis, aminoglycosides must be added in case of Enterobacteriacae, mainly before 3 months of age. Second line antibiotic therapy is adapted according to the clinical and bacteriological response on Day 2. When the minimal inhibitory concentration (MIC) of pneumococcal strain is less than 0.5mg/L, third generation cephalosporin should be continued alone for a total of 10 days. In other cases, a second lumbar puncture is necessary and the initial regimen, with or without rifampicin combination, should be used for 14 days. Amoxicillin during 3 weeks, associated with gentamycin or cotrimoxazole is recommended for listeriosis.

Pneumococcal meningitis in Taiwanese children: emphasis on clinical outcomes and prognostic factors

Pneumococcal meningitis causes high morbidity or mortality in childhood despite the progress in medicine. Children with pneumococcal meningitis were identified and retrospectively reviewed. Forty-nine children were eligible, with mortality in 24.5% of all and neurological sequelae in 40.5% of survivors. In the analysis of clinical profiles, ventilator support (p = 0.001), septic shock (p < 0.001), multiple organ failure (p < 0.001) and lower cerebrospinal fluid (CSF) leukocyte count (p = 0.001) were more frequently found in non-survivors. Besides, CSF protein (p = 0.006) was higher in survivors with neurological sequelae. Initial dexamethasone usage and disease severity did not affect the occurrence of neurological sequelae. Multivariate logistic regression analysis revealed that CSF leukocyte count <or=200 mm(-3) (p = 0.013) and protein level >or=330 g l(-1) (p = 0.022) were significantly risk factors associated with poor outcomes, and physicians should be cautious if such conditions occur.

Lumbar puncture and brain herniation in acute bacterial meningitis: a review

There has been controversy regarding the risk of cerebral herniation caused by a lumbar puncture (LP) in acute bacterial meningitis (ABM). This review discusses in detail the issues involved in this controversy. Cerebral herniation occurs in about 5% of patients with ABM, accounting for about 30% of the mortality. In many reports, LP is temporally strongly associated with this event of herniation and is most likely causative based on pathophysiologic arguments. Although a computed tomography (CT) scan of the head is useful to find contraindications to an LP, a normal CT scan in ABM does not mean that an LP is safe. Clinical signs of "impending" herniation are the best predictors of when to delay an LP because of the risk of precipitating herniation, even with a normal CT scan. Some of these clinical signs to be considered are deteriorating level of consciousness (particularly to a Glasgow Coma Scale of <or= 11), brainstem signs (including pupillary changes, posturing, or irregular respirations), and a very recent seizure. The risk of not doing an LP when it is contraindicated because of concern of the risk of herniation is extremely small. In those considered high risk for herniation, interventions to control intracranial pressure, such as attention to airway, breathing, and circulation, with a mannitol infusion and antibiotics started, should be the priorities, followed by an urgent CT scan and not an LP.

Mortalité par méningites à pneumocoque chez l'enfant. Facteurs pronostiques à propos d'une série de 73 observations

OBJECTIVE

Despite advances in antibiotic therapy strategies and pediatric intensive care, prognosis of Streptococcus pneumoniae meningitis remains very poor. To determine the factors associated with hospital mortality of children with pneumococcal meningitis.

METHODS

We conducted a retrospective study of 73 cases of childhood pneumococcal meningitis admitted in 4 teaching hospitals in the center of Tunisia during a 8-year period (1995-2002).

RESULTS

Hospital mortality was 13.7% (10 of 71 patients), and neurologic sequela were observed in 34.5% of survivors. Based on univariable analysis, five variables were associated with the outcome: Pediatric Risk of Mortality score (p < 0.001), coma (p=0.0009), use of mechanical ventilation (p=0.0001), convulsions (p = 0.0449), and shock (p=0.0085). In multivariable analysis, only 2 factors were independently associated with in-hospital mortality: Pediatric Risk of Mortality score and the use of mechanical ventilation. 11.8% of pneumococcal isolates were intermediate and resistant to penicillin. Non-susceptible pneumococcus strains to penicillin and the use of steroids were not associated significantly with the mortality rate.

CONCLUSIONS

Pneumococcal meningitis remains a devastating childhood disease. Two variables were independently associated with the in-hospital death in our series (high Pediatric Risk of Mortality score, and the use of mechanical ventilation). According to these data we may recommend the inclusion of vaccination against streptococcus pneumonia in the children's immunization program in Tunisia.

