Helicobacter fennelliae Localization to Diffuse Areas of Human Intestine, Japan.

The site of enterohepatic Helicobacter colonization/infection in humans is still unknown. We report microbiologically and histopathologically confirmed H. fennelliae localization in the large intestine in an immunocompromised patient in Japan. This case contributes to better understanding of the life cycle of enterohepatic Helicobacter species.

A case of mild encephalitis associated with COVID-19.

We report a case of mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) in a 31-year-old man. He had been diagnosed with mild COVID-19 3 days earlier and presented to the emergency department with altered mental status. Brain magnetic resonance imaging (MRI) showed a high-intensity area confined to the splenium of the corpus callosum on diffusion-weighted imaging, which is consistent with MERS. MERS is characterized by a reversible change in the splenium of the corpus callosum. MERS secondary to COVID-19 has been reported recently. It is important to consider MERS in COVID-19 patients with impaired consciousness.

Predictive scoring system for distinguishing Stenotrophomonas maltophilia bacteremia from Pseudomonas aeruginosa bacteremia in patients with hematological malignancies.

Difficulties in immediately distinguishing Stenotrophomonas maltophilia (SM) bacteremia from Pseudomonas aeruginosa (PA) bacteremia in the clinical setting can lead to treatment delay. We aimed to develop a scoring system to immediately distinguish SM bacteremia from PA bacteremia using clinical indicators. We enrolled cases of SM and PA bacteremia in adult patients with hematological malignancies between January 2011 and June 2018. The patients were randomized into derivation and validation cohorts (2:1), and a clinical prediction tool for SM bacteremia was developed and verified. In total, 88 SM and 85 PA bacteremia cases were identified. In the derivation cohort, the following independent predictors of SM bacteremia were identified: no evidence of PA colonization, antipseudomonal ß-lactam breakthrough bacteremia, and central venous catheter insertion. We scored each of the three predictors according to their regression coefficient (2, 2, and 1, respectively). Receiver operating characteristic curve analysis confirmed the score's predictive performance, with an area under the curve of 0.805. The combined sensitivity and specificity (0.655 and 0.821) was highest with a cut-off value of 4 points. Positive and negative predictive values were 79.2% (19/24) and 69.7% (23/33), respectively. This novel predictive scoring system is potentially useful for distinguishing SM bacteremia from PA bacteremia, which would facilitate immediate administration of appropriate antimicrobial therapy.

Multicenter, single-blind, randomized controlled study of the efficacy and safety of favipiravir and nafamostat mesilate in patients with COVID-19 pneumonia.

OBJECTIVES: To evaluate the efficacy and safety of nafamostat combined with favipiravir for the treatment of COVID-19. METHODS: We conducted a multicenter, randomized, single-blind, placebo-controlled, parallel assignment study in hospitalized patients with mild-to-moderate COVID-19 pneumonia. Patients were randomly assigned to receive favipiravir alone (n = 24) or nafamostat with favipiravir (n = 21). The outcomes included changes in the World Health Organization clinical progression scale score, time to improvement in body temperature, and improvement in oxygen saturation (SpO2). RESULTS: There was no significant difference in the changes in the clinical progression scale between nafamostat with favipiravir and favipiravir alone groups (median, -0.444 vs -0.150, respectively; least-squares mean difference, -0.294; P = 0.364). The time to improvement in body temperature was significantly shorter in the combination group (5.0 days; 95% confidence interval, 4.0-7.0) than in the favipiravir group (9.0 days; 95% confidence interval, 7.0-18.0; P =0.009). The changes in SpO2 were greater in the combination group than in the favipiravir group (0.526% vs -1.304%, respectively; least-squares mean difference, 1.831; P = 0.022). No serious adverse events or deaths were reported, but phlebitis occurred in 57.1% of the patients in the combination group. CONCLUSION: Although our study showed no differences in clinical progression, earlier defervescence, and recovery of SpO2 were observed in the combination group.

Universal admission screening for COVID-19 using quantitative antigen testing and questionnaire screening to prevent nosocomial spread.

