Bacterial meningitis: newer concepts of pathophysiology and neurologic sequelae

Clinical analysis on 430 cases of infantile purulent meningitis

Background

Purulent meningitis (PM) usually caused by a variety of pyogenic infection, is a kind of central nervous system infectious disease mostly common in children. It is easily misdiagnosed and its symptoms are varied. Excessive application of broad-spectrum antibiotics results in increased sickness and death of infants and young children. In this study, clinical data of 430 cases of PM in infants were analyzed to summarize the clinical experiences so as to achieve early diagnosis and early treatment of PM.

Results

Male-to-female ratio was 1.61:1, and the median age of incidence was 0.42 years. May was the modal month of onset (11.7%). Main clinical manifestations were fever (89.3%), vomiting (67.2%), mental fatigue (62.1%), anterior fontanelle full/bulging/high tension (54.2%), convulsion (52.6%), and meningeal irritation sign (24.7%). Cerebrospinal fluid (CSF) bacterial culture was done for 420 cases, of which 1.2% cases were positive. Blood culture was done for 146 cases of which 15.1% were positive. 175 (40.7%) cases had complications, among which 133 cases (76.0%) were subdural effusion, 21 cases (12.0%) were epilepsy.

Conclusion

Infantile PM is common in Spring, and May is the modal month of onset. The CSF/blood pathogen detection rate is very low and it is difficult to find evidence of cause. Fever, vomiting, mental fatigue and anterior fontanelle full/bulging/high tension, convulsion are the main clinical manifestations on which diagnosis depends. For those children diagnosed as PM and still having recurrent fever and prominent anterior fontanelle after treatment, clinicians should consider the probability of subdural effusion and treat them with brain imaging test on time.

Infantile subdural empyema: The role of brain sonography and percutaneous subdural tapping in a resource-challenged region

Background:

This study explored the outcome of children with patent anterior fontanelles who were treated with trans-fontanelle ultrasound scan (TFUSS), which is more affordable and available than CT scan and MRI in the diagnosis of childhood intracranial pathologies and treatment of subdural empyema, in developing countries.

Patients and Methods:

Seventeen infants with post-meningitic subdural empyema, diagnosed using trans-fontanelle ultrasound alone and treated with subdural tapping over a 31-months period, were studied.

Results:

Eleven patients presented with grades II and III Bannister and William grading for level of consciousness in intracranial subdural empyema. Aspirate from 7 (41.2%) patients were sterile. The most common organisms isolated were Streptococcus faecalis 3 (17.6%), Haemophilus Influenza 2 (11.8) and Staphylococcus aureus 2 (11.8), multiple organisms were isolated in three of the patients. Ninety-four percent (94%) of the patients had good outcome. Five subjects developed hydrocephalus, one patient had a recurrence of subdural empyema, four patients had residual hemiparesis, two of the four patients had speech difficulties, while one patient (~6%) died.

Conclusion:

While CT and MRI remain the gold standard for investigating intracranial lesions, transfontanelle ultrasonography is adequate for diagnosis of infantile subdural empyema in resource-challenged areas. Percutaneous subdural tap is an affordable and effective therapy in such patients with financial challenges.

Central nervous system infection in the pediatric population

Infection of the central nervous system is a life-threatening condition in the pediatric population. Almost all agents can cause infection within the central nervous system and the extent of infection ranges from diffuse involvement of the meninges, brain, or the spinal cord to localized involvement presenting as a space-occupying lesion. Modern imaging techniques define the anatomic region infected, the evolution of the disease, and help in better management of these patients. Acute bacterial meningitis remains a major cause of mortality and long-term neurological disability. Fortunately, the incidence of infection after clean craniotomy is < 5%, but it leads to significant morbidity as well as fiscal loss. The most significant causative factor in postcraniotomy infections is postoperative CSF leak. Cerebral abscess related to organic congenital heart disease is one of the leading causes of morbidity and mortality in the pediatric population. The administration of prophylactic antibiotics is indicated for contaminated and clean-contaminated wounds.

Clinical evaluation of a group B meningococcal N-propionylated polysaccharide conjugate vaccine in adult, male volunteers

The safety and immunogenicity of a group B meningococcal vaccine, consisting of N-propionylated (NPr) B capsular polysaccharide conjugated to tetanus toxoid, was tested for the first time, in 17 healthy male volunteers aged between 18 and 40 years. Four escalating dosages of vaccine were tested and each was given as three intramuscular injections at 4-week intervals. The vaccine was well tolerated and induced only mild and transient, dose-dependent, injection-site reactions. One month after the last injection, there was no evidence of the production of autoantibodies or antibodies binding to PSA-NCAM. The vaccine induced an increase in the pre-existing titres of IgM specific to B polysaccharide and NPr B polysaccharide. Moreover, it induced IgG antibodies specific to NPr B polysaccharide, which were undetectable before vaccination. However, no functional activity of vaccine-induced antibodies was demonstrated in bactericidal assays, opsonophagocytic tests or passive protection tests.

