Mortality indicators in pneumococcal meningitis: therapeutic implications.

BACKGROUND: The aim of this study was to delineate mortality indicators in pneumococcal meningitis with special emphasis on therapeutic implications. METHODS: This retrospective, multicenter cohort study involved a 15-year period (1998-2012). Culture-positive cases (n=306) were included solely from 38 centers. RESULTS: Fifty-eight patients received ceftriaxone plus vancomycin empirically. The rest were given a third-generation cephalosporin alone. Overall, 246 (79.1%) isolates were found to be penicillin-susceptible, 38 (12.2%) strains were penicillin-resistant, and 22 (7.1%) were oxacillin-resistant (without further minimum inhibitory concentration testing for penicillin). Being a critical case (odds ratio (OR) 7.089, 95% confidence interval (CI) 3.230-15.557) and age over 50 years (OR 3.908, 95% CI 1.820-8.390) were independent predictors of mortality, while infection with a penicillin-susceptible isolate (OR 0.441, 95% CI 0.195-0.996) was found to be protective. Empirical vancomycin use did not provide significant benefit (OR 2.159, 95% CI 0.949-4.912). CONCLUSIONS: Ceftriaxone alone is not adequate in the management of pneumococcal meningitis due to penicillin-resistant pneumococci, which is a major concern worldwide. Although vancomycin showed a trend towards improving the prognosis of pneumococcal meningitis, significant correlation in statistical terms could not be established in this study. Thus, further studies are needed for the optimization of pneumococcal meningitis treatment.

Doxycycline reduces mortality and injury to the brain and cochlea in experimental pneumococcal meningitis.

Bacterial meningitis is characterized by an inflammatory reaction to the invading pathogens that can ultimately lead to sensorineural hearing loss, permanent brain injury, or death. The matrix metalloproteinases (MMPs) and tumor necrosis factor alpha-converting enzyme (TACE) are key mediators that promote inflammation, blood-brain barrier disruption, and brain injury in bacterial meningitis. Doxycycline is a clinically used antibiotic with anti-inflammatory effects that lead to reduced cytokine release and the inhibition of MMPs. Here, doxycycline inhibited TACE with a 50% inhibitory dose of 74 microM in vitro and reduced the amount of tumor necrosis factor alpha released into the cerebrospinal fluid by 90% in vivo. In an infant rat model of pneumococcal meningitis, a single dose of doxycycline (30 mg/kg) given as adjuvant therapy in addition to ceftriaxone 18 h after infection significantly reduced the mortality, the blood-brain barrier disruption, and the extent of cortical brain injury. Adjuvant doxycycline (30 mg/kg given subcutaneously once daily for 4 days) also attenuated hearing loss, as assessed by auditory brainstem response audiometry, and neuronal death in the cochlear spiral ganglion at 3 weeks after infection. Thus, doxycycline, probably as a result of its anti-inflammatory properties, had broad beneficial effects in the brain and the cochlea and improved survival in this model of pneumococcal meningitis in infant rats.

Moxifloxacin in experimental Streptococcus pneumoniae cerebritis and meningitis.

Rifampin, a protein synthesis inhibitor, reduced mortality in a mouse model of meningitis compared to bacteriolytic cephalosporin standard therapy. To assess whether moxifloxacin (known to cause a less rapid bacteriolysis than cephalosporins) can similarly reduce mortality, mice infected with Streptococcus pneumoniae by deep intracerebral injection were treated subcutaneously with either 200 mg/kg of moxifloxacin or ceftriaxone every 8 hours for 5 days (n = 49 each). They were then observed for an additional 8 days. Overall mortalities were 35 and 29 in moxifloxacin- and ceftriaxone-treated mice, respectively (p = 0.29). Kaplan-Meier survival analysis also revealed no statistically significant differences (p = 0.32). Moxifloxacin failed to reduce mortality compared to cephalosporin standard therapy.

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

BACKGROUND: The relationship of antibiotic susceptibility to clinical outcome in children with pneumococcal meningitis is uncertain. Previous studies have been limited by inclusion of relatively few patients infected with nonsusceptible pneumococci and inconsistent use of empiric vancomycin. METHODS: Medical records of 86 children with culture-confirmed pneumococcal meningitis at a single institution from October, 1991, to October, 1999, were retrospectively reviewed, and differences in presentation and outcome based on antibiotic susceptibility of pneumococcal isolates were assessed. RESULTS: Of 86 isolates 34 were nonsusceptible to penicillin (12 resistant). Of 60 isolates for which cefotaxime susceptibility data were available, 17 were nonsusceptible (12 resistant). Antibiotic susceptibility was not significantly associated with death, intensive care unit admission, mechanical ventilation, focal neurologic deficits, seizures, secondary fever, abnormal neuroimaging studies or hospital days. Children with penicillin-resistant isolates had significantly higher median blood leukocyte counts (24,100/microliter vs. 15,700/microliter, P = 0.03) and lower median CSF protein concentrations (85 mg/dl vs. 219 mg/dl, P = 0.04), were more likely to have a CSF glucose concentration of > or = 50 mg/dl (7 of 11 vs. 15 of 68, P = 0.009) and had lower rates of sensorineural hearing loss (1 of 8 vs. 25 of 40, P = 0.02) than children with isolates that were not resistant to penicillin. Children with cefotaxime-nonsusceptible isolates had an increased median duration of primary fever compared with those with nonsusceptible strains (6 days vs. 3.5 days, P = 0.02). CONCLUSIONS: In children with pneumococcal meningitis, penicillin resistance was associated with a reduced risk of hearing loss, while cefotaxime resistance was associated with a longer duration of fever. Other outcome measures were not significantly influenced by the antibiotic susceptibility of pneumococcal isolates.

[Treatment and outcome of pneumococcal meningitis in adults. Study of a recent series of 70 episodes]. / Terapéutica y evolución de la meningitis neumocócica en el adulto. Estudio de una serie reciente de 70 episodios.

BACKGROUND: Pneumococcal meningitis (PM) is an infection with high morbidity and mortality. The aim of this study was to evaluate the most relevant clinical, epidemiologic and evolutive characteristics of a recent series of adult patients with this disease. METHODS: Over a period of 10 years all the patients with PM diagnosed by isolation of this microorganism in the cerebrospinal fluid (CSF) were evaluated from a clinical, therapeutic and evolutive points of view. The impact of the new therapies in the disease and the variables associated with mortality were analyzed. RESULTS: Seventy episodes of PM were diagnosed, 60% being found in patients over the age of 50 years. The male/female relationship was 2/1. Fifty-three percent of the patients had other underlying diseases. Acute otitis media (AOM) was the source in 34% of the cases, in 11% the patients had a fistula of CSF and in 9% a pneumonia. At the time of diagnosis 74% of the patients had some degree of reduction in the level of consciousness and in 40% of the episodes the presence of neurologic local manifestations were observed. A decrease in sensitivity to penicillin was observed in 33% of the microorganisms isolated. Third generation cephalosporins were used as initial treatment in 57 episodes and penicillin in other 11 episodes. Adjuvant treatment with dexamethasone, mannitol and/or diphenylhydantoin was administered in 54% of the patients. Overall mortality was 23%: the factors associated with an unfavourable evolution were the existence of underlying disease, deep alteration in the level of consciousness at the time of diagnosis, the coexistence of pneumonia and the absence of adjuvant therapy. CONCLUSIONS: Mortality in pneumococcal meningitis is high. The most relevant risk factor is the initial degree of consciousness. Adjuvant therapies probably determine a reduction in the rate of mortality.