Brain Abscess Caused by Oral Cavity Bacteria: A Nationwide, Population-based Cohort Study.

BACKGROUND: Oral cavity bacteria are the most frequent etiology of brain abscess. Yet, data on the clinical presentation and outcome are scarce. METHODS: We performed a nationwide, population-based study comprising all adults (aged ≥18 years) with brain abscess due to oral cavity bacteria in Denmark from 2007 through 2020. Prognostic factors for unfavorable outcome (Glasgow outcome scale, 1-4) were examined using modified Poisson regression to compute adjusted relative risks (RRs) with 95% confidence intervals (CIs). RESULTS: Among 287 identified patients, the median age was 58 years (interquartile range, 47-66), and 96 of 287 (33%) were female. Preexisting functional impairment was absent or mild in 253 of 280 (90%), and risk factors for brain abscess included immunocompromise in 95 of 287 (33%), dental infection in 68 of 287 (24%), and ear-nose-throat infection in 33 of 287 (12%). Overall, a neurological deficit was present in 246 of 276 (86%) and in combination with headache and fever in 64 of 287 (22%). Identified microorganisms were primarily the Streptococcus anginosus group, Fusobacterium, Actinomyces, and Aggregatibacter spp., and 117 of 287 (41%) were polymicrobial. Unfavorable outcome occurred in 92 of 246 (37%) at 6 months after discharge and was associated with antibiotics before neurosurgery (RR, 3.28; 95% CI, 1.53-7.04), rupture (RR, 1.89; 95% CI, 1.34-2.65), and immunocompromise (RR, 1.80; 95% CI, 1.29-2.51), but not with specific targeted antibiotic regimens. Identified dental infection was associated with favorable prognosis (RR, 0.58; 95% CI, .36-.93). CONCLUSIONS: Brain abscess due to oral cavity bacteria often occurred in previously healthy individuals without predisposing dental infections. Important risk factors for unfavorable outcome were rupture and immunocompromise. However, outcome was not associated with specific antibiotic regimens supporting carbapenem-sparing strategies.

Clinical features and prognostic factors in adults with brain abscess.

Studies on brain abscess are hampered by single-centre design with limited sample size and incomplete follow-up. Thus, robust analyses on clinical prognostic factors remain scarce. This Danish nationwide, population-based cohort study included clinical details of all adults (≥18 years) diagnosed with brain abscess in the Danish National Patient Registry from 2007 through 2014 and the prospective clinical database of the Danish Study Group of Infections of the Brain covering all Danish departments of infectious diseases from 2015 through 2020. All patients were followed for 6 months after discharge. Prognostic factors for mortality at 6 months after discharge were examined by adjusted modified Poisson regression to compute relative risks with 95% confidence intervals (CI). Among 485 identified cases, the median age was 59 years [interquartile range (IQR 48-67)] and 167 (34%) were female. The incidence of brain abscess increased from 0.4 in 2007 to 0.8 per 100 000 adults in 2020. Immuno-compromise was prevalent in 192/485 (40%) and the clinical presentation was predominated by neurological deficits 396/485 (82%), headache 270/411 (66%), and fever 208/382 (54%). The median time from admission until first brain imaging was 4.8 h (IQR 1.4-27). Underlying conditions included dental infections 91/485 (19%) and ear, nose and throat infections 67/485 (14%), and the most frequent pathogens were oral cavity bacteria (59%), Staphylococcus aureus (6%), and Enterobacteriaceae (3%). Neurosurgical interventions comprised aspiration 356/485 (73%) or excision 7/485 (1%) and was preceded by antibiotics in 377/459 (82%). Fatal outcome increased from 29/485 (6%) at discharge to 56/485 (12%) 6 months thereafter. Adjusted relative risks for mortality at 6 months after discharge was 3.48 (95% CI 1.92-6.34) for intraventricular rupture, 2.84 (95% CI 1.45-5.56) for immunocompromise, 2.18 (95% CI 1.21-3.91) for age >65 years, 1.81 (95% CI 1.00-3.28) for abscess diameter >3 cm, and 0.31 (95% CI 0.16-0.61) for oral cavity bacteria as causative pathogen. Sex, neurosurgical treatment, antibiotics before neurosurgery, and corticosteroids were not associated with mortality. This study suggests that prevention of rupture of brain abscess is crucial. Yet, antibiotics may be withheld until neurosurgery, if planned within a reasonable time period (e.g. 24 h), in some clinically stable patients. Adjunctive corticosteroids for symptomatic perifocal brain oedema was not associated with increased mortality.