Radiologic study of injection drug use complications

The complications of injection drug use (IDU) can lead to a wide variety of clinical problems that range from complications localized to the injection site to more disseminated disease. The radiologic workup of these problems uses multiple modalities, depending on the location and type of problem to be investigated. This article discusses and illustrates some of the local and disseminated complications that can occur after IDU.

Burden of meningitis and other severe bacterial infections of children in africa: implications for prevention

Apart from meningococcal disease in the sub-Saharan meningitis belt, the incidence and impact of life-threatening bacterial diseases in children across Africa have not been quantified. The clinical and epidemiological data on pneumococcal, Haemophilus influenzae type b (Hib), and other forms of bacterial meningitis, as well as data on other severe bacterial infections throughout the continent were scrutinized. Pneumococci were the leading causative agents of nonepidemic meningitis and other bacteremic diseases, followed by Hib. Meningococcal diseases were less common. Mortality rates associated with pneumococcal, Hib, and meningococcal meningitis were 549 (45%) of 1211 patients, 389 (29%) of 1352 patients, and 104 (8%) of 1236 patients, respectively; sequelae occurred in 50%, 40%, and 10% of cases. At 0-4 years of age, the estimated incidences of Hib meningitis and all classic Hib diseases were 70 and 100 cases per 100,000 population per year, accounting for approximately 90,000 and 120,000 cases per year, respectively. Including older age groups and, especially, nonbacteremic Hib pneumonia in the estimates of Hib disease in Africa increased the overall numbers manifold; the numbers of pneumococcal infections were even greater. The only realistic way to combat these severe infections efficaciously would be through widespread vaccination, starting with Hib conjugates.

Juxtapositioning of the temporalis muscle for intractable subdural empyema in infants

We present a case of refractory infantile subdural empyema secondary to pneumococcal meningitis. Initial treatment was with antibiotics and multiple burr hole drainage of the subdural space. As there was no significant improvement with this standard procedure, craniectomy, and juxtapositioning of the temporalis muscle was conducted and the patient recovered promptly.

The cps locus of Streptococcus suis serotype 2: genetic determinant for the synthesis of sialic acid

The capsule of S. suis serotype 2 is composed of glucose, galatose, N-acetylglucosamine, rhamnose and sialic acid. Recently, we described a major part of the cps2 locus of S. suis serotype 2. Based on sequence homology genes encoding potential glucosyl-, galactosyl-, N-acetylglucosaminyl- and rhamnosyltransferase activities could be identified. However, we did not find genes involved in the synthesis of sialic acid. Here, we describe the cloning and characterization of a remaining part of the cps2 locus. Based on the establish sequence 11 potential genes, designated orf2L, orf2M, orf2N, cps2O to cps2T, orf2U and orf2V were identified. A gene homologous to genes involved in the polymerization of the repeating oligosaccharide unit (cps2O) as well as genes involved in the synthesis of sialic acid (cps2P to cps2T) were identified. Moreover, hybridizing experiments showed that the genes involved in the sialic acid synthesis are present in S. suis serotype 1, 2, 14, 27 and 1/2. The orf2M and orf2N regions showed similarity to proteins involved in the polysaccharide biosynthesis of other Gram-positive bacteria. However, these regions seemed to be truncated or were non-functional as the result of frame-shift or point mutations. At its 3;-end the cps2 locus contained two insertional elements (orf2U and orf2V), both of which seemed to be non-functional.

Inappropriate secretion of antidiuretic hormone in acute bacterial meningitis

Sixty children aged from 1 month to 12 years (mean (SD) 3.18 (3.49) years) with acute bacterial meningitis were studied for the incidence, clinical manifestations and outcome of the inappropriate secretion of antidiuretic hormone syndrome (SIADH). Serum sodium levels and osmolality of serum and urine were estimated on admission and on days 3 and 10. SIADH was diagnosed in 22 out of 60 cases (36.7%) on admission and in six of 48 cases (12.5%) on day 3. Hyponatraemia without SIADH, attributed to vomiting and fever, was detected in seven cases (11.7%). Serum sodium levels returned to normal within 48 hours in these cases. Serum osmolality and sodium levels took longer to return to normal values in patients with SIADH. However, none of the cases showed any evidence of SIADH on the 10th day. A significant correlation with SIADH was observed in cases with evidence of severe meningeal inflammation (p < 0.001). The incidence of SIADH was highest with Streptococcus pneumoniae (75%), followed by Haemophilus influenzae (57.1%). Overall mortality was 26.7%, and mortality was significantly higher (p < 0.001) in cases with SIADH, all of whom died during the 1st 72 hours. Ten out of 22 cases (45.4%) with SIADH who survived beyond the 1st 72 hours had an uneventful course even though all of them had biochemical evidence of SIADH on the 3rd day. Mortality was quite high also in children with severe malnutrition (75%) and in those with S. pneumoniae as the aetiological organism (75%).

The impact of perioperative factors on subsequent intelligence quotient deficits in children treated for medulloblastoma/posterior fossa primitive neuroectodermal tumors

BACKGROUND

Despite success in treating children with medulloblastoma/posterior fossa primitive neuroectodermal tumor (PF PNET), some children survive with significant neurocognitive sequelae. This study was performed to understand better the significance of perioperative factors on subsequent full scale intelligence quotient (FSIQ) deterioration in these children.

METHODS

Twenty-eight children who underwent prospective and serial neurocognitive testing were studied. All children underwent surgery followed by radiotherapy with or without chemotherapy between 1983 and 1987 for medulloblastoma/PF PNET and were disease free when this study was conducted. IQ testing was performed before surgery and after the completion of radiation therapy. The clinical courses of the patients were correlated with changes in the corresponding intelligence quotients of each child. Factors correlating with neurocognitive declines were examined by chi-square or Fisher exact test analysis. Differences in mean IQs were examined by the t test. Factors found to be significant were analyzed by exact logistic regression analysis.

RESULTS

The presence of adverse factors such as neurologic deficits, meningitis, or shunt infections, or the need for repeat surgery was correlated significantly with IQ deficits after treatment. Of the subset of children with one or more of these factors, 13 of 16 (81%) sustained decreases in FSIQ; 7 of 16 (43.8%) had decreases of 20 points of more. In contrast, only 3 of 12 (25%) of the children without the factors sustained FSIQ decreases, and no child sustained a decrease of more than 13 points. The mean FSIQ change after treatment in the group with factors was -15.7 (95% confidence interval [CI]: -24.0, -8.4), and the median was -18. The mean FSIQ change in the group without factors was 4.8 (95% CI: -0.5, 10.1), and the median was 5. The difference in mean FSIQ change between the two groups was significant (P < 0.0001). On univariate analysis, both the presence of adverse factors and an age less than six years correlated with neurocognitive deficit. On regression analysis, only the presence of adverse factors was significant (odds ratio 11.53; 95% CI, 1.65-116.58; P = 0.009), whereas age was not (P = 0.27).

CONCLUSIONS

Perioperative events or complications may account for some of the neurocognitive deterioration seen in these children after treatment, especially in the very young. The occurrence of these factors is associated with a significantly greater risk of IQ deterioration. Studies of the neurocognitive effects of treatment for children with medulloblastoma/PF PNET should include an analysis of these postoperative factors.

Clinical usefulness of cerebrospinal fluid bacterial antigen studies

A retrospective chart review was performed to evaluate the effect that positive results of cerebrospinal fluid bacterial antigen tests had on the care of patients with presumed bacterial meningitis. Of 901 tests ordered, costing $26,000 per year, 29 showed positive results--and only four of these affected patient care. By using cerebrospinal fluid bacterial antigen testing only when another test does not identify an organism, or in an attempt to determine central nervous system infection late in therapy for presumed sepsis, one can greatly reduce costs with no detrimental effect on patients.

Viral meningitis. Tips to rapidly diagnose treatable causes

Viral meningitis is a common illness among children and is most often caused by enteroviruses. Diagnosis is made on the basis of clinical findings and analysis of the cerebrospinal fluid. Important conditions to consider in diagnosis are partially treated bacterial meningitis, tuberculous meningitis, fungal meningitis, other infections, and central nervous system tumor. Ruling out treatable causes early is important. Treatment of enteroviral meningitis is supportive, and the prognosis is usually very good, although significant neurologic sequelae have been reported.

Pediatric bacterial meningitis: is prior antibiotic therapy associated with an altered clinical presentation?

STUDY HYPOTHESIS

The clinical features of children treated with oral antibiotics before the diagnosis of bacterial meningitis differ from those who receive no antibiotics.

DESIGN

Retrospective case series.

SETTING

University medical center.

PARTICIPANTS

Two hundred fifty-eight children 24 months old or younger with bacterial meningitis hospitalized during a 12-year period. Eighty-three children were treated with oral antibiotics before the diagnosis of meningitis, and 175 children were not.

INTERVENTIONS

None.