BACKGROUND: In this study, we investigated diagnostic accuracy of quantitative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen testing and whether universal screening was effective to prevent a nosocomial outbreak of coronavirus disease 2019 (COVID-19). METHODS: All adult patients admitted to an acute-care hospital in Tokyo, Japan, after receiving LUMIPULSE SARS-CoV-2 Ag using a nasopharyngeal swab and a brief questionnaire to evaluate symptoms and exposures from December 3, 2020 to March 20, 2021 were included. RESULTS: Of the 5191 patients, 53 were antigen-positive, 19 were inconclusive and 5119 were negative. The sensitivity and specificity (positive or inconclusive results) of the quantitative antigen test for COVID-19 diagnosis at admission was 0.957 (95% confidence interval [CI]: 0.855-0.995) and 0.995 (95% CI: 0.992-0.997), respectively. Six asymptomatic patients were identified on admission. Two patients were antigen-negative and diagnosed with COVID-19 later; however, they had been isolated prior to diagnosis because both had symptoms of COVID-19 and exposure. No nosocomial infections occurred during the period. CONCLUSION: Quantitative SARS-CoV-2 antigen testing was found to be valid for the early detection of asymptomatic COVID-19 patients as a universal screening test on admission.

Factors Associated with Breakthrough Fungemia Caused by Candida, Trichosporon, or Fusarium Species in Patients with Hematological Disorders.

Limited data are available on breakthrough fungemia, defined as fungemia that develops on administration of antifungal agents, in patients with hematological disorders. We reviewed the medical and microbiological records of adult patients with hematological diseases who had breakthrough fungemia between January 2008 and July 2019 at Toranomon Hospital and Toranomon Hospital Kajigaya in Japan. A total of 121 cases of breakthrough fungemia were identified. Of the 121 involved patients, 83, 11, 5, and 22 were receiving micafungin, voriconazole, itraconazole, and liposomal amphotericin B, respectively, when the breakthrough occurred. Of the 121 causative breakthrough fungal strains, 96 were Candida species, and the rest were 13 cases of Trichosporon species, 7 of Fusarium species, 2 of Rhodotorula mucilaginosa, and 1 each of Cryptococcus neoformans, Exophiala dermatitidis, and Magnusiomyces capitatus. The crude 14-day mortality rate of breakthrough fungemia was 36%. Significant independent factors associated with the crude 14-day mortality rate were age of ≥60 years (P = 0.011), chronic renal failure (P = 0.0087), septic shock (P < 0.0001), steroid administration (P = 0.0085), and liposomal amphotericin B breakthrough fungemia (P = 0.0011). An absolute neutrophil count of >500/µL was significantly more common in candidemia in the multivariate analysis (P = 0.0065), neutropenia and nonallogeneic hematopoietic stem cell transplants were significantly more common in Trichosporon fungemia (P = 0.036 and P = 0.033, respectively), and voriconazole breakthrough fungemia and neutropenia were significantly more common in Fusarium fungemia (P = 0.016 and P = 0.016, respectively). The epidemiological and clinical characteristics of breakthrough fungemia of patients with hematological disorders were demonstrated. Some useful factors to predict candidemia, Trichosporon fungemia, and Fusarium fungemia were identified.

Clinical and Microbiological Characteristics of Proven Invasive Aspergillosis Due to Rare/Cryptic Species in Allogeneic Hematopoietic Stem Cell Transplant Recipients.

There are few reports on the clinical course of proven invasive aspergillosis (IA) due to rare/cryptic species in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. We retrospectively reviewed the electronic medical records of patients who underwent allo-HSCT between January 2012 and December 2018. Of 934 allo-HSCT recipients, 10 were diagnosed with proven IA and 61 were diagnosed with probable IA. DNA sequencing was performed in cases of proven IA, and Aspergillus could be identified to the species level in 8 of the 10 cases. Three were due to A. fumigatus, and 5 were due to rare/cryptic Aspergillus species, namely, A. turcosus, A. felis, A. viridinutans, A. nidulans, and A. calidoustus. In these 8 patients, no patients with IA due to A. fumigatus died, whereas 3 of the 5 with IA due to rare/cryptic species died within 12 weeks. The 2 surviving cases of IA due to rare/cryptic species were treated with surgical resection and antifungal treatment. Susceptibility testing for cryptic species in 4 cases showed an amphotericin B MIC > 1 mg/L in 3 cases, itraconazole MIC > 1 mg/L in 2 cases, and voriconazole MIC > 1 mg/L in 2 cases. In conclusion, more than half of the causative pathogens of proven IA were rare/cryptic species, so it is important to accurately identify the Aspergillus species. In addition, surgical treatment might be an important option in cases of proven IA, given the possibility that the causative organisms are azole-resistant A. fumigatus or rare/cryptic species.

Clinical characteristics and drug susceptibility patterns of Corynebacterium species in bacteremic patients with hematological disorders.

The aim of this study was to clarify the clinical and microbiological characteristics of Corynebacterium bacteremia in hematological patients. We retrospectively reviewed the medical records of patients with Corynebacterium bacteremia from April 2013 to June 2018. The causative Corynebacterium species were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Drug susceptibility tests were performed using the broth microdilution method recommended by the Clinical and Laboratory Standards Institute. In total, 147 cases of Corynebacterium bacteremia were identified during the study period. Corynebacterium striatum was the most frequent pathogen. Catheter-related bloodstream infection was diagnosed in 19.7% of all patients, and moderate/severe oral or severe gastrointestinal mucosal impairment was detected in 19.7%. Polymicrobial infection was found in about 20% of cases, with Enterococcus faecium being the most frequent isolate. The overall 30-day mortality was 34.7% (51/147). Multivariate analysis showed that E. faecium co-infection (odds ratio (OR) 9.3; 95% confidence interval (CI) 2.1-40), systemic corticosteroids (OR 3.6; 95% CI 1.4-8.9), other immunosuppressive drugs (OR 0.32; 95% CI 0.13-0.76), and a Pitt bacteremia score ≥4 (OR 12; 95% CI 3.9-40) were significant risk factors for overall 30-day mortality. The drug susceptibility rates for beta-lactam antimicrobial agents were quite low. All isolates were susceptible to glycopeptides and linezolid. However, some C. striatum isolates were resistant to daptomycin. Corynebacterium bacteremia can occur in the presence of several types of mucosal impairment. Our drug susceptibility data indicate that Corynebacterium bacteremia in hematological patients could be treated by glycopeptides or linezolid.

Stenotrophomonas maltophilia bloodstream infections in adult recipients of umbilical cord blood transplantation.

Limited data are available on Stenotrophomonas maltophilia bloodstream infections (SM-BSIs) and the therapeutic efficacy of trimethoprim-sulfamethoxazole (SXT) against SM-BSI in umbilical cord blood transplant (uCBT) recipients. Medical and microbiological records of adult patients who received uCBTs between December 2008 and December 2015 at Toranomon Hospital (Tokyo, Japan) were reviewed. The efficacy and safety of SXT were evaluated only for recipients who were treated with ≥7 days of intravenous SXT for SM-BSI (evaluation cohort). Of 561 uCBT recipients, 34 developed SM-BSI. Diabetes mellitus (P = .005) and age ≥ 60 years (P = .013) were significant independent risk factors for SM-BSI. Moreover, SM-BSI was identified as an independent risk factor for all-cause mortality up to 100 days following uCBT (P = .025). Of the 34 recipients with SM-BSI, 24 were treated with an intravenous SXT-containing regimen (iSXT-CR). Septic shock (P = .0021), pneumonia (P = .011), neutropenia (P = .0015), and systemic steroid administration (P = .018) were identified as significant independent risk factors for 7-day crude mortality. The evaluation cohort included nine recipients. Doses of SXT were 2.4 to 6.9 mg/kg/day of the trimethoprim component. Of the nine recipients, five developed SM-BSI during the pre-engraftment phase. The 30-day crude-mortality rate and clinical cure rate of the cohort were 22% and 67%, respectively. Only one of the nine recipients experienced significant neutrophil toxicity. In this study, the epidemiology of SM-BSI in uCBT recipients was determined and its negative impact on survival was demonstrated. A low- to moderate-dose iSXT-CR appeared to be a tolerable and important therapeutic option for SM-BSI in the uCBT setting, including during the pre-engraftment phase.

The impact of graft cell source on bloodstream infection in the first 100 days after allogeneic hematopoietic cell transplantation.

Bloodstream infection (BSI) is a major infectious complication after allogeneic hematopoietic cell transplantation (HCT). To clarify the impact of graft cell source on the incidence of BSI after transplantation, we retrospectively examined 782 adult patients receiving their first allogeneic HCT: 122 recipients of related peripheral blood stem cells or bone marrow, 215 recipients of unrelated bone marrow, and 445 recipients of unrelated umbilical cord blood (U-CB). The cumulative incidence of BSI was 42.5% at 100 days after transplantation (95% confidence interval, 39.0-46.0). Gram-positive cocci were present in 64.2% of detected isolates. Among the pre-transplant factors including age, performance status, primary disease, disease status, graft cell source, sex and ABO blood type matching, and the intensity of conditioning regimen, U-CB use was identified as the most significant risk factor for BSI by multivariate analysis (hazard ratio, 1.76; 95% confidence interval, 1.40-2.22; p < 0.00001). Among the U-CB recipients, those who are not in remission at the time of transplantation were at the greatest risk of BSI (hazard ratio, 1.69; 95% confidence interval, 1.14-2.50; p < 0.01). The study makes it clear that graft cell source has an impact on BSI development after allogeneic HCT.

Reverse Transcription Loop-Mediated Isothermal Amplification Assay-Based Infection Control Strategies for COVID-19 in a Hospital Under the State of Emergency in Tokyo, Japan in Spring 2020.

Studies describing reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay-based infection control strategies (LAMP-based ICSs) for coronavirus disease 2019 (COVID-19) are limited. We reviewed the medical records of cases in which RT-LAMP was performed. Standard ICSs and LAMP-based ICSs were implemented during the study period. The strategies were intended to impose longer periods of infection control precautions (ICPs) for specific patients, such as those with a history of exposure to COVID-19 patients and/or bilateral ground glass opacities (bGGO) on chest computed tomography (CT). Of 212 patients, which included 13 confirmed COVID-19 patients in the diagnostic cohort, exposure to COVID-19 patients (P <0.0001) and chest CT bGGO (P = 0.0022) were identified as significant predictors of COVID-19. In the 173 hospitalized patients in which the results of the first RT-LAMP were negative, the duration of ICPs was significantly longer in patients with exposure to COVID-19 and/or a high clinical index of suspicion and patients with bGGO than in the remaining patients (P = 0.00046 and P = 0.0067, respectively). Additionally, no confirmed COVID-19 cases indicating nosocomial spread occurred during the study period. Establishing a comprehensive system that combines rational LAMP-based ICSs with standard ICSs might be useful for preventing nosocomial spread.

Characteristics of gram-negative bacteremia during febrile neutropenia among allogeneic hematopoietic stem cell transplant recipients on levofloxacin prophylaxis.