Experimental animal models for brain abscess: a systematic review.

BACKGROUND: Brain abscess (BA) is a rare, but severe infection and experimental BA animal models may prove crucial for advances in treatment. This review describes the development of experimental BA models and the clinical advances obtained from these, in a historical perspective. MATERIAL AND METHODS: Experimental BA studies from inception until June 15, 2022, were included by searching the PubMed and Embase databases. Inclusion required the use of an experimental BA animal model. Non-bacterial BA models, in vitro studies, veterinarian case-reports, and articles written in non-English language were excluded. Bias was not systematically assessed, and the review was not registered at the PROSPERO. RESULTS: 79 studies were included. The majority of animal BA models have been based on small rodents using Staphylococcus aureus. The models have delineated the natural development of BA and provided detailed descriptions of the histopathological characteristics consisting of a necrotic centre surrounded by layers of inflammatory cells and fibroblasts encapsulated by a dense collagenous layer. Radiological studies of animal BA have been shown to correlate with the corresponding stages of human BA in both computed tomography and magnetic resonance imaging and may guide diagnosis as well as the timing of neurosurgical intervention. Moreover, pharmacokinetic studies of the intracavitary penetration of various antimicrobials have helped inform medical treatment of BA. Other studies have examined the diverse effects of corticosteroids including decreased cerebral oedema, intracranial pressure, and intracavitary drug concentration, whereas concerns on decreased or weakened capsule formation could not be confirmed. Finally, studies on the immunological response to BA have highlighted potential future immunomodulatory targets. CONCLUSIONS: Animal models have been vital for improvements in the management of BA. Experimental BA models resembling human disease including polymicrobial infection by oral cavity flora in large animals are needed.

Venous Thromboembolism and Major Bleeding in Patients With Coronavirus Disease 2019 (COVID-19): A Nationwide, Population-Based Cohort Study.

BACKGROUND: Venous thromboembolism (VTE) is a potentially fatal complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and thromboprophylaxis should be balanced against risk of bleeding. This study examined risks of VTE and major bleeding in hospitalized and community-managed SARS-CoV-2 patients compared with control populations. METHODS: Using nationwide population-based registries, 30-day risks of VTE and major bleeding in SARS-CoV-2 positive patients were compared with those of SARS-CoV-2 test-negative patients and with an external cohort of influenza patients. Medical records of all COVID-19 patients at 6 departments of infectious diseases in Denmark were reviewed in detail. RESULTS: The overall 30-day risk of VTE was 0.4% (40/9460) among SARS-CoV-2 patients (16% hospitalized), 0.3% (649/226 510) among SARS-CoV-2 negative subjects (12% hospitalized), and 1.0% (158/16 281) among influenza patients (59% hospitalized). VTE risks were higher and comparable in hospitalized SARS-CoV-2 positive (1.5%), SARS-CoV-2 negative (1.8%), and influenza patients (1.5%). Diagnosis of major bleeding was registered in 0.5% (47/9460) of all SARS-CoV-2 positive individuals and in 2.3% of those hospitalized. Medical record review of 582 hospitalized SARS-CoV-2 patients observed VTE in 4% (19/450) and major bleeding in 0.4% (2/450) of ward patients, of whom 31% received thromboprophylaxis. Among intensive care patients (100% received thromboprophylaxis), risks were 7% (9/132) for VTE and 11% (15/132) for major bleeding. CONCLUSIONS: Among people with SARS-CoV-2 infection in a population-based setting, VTE risks were low to moderate and were not substantially increased compared with SARS-CoV-2 test-negative and influenza patients. Risk of severe bleeding was low for ward patients, but mirrored VTE risk in the intensive care setting.

