Cross-sectional surveillance study of long COVID in Toyonaka city, Osaka prefecture, Japan

BACKGROUND

As the COVID-19 epidemic continues, concerns about long-term health impacts, specifically long COVID, persist. While the prevalence and symptomatology of long COVID have been explored in various global contexts, large-scale cohort studies in Japan remain limited, especially after the advent of the Omicron variant.

METHODS

In this observational study, 4,047 residents with a history of COVID-19 living in Toyonaka City, Osaka Prefecture, were assessed for long COVID symptoms using the VOICE mobile application and a paper survey. Respondents provided demographic and health information, as well as information regarding COVID-19 infection and subsequent symptoms. A Cox proportional hazard regression model was used to estimate the multivariable-adjusted hazard ratios and 95 % confidence intervals for overall morbidity of long COVID symptoms.

RESULTS

The survey found that 5.2 % of participants reported the persistence of one or more symptoms at 30 days post-onset. Fatigue was the most commonly reported symptom (1.75 %), followed by hair loss (1.41 %), and cough (1.28 %). Factors associated with an increased risk of experiencing long COVID symptoms included BMI, severe illness during the acute phase, and infection with certain COVID-19 variant strains, including Alpha, Delta, and Omicron. However, the incidence rate of long COVID appears to be decreasing with the dominance of the Omicron variant.

CONCLUSIONS

This large-scale study from Toyonaka City suggests a 5.2 % prevalence rate for persistent COVID-19 symptoms 4 weeks post-infection, potentially indicating a lower prevalence of long COVID in Japanese populations after the rise of the Omicron variant.

Analysis of the effectiveness of combination antimicrobial therapy for Legionnaires' disease: A nationwide inpatient database study

OBJECTIVES

The effectiveness of monotherapy and combination therapy with quinolones and macrolides for treating Legionnaires' disease remains uncertain; this study aimed to assess the comparative effectiveness of three treatment approaches.

METHODS

Using a nationwide inpatient database, we analyzed 3560 eligible patients hospitalized for Legionnaires' disease between April 1, 2014, and March 31, 2021; patients were divided into combination therapy, quinolone monotherapy, and macrolide monotherapy groups according to the antibiotics administered within 2 days of admission. We compared in-hospital mortality, total hospitalization costs, and length of stay across these groups using multiple propensity score analysis with inverse probability of treatment weighting.

RESULTS

Of the 3560 patients, there were 564 (15.8%), 2221 (62.4%), and 775 (21.8%) patients in the combination therapy, quinolone monotherapy, and macrolide monotherapy groups, respectively. No significant differences were observed in in-hospital mortality between combination therapy and quinolone monotherapy groups, and between combination therapy and macrolide monotherapy groups. There were no significant differences in total hospitalization costs or length of stay among the three groups.

CONCLUSION

The study suggests that there may not be a significant advantage in using a combination of quinolones and macrolides over monotherapy for the treatment of Legionnaires' disease. Given the potential for increased side effects, careful consideration is advised when choosing this combination therapy.

Oral mouthwashes for asymptomatic to mildly symptomatic adults with COVID-19 and salivary viral load: a randomized, placebo-controlled, open-label clinical trial

BACKGROUND

Recent randomized clinical trials suggest that the effect of using cetylpyridinium chloride (CPC) mouthwashes on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load in COVID-19 patients has been inconsistent. Additionally, no clinical study has investigated the effectiveness of on-demand aqueous chlorine dioxide mouthwash against COVID-19.

METHODS

We performed a randomized, placebo-controlled, open-label clinical trial to assess for any effects of using mouthwash on the salivary SARS-CoV-2 viral load among asymptomatic to mildly symptomatic adult COVID-19-positive patients. Patients were randomized to receive either 20 mL of 0.05% CPC, 10 mL of 0.01% on-demand aqueous chlorine dioxide, or 20 mL of placebo mouthwash (purified water) in a 1:1:1 ratio. The primary endpoint was the cycle threshold (Ct) values employed for SARS-CoV-2 salivary viral load estimation. We used linear mixed-effects models to assess for any effect of the mouthwashes on SARS-CoV-2 salivary viral load.

RESULTS

Of a total of 96 eligible participants enrolled from November 7, 2022, to January 19, 2023, 90 were accepted for the primary analysis. The use of 0.05% CPC mouthwash was not shown to be superior to placebo in change from baseline salivary Ct value at 30 min (difference vs. placebo, 0.640; 95% confidence interval [CI], -1.425 to 2.706; P = 0.543); 2 h (difference vs. placebo, 1.158; 95% CI, -0.797 to 3.112; P = 0.246); 4 h (difference vs. placebo, 1.283; 95% CI, -0.719 to 3.285; P = 0.209); 10 h (difference vs. placebo, 0.304; 95% CI, -1.777 to 2.385; P = 0.775); or 24 h (difference vs. placebo, 0.782; 95% CI, -1.195 to 2.759; P = 0.438). The use of 0.01% on-demand aqueous chlorine dioxide mouthwash was also not shown to be superior to placebo in change from baseline salivary Ct value at 30 min (difference vs. placebo, 0.905; 95% CI, -1.079 to 2.888; P = 0.371); 2 h (difference vs. placebo, 0.709; 95% CI, -1.275 to 2.693; P = 0.483); 4 h (difference vs. placebo, 0.220; 95% CI, -1.787 to 2.226; P = 0.830); 10 h (difference vs. placebo, 0.198; 95% CI, -1.901 to 2.296; P = 0.854); or 24 h (difference vs. placebo, 0.784; 95% CI, -1.236 to 2.804; P = 0.447).

CONCLUSIONS

In asymptomatic to mildly symptomatic adults with COVID-19, compared to placebo, the use of 0.05% CPC and 0.01% on-demand aqueous chlorine dioxide mouthwash did not lead to a significant reduction in SARS-CoV-2 salivary viral load. Future studies of the efficacy of CPC and on-demand aqueous chlorine dioxide mouthwash on the viral viability of SARS-CoV-2 should be conducted using different specimen types and in multiple populations and settings.

Clostridium butyricum Bacteremia Associated with Probiotic Use, Japan

Clostridium butyricum, a probiotic commonly prescribed in Asia, most notably as MIYA-BM (Miyarisan Pharmaceutical Co., Ltd.; https://www.miyarisan.com), occasionally leads to bacteremia. The prevalence and characteristics of C. butyricum bacteremia and its bacteriologic and genetic underpinnings remain unknown. We retrospectively investigated patients admitted to Osaka University Hospital during September 2011-February 2023. Whole-genome sequencing revealed 5 (0.08%) cases of C. butyricum bacteremia among 6,576 case-patients who had blood cultures positive for any bacteria. Four patients consumed MIYA-BM, and 1 patient consumed a different C. butyricum-containing probiotic. Most patients had compromised immune systems, and common symptoms included fever and abdominal distress. One patient died of nonocclusive mesenteric ischemia. Sequencing results confirmed that all identified C. butyricum bacteremia strains were probiotic derivatives. Our findings underscore the risk for bacteremia resulting from probiotic use, especially in hospitalized patients, necessitating judicious prescription practices.

Using novel micropore technology combined with artificial intelligence to differentiate Staphylococcus aureus and Staphylococcus epidermidis

Methods for identifying bacterial pathogens are broadly categorised into conventional culture-based microbiology, nucleic acid-based tests, and mass spectrometry. The conventional method requires several days to isolate and identify bacteria. Nucleic acid-based tests and mass spectrometry are relatively rapid and reliable, but they require trained technicians. Moreover, mass spectrometry requires expensive equipment. The development of a novel, inexpensive, and simple technique for identifying bacterial pathogens is needed. Through combining micropore technology and assembly machine learning, we developed a novel classifier whose receiver operating characteristic (ROC) curve showed an area under the ROC curve of 0.94, which rapidly differentiated between Staphylococcus aureus and Staphylococcus epidermidis in this proof-of-concept study. Morphologically similar bacteria belonging to an identical genus can be distinguished using our method, which requires no specific training, and may facilitate the diagnosis and treatment of patients with bacterial infections in remote areas and in developing countries.

Epidemiology of post-COVID conditions beyond 3 years and factors associated with their persistence longer than 2 years: A cross-sectional study

OBJECTIVE

This study aimed to investigate the epidemiology of post-coronavirus disease 2019 (COVID-19) conditions (PCCs) beyond 3 years and identify factors associated with their persistence longer than 2 years.

STUDY DESIGN

Cross-sectional questionnaire-based survey.

METHODS

We surveyed patients who had recovered from COVID-19 and visited our institution from February 2020 to November 2021. Demographic and clinical data and information on the presence and duration of PCCs were obtained. We identified factors associated with the persistence of PCCs longer than 2 years using multivariate linear regression analyses.

RESULTS

Among 935 patients surveyed, 407 completed the survey. Among them, 360 patients had mild disease in the acute phase. The proportions of participants with at least one symptom at 1, 2, and 3 years after symptom onset or COVID-19 diagnosis were 33.2%, 29.8%, and 5.7%, respectively. The numbers of participants with and without any residual symptoms 2 years after the onset of COVID-19 were 87 and 193, respectively. After multivariate adjustment, persistence of PCCs longer than 2 years was associated with lower body mass index, presence of any underlying medical conditions, and number of symptoms lasting for more than 1 month ≥ 5.

CONCLUSIONS

The prevalence of PCCs decreased 2 years after symptom onset or COVID-19 diagnosis. We also identified factors associated with PCC persistence longer than 2 years, which could help primary care physicians and patients with PCCs predict the duration of PCCs and better understand their natural history, thus reducing patients' anxiety about their duration.

Analysis of Differences in Characteristics of High-Risk Endemic Areas for Contracting Japanese Spotted Fever, Tsutsugamushi Disease, and Severe Fever With Thrombocytopenia Syndrome

Background

Tick-borne infections, including tsutsugamushi disease, Japanese spotted fever, and severe fever with thrombocytopenia syndrome (SFTS), are prevalent in East Asia with varying geographic distribution and seasonality. This study aimed to investigate the differences in the characteristics among endemic areas for contracting each infection.

Methods

We conducted an ecologic study in Japan, using data from a nationwide inpatient database and publicly available geospatial data. We identified 4493 patients who were hospitalized for tick-borne infections between July 2010 and March 2021. Mixed-effects modified Poisson regression analysis was used to identify factors associated with a higher risk of contracting each tick-borne disease (Tsutsugamushi, Japanese spotted fever, and SFTS).

Results

Mixed-effects modified Poisson regression analysis revealed that environmental factors, such as temperature, sunlight duration, elevation, precipitation, and vegetation, were associated with the risk of contracting these diseases. Tsutsugamushi disease was positively associated with higher temperatures, farms, and forests, whereas Japanese spotted fever and SFTS were positively associated with higher solar radiation and forests.

Conclusions

Our findings from this ecologic study indicate that different environmental factors play a significant role in the risk of transmission of tick-borne infections. Understanding the differences can aid in identifying high-risk areas and developing public health strategies for infection prevention. Further research is needed to address causal relationships.

Epidemiological trends of traveler's diarrhea in Japan: An analysis of imported infectious disease registry data from 2017-2022

Traveler's diarrhea (TD) is a global problem, and identifying the causative organisms of TD is important for adequate treatment. Therefore, this study retrospectively analyzed TD cases in patients who returned to Japan after traveling abroad to determine the causative organisms by travel region. We included patients with a final diagnosis of TD registered in the Japan Registry for Infectious Diseases from Abroad database from September 25, 2017, to September 1, 2022, from 14 medical institutions. A total of 919 patients were analyzed; the causative TD pathogen was identified in 188 cases (20%), of which 154 were caused by diarrheagenic bacteria, the most common being Campylobacter spp. (64%). A 2.2 mg/dL C-reactive protein concentration cutoff value had some predictive ability for bacterial TD (negative predictive value, 89%). Therefore, the C-reactive protein level may help rule out bacterial diarrhea and prevent unnecessary antimicrobial administration when patients cannot provide a stool specimen.

Epidemiological analysis of Legionella pneumonia in Japan: A national inpatient database study

BACKGROUND

Legionella pneumonia, a severe form of pneumonia, is caused by Legionella bacteria. The epidemiology of Legionnaires' disease in Japan, including seasonal trends, risk factors for severe disease, and fatality rates, is unclear. This study examined the epidemiology of Legionella pneumonia in Japan.

METHODS

This retrospective cohort study included data of adult patients hospitalized for Legionella pneumonia (identified using the ICD-10 code, A481) in the Japanese Diagnosis Procedure Combination inpatient database, from April 2011 to March 2021. We performed multivariable logistic regression analysis to explore the prognostic factors of in-hospital mortality.

RESULTS

Of 7370 enrolled hospitalized patients from 1140 hospitals (male, 84.4%; aged >50 years, 87.9%), 469 (6.4%) died during hospitalization. The number of hospitalized patients increased yearly, from 658 in 2016 to 975 in 2020. Multivariable logistic regression analysis revealed that higher in-hospital mortality was associated with older age, male sex, lower body mass index, worsened level of consciousness, comorbidities (congestive heart failure, chronic renal diseases, and metastasis), hospitalization from November to May, and ambulance use. However, lower in-hospital mortality was associated with comorbidity (liver diseases), hospitalization after 2013, and hospitalization in hospitals with higher case volume.

CONCLUSIONS

The characterized epidemiology of Legionella pneumonia in Japan revealed a high mortality rate of 6.4%. To the best of our knowledge, this is the first study to demonstrate a higher mortality rate in winter and in patients with congestive heart failure and metastasis. Further research is needed to understand the complex interplay between the prognostic factors of Legionella pneumonia.

Protocol for a Randomized, Open-Label Clinical Trial on the Effect of Mouthwash on Salivary SARS-CoV-2 Load

Mouthwashes containing cetylpyridinium chloride (CPC) or on-demand aqueous chlorine dioxide (ACD) have potential to reduce the salivary severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) load in individuals with SARS-CoV-2 infection. This study will evaluate the effect of CPC and on-demand ACD mouthwashes on salivary SARS-CoV-2 levels in individuals with acute asymptomatic or mild SARS-CoV-2 infection (COVID-19) staying in a residential recuperation facility in Osaka, Japan. This randomized, open-label clinical trial will include three equal-sized groups (CPC mouthwash, on-demand ACD mouthwash, and placebo), with 30 participants per group. A stratified replacement block method will be used to ensure balanced allocation based on symptom presence and days since symptom onset. Participants will use mouthwash at set times for 7 days or until the end of recuperation. Saliva samples will be collected at multiple time points and tested for SARS-CoV-2 using quantitative reverse transcription polymerase chain reaction. The primary outcome will be changes in salivary SARS-CoV-2 viral load 2 h after the first mouthwash use compared with the pre-mouthwash level. Secondary outcomes will include changes in salivary viral load and clinical parameters at different time points. This study was registered with the Japan Registry of Clinical Trials on 18 October 2022 (jRCTs051220107).

Efficacy and Safety of Treatment with Plasma from COVID-19-Recovered Individuals

Convalescent plasma therapy, which involves administering plasma from recovered coronavirus disease 2019 (COVID-19) patients to infected individuals, is being explored as a potential treatment for severe cases of COVID-19. This study aims to evaluate the efficacy and safety of convalescent plasma therapy in COVID-19 patients with moderate to severe illness. An open-label, single-arm intervention study was conducted without a control group. Plasma collected from recovered COVID-19 patients was administered to eligible participants. The primary endpoint was the proportion of patients who were placed on artificial ventilation or died within 14 days of transfusion. Secondary endpoints included clinical improvement, viral load measurements, and adverse event monitoring. A total of 59 cases were included in the study. The primary endpoint was evaluated by comparing the rate obtained in the study to an existing rate of 25%. The study also assessed clinical improvement, viral load changes, and safety endpoints through adverse event monitoring. Convalescent plasma therapy shows potential as a treatment option for COVID-19. This study aimed to provide evidence for the efficacy and safety of this therapy and may contribute to its future use in treating severe cases of COVID-19.

Analysis of Concentrated COVID-19 Outbreaks in Elderly Facilities in Suita City, Osaka Prefecture, Japan

There are several types of facilities for elderly individuals in Japan. Infection control efforts, such as care provision and medical care access, differ according to the type of facility. Elderly individuals at these facilities who were infected with coronavirus disease 2019 (COVID-19) experienced severe illness and mortality. This study aimed to determine the characteristics of concentrated COVID-19 outbