Pulmonary embolism after dexamethasone treatment for COVID-19: a case report.

BACKGROUND: Although the RECOVERY trial showed that dexamethasone was efficacious for the treatment of coronavirus disease 2019 (COVID-19), its impact on the risk of pulmonary embolism (PE) and other serious procoagulant events was not assessed. CASE PRESENTATION: Here we report the case of a previously healthy 83-year-old woman with COVID-19, without any genetic predisposition to thrombosis. She developed moderate respiratory distress 12 days after symptom onset and a 10-day course of dexamethasone therapy was initiated. Her clinical condition and imaging findings improved initially; however, they deteriorated after the completion of dexamethasone therapy, despite the improvement in her pneumonia and viral clearance. Laboratory tests showed markedly raised serum D-dimer, ferritin, and sIL-2R levels, and contrast-enhanced computed tomography showed deep vein thrombosis (DVT) in the left iliac vein and PE of the right pulmonary artery. The DVT and PE were successfully treated using intravenous heparin administration. CONCLUSIONS: This case illustrates the potential risk of rebound inflammation and procoagulant events following dexamethasone withdrawal. We believe that COVID-19-induced DVT and PE can be affected by dexamethasone therapy. Although dexamethasone reduces procoagulant factors, increases anticoagulant factors, and modulates cytokines, which can suppress/delay thrombus formation during treatment, it confers the risk for rebound cytokine production after treatment completion, triggering cytokine and coagulation cascades that can lead to thromboembolic diseases. In this critical clinical period, the patient's deteriorating condition may be overlooked because of the masking effects of dexamethasone treatment on fever and other clinical conditions and laboratory changes. Clinicians should follow-up coagulation markers carefully and contrast-enhanced computed tomography is useful for detecting coagulation; and, if PE occurs, therapeutic heparin administration is essential because emboli can also generate cytokines.

Exploring the Factors Affecting the Transferability of Vancomycin to Cerebrospinal Fluid in Postoperative Neurosurgical Patients with Bacterial Meningitis.

Vancomycin (VCM) is a standard treatment for bacterial meningitis. However, little is known about the transferability of VCM to cerebrospinal fluid (CSF), thus evidence of the transferability of VCM to CSF during bacterial meningitis is needed. In this study, we evaluated the concentration of VCM in the plasma and CSF of postoperative neurosurgical patients with bacterial meningitis and evaluated the factors that affect the transferability of VCM to CSF. The concentrations of VCM in plasma (trough) and CSF were determined in eight patients (four males and four females) with bacterial meningitis who were treated with VCM using HPLC. The ratio of the VCM concentrations in CSF/plasma was also calculated by estimating the blood VCM concentration at the same time as the VCM concentration in CSF was measured. The results showed that the VCM concentration in CSF was 0.9-12.7 µg/mL and the CSF/plasma VCM concentration ratio was 0.02-0.62. We examined the effect of drainage on the transferability of VCM to CSF, which showed that the VCM concentration in CSF and the CSF/plasma VCM concentration ratio were significantly higher in patients not undergoing drainage than in patients who were undergoing drainage. The CSF protein and glucose concentrations, which are diagnostic indicators of meningitis, were positively correlated with the VCM concentration in CSF and the CSF/plasma VCM concentration ratio. Thus, VCM transferability to CSF may be affected by changes in the status of the blood-brain barrier and blood-cerebrospinal fluid barrier due to drainage or meningitis.

Influences of protein levels on the cerebrospinal fluid distribution of ceftazidime & ceftriaxone in the cerebrospinal fluid of patients with inflamed meningitis.

INTRODUCTION: Ceftazidime and ceftriaxone are used to treat various gram-negative pathogens, such as Streptococcus pneumoniae and Pseudomonas aeruginosa, and have shown excellent therapeutic efficacy against bacterial meningitis. However, there is insufficient information on the pharmacokinetic characteristics of their cerebrospinal distribution. Here, we investigated the association of clinical laboratory data in cerebrospinal fluid with ceftazidime and ceftriaxone concentration in the cerebrospinal fluid of patients with inflamed meningitis. METHODS: Cerebrospinal fluid samples were collected from eight adult patients with inflamed meningitis who intravenously received either ceftazidime or ceftriaxone (ceftazidime: a total of 25 samples from three patients, ceftriaxone: a total of 12 samples from five patients). Total cell number, protein concentration, and glucose concentration in the cerebrospinal fluid were retrospectively collected from electronic medical charts. All ceftazidime and ceftriaxone concentrations in the cerebrospinal fluid were determined using high-performance liquid chromatography. RESULTS: Both ceftazidime and ceftriaxone concentrations in cerebrospinal fluid correlated with protein concentration in cerebrospinal fluid; however, no significant correlation was observed in total cell number and glucose concentration in cerebrospinal fluid. CONCLUSIONS: This is the first report on the relationship between the cerebrospinal distribution of these antibiotics and clinical laboratory data in cerebrospinal fluid of adult patients with meningitis.

Peak C-reactive protein levels do not predict 30-day mortality for bacteremia: A retrospective cohort study.

INTRODUCTION: Although peak C-reactive protein (CRP) levels are correlated with the prognosis of some diseases, there have been no reports regarding the association between peak CRP levels and mortality in patients with bacteremia. The present study aimed to determine the association between peak CRP levels and prognosis in patients with bacteremia. METHODS: This retrospective cohort study was conducted in a single tertiary hospital and included patients with bacteremia admitted to the emergency department from November 2012 to March 2017. Cox regression analysis was performed to examine the association between peak CRP levels and 30-day mortality. We also performed propensity score adjustment using potential confounding factors. RESULTS: One hundred fifty-nine patients were included in the study. Peak CRP levels were significantly higher in the ß-hemolytic streptococci (P = 0.001) and Streptococcus pneumoniae (P = 0.003) groups. The C-statistic of the multivariate logistic regression model for the propensity score was 0.88. For 30-day mortality, peak CRP levels >20 mg/dL did not show significance in the Cox regression analysis (hazard ratio, 0.866; 95% confidence interval, 0.489-1.537; P = 0.62). Even after propensity score adjustment, no significance was noted (hazard ratio, 0.865; 95% confidence interval, 0.399-1.876; P = 0.71). CONCLUSIONS: Peak CRP levels were not an independent predictor of mortality in patients with bacteremia in the emergency department. Clinicians should consider that patients with extremely high peak CRP levels do not necessarily have high mortality and vice versa.

The first report of human meningitis and pyogenic ventriculitis caused by Streptococcus suis: A case report.

Streptococcus suis, a gram-positive facultative anaerobe commonly found in pigs, is an emerging zoonotic pathogen. Herein, we describe a case of a 45-year-old male Japanese meat wholesaler with S. suis meningitis and pyogenic ventriculitis. S. suis was isolated from his blood and cerebrospinal fluid culture, and sequence type (ST) and serotype were confirmed to be ST1 and serotype 2, respectively, by multilocus sequence typing and the Quellung reaction. Magnetic resonance imaging (MRI) revealed right labyrinthitis and pyogenic ventriculitis. The patient was treated with ceftriaxone and ampicillin for 24 days; the treatment was deemed successful based on negative blood cultures on day 4. However, the patient experienced hearing loss and a vestibular nerve disorder. S. suis is a rare pathogen in Japan but can cause severe infection and sequelae. To the best of our knowledge, this is the first report of a human case of pyogenic ventriculitis caused by S. suis. Our findings suggest that S. suis infection should be considered when hearing impairment is present in a patient with bacterial infection and that MRI can help detect ventriculitis, which can necessitate a prolonged treatment duration.

[Confusion Over the Term "Contamination Rate" as It Pertains to Blood Cultures].

The blood culture contamination rate is often used to validate specimen-collection procedures. CUMITECH has set its optimal target to be 2% to 3%. However, the term "contamination rate" has been defined in many ways, limiting its generalizability. The definitions used in earlier studies can be divided into two categories; definitions based on clinical judgements, and those based on preset rules. According to each principle, the equation must be composed of a defined numerator and denominator. The problem with clinical definitions is that the decision is inevitably subjective, and the process is too cumbersome. Also, if the number of positive cultures is used as the denominator, the value would be equivalent to the positive predictive value, given that contamination is regarded as a "positive case." Thus, the value would not be useful for validating a procedure. On the other hand, when the preset algorithm was adopted, true infection would, to some degree, inevitably be classified as contamination. Also, if the algorithm adopted the number of blood culture sets as the denominator and contamination was defined as the identification of 1 or more specified organisms in only 1 of multiple sets of blood cultures, its theoretical maximum value would not be 100%. This is a problem because the value is a mixture of several numbers with different scales. In other words, whether the blood cultures are collected once, twice, or thrice or more a day would affect the result. The study cited by CUMITECH aimed to evaluate the equivalence between the clinical definition and the laboratory definition with preset rules, rather than to establish a benchmark for the contamination rate. It is undesirable for the number to be perceived as a benchmark. "A Guide to Blood Culture" (2013) by the Japanese Society for Clinical Microbiology introduced a calculation for the contamination rate, but the definition of the term "number of specimens" in the formula is ambiguous. In addition, the references cited in the guide do not concern contamination and do not even mention the definition of contamination rate. Thus, it is impossible to confirm the definition. In view of the weaknesses of these previous works, we defined the contamination rate as a benchmark for the validation of blood culture procedures as follows. [number of series in which 1 or more specified organisms (*) were identified in only 1 of multiple sets of blood cultures]/[total number of multiple sets of blood cultures in the series] *coagulase-negative staphylococci, Propionibacterium acnes, Micrococcus spp., Viridans-group streptococci, Corynebacterium spp., and Bacillus spp., but not B. anthracis.

[A Case of Bacteremia Which Followed a Urinary Tract Infection by Oligella urethralis].

An 82-year-old bedridden man with sequelae from a cerebral infarction was admitted to a welfare institution for the elderly. He developed a high fever and hematuria and was prescribed levofloxacin for the treatment of a suspected urinary tract infection. Although his condition improved, the symptoms subsequently recurred; therefore, levofloxacin was again administered. He remained febrile and was admitted to a hospital due to recalcitrant urinary tract infection. Immediately after admission, he developed ischuria and pyuria. Urine and blood cultures at admission indicated the presence of levofloxacin-resistant Oligella urethralis (O. urethralis). He recovered with ceftriaxone medication. To our knowledge, this is the first report of bacteremia associated with a urinary tract infection caused by O. urethralis in Japan.

Prognostic Factors for Japanese Adults With Acute Community-Acquired Bacterial Meningitis: A Retrospective Study.

Background This study aimed to determine if the cerebrospinal fluid (CSF) cell count is useful for predicting the infection severity or prognosis in Japanese adults with community-acquired bacterial meningitis. Methodology This study retrospectively evaluated the prognosis of patients diagnosed with community-acquired bacterial meningitis at our hospital from January 2004 to December 2021 using the modified Rankin scale (mRs) (Showa General Hospital; N = 39). Patients were classified into the following two groups: (i) favorable (mRs: 0-3) and (ii) unfavorable (mRs: 4-6). Eight factors were selected and compared with outcomes, and then two factors were evaluated from those, and a multivariate logistic regression was used to determine the significant variables. Results CSF cell count was observed to be associated with poor prognoses (odds ratio (OR) = 0.86, 95% confidence interval (CI) = 0.99995-0.99999, p = 0.0012). Glasgow coma scale (GCS) score on admission was also observed to be associated with poor prognoses (OR = 0.93, 95% CI = 0.89145-0.97290, p = 0.0029). Conclusions Low CSF cell count and low GCS on admission were observed as risk factors for poor prognoses in patients with bacterial meningitis.

Phenotypic and Genotypic Traits of Pasteurella multocida subsp. septica Isolates From the Wounds of Two Patients Due to Dog or Cat Biting, 2023.

We describe the phenotypic and genotypic traits of Pasteurella multocida subsp. septica isolates from the dog/cat bite wounds of two patients in 2023. A 79-year-old man with diabetes mellitus and cerebral infarction who was bitten by a dog on his left hand developed deep inflammation under the tendon between his left fourth and fifth fingers. The patient's condition was resolved with antimicrobial treatment and surgical intervention. Another patient, a healthy 49-year-old woman who was bitten by a cat on her left hand, developed superficial inflammation of the left thumb and index finger. The patient's condition improved with antimicrobial treatment without surgical intervention. The isolates from the two patients had similar biochemical properties, and the antimicrobial susceptibility data for both isolates indicated erythromycin resistance. Genotypic analyses revealed clade 2 on the dendrogram of repetitive sequence-based fingerprinting, capsule serogroup cap genotype A, and hsf-1-nanH-pmHAS (virulence-associated genes). Our observations show that the two isolates have similar phenotypic and genotypic traits, regardless of differences in patient background, biting pets, wound inflammation, or the necessity of surgical intervention.

Listeria monocytogenes bacteremia one month after contact with raw venison: A case report.

Listeria monocytogenes is a gram-positive bacillus that causes food poisoning. Listeriosis causes gastrointestinal infections and occasionally leads to fatal bacteremia in older adults. The symptoms of Listeria infections are non-specific and difficult to diagnose. We describe a case of Listeria bacteremia in an 82-year-old Japanese woman who had handled raw venison one month prior to becoming ill, but had not consumed any. No other possible sources of infection were identified. She presented with a fever without any focal symptoms. Computed tomography revealed enteritis with mucosal damage. Blood culture revealed bacteria with gram-positive rod morphology, that were confirmed as L. monocytogenes using mass spectrometry. The patient was treated with intravenous ampicillin and made a full recovery. This case illustrates the virulence of L. monocytogenes, which can cause bacteremia from handling contaminated food, even without consumption.

Community-acquired Pseudomonas aeruginosa Osteomyelitis Caused by an Injury from a Dishwasher.

A 70-year-old healthy woman came to our hospital with right index finger pain and swelling after an injury incurred due to a commercial dishwasher. X-ray of the hand showed osteolysis around the distal interphalangeal joint. A further examination revealed Pseudomonas aeruginosa in the unexposed pus, so the patient was treated with a total of 10 weeks of cefepime, followed by levofloxacin and debridement twice. While this may have been a case of bacterial replacement, we should still consider P. aeruginosa infection in healthy adults when faced with an episode of waterborne injury.

The first case of bloodstream infection by Candida intermedia in Japan: the importance of molecular identification.

A 65-year-old Chinese man with diabetes mellitus was admitted to our hospital complaining of bloody sputum, fever, and dyspnea. Despite antibiotic treatment, his condition deteriorated, necessitating mechanical ventilation. Diffuse alveolar hemorrhage was suspected, and steroid therapy was initiated. Although his condition improved and he was extubated, the fever recurred twice, and on both occasions blood cultures yielded yeasts. The yeasts were misidentified as Cryptococcus humicola with a commercially available phenotype test (API ID32C), which did not match the clinical profile, and molecular identification was then performed. The isolates were identified as Candida intermedia by molecular phylogenetic analyses of the chromosomal regions coding for the D1/D2 domain of the large-subunit 26S rRNA gene. The patient responded well to several antifungal agents and was discharged on the 34th hospital day. To our knowledge, this is the first case of C. intermedia infection reported in Japan, and the tenth case reported in the international medical literature.

Bacteremia Caused by Both Legionella pneumophila Serogroup 2 and Helicobacter cinaedi.

A 74-year-old woman with a history of pure red cell aplasia and hypogammaglobulinemia developed pneumonia. A urine antigen test and sputum subculture on buffered charcoal yeast extract (BCYE)α agar were positive for Legionella pneumophila. Serological testing identified L. pneumophila serogroup 2. An aerobic blood culture also became positive on day 5; its subculture on BCYEα agar revealed the same pathogen, but that on blood agar revealed Helicobacter cinaedi. We thus diagnosed her with bacteremia caused by both pathogens. Hence, in cases of H. cinaedi bacteremia along with pneumonia, the screening of other pathogens including L. pneumophila is needed.

Different intra-cerebrospinal distribution of linezolid in patients with inflammatory meningitis.

Linezolid has excellent antibiotic activity against gram-positive organisms and is expected to be an alternative to vancomycin for the treatment of bacterial meningitis. Accumulated evidence has shown the superior pharmacokinetic characteristics of linezolid to vancomycin, such as cerebrospinal fluid penetration. However, in the treatment of meningitis, pharmacokinetic information regarding the intra-cerebrospinal distribution of linezolid and the effects of drainage on the linezolid concentration in the cerebrospinal fluid are unclear. This report describes two patient cases, in which the linezolid concentrations in the cerebrospinal fluid were in the following order: subarachnoid space (cisternal drainage and lumbar puncture) ≥ third ventricle > lateral ventricle. In addition, the linezolid concentration in the cerebrospinal fluid, collected via lumbar puncture, tended to increase after removal of the drainage. This report is novel in presenting two cases of meningitis that showed different intra-cerebrospinal distribution of linezolid in various parts of the central nervous system and an increased linezolid concentration in the cerebrospinal fluid after removal of the drainage.

[Isolation of the yeast-like fungus Stephanoascus ciferrii by culturing the aural discharge of a patient with intractable otitis media. Case report].

As longer lives have become possible due to advances in medical technology and diagnostic technology in recent years, weakly toxic fungus have been emerging as causative agents of opportunistic infections, primarily in high-risk groups. We report a case in which the yeast-like fungus Stephanoascus ciferii, which has morphological characteristics that differ from those of the more common Candida species, was isolated by culturing the aural discharge of a patient with intractable otitis media. Drug susceptibility testing showed that it was resistant to fluconazole, flucytosine, and itraconazole, suggesting that it is a species that has a strong tendency to become resistant. The principal sites of infection by Stephanoascus ciferii are thought to be in the ENT area, but in other countries it has been isolated from patients with acute myeloid leukemia and immunodeficiency as well as superficial mycoses, and it may also be a causative agent of deep mycoses. We therefore think that it is necessary to bear in mind detection in other areas outside the ENT field and to adequately monitor the circumstances under which this fungus is isolated.

Case studies of SARS-CoV-2 treated with favipiravir among patients in critical or severe condition.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak is rising globally. However, clinically effective antiviral treatments are not established. Favipiravir may prevent pneumonia and acute respiratory distress syndrome aggravation. We describe SARS-CoV-2-positive patients, two of whom were in a critical condition and one of whom was in a severe condition, who were administered favipiravir for their deteriorating conditions and cured.

[A case of sarcoidosis complicated with repeated hemoptysis].

A 53-year-old woman was admitted to our hospital complaining of repeated hemoptysis. Her past history indicate uveitis at age 48. Chest HRCT findings showed the thickening of broncho-vascular bundles, interlobular septal thickening, and patchy ground-glass attenuation, but no hilar and mediastinal lymphadenopathy. BALF and TBLB were not diagnostic. Her hemoptysis was persistent, and we performed VATS biopsy, which revealed diffuse epithelioid cell granulomas with multinucleated giant cells along vessels and intra-alveolar spaces, consistent with sarcoidosis. Sarcoidosis was therefore diagnosed. She was treated with steroids, and her CT findings improved, but her hemoptysis was persistent. Bronchial artery angiography revealed micro-aneurysms in the left bronchial artery and shunt to the pulmonary vein form the right bronchial artery. We decided that the etiology of her hemoptysis was from micro-aneurysms in the left bronchial artery. We concluded that hemorrhage from vascular lesions, including the bronchial artery, could be complications in cases of sarcoidosis.

[Case of thalidomide-induced interstitial pneumonia].

A 68-year-old man with multiple myeloma was admitted to our hospital complaining of slight fever and dyspnea on effort 4 months after treatment with thalidomide. Chest HRCT findings showed diffuse ground-glass attenuation, small nodules, and interlobular septal thickening in bilateral lungs. BAL showed marked lymphocytosis, and TBLB revealed alveolitis with exudative change, consistent with drug-induced interstitial pneumonitis. His thalidomide treatment was withdrawn and his symptoms and HRCT findings improved. Therefore, we diagnosed thalidomide-induced interstitial pneumonitis. Thalidomide-induced interstitial pneumonitis is rare, and only 4 cases have been reported in the literature. We concluded that we should consider thalidomide-induced interstitial pneumonitis in cases with multiple myeloma following thalidomide treatment.

Machine learning analysis to identify the association between risk factors and onset of nosocomial diarrhea: a retrospective cohort study.

BACKGROUND: Although several risk factors for nosocomial diarrhea have been identified, the detail of association between these factors and onset of nosocomial diarrhea, such as degree of importance or temporal pattern of influence, remains unclear. We aimed to determine the association between risk factors and onset of nosocomial diarrhea using machine learning algorithms. METHODS: We retrospectively collected data of patients with acute cerebral infarction. Seven variables, including age, sex, modified Rankin Scale (mRS) score, and number of days of antibiotics, tube feeding, proton pump inhibitors, and histamine 2-receptor antagonist use, were used in the analysis. We split the data into a training dataset and independant test dataset. Based on the training dataset, we developed a random forest, support vector machine (SVM), and radial basis function (RBF) network model. By calculating an area under the curve (AUC) of the receiver operating characteristic curve using 5-fold cross-validation, we performed feature selection and hyperparameter optimization in each model. According to their final performances, we selected the optimal model and also validated it in the independent test dataset. Based on the selected model, we visualized the variable importance and the association between each variable and the outcome using partial dependence plots. RESULTS: Two-hundred and eighteen patients were included. In the cross-validation within the training dataset, the random forest model achieved an AUC of 0.944, which was higher than in the SVM and RBF network models. The random forest model also achieved an AUC of 0.832 in the independent test dataset. Tube feeding use days, mRS score, antibiotic use days, age and sex were strongly associated with the onset of nosocomial diarrhea, in this order. Tube feeding use had an inverse U-shaped association with the outcome. The mRS score and age had a convex downward and increasing association, while antibiotic use had a convex upward association with the outcome. CONCLUSION: We revealed the degree of importance and temporal pattern of the influence of several risk factors for nosocomial diarrhea, which could help clinicians manage nosocomial diarrhea.

A Case Report of an Intrathoracic Mass Lesion Caused by Arcanobacterium haemolyticum that Required Exclusion of a Malignant Tumor Diagnosis.

A 57-year-old man with untreated diabetes mellitus was admitted to our hospital due to an intrathoracic mass lesion infiltrating the vertebral body and mediastinum. The mass was suspected to be invasive lung cancer; however, percutaneous needle biopsy revealed that the mass was inflammatory granulation tissue caused by an Arcanobacterium haemolyticum infection. To the best of our knowledge, this is the first report of an intrathoracic mass lesion caused by an A. haemolyticum infection. When an intrathoracic mass lesion is suspected, clinicians should consider possible infections that cause granulation tissue, such as A. haemolyticum. This is particularly important in immunocompromized hosts such as patients with diabetes.