Early vancomycin therapy and adverse outcomes in children with pneumococcal meningitis

BACKGROUND

Experts recommend that children with suspected pneumococcal meningitis should empirically receive combination therapy with vancomycin plus either ceftriaxone or cefotaxime. The relationship between timing of the first dose of vancomycin relative to other antibiotics and outcome in these children, however, has not been addressed.

METHODS

Medical records of children with pneumococcal meningitis at a single institution from 1991-2001 were retrospectively reviewed. Vancomycin start time was defined as the number of hours from initiation of cefotaxime or ceftriaxone therapy until the administration of vancomycin therapy. Outcome variables were death, sensorineural hearing loss, and other neurologic deficits at discharge. Associations between independent variables and outcome variables were assessed in univariate and multiple logistic regression analyses.

RESULTS

Of 114 subjects, 109 received empiric vancomycin therapy in combination with cefotaxime or ceftriaxone. Ten subjects (9%) died, whereas 37 (55%) of 67 survivors who underwent audiometry had documented hearing loss, and 14 (13%) of 104 survivors were discharged with other neurologic deficits. Subjects with hearing loss had a significantly shorter median vancomycin start time than did those with normal hearing (<1 vs 4 hours). Vancomycin start time was not significantly associated with death or other neurologic deficits in univariate or multivariate analyses. Multiple logistic regression revealed that hearing loss was independently associated with vancomycin start time <2 hours, blood leukocyte count <15000/microL, and cerebrospinal fluid glucose concentration <30 mg/dL.

CONCLUSIONS

Early empiric vancomycin therapy was not clinically beneficial in children with pneumococcal meningitis but was associated with a substantially increased risk of hearing loss. It may be prudent to consider delaying the first dose of vancomycin therapy until > or =2 hours after the first dose of parenteral cephalosporin in children beginning therapy for suspected or confirmed pneumococcal meningitis.

Risk factors for mortality in Paraguayan children with pneumococcal bacterial meningitis

BACKGROUND

Over the last decade Streptococcus pneumoniae has emerged as the most common bacterial pathogen for meningitis in all age groups, beyond the neonatal period.

OBJECTIVE

To determine the epidemiological and clinical characteristics; and risk factors for mortality of pneumoccocal meningitis in children in a developing transitional country.

MATERIALS AND METHODS

A retrospective study that included patients<15 years of age admitted at the Instituto de Medicina Tropical of Paraguay, from January 1990 until December 2003 with the diagnosis of bacterial meningitis caused by S. pneumoniae. Clinical and laboratory data were collected and analysed in order to identify risk factors associated with morbidity and mortality outcomes of this infection.

RESULTS

Seventy-two patients (between the ages of 35 days and 14 years) were identified. Forty-two per cent of patients had seizures prior to or at the time of admission, 36% were admitted in a comatose state, and 19% with shock. Mortality was 33% (24/72), and 18% of the survivors (11/60) developed severe sequelae. Upon admission, the following variables were strongly correlated with mortality: age<12 months (P=0.007), the presence of seizures (P=0.0001) or development of seizures 48 h after admission (P=0.01), a cerebrospinal fluid (CSF) glucose level of <10 mg/dl (P=0.01), CSF albumin>200 mg/dl (P=0.0003), an absolute blood neutrophil count<2000/mm3 (P=0.006) and a haemoglobin value of <9 g/dl (P=0.0001).

CONCLUSIONS

This study confirms the high morbidity and mortality associated with S. pneumoniae meningitis in Paraguay. Certain clinical parameters and laboratory findings in blood and CSF at the time of admission could be used as predictors for mortality or severe sequelae among survivors.

Pneumococcal meningitis in a pediatric intensive care unit: prognostic factors in a series of 49 children

BACKGROUND

Despite advances in antibiotic therapy strategies and in pediatric intensive care, prognosis of Streptococcus pneumoniae meningitis remains very poor. However, few prognostic studies have been published, especially in pediatric populations.

METHODS

We conducted a prognostic study to determine the factors associated with hospital mortality of 49 children admitted in a single pediatric intensive care unit during a 12-yr period (1990-2002).