The aim of this study is to clarify the characteristics of gram-negative bacteremia (GNB), including extended-spectrum ß-lactamase (ESBL)-producing pathogens, among allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients on levofloxacin (LVFX) prophylaxis. A retrospective analysis on GNB at the first episode of febrile neutropenia (FN) was conducted among allo-HSCT recipients (age ≥ 20 years) on 500 mg/day of oral LVFX prophylaxis. Epidemiological and microbiological features of GNB were investigated and compared between the inappropriate and appropriate empiric therapy groups. In total, FN occurred in 414 allo-HSCT cases, and bacteremia at the first episode of FN occurred in 169 cases. Overall, 29 GNB cases were documented, and the causative organisms identified were Escherichia coli in 21 cases (including 10 ESBLs), Klebsiella pneumoniae in 2, Pseudomonas aeruginosa in 2, and other in 4. The crude 30-day mortality rate was not significantly different among cases of GNB (6.9%), gram-positive bacteremia (GPB) (7.1%), or non-bacteremia (5.4%; P = 0.78). Cefepime (CFPM) was administered in all cases in the inappropriate empiric therapy group, and all causative organisms were ESBL-producing E. coli (ESBL-EC). All patients in the inappropriate empiric therapy group had a low Pitt bacteremia score (≤ 2). Thirty-day mortality did not differ significantly between the inappropriate and appropriate empiric therapy groups (1/10 vs. 1/15, P = 0.61). In conclusion, GNB was not a significant cause of death. In LVFX breakthrough ESBL-EC bacteremia among allo-HSCT recipients, the administration of CFPM as empiric therapy did not lead to significantly poor prognosis. Empiric CFPM administration might be an acceptable strategy.

Differences in Ocular Complications Between Candida albicans and Non-albicans Candida Infection Analyzed by Epidemiology and a Mouse Ocular Candidiasis Model.

Objectives: Candida species are a major cause of hospital infections, including ocular candidiasis, but few studies have examined the propensities of specific species to invade the eye or the unique immunological responses induced. This study examined the frequency and characteristics of species-specific Candida eye infections by epidemiology and experiments using a mouse ocular candidiasis model. Methods: We reviewed medical records of candidemia patients from January 2012 to March 2017. We also evaluated ocular fungal burden, inflammatory cytokine and chemokine profiles, and inflammatory cell profiles in mice infected with Candida albicans, Candida glabrata, or Candida parapsilosis. Results: During the study period, 20 ocular candidiasis cases were diagnosed among 99 candidemia patients examined by ophthalmologists. Although C. parapsilosis was the most frequent candidemia pathogen, only C. albicans infection was significantly associated with ocular candidiasis by multivariate analysis. In mice, ocular fungal burden and inflammatory mediators were significantly higher during C. albicans infection, and histopathological analysis revealed invading C. albicans surrounded by inflammatory cells. Ocular neutrophil and inflammatory monocyte numbers were significantly greater during C. albicans infection. Conclusion: Candida albicans is strongly associated with ocular candidiasis due to greater capacity for invasion, induction of inflammatory mediators, and recruitment of neutrophils and inflammatory monocytes.

Micafungin Breakthrough Fungemia in Patients with Hematological Disorders.

Limited data are available on micafungin breakthrough fungemia (MBF), fungemia that develops on administration of micafungin, in patients with hematological disorders. We reviewed medical and microbiological records of patients with hematological disorders who developed MBF between January 2008 and June 2015. A total of 39 patients with MBF were identified, and Candida (30 strains) and non-Candida (9 strains) fungal species were recognized as causative strains. Among 35 stored strains, Candida parapsilosis (14 strains), Trichosporon asahii (7 strains), Candida glabrata (5 strains), and other fungal species (9 strains) were identified by sequencing. Neutropenia was identified as an independent predictor of non-Candida fungemia (P = 0.023). T. asahii was the most common causative strain (7/19) during neutropenia. The 14-day crude mortality rate of patients treated with early micafungin change (EMC) to other antifungal agents was lower than that of the patients not treated with EMC (14% versus 43%, P = 0.044). Most of the stored causative Candida strains were susceptible (80%) or showed wild-type susceptibility (72%) to micafungin. The MICs of voriconazole for T. asahii were low (range, 0.015 to 0.12 µg/ml), whereas the MICs of amphotericin B for T. asahii were high (range, 2 to 4 µg/ml). MBF caused by non-Candida fungus should be considered, especially in patients with neutropenia. EMC could improve early mortality. Based on epidemiology and drug susceptibility profiling, empirical voriconazole-containing therapy might be suitable for treating MBF during neutropenia to cover for T. asahii.