α,ß-trehalose, an intracellular substance in resting cyst of colpodid ciliates as a key to environmental tolerances.

α,α-trehalose is a well-known sugar that plays a key role in establishing tolerance to environmental stresses in many organisms, except unicellular eukaryotes. However, almost nothing is known about α,ß-trehalose, including their synthesis, function, and even presence in living organisms. In this study, we identified α,ß-trehalose in the resting cyst, a dormancy cell form characterized by extreme tolerance to environmental stresses, of the ciliated protist Colpoda cucullus, using high-performance liquid chromatography (HPLC), and a proton nuclear magnetic resonance (1H NMR). Gene expression analysis revealed that the expression of trehalose-6-phosphate synthase (TPS), glycosyltransferase (GT), alpha-amylase (AMY), and trehalose transporter 1 (TRET1), were up-regulated in encystment, while the expression of α-glucosidase 2 (AG2) and trehalase (TREH) was up-regulated in excystment. These results suggest that α,ß-trehalose is synthesized during encystment process, while and contributes to extreme tolerances to environmental stressors, stored carbohydrates, and energy reserve during resting cyst and/or during excystment.

Invalidity of JRS atypical pneumonia prediction score in Omicron variant of COVID-19 pneumonia.

BACKGROUND: We evaluated whether the Japanese Respiratory Society (JRS) atypical pneumonia prediction score can be adapted for the diagnosis of COVID-19 pneumonia due to Omicron BA.1, BA.2, and BA.5 subvariants. METHODS: We enrolled a total of 547 patients with community-acquired COVID-19 pneumonia. Of the COVID-19 pneumonia patients, 198 cases were the Omicron BA.1 subvariant, 127 cases were the Omicron BA.2 subvariant, and 222 cases were the Omicron BA.5 subvariant. Patients with extremely severe pneumonia were excluded and finally 524 patients were analyzed. RESULTS: Rates of conformity for the six predictors were identical among the three Omicron groups, and high rates of conformity were observed in the following predictors: adventitious sounds; etiological agent; and a peripheral WBC count. The sensitivities of the diagnosis of atypical pneumonia in patients with COVID-19 pneumonia based on four or more predictors were 49.0% in the BA.1 subvariant group, 58.1% in the BA.2 subvariant group, and 51.0% in the BA.5 subvariant group. The diagnostic sensitivities for Omicron BA.1, BA.2, and BA.5 subvariant groups were 96.6%, 100%, and 96.4% for non-elderly (aged <60 years) patients and 28.4%, 29.7%, and 34.2% for elderly (aged ≥60 years) patients, respectively. CONCLUSIONS: In Omicron variant of COVID-19, the JRS atypical pneumonia prediction score is a useful tool for distinguishing between COVID-19 pneumonia and bacterial pneumonia only in patients aged <60 years.

Functional decline at 1 year in hospitalized elderly pneumonia with SARS-CoV-2 Omicron variant: Comparison with the ancestral strain and Alpha variant.

In the SARS-CoV-2 Omicron period, the pattern of pneumonia changed from primarily viral pneumonia to pneumonia mixed with bacteria in the elderly. We investigated functional outcomes at 1 year after hospital discharge in patients with primary Omicron pneumonia and pneumonia mixed with bacteria, mainly aspiration pneumonia. Functional decline rates calculated using the Barthel Index at 1 year after hospital discharge were significantly higher in the pneumonia mixed with bacteria group than the primary viral pneumonia group (42.6% vs. 20.5%, p < 0.0001). It is necessary to consider early rehabilitation and treatment in elderly patients even when the predominant strain is the Omicron variant.

Is the JRS atypical pneumonia prediction score useful in detecting COVID-19 pneumonia under nursing or healthcare settings?