METHODS

The emergency department chart and hospital records were reviewed for presenting demographic, historical, physical examination, and laboratory features. Clinical features of pretreated and untreated patients were compared.

RESULTS

Pretreated children demonstrated less frequent temperature of 38.3 C or higher, altered mental status and a longer duration of symptoms before diagnosis, with more frequent vomiting; ear, nose, and throat infections; and physician visits in the week before detection of meningitis (P less than .05 for all comparisons). There was no difference in incidence of upper respiratory symptoms, seizures, nuchal rigidity, Kernig's and Brudzinski's signs, focal neurologic signs, mortality, and length of hospitalization between groups.

CONCLUSION

Clinical features of children who have taken antibiotics before the detection of meningitis differ significantly from those who have not undergone antibiotic therapy. Physicians should be aware of these differences when evaluating young children on antibiotics for the possibility of meningitis.

Types of fluid disorder in children with bacterial meningitis

As part of a prospective study of children with bacterial meningitis we analyzed in 36 patients of our hospital the fluid balance on admission and during the first three days of treatment. On admission 10 of them (28%) had inappropriate antidiuretic hormone secretion SIADH, 10 (28%) hypo-osmolal and 10 (28%) iso-osmolal contraction. Six patients (17%) had no clear fluid disorder. The patients with SIADH had significantly lower mean serum NA+ (127 vs. 132 mEq/l, p less than 0.01) and higher mean urine Na+ (111 vs. 26 mEq/l, p less than 0.01) concentration as well as higher mean urinary Na+/K+ ratio (2.23 vs. 0.365, p less than 0.005) than the patients with hypo-osmolal contraction. They also tended to be younger and have a shorter history of fever. The patients with SIADH had a less strict fluid restriction than the patients with hypo-osmolal contraction, and their fluid balance normalized more slowly. Our findings support initial water restriction for all children with bacterial meningitis.

A comparison of central nervous lesions directly induced by Escherichia coli lipopolysaccharide in piglets, calves, rabbits and mice

To evaluate the role of endotoxin during Gram-negative bacterial meningitis, the nervous lesions of piglets, calves, rabbits and mice were compared by direct inoculation of Escherichia coli lipopolysaccharide into the central nervous system. Suppurative leptomeningitis was induced in piglets by small doses of lipopolysaccharide. Mice also had a mild suppurative inflammation in the leptomeninges. In contrast, calves showed suppurative pachymeningitis, but no lesions in the leptomeninges. Leptomeningeal inflammation was not induced in rabbits. Induction of the leptomeningitis by endotoxin was compared with sensitivity to intravenous or intraperitoneal endotoxin in these species.

[The epidemiology of meningitis caused by Streptococcus pneumoniae in a metropolitan area, Brazil, 1960-1977]

The epidemiology of meningitis caused by S. pneumoniae in the city of S. Paulo, Brazil, during the period 1960-77 is analysed. Data were obtained directly from the patients' records and registered on a pre-coded form. Cases of S. pneumoniae meningitis were confirmed by gram stain and/or culture of the cerebrospinal fluid (CSF). During the period 1960-77, there was confirmation of 1,965 cases of S. pneumoniae meningitis, giving an average rate of 1.9 per 100,000 inhabitants. Children of less than 5 years of age accounted for 52% of cases and 39% were less than 1 year old. The average rates for children below 1 year of age were 37 and 30 per 100,000 inhabitants, respectively, for the periods 1960-69 and 1970-77. The rate of incidence for the peripheral zone--2.2 per 100,000 inhabitants--was practically double the rate for the central area--1.2 per 100,000 inhabitants--in the 1960's. The age standardized rates were 1.6, 1.5 and 2.0 for central, intermediate, and peripheral zones, respectively. In the 1970's these rates were 1.4, 1.5 and 2.0. The average case fatality rate for the period was 47% which was inversely proportional to the number of CSF leucocytes at first examination. For children less than year old, the case fatality rate was 60% for the same period.

Haemophilus influenzae meningitis with prolonged hospital course

A retrospective evaluation of Haemophilus influenzae type b meningitis observed over a 2-year period documented 86 cases. Eight of these patients demonstrated an unusual clinical course characterized by persistent fever (duration: greater than 10 days), cerebrospinal fluid pleocytosis, profound meningeal enhancement on computed tomography, significant morbidity, and a prolonged hospital course. The mean age of these 8 patients was 6 months, in contrast to a mean age of 14 months for the entire group. Two patients had clinical evidence of relapse. Four of the 8 patients tested for latex particle agglutination in the cerebrospinal fluid remained positive after 10 days. All patients received antimicrobial therapy until they were afebrile for a minimum of 5 days. Subsequent neurologic examination revealed a persistent seizure disorder in 5 patients (62.5%), moderate-to-profound hearing loss in 2 (25%), mild ataxia in 1 (12.5%), and developmental delay with hydrocephalus which required shunting in 1 (12.5%). One patient had no sequelae.