RESULTS

Hospital mortality was 49% (24 of 49 patients), and neurologic sequels were observed in 47% of survivors. Among them, 90% had permanent sensory deafness. Based on univariable analyses, seven variables were associated with the outcome: Pediatric Risk of Mortality II score (p = .000005), Glasgow Coma Score of >8 (p = .001), use of mechanical ventilation (p = .001), platelet count (p = .007), white blood cells count (p = .002), cerebrospinal fluid glucose level (p = .02), and lack of corticosteroids use (p = .02). In multivariable analysis, only three factors were independently associated with in-hospital mortality: Pediatric Risk of Mortality II score (hazard ratio, 1.13; 95% confidence interval, 1.06-1.20; p = .0002), platelets count of >200 x 10/L (hazard ratio, 0.25; 95% confidence interval, 0.08-0.81; p = .021) and white blood cell count above 5 x 10/L (hazard ratio, 0.31; 95% confidence interval, 0.11-0.87; p = .026).

CONCLUSIONS

S. pneumoniae meningitis remains a devastating childhood disease in developed countries. Three variables were independently associated with the in-hospital death in our series-high Pediatric Risk of Mortality II score, low white blood cells count, and low platelet count-reflecting the main importance of severe sepsis and neurologic presentation in establishing the prognosis of these patients.

A population based study of the impact of corticosteroid therapy and delayed diagnosis on the outcome of childhood pneumococcal meningitis

BACKGROUND

Despite an extensive literature, the impact of both adjunctive steroid therapy and delayed diagnosis on the outcome of childhood pneumococcal meningitis is controversial.

AIM

To determine the independent contribution of corticosteroid therapy and delayed diagnosis on the outcome of childhood pneumococcal meningitis in a representative population with good access to medical services.

METHODS

Data were obtained from laboratories and hospital records to assemble a population register in Sydney, Australia, 1994-99. Follow up questionnaires were completed by attending physicians.

RESULTS

A total of 122 cases of pneumococcal meningitis aged 0-14 years were identified. Almost 50% of 120 children with available records either died (n = 15) or had permanent neurological impairment (n = 39). Early use (before or with parenteral antibiotics) of corticosteroids protected against death or severe morbidity (adjusted OR 0.21, 95% CI 0.05 to 0.77). Delayed diagnosis was associated with increased morbidity in survivors (OR 3.4, 95% CI 1.03 to 11.4) but not with increased mortality.

CONCLUSION

In a population with good access to health care and after adjusting for other known prognostic variables, early recognition of pneumococcal meningitis and treatment with adjunctive dexamethasone significantly improves outcomes. These data add to those from randomised controlled trials. Implementation requires development of protocols and guidelines for use in emergency departments.

Reference group choice and antibiotic resistance outcomes

Two types of cohort studies examining patients infected with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) were contrasted, using different reference groups. Cases were compared to uninfected patients and patients infected with the corresponding, susceptible organism. VRE and MRSA were associated with adverse outcomes. The effect was greater when uninfected control patients were used.

Antibiotic resistant infections due to Streptococcus pneumoniae: impact on therapeutic options and clinical outcome

PURPOSE OF REVIEW

Streptococcus pneumoniae is a major cause of morbidity and mortality in the pediatric population. The development of increasing resistance to multiple classes of antibiotics is making treatment of infections due to this organism much more difficult. The ultimate impact of high-level antibiotic resistance on therapeutic options and clinical outcomes of various pneumococcal infections is unclear and remains to be determined. Use of the conjugate pneumococcal vaccine has markedly decreased invasive pneumococcal disease in children under 5 years of age; however, its impact on decreasing antibiotic resistance is currently unknown.

RECENT FINDINGS

Studies suggest that response to therapy and clinical outcome of infections due to pneumococcal isolates with intermediate resistance to the beta-lactam antibiotics is no different from that of infections due to susceptible isolates. However, evidence is accumulating that infections caused by highly resistant pneumococcal isolates are associated with higher rates of treatment failure and mortality than infections due to susceptible strains.

SUMMARY

Use of a conjugate pneumococcal vaccine in conjunction with educational intervention programs that promote appropriate and judicious antibiotic use is a safe and effective means of decreasing the prevalence of pneumococcal disease in the pediatric population, decreasing the use of broad-spectrum antibiotic agents and potentially decreasing the amount of antibiotic resistance currently being seen.