BACKGROUND: SARS-CoV-2 causes frequent outbreaks in elderly care facilities that meet the criteria for nursing and healthcare-associated pneumonia (NHCAP). We evaluated whether the Japanese Respiratory Society (JRS) atypical pneumonia prediction score could be adapted to the diagnosis of nursing and healthcare acquired COVID-19 (NHA-COVID-19) with pneumonia. METHODS: We analyzed 516 pneumonia patients with NHA-COVID-19 and compared them with 1505 pneumonia patients with community-associated COVID-19 (CA-COVID-19). NHA-COVID-19 patients were divided into six groups; 80 cases had the ancestral strain, 76 cases had the Alfa variant, 30 cases had the Delta variant, 120 cases had the Omicron subvariant BA.1, 53 cases had the Omicron subvariant BA.2, and 157 cases had the Omicron subvariant BA.5. RESULTS: The sensitivities of the diagnosis of atypical pneumonia in patients with NHA-COVID-19 based on four or more predictors were 22.8 % in the ancestral strain group, 32.0 % in the Alfa variant group, 34.5 % in the Delta variant group, 23.1 % in the BA.1 subvariant group, 32.7 % in the BA.2 subvariant group, and 30.4 % in the BA.5 subvariant group. The diagnostic sensitivity for the presumptive diagnosis of atypical pneumonia was significantly lower for NHA-COVID-19 than for CA-COVID-19 (28.2 % vs 64.1 %, p < 0.0001). CONCLUSIONS: Our present study demonstrated that the JRS atypical pneumonia prediction score is not a useful tool in elderly patients even if there is a lot of atypical pneumonia in the NHCAP group. The caution is necessary that JRS atypical pneumonia prediction score was not fully applied to prediction for NHA-COVID-19 pneumonia.

Nursing and healthcare-associated pneumonia due to SARS-CoV-2 Omicron variant.

BACKGROUND: There were many differences in the clinical characteristics between nursing and healthcare-associated pneumonia (NHCAP) and community-acquired pneumonia (CAP) due to the SARS-CoV-2 ancestral strain, Alpha variant and Delta variant. With the replacement of the Delta variant by the Omicron variant, the Omicron variant showed decreased infectivity to lung and was less pathogenic. We investigated the clinical differences between NHCAP and CAP due to the Omicron variant. METHODS: We analyzed 516 NHCAP and 547 CAP patients with COVID-19 pneumonia. Of 516 patients with COVID-19 NHCAP, 330 cases were the Omicron variant (120 cases were BA.1, 53 cases were BA.2, and 157 cases were BA.5 subvariants) and 186 cases were non-Omicron variants. RESULTS: The median age, frequency of comorbid illness, rates of intensive care unit (ICU) stay, and mortality rate were significantly higher in Omicron patients with NHCAP than in those with CAP. Rates of ICU stay and in-hospital mortality were significantly higher in NHCAP patients with non-Omicron variants compared with those in the Omicron variant group. No clinical differences were observed in patients with NHCAP among the Omicron BA.1, BA.2, and BA.5 subvariant groups. CONCLUSIONS: The present study supported that the NHCAP category is necessary not only for bacterial pneumonia but also viral pneumonia. It is necessary to consider prevention and treatment strategies depending on the presence or absence of applicable criteria for NHCAP.

Comparison of pneumonia severity scores for COVID-19 patients with the Omicron variant.

INTRODUCTION: We demonstrated that there was a significant relationship between the severity measured using the A-DROP scoring system and the mortality rate in patients with COVID-19 community-acquired pneumonia (CAP) in the ancestral strain, Alpha variant, and Delta variant. We investigated the usefulness of the A-DROP scoring system in SARS-CoV-2 Omicron variant CAP and compared it with severity scores, the Pneumonia Severity Index (PSI) and CURB-65 score. METHODS: We analyzed a total of 547 patients with COVID-19 CAP Omicron variant; 198 cases were the BA.1 subvariant, 127 cases were the BA.2 subvariant, and 222 cases were the BA.5 subvariant, respectively. RESULTS: The mortality rates in patients with COVID-19 CAP among the three Omicron subvariants were identical in each pneumonia severity group. The mortality rate in patients with the Omicron variant was 0 % in patients classified with mild disease, 0.6 % in those with moderate disease, 10.4 % in those with severe disease, and 34.8 % in those with extremely severe disease. The mortality rate in patients with COVID-19 CAP increased depending on the severity classified according to the A-DROP system in each of the Omicron subvariants (Cochran-Armitage trend test; p < 0.001). The values of the area under the curve in Receiver Operating Characteristic analysis for prediction of 30-day mortality was 0.881, 0.879, and 0.863 for A-DROP, PSI, and CURB-65, respectively. There were no significant differences in the predictive ability of each pneumonia severity score. CONCLUSIONS: Our results demonstrated that the A-DROP scoring system is useful for predicting mortality in patients with COVID-19 CAP.

Preparation and characterization of carboxymethylated Aureobasidium pullulans ß-(1 → 3, 1 → 6)-glucan and its in vitro antioxidant activity.

Aureobasidium pullulans ß-(1 â†’ 3, 1 â†’ 6)-glucan (APG) has a high degree of ß-(1 â†’ 6)-glucosyl branching and a regular triple helical structure similar to that of schizophyllan. In this study, APG was carboxymethylated to different degrees of substitution (DS = 0.51, 1.0, and 2.0, denoted CMAPG 1-3, respectively) using a heterogeneous reaction. With increasing DS, the triple-helix structure drastically decreased and converted to a random coil structure in CMAPG 3. Further, aqueous solutions of CMAPG changed from pseudoplastic fluids to perfect Newtonian liquids with increasing DS, indicating that the intra- and intermolecular hydrogen bonds had been cleaved by the substituents to form a random coil structure. In addition, APG and CMAPG solutions exhibited scavenging ability against hydroxyl, organic, and sulfate radicals. It was also found that the carboxymethylation of APG drastically enhanced the organic radical scavenging ability. On the basis of the relationship between the DS and radical scavenging ability of the CMAPG samples, we believe hydroxyl and organic radicals were preferably scavenged by the donation of hydrogen atoms from the glucose rings and the methylene moieties of the carboxymethyl groups, respectively. Considering the obtained results, CMAPG and APG are expected to have applications in pharmaceuticals, functional foods, and cosmetics as antioxidant polysaccharides.

In situ characterization of the agglutination of lectins via cross-linking of carbohydrates by time-resolved measurement of forward static light scattering.

We present real-time observations of a structurally variable process for cross-linking agglutination between multivalent lectins and glycoclusters using a small-angle forward static light scattering (F-SLS) technique. In this study, a cross-linking agglutination reaction was carried out using a tetravalent Neu5Acα2,6LacNAc-glycocluster and Sambucus sieboldiana agglutinin (SSA). The scattering intensity of time-resolved F-SLS increased with formation of the Neu5Acα2,6LacNAc-glycocluster-SSA cross-linked complex. Using this approach, fine sequential cross-linking agglutination between glycoclusters and lectins was observed in real-time. The rate of increase in the intensity of time-resolved F-SLS increased with the concentration of sialo-glycoclusters and SSA. Structural analysis based on the fractal dimension using time-resolved F-SLS patterns revealed that the density of the aggregates changed with progression of the cross-linking reaction until equilibrium was reached. This is the first report to evaluate the cross-linking agglutination reaction between glycoclusters and lectins and analysis of the subsequent structure of the obtained aggregates using time-resolved measurements of F-SLS.

Clinical Efficacy of the Neutralizing Antibody Therapy Sotrovimab in Patients with SARS-CoV-2 Omicron BA.1 and BA.2 Subvariant Infections.

Sotrovimab, an antibody active against severe acute respiratory syndrome coronavirus 2 that neutralizes antibodies, reduced the risk of COVID-19-related hospitalization or death in studies conducted before the emergence of the Omicron variant. The objective of this study is to evaluate the clinical efficacy of sotrovimab in patients with mild to moderate COVID-19 Omicron BA.1 and BA.2 subvariant infections using a propensity score matching method. The propensity score-matched cohort study population was derived from patients who received sotrovimab. We derived a comparator group from an age- and sex-matched population who were recuperating in a medical facility after COVID-19 infection or from elderly person entrance facilities during the same period who were eligible for but did not receive sotrovimab treatment. In total, 642 patients in the BA.1 subvariant group and 202 in the BA.2 subvariant group and matched individuals were analyzed. The outcome was the requirement for oxygen therapy. In the treatment group, 26 patients with the BA.1 subvariant and 8 patients with the BA.2 subvariant received oxygen therapy. The administration of oxygen therapy was significantly lower in the treatment group than in the control group (BA.1 subvariant group, 4.0% vs. 8.7%, p = 0.0008; BA.2 subvariant group, 4.0% vs. 9.9%, p = 0.0296). All these patients were admitted to our hospitals and received additional therapy and then recovered. No deaths were observed in either group. Our results demonstrate that the sotrovimab antibody treatment may be associated with a reduction in the requirement for oxygen therapy among high-risk patients with mild to moderate COVID-19 Omicron BA.1 and BA.2 subvariants.

Validation of JRS atypical pneumonia score in patients with community-acquired Chlamydia psittaci pneumonia.

INTRODUCTION: The Japanese Respiratory Society (JRS) atypical pneumonia score is a useful tool for the rapid presumptive diagnosis of atypical pneumonia. We investigated the clinical features of community-acquired pneumonia (CAP) due to Chlamydia psittaci and validated the JRS atypical pneumonia score in patients with C. psittaci CAP. METHODS: This study was conducted at 30 institutions and assessed a total of 72 sporadic cases with C. psittaci CAP, 412 cases with Mycoplasma pneumoniae CAP, and 576 cases with Streptococcus pneumoniae CAP. RESULTS: Sixty-two of 72 patients with C. psittaci CAP had a history of avian exposure. Among the six parameters of the JRS score, matching rates of four parameters were significantly lower in the C. psittaci CAP than the M. pneumoniae CAP in the following parameters: age <60 years, no or minor comorbid illness, stubborn or paroxysmal cough, and absence of chest adventitious sounds. The sensitivity of the diagnosis of atypical pneumonia in patients with C. psittaci CAP was significantly lower than the M. pneumoniae CAP (65.3% and 87.4%, p < 0.0001). When the diagnostic sensitivity was analyzed for different ages, the diagnostic sensitivities for the C. psittaci CAP were 90.5% for non-elderly patients and 30.0% for elderly patients. CONCLUSIONS: The JRS atypical pneumonia score is a useful tool for distinguishing between C. psittaci CAP and bacterial CAP in patients aged <60 years, but not in patients aged ≥60 years. A history of avian exposure in middle-aged patients with normal white blood cell count may be suggestive of C. psittaci pneumonia.

Heterologous expression of the lectin CmRlec from Cordyceps militaris (Cordycipitaceae, Ascomycota) in Escherichia coli.

Ascomycete lectins may play an important role in their life cycle. In this report, we mined a ricin B-type lectin, named CmRlec, from the Cordyceps militaris genome by homology search. Furthermore, we succeeded in the soluble expression of CmRlec using ß-glucuronidase as a solubilization tag and demonstrated that this lectin is a novel chitin-recognizing lectin.

Assessment of the pneumonia severity score in community-acquired and nursing and healthcare-associated pneumonia due to COVID-19.

INTRODUCTION: The Japanese Respiratory Society (JRS) pneumonia guidelines recommend simple predictive rules, the A-DROP scoring system, for assessment of the severity of community-acquired pneumonia (CAP) and nursing and healthcare-associated pneumonia (NHCAP). We evaluated whether the A-DROP system can be adapted for assessment of the severity of coronavirus disease 2019 (COVID-19) pneumonia. METHODS: Data from 1141 patients with COVID-19 pneumonia were analyzed, comprising 502 patients observed in the 1st to 3rd wave period, 338 patients in the 4th wave and 301 patients in the 5th wave in Japan. RESULTS: The mortality rate and mechanical ventilation rate were 0% and 1.4% in patients classified with mild disease (A-DROP score, 0 point), 3.2% and 46.7% in those with moderate disease (1 or 2 points), 20.8% and 78.3% with severe disease (3 points), and 55.0% and 100% with extremely severe disease (4 or 5 points), indicating an increase in the mortality and mechanical ventilation rates in accordance with severity (Cochran-Armitage trend test; p = <0.001). This significant relationship between the severity in the A-DROP scoring system and either the mortality rate or mechanical ventilation rate was observed in patients with COVID-19 CAP and NHCAP. In each of the five COVID-19 waves, the same significant relationship was observed. CONCLUSIONS: The mortality rate and mechanical ventilation rate in patients with COVID-19 pneumonia increased depending on severity classified according to the A-DROP scoring system. Our results suggest that the A-DROP scoring system can be adapted for the assessment of severity of COVID-19 CAP and NHCAP.

Prognosis of activities of daily living function in hospitalized patients with nursing and healthcare-associated pneumonia due to COVID-19.

Nursing and healthcare-associated pneumonia (NHCAP) is associated with decreased physical function. We investigated the functional outcomes at 1 year after hospital discharge in patients with COVID-19 pneumonia. Functional decline rates for calculating the Barthel Index at the time of hospital discharge and at 1 year after hospital discharge were significantly higher in the NHCAP group than the community-acquired pneumonia group (at hospital discharge, 54.0% vs. 31.2%, respectively, p < 0.0001; 1 year follow-up, 37.9% vs. 8.6%, respectively, p < 0.0001). It is necessary to consider early rehabilitation, and treatment depending on the presence or absence of applicable criteria for NHCAP.

CmLec4, a lectin from the fungus Cordyceps militaris, controls host infection and fruiting body formation.

Fungi belonging to the Ascomycete genus Cordyceps are endoparasitoids and parasites, mainly of insects and other arthropods. Cordyceps militaris has been used as a therapeutic drug for cancer patients. However, the infection, parasitism, and fruiting body formation mechanisms of this fungus are still unknown. Based on our hypothesis that lectin(s) is involved in the interaction between the C. militaris fungi and insects, we partially purified and characterized a new lectin from C. militaris, designated CmLec4. In addition, we searched for substance(s) in the infected silkworm extracts that could bind to CmLec4, and succeeded in purifying the sex-specific storage protein 2 as a specific binding target. To examine function of the binding protein during the process of parasitism, we investigated the effect of recombinant CmLec4 on silkworms by inoculating the protein into silkworm pupae, and found that it significantly delayed emergence compared to the control. Furthermore, cmlec4 gene knockout strains constructed in this study produced markedly lower amounts of fruiting body than the wild-type strain. All the results revealed that the lectin CmLec4 produced by C. militaris would be involved in the infection into silkworm and fruiting body formation from the host.

Changes in diagnostic usefulness of the JRS scoring system in COVID-19 pneumonia by SARS-CoV-2 vaccination.

INTRODUCTION: The Japanese Respiratory Society (JRS) scoring system is a useful tool for the rapid presumptive diagnosis of atypical pneumonia in non-elderly (aged <60 years) patients. As SARS-CoV-2 vaccination progresses, COVID-19 in elderly people has markedly reduced. We investigated changes in diagnostic usefulness of the JRS scoring system in COVID-19 pneumonia between the Delta variant group (vaccination period) and non-Delta variant group (before the vaccination period). METHODS: This study was conducted at five institutions and assessed a total of 1121 patients with COVID-19 pneumonia (298 had the Delta variant). During the vaccination period, the Delta variant has spread and replaced the Alfa variant. We evaluated the vaccination period as the Delta variant group. RESULTS: Among the six parameters of the JRS scoring system, matching rates of two parameters were higher in the Delta variant group than the non-Delta variant group (pre-vaccination period): age <60 years (77.5% vs 42.2%, P < 0.0001) and no or minor comorbid illness (69.1% vs 57.8%, p = 0.0007). The sensitivity of the diagnosis of atypical pneumonia in patients with COVID-19 pneumonia was significantly higher in the Delta variant group compared with the non-Delta variant group (80.2% vs 58.3%, p < 0.0001). When the diagnostic sensitivity was analyzed for different ages, the diagnostic sensitivities for the Delta variant and non-Delta variant groups were 92.6% and 95.5% for non-elderly patients and 39.1% and 32.5% for elderly patients, respectively. CONCLUSIONS: Our results demonstrated that the JRS scoring system is a useful tool for distinguishing between COVID-19 pneumonia and bacterial pneumonia in the COVID-19 vaccination period, but not before the vaccination period.

Optimization of the conditions for the immobilization of glycopolypeptides on hydrophobic silica particulates and simple purification of lectin using glycopolypeptide-immobilized particulates.

Glycopolypeptide-immobilized particulates exhibit high binding selectivities and affinities for several analytes. However, to date, the conditions for the synthesis of glycopolypeptide-immobilized particulates have not been optimized and the application of these particulates as carriers for affinity chromatography has not been reported. Accordingly, herein, as a model compound for determining the optimal conditions for the immobilization of an artificial glycopolymer on hexyl-containing hybrid silica particulates (HSPs), the glycopolypeptide poly [GlcNAcß1,4GlcNAc-ß-NHCO-(CH2)5NH-/CH3(CH2)9NH-/γ-PGA] (3) containing multivalent chitobiose moieties and multivalent decyl groups with a γ-polyglutamic acid backbone was synthesized. Immobilization of 3 on HSPs under each condition was evaluated by a lectin-binding assay using wheat germ (Triticum vulgaris) agglutinin (WGA), which is an N-acetylglucosamine-binding lectin. As a result, the optimal immobilization conditions for HSPs at 25 mg/mL were obtained at dimethyl sulfoxide (DMSO) concentration of reaction solvent in the range of 1(DMSO):9(water) to 4(DMSO):6(water) and a compound 3 concentration in the range of 125 nM-1250 nM. Furthermore, the influence of the alkyl group structure introduced into glycopolypeptide for imparting hydrophobicity to it on the immobilization of glycopolypeptide on HSPs was investigated. As a result of comparing three types, poly [GlcNAcß1,4GlcNAc-ß-NHCO-(CH2)5NH-/γ-PGA] (1) with no alkyl group, poly [GlcNAcß1,4GlcNAc-ß-NHCO-(CH2)5NH-/CH3(CH2)4NH-/γ-PGA] (2) with a pentyl group, and 3 with a decyl group, 3 showed the best immobilization efficiency on HSPs. Finally, 1 mg 3-immobilized HSPs prepared under the optimum conditions adsorbed approximately 7.5 µg WGA in a structure-specific manner. We also achieved a simple WGA purification from raw wheat germ extract as a practical example using 3-immobilized HSPs. We believe that in the future, these glycopolypeptide-immobilized particulates will be used not only for the purification of plant lectins, but also as specific adsorbents for various lectins-like substances such as in vivo lectins, pathogenic viruses, and toxin proteins.

Clinical efficacy of casirivimab-imdevimab antibody combination treatment in patients with COVID-19 Delta variant.

INTRODUCTION: Casirivimab-imdevimab, an antibody cocktail containing two severe acute respiratory syndrome coronavirus 2 neutralizing antibodies, reduces the viral load and the risk of coronavirus disease 2019 (COVID-19)-related hospitalization or death. The objective of this study was to evaluate the clinical efficacy of casirivimab-imdevimab in patients with COVID-19 Delta variant in Japan. METHODS: This study was conducted at five institutions and assessed a total of 461 patients with COVID-19 who met the inclusion criteria. The treatment group received a dose of casirivimab-imdevimab consisting of a cocktail of two monoclonal antibodies, (casirivimab 600 mg and imdevimab 600 mg intravenously). The control consisted of age- and sex-matched COVID-19 patients (n = 461) who sufficed the inclusion criteria but did not receive casirivimab-imdevimab. The outcome was the requirement of oxygen therapy. RESULTS: In the treatment group, patients received oxygen therapy (n = 30), nasal canula (n = 23), high flow nasal cannula (n = 5), and mechanical ventilation (n = 2). In the control group, patients received oxygen therapy (n = 56), nasal canula (n = 45), high flow nasal cannula (n = 8), and mechanical ventilation (n = 3). The administration of oxygen therapy was significantly lower in the treatment group than the control group (6.5% vs. 12.1%, P = 0.0044). All these patients admitted to our hospitals and received additional therapy and recovered. CONCLUSIONS: Our results demonstrate that the casirivimab-imdevimab combination antibody treatment is associated with reduced rates of requiring oxygen therapy among high-risk patients with COVID-19 Delta variant.

Clinical features of nursing and healthcare-associated pneumonia due to COVID-19.

INTRODUCTION: The objective of this study was to clarify the clinical differences between nursing and healthcare-associated pneumonia (NHCAP) and community-acquired pneumonia (CAP) due to COVID-19. We also investigated the clinical characteristics to determine whether there is a difference between the variant and non-variant strain in patients with NHCAP due to COVID-19. In addition, we analyzed the clinical outcomes in NHCAP patients with mental disorders who were hospitalized in a medical institution for treatment of mental illness. METHODS: This study was conducted at five institutions and assessed a total of 836 patients with COVID-19 pneumonia (154 cases were classified as NHCAP and 335 had lineage B.1.1.7.). RESULTS: No differences in patient background, clinical findings, disease severity, or outcomes were observed in patients with NHCAP between the non-B.1.1.7 group and B.1.1.7 group. The median age, frequency of comorbid illness, rates of intensive care unit stay, and mortality rate were significantly higher in patients with NHCAP than in those with CAP. Among the patients with NHCAP, the mortality rate was highest at 37.5% in patients with recent cancer treatment, followed by elderly or disabled patients receiving nursing care (24.3%), residents of care facilities (23.0%), patients receiving dialysis (13.6%), and patients in mental hospitals (9.4%). CONCLUSIONS: Our results demonstrated that there were many differences in the clinical characteristics between NHCAP patients and CAP patients due to COVID-19. It is necessary to consider the prevention and treatment content depending on the presence or absence of applicable criteria for NHCAP.