Association of Lumbar Puncture With Spinal Hematoma in Patients With and Without Coagulopathy.

Importance: Coagulopathy may deter physicians from performing a lumbar puncture. Objective: To determine the risk of spinal hematoma after lumbar puncture in patients with and without coagulopathy. Design, Setting, and Participants: Danish nationwide, population-based cohort study using medical registries to identify persons who underwent lumbar puncture and had cerebrospinal fluid analysis (January 1, 2008-December 31, 2018; followed up through October 30, 2019). Coagulopathy was defined as platelets lower than 150 × 109/L, international normalized ratio (INR) greater than 1.4, or activated partial thromboplastin time (APTT) longer than 39 seconds. Exposures: Coagulopathy at the time of lumbar puncture. Main Outcomes and Measures: Thirty-day risk of spinal hematoma. Risks were provided as numbers and percentages with 95% CIs. Secondary analyses included risks of traumatic lumbar puncture (>300 × 106 erythrocytes/L after excluding patients diagnosed with subarachnoid hemorrhage). Adjusted hazard rate ratios (HRs) were computed using Cox regression models. Results: A total of 83 711 individual lumbar punctures were identified among 64 730 persons (51% female; median age, 43 years [interquartile range, 22-62 years]) at the time of the procedure. Thrombocytopenia was present in 7875 patients (9%), high INR levels in 1393 (2%), and prolonged APTT in 2604 (3%). Follow-up was complete for more than 99% of the study participants. Overall, spinal hematoma occurred within 30 days for 99 of 49 526 patients (0.20%; 95% CI, 0.16%-0.24%) without coagulopathy vs 24 of 10 371 patients (0.23%; 95% CI, 0.15%-0.34%) with coagulopathy. Independent risk factors for spinal hematoma were male sex (adjusted hazard ratio [HR], 1.72; 95% CI, 1.15-2.56), those aged 41 through 60 years (adjusted HR, 1.96; 95% CI, 1.01-3.81) and those aged 61 through 80 years (adjusted HR, 2.20; 95% CI, 1.12-4.33). Risks did not increase significantly according to overall severity of coagulopathy, in subgroup analyses of severity of coagulopathy by pediatric specialty or medical indication (infection, neurological condition, and hematological malignancy), nor by cumulative number of procedures. Traumatic lumbar punctures occurred more frequently among patients with INR levels of 1.5 to 2.0 (36.8%; 95% CI, 33.3%-40.4%), 2.1 to 2.5 (43.7%; 95% CI, 35.8%-51.8%), and 2.6 to 3.0 (41.9% 95% CI 30.5-53.9) vs those with normal INR (28.2%; 95% CI, 27.7%-28.75%). Traumatic spinal tap occurred more often in patients with an APTT of 40 to 60 seconds (26.3%; 95% CI, 24.2%-28.5%) vs those with normal APTT (21.3%; 95% CI, 20.6%-21.9%) yielding a risk difference of 5.1% (95% CI, 2.9%-7.2%). Conclusions and Relevance: In this Danish cohort study, risk of spinal hematoma following lumbar puncture was 0.20% among patients without coagulopathy and 0.23% among those with coagulopathy. Although these findings may inform decision-making about lumbar puncture by describing rates in this sample, the observed rates may reflect bias due to physicians selecting relatively low-risk patients for lumbar puncture.

Risk Factors and Prognosis of Epilepsy Following Brain Abscess: A Nationwide Population-Based Cohort Study.

BACKGROUND AND OBJECTIVES: Epilepsy in patients with brain abscess is frequent, but risk factors and prognosis remain undetermined. This study examined risk factors of epilepsy among survivors of brain abscess and associated prognosis. METHODS: Nationwide, population-based healthcare registries were used to compute cumulative incidences and cause-specific adjusted hazard rate ratios (adj. HRRs) with 95% CIs for epilepsy among 30-day survivors of brain abscess from 1982 through 2016. Data were enriched with clinical details by medical record review of patients hospitalized from 2007 through 2016. Adjusted mortality rate ratios (adj. MRRs) were examined using epilepsy as a time-dependent variable. RESULTS: The study included 1,179 30-day survivors of brain abscess among whom 323 (27%) developed new-onset epilepsy after a median of 0.76 years (interquartile range [IQR] 0.24-2.41). At admission for brain abscess, the median age was 46 years (IQR 32-59) in patients with epilepsy compared with 52 years (IQR 33-64) in those without epilepsy. The proportion of female individuals was similar in patients with and without epilepsy (37%). Adj. HRRs for epilepsy were 2.44 (95% CI 1.89-3.15) for aspiration or excision of brain abscess, 2.37 (1.56-3.60) for alcohol abuse, 1.75 (1.27-2.40) for previous neurosurgery or head trauma, 1.62 (1.17-2.25) for stroke, and 1.55 (1.04-2.32) for age group 20-39 years. Cumulative incidences were increased in patients with alcohol abuse (52% vs 31%), aspiration or excision of brain abscess (41% vs 20%), previous neurosurgery or head trauma (41% vs 31%), and stroke (46% vs 31%). Analysis using clinical details from medical record review of patients from 2007 through 2016 demonstrated adj. HRRs of 3.70 (2.24-6.13) for seizures at admission for brain abscess and 1.80 (1.04-3.11) for frontal lobe abscess. By contrast, adj. HRR was 0.42 (0.21-0.86) for occipital lobe abscess. Using the entire registry-based cohort, patients with epilepsy had an adj. MRR of 1.26 (1.01-1.57). DISCUSSION: Important risk factors of epilepsy were seizures during admission for brain abscess, neurosurgery, alcoholism, frontal lobe abscess, and stroke. Epilepsy was associated with an increased mortality. Antiepileptic treatment may be guided by individual risk profiles, and a specialized follow-up is highlighted by an increased mortality in survivors with epilepsy.

Efficacy of the TMPRSS2 inhibitor camostat mesilate in patients hospitalized with Covid-19-a double-blind randomized controlled trial.

BACKGROUND: The trans-membrane protease serine 2 (TMPRSS2) is essential for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cell entry and infection. Efficacy and safety of TMPRSS2 inhibitors in patients with coronavirus disease 2019 (Covid-19) have not been evaluated in randomized trials. METHODS: We conducted an investigator-initiated, double-blind, randomized, placebo-controlled multicenter trial in patients hospitalized with confirmed SARS-CoV-2 infection from April 4, to December 31, 2020. Within 48 h of admission, participants were randomly assigned in a 2:1 ratio to receive the TMPRSS2 inhibitor camostat mesilate 200 mg three times daily for 5 days or placebo. The primary outcome was time to discharge or clinical improvement measured as ≥2 points improvement on a 7-point ordinal scale. Other outcomes included 30-day mortality, safety and change in oropharyngeal viral load. FINDINGS: 137 patients were assigned to receive camostat mesilate and 68 to placebo. Median time to clinical improvement was 5 days (interquartile range [IQR], 3 to 7) in the camostat group and 5 days (IQR, 2 to 10) in the placebo group (P = 0·31). The hazard ratio for 30-day mortality in the camostat compared with the placebo group was 0·82 (95% confidence interval [CI], 0·24 to 2·79; P = 0·75). The frequency of adverse events was similar in the two groups. Median change in viral load from baseline to day 5 in the camostat group was -0·22 log10 copies/mL (p <0·05) and -0·82 log10 in the placebo group (P <0·05). INTERPRETATION: Under this protocol, camostat mesilate treatment was not associated with increased adverse events during hospitalization for Covid-19 and did not affect time to clinical improvement, progression to ICU admission or mortality. ClinicalTrials.gov Identifier: NCT04321096. EudraCT Number: 2020-001200-42.