[Pneumococcal meningitis and resistant bacteria]

The emergence of resistance has imposed a modification of the protocols for the treatment of Streptococcus pneumoniae (S pneumoniae) bacterial meningitis. Amoxicillin is no longer adapted. As resistance to C3G appeared, a synergistic effect of an association C3G + vancomycine was demonstrated. Thus currently this association should be recommended in any case of meningitis supposedly due to S pneumoniae. The treatment is then modified according to the evolution and the minimal inhibition concentration (MIC) of the bacteria. The strains carrying a high level of resistance to cephalosporin (MIC > or = 4 micrograms ml-1) or tolerant to vancomycine may cause a therapeutic failure despite an increase of the dosage of cephalosporin. Rifampicin, fosfomycine, or imipenem (despite its risk of convulsions), may represent alternative options, as long as we do not have safe quinolones active on resistant strains of S. pneumoniae. Dexamethasone has been formerly implicated in the relapse of pneumococcal meningitis. Furthermore, its use is questionable since no evidence of a therapeutic benefit has been clearly demonstrated. As a consequence of the resistance phenomenon the management of S. pneumoniae meningitis must include particular measures: at least resistance to penicillin must be checked by the oxacilline disk and the MIC to C3G must be measured by E test; aCSF sample should be obtained between 36 and 48 hours following the beginning of the treatment to check its sterilization. All recent studies have shown a similar prognosis of meningitis due to resistant S. pneumoniae as compared to those due to sensitive strains. However, these data should be interpreted with caution since in these studies, pneumococcus resistant to cephalosporin (the real problem) are not separated from those only resistant to penicillin. Furthermore, presently, the incidence of strains highly resistant to cephalosporin is still low. The new conjugated vaccine against pneumococcus should change the situation if its ability to prevent the circulation of resistant strains is confirmed.

Outcome of penicillin-nonsusceptible Streptococcus pneumoniae meningitis: a nested case-control study

BACKGROUND

There are few data comparing the clinical features, management and outcome of penicillin-nonsusceptible (PNSP) meningitis patients with penicillin-susceptible (PSSP) meningitis patients.

METHODS

We performed a retrospective, nested case-control study comparing cases with PNSP meningitis with controls with PSSP meningitis obtained from the Immunization Monitoring Program, Active (IMPACT) cross-Canada surveillance study of invasive infections.

RESULTS

There were 30 PNSP meningitis cases (10.1% of total) and 45 PSSP meningitis controls from 6 centers obtained from 297 meningitis cases in the IMPACT database from 1991 through 1999. Vancomycin was used for empiric therapy in no cases and controls in 1991 to 1993 and in all cases in 1999. A third generation cephalosporin was used in 93.3% of confirmed PNSP cases, and 70.0% also received vancomycin and/or rifampin. Penicillin was used in 66.7% of confirmed PSSP cases. PNSP cases were more likely than PSSP controls to have a second lumbar puncture (odds ratio, 4.1; P= 0.01). PNSP cases were treated with intravenous antibiotics for an average of 15.6 days compared with 12.3 days for controls ( P= 0.04). Among PNSP cases, those patients who did not receive empiric vancomycin were treated with intravenous antibiotics for an average of 18.5 days compared with 12.0 days for those who did receive empiric vancomycin ( P= 0.04). The overall mortality was 5.3%, and 36.6% of survivors had >or=1 neurologic sequelae, including 19.7% with hearing loss. In multivariate statistical models, PNSP was not a risk factor for intensive care unit admission or neurologic sequelae.

CONCLUSIONS

Management of suspected bacterial meningitis and confirmed meningitis in Canadian children changed in the past decade. Treatment of PNSP meningitis is significantly different from that for PSSP meningitis. These changes have occurred in response to the emergence of PNSP in Canada. Neurologic sequelae remain common after meningitis, but there are no differences between PNSP cases and PSSP cases.

Management of pneumococcal meningitis

During the past decade antibiotic resistance among Streptococcus pneumoniae isolates has complicated the empiric approach to and treatment of pneumococcal meningitis. Standard empiric therapy for suspected bacterial meningitis for infants and children older than 1 month of age is the combination of cefotaxime or ceftriaxone and vancomycin. Treatment is modified after antimicrobial susceptibilities are available. The optimal treatment of pneumococcal meningitis caused by strains with a cefotaxime/ceftriaxone MIC >2 microg/ml is unknown, although the addition of rifampin to the initial combination is generally recommended. The role of newer agents including quinolones is under investigation. Dexamethasone remains the only adjunctive antiinflammatory therapy to consider. The empiric approach to the child with suspected bacterial meningitis who has received the pneumococcal conjugate vaccine currently remains unchanged.