[Bacterial meningitis in infants: neurological aspects]

Clinical, neurologic and laboratory aspects of bacterial meningitis in the newborn infant are critically reviewed taking into account author's experience. Pathophysiologic data on acute phase phenomena in the CNS are analysed for this purpose.

Changes in bacterial meningitis

In 1964, one of us (WHG) undertook a retrospective study of bacterial meningitis in childhood in the north east of Scotland during the period 1946-61. We have recently carried out a similar review of cases occurring during 1971-86, to compare the incidence, mortality, and bacteriological patterns. During the earlier period 285 cases occurred, a total incidence of 16.9/100,000 children per year. In the later period 274 children were affected, an annual incidence of 17.8/100,000. The overall mortality rate fell dramatically from 11.9% to 1.8%, the latter figure comparing favourably with recent published studies from Scandinavia and the United States. There was a change in the bacteriological profile in the second period with a significant rise in cases due to Haemophilus influenzae at all ages. A fall in cases of meningococcal meningitis was significant in infants under 1 year of age only. Possible reasons for the change in the bacteriological pattern are discussed.

The role of cytokines in the generation of inflammation and tissue damage in experimental gram-positive meningitis

Cytokines mediate many host responses to bacterial infections. We determined the inflammatory activities of five cytokines in the central nervous system: TNF-alpha, IL-1 alpha, IL-1 beta, macrophage inflammatory protein 1 (MIP-1), and macrophage inflammatory protein 2 (MIP-2). Using a rabbit model of meningeal inflammation, each cytokine (except IL-1 beta) induced enhanced blood brain barrier permeability, leukocytosis in cerebrospinal fluid, and brain edema. Homologous antibodies to each mediator inhibited leukocytosis and brain edema, and moderately decreased blood brain barrier permeability. In rabbits treated with anti-CD-18 antibody to render neutrophils dysfunctional for adhesion, each cytokine studied lost the ability to cause leukocytosis and brain edema. After intracisternal challenge with pneumococci, antibodies to TNF or IL-1 prevented inflammation, while anti-MIP-1 or anti-MIP-2 caused only a 2-h delay in the onset of inflammation. We suggest these cytokines have multiple inflammatory activities in the central nervous system and contribute to tissue damage during pneumococcal meningitis.

Hospital-acquired neonatal bacterial meningitis: the impacts of cefotaxime usage on mortality and of amikacin usage on incidence

All cases of bacterial meningitis in the neonatal unit at King Edward VIII Hospital, Durban for the period 1 January 1981 to 31 December 1987 were reviewed. In particular, we looked at the impact of cefotaxime on mortality rates and amikacin on the incidence of hospital-acquired Gram-negative bacillary (GNB) meningitis. Klebsiella was found to be the commonest cause of neonatal meningitis, followed by Escherichia coli and Streptococcus agalactiae. Eighty-four per cent of all cases of GNB meningitis presented more than 3 days after birth, with the vast majority being caused by gentamicin-resistant Klebsiella. A decline in the incidence of meningitis from 1.27/1000 live births in 1981 and 0.95/1000 for the period 1981-1986 to 0.22/1000 live births in 1987, with no cases of Klebsiella meningitis being seen in that year, coincided with the exclusive use of amikacin as the parenteral aminoglycoside in place of gentamicin in the unit after August 1986. The initial decline in the incidence of meningitis from 0.93/1000 in 1985 to 0.46/1000 in 1986 was attributed to the introduction in 1985 of strict hand disinfection measures to prevent cross-infection in the unit. The case mortality rate (CMR) fell from 0.65 for the period 1981-1984 to 0.42 for the period 1985-1987, and we believe this was largely a result of the introduction of cefotaxime in 1984 as first-line therapy for GNB meningitis, together with better patient care facilities.(ABSTRACT TRUNCATED AT 250 WORDS)

Definition of a bacterial virulence factor: sialylation of the group B streptococcal capsule

Sialylation of bacterial capsules has been proposed as an important virulence factor for several species of encapsulated pathogens, including group B Streptococcus. We have constructed a transposon mutant strain of type III group B Streptococcus that expresses a capsular polysaccharide differing from the wild type only in that the mutant strain's capsule lacks sialic acid. The mutant polysaccharide is antigenically identical to the capsular polysaccharide of type 14 Streptococcus pneumoniae, as predicted by the structures of the type III group B Streptococcus and S. pneumoniae polysaccharides. Loss of capsular sialic acid was associated with loss of virulence in the mutant strain in a neonatal rat model of lethal group B Streptococcus infection. These studies demonstrate directly that capsular sialic acid is a critical virulence determinant for type III group B Streptococcus and support the general hypothesis that surface sialylation aids pathogenic microorganisms in evading host defenses.

[Latex agglutination tests of the cerebrospinal fluid in bacterial meningitis: an analysis of 333 cases]

The study is based on 333 cerebrospinal fluid (CSF) samples from patients with clinical diagnosis of acute bacterial meningites. The aim of the study is a critical evaluation on latex agglutination tests in CSF for H. influenzae type b, N. meningitidis A and C, and S. pneumoniae. These tests are compared with direct examination (Gram method), and culture results. It was shown that results of the latex test in the CSF are basic for rapid diagnosis of etiological agent in a bacterial meningitis. Data on 106 CSF samples confirmed the etiology through latex tests in 98.2% for H. influenzae type b, in 15.8% for N. meningitidis A or C, in 96.8% for S. pneumoniae. Emphasis is given for evidence of antibiotic therapy previous to CSF collection, which may be responsible for the great number of negative results registered in the present series.

Cefotaxime versus penicillin-chloramphenicol in purulent meningitis: a controlled single-blind clinical trial

In a prospective, controlled, randomized single-blind clinical trial, treatment with cefotaxime (CTX) was compared with that with standard therapy (ST), which consisted of a penicillin-chloramphenicol combination with or without sulphadiazine, in 31 patients (excluding neonates) with proven bacterial meningitis. The two groups of patients were comparable in age, sex, clinical presentation and causative pathogens. The case fatality rate was 12.5% for the CTX group and 20% for the ST group, but this difference was not significant. The times taken for the cerebrospinal fluid (CSF) to become sterile and the temperature to normalize, the mean duration of treatment, complications and adverse effects were similar for the two regimens. Neurological or developmental abnormalities on follow-up were not significantly different for the two groups. It is concluded that CTX is a suitable alternative for treatment of bacterial meningitis in infants and children.

Sequelae of epidemic meningococcal meningitis in Africa

Audiological and other long-term neurological sequelae were determined in 157 cases and their controls matched for age, sex and village 6 to 12 months after an epidemic of group A meningococcal meningitis in rural West Africa. 19 cases (12.1%) and 3 controls (1.9%) had moderate or severe neurological sequelae of any type (P less than 0.001); 6 cases (3.9%) and no controls had severe or profound sensorineural hearing loss (P = 0.03). There was no difference in conductive hearing loss between cases and controls. Other cranial nerve sequelae (except visual defects) and generalized neurological and motor and co-ordination sequelae were also significantly increased in cases. Sensorineural hearing loss and other cranial nerve sequelae occurred significantly more frequently in males than in females, and co-ordination sequelae more frequently in cases aged 10 years or more than in younger cases. Sensorineural hearing loss and loss of visual acuity were found significantly more frequently in cases whose treatment was delayed for 4 d or more, compared with those who received treatment sooner.

Antibiotic therapy for severe infections in infants and children

In infants and children, drug absorption, distribution, metabolism, and excretion may differ considerably from these factors in adults; thus, differences also exist in therapeutic efficacy and toxicity of various antibiotics. Because of known toxicity, certain drugs--such as chloramphenicol in high doses, the sulfonamides, and tetracycline--should not be used in neonates. Antibiotic therapy should be modified in neonates because of biologic immaturity of organs important for the termination of drug action. Because of poor conjugation, inactivation, or excretion, the serum concentrations of many antibiotics may be higher and more prolonged in neonates than in older infants. Thus, the dosages of many antibiotics must be lower and the intervals between administration must be longer. The appearance of strains of ampicillin-resistant Haemophilus influenzae, the slow development of resistance to chloramphenicol among gram-negative and gram-positive bacteria, and the development of improved analytic methods to measure chloramphenicol have all resulted in the use of this drug in select cases of serious infection in children beyond the neonatal age. Third-generation cephalosporins have an important role in empiric treatment of pediatric bacterial meningitis because of their ability to penetrate the central nervous system and their effectiveness against ampicillin- or chloramphenicol-resistant Haemophilus strains and against many gram-negative bacteria in the Enterobacteriaceae group.

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.

Bacterial meningitis: diagnosis and initial antibiotic therapy

Despite advances in antibiotic treatment, bacterial meningitis remains a significant cause of mortality and morbidity among children. In population-based studies in the United States, the incidence of bacterial meningitis is estimated to be 4.6 to 10 per 100,000 population per year. Every year more than two thousand deaths due to bacterial meningitis are reported in the United States, most of these in previously healthy children. This article reviews diagnosis and management of this puzzling disease entity.

Cerebrospinal fluid cultures and analysis

Prompt and accurate diagnosis of acute central nervous system infections is of vital importance to the emergency physician. With the advent of modern antimicrobial therapy, the nearly uniformly fatal outcome of untreated bacterial meningitis can be reduced substantially. Proper test selection is crucial in arriving at a correct and timely diagnosis. A variety of tests are currently available for evaluation of the patient with an acute central nervous system infection. We review the current state of the art in central nervous system testing. Cost considerations and an algorithm for efficient selection of appropriate tests are presented.

Pediatric brain computed tomography

Computed tomography today provides good anatomic depiction of the brain and its gross disease processes that have as a manifestation alteration of brain density, disturbance in blood-brain barrier, or mass effect. As such, computed tomography often provides valuable diagnostic information in the appropriate clinical setting. This article reviews many of the more common pediatric central nervous system disease states that have been demonstrated more easily as a result of computed tomography.

Bacterial meningitis in the neonatal infant

Meningitis occurs more often in the neonatal period than at any other time of life. It is often the result of maternal infection and occurs more often in the prematurely born infant and in those born after prolonged rupture of the membranes. Even with early treatment, the chance for survival is limited and the likelihood of complications among survivors is high.

Subdural empyema in infant meningitis: diagnosis, therapy, and prognosis

Collections of subdural fluid during the course of infant Hemophilus influenzae meningitis have been demonstrated in the past by routine subdural taps and, more recently, by computed tomography. While the fluid is usually a benign effusion, the clinical picture and CT pattern may suggest a subdural abscess (empyema) necessitating further subdural punctures. This is a review of nine infants with subdural empyema. As reported in the literature, a remarkably good prognosis is apparent following treatment with subdural taps and systemic antibiotics. Six of seven H. influenzae cases were ampicillin-resistant in this series.

Pathomorphology and pathogenesis of bacterial meningoventriculitis of neonatal ungulates

Bacterial meningoventriculitis was studied in 26 neonatal ungulates. Preceded by a substantial bacteremia, usually due to Escherichia coli, the fibrinopurulent inflammation involved leptomeninges, choroid plexuses, and ventricle walls, but largely spared the neuraxial parenchyma. It is proposed that this surface-relatedness results from the transport of bacteria by monocytes of low bactericidal power, migrating by normal pathways to maintain significant surface populations of macrophages. The neuraxial parenchyma is spared because of its normal lack of a macrophage population. A similar pathogenesis would hold for the frequent concurrent appearance of serositis and synovitis.

Bacterial meningitis in the patient at risk: intrinsic risk factors and host defense mechanisms

Bacterial meningitis remains a relatively common disease worldwide (40,000 cases per year in the United States) and the mortality rate has not improved in over 30 years. Certain host factors increase the risk of acquiring meningitis and include: age (increased at extremes of life), male sex, low socioeconomic status (crowding), black race, recent nasopharyngeal carriage of a virulent strain, absence of specific bactericidal antibody, maternal factors at birth (neonatal disease), various immunologic defects (neonates, antibody or terminal complement component deficiency, splenectomy, and immunosuppression including the acquired immune deficiency syndrome), and certain chronic diseases (such as alcoholism, cirrhosis, and diabetes mellitus). Bacterial meningitis represents an infection in an area of impaired host resistance. The blood-brain barrier is a major protective mechanism for the central nervous system against circulating bacteria. However, once bacteria gain entry into the subarachnoid space, host defenses are inadequate. Polymorphonuclear leukocytes are at a disadvantage in the fluid medium of the cerebrospinal fluid and surface phagocytosis is inefficient. In addition, antibody and complement concentrations are low (or absent) in purulent cerebrospinal fluid early in the disease course. Functional opsonic and bactericidal activity is lacking; therefore, efficient phagocytosis of encapsulated meningeal pathogens is limited. The result is huge population densities (often 10(7) to 10(8) cfu per milliliter) of bacteria in cerebrospinal fluid. This finding suggests that bactericidal antibiotics with cerebrospinal fluid concentrations much greater than the minimal bacterial concentration of the pathogen are optimal for therapy of meningitis; this principle has been shown in experimental animal models and supported by therapeutic studies in human subjects.

[Neurological and cerebrospinal fluid evaluation in children with serogroup A meningococcal meningitis]

Our aim is to present the results obtained from the evaluation of the neurological examination as well as chemical and cytologic data from the CSF obtained at the admission and discharge of 255 children aged between zero and 12 years with a diagnosis of serogroup A meningococcal meningitis made at the Hospital Emilio Ribas in São Paulo, Brasil, in the years of 1976 and 1977. By the time of their admission, 27 patients (10,59%) showed positive neurologic findings besides meningeal signs. Seizures were the most common ones, with higher incidence in children under 13 months; ataxia, deafness, motor deficits, neuro-psychomotor involution, subdural effusions and disturbed behavior followed in that order. Subdural effusions were found only in those under 13 months. A fatal outcome was registered in eleven (4,31%) patients, of which nine died in the first 24 hours after admission. By the time of hospital discharge 14 patients (5,49%) had neurological abnormalities, deafness and ataxia being the most common ones, in the older patients. Under 13 months, developmental involution predominated. There is no need of CSF evaluation for antibiotic therapy interruption in patients with meningococcal meningitis.

875 cases of bacterial meningitis: diagnostic procedures and the impact of preadmission antibiotic therapy. Part III of a three-part series

Data on the bacteriological findings, diagnostic measures and clinical course of 875 patients with bacterial meningitis are presented. Findings from the medical records and from a follow-up questionnaire survey of 667 of these cases revealed no significant difference between patients treated with antibiotics before admission (pretreated) and those who were not treated before admission (non-pretreated) with respect to clinical condition on admission, mortality and late sequelae. Pretreatment was, however, associated with a longer duration of symptoms. Apart from cases due to Neisseria meningitidis, there were no significant differences in diagnostic findings between pretreated and non-pretreated cases. In the group of pretreated meningococcal patients, however, positive blood cultures, pleiocytosis in the cerebrospinal fluid (CSF) and positive cultures from sites other than blood and CSF were less frequent than in the non-pretreated cases.

Antigenic similarities between brain components and bacteria causing meningitis. Implications for vaccine development and pathogenesis

Glycopeptides containing polysialic acid units were isolated from human and rat brain and tested for reactivity with antibodies against meningococcal capsules. The polysialosyl glycopeptides bound specifically to horse antiserum against meningococcus group B. The interaction was inhibited by capsular polysaccharides from meningococcus group B but not groups A or C. The capsular polysaccharide of Escherichia coli K1, which is immunochemically similar to the group B polysaccharide, also inhibited binding. These findings could explain the failure to develop efficient vaccines against group B meningococcus or E coli K1 and also suggest that immunological tolerance could be a factor in the pathogenesis of meningitis caused by these bacteria. The presence of the cross-reactive brain component calls for caution in efforts to develop capsular polysaccharide vaccines from these bacteria or the proposed use of passively administered antibodies as immunotherapy of neonatal meningitis.

Cerebral perfusion pressure in central nervous system infections of infancy and childhood

Central nervous system infections may be complicated by development of severe brain edema, which can be a significant factor in mortality and morbidity. Increased intracranial pressure can cause additional damage to the central nervous system by impairment of cerebral blood flow, which is dependent on cerebral perfusion pressure. A reduction of cerebral perfusion pressure, caused by elevation of intracranial pressure, may cause cerebral ischemia. We studied cerebral perfusion pressure in 17 patients, ages 45 days to 11 years, with severe central nervous system infections and who were in deep coma. Meningitis was diagnosed in 64.7%, and encephalitis in 29.4%. The patients who survived (64.7%) did not differ significantly from those who died (36.5%) in severity of disease and maximal intracranial pressure during the course of the illness. A striking difference in minimal cerebral perfusion pressure recorded was found between survivors and nonsurvivors: all patients with minimal cerebral perfusion pressure greater than 30 mm Hg survived, whereas those with lower pressure died. In survivors, cerebral perfusion pressure could be maintained adequately by reduction of intracranial pressure, but nonsurvivors developed noncompliance of brain tissue, and cerebral perfusion pressure could not be maintained at levels that ensure adequate cerebral blood flow, resulting in cerebral ischemia and death. Continuous monitoring of mean arterial blood pressure and intracranial pressure in children with severe central nervous system infections will enable rapid diagnosis and initiation of treatment when cerebral perfusion pressure is reduced to critical levels. Such treatment might improve the prognosis.

Serial CT scans in Haemophilus influenzae meningitis of childhood

Eleven children admitted to hospital with H. influenzae meningitis had computerized tomographic head scans during the acute stage of the illness. 10 of the 11 had at least one other scan between two weeks and 30 months later. This study evaluated the changes seen in the scans in relation to the evolution of the illness, especially with reference to subdural effusions and communicating hydrocephalus. The early scans were found to have no significance in predicting clinical outcome. However, a temporary developmental lag occurred in those children with subdural effusions, transient communicating hydrocephalus, and without permanent neurological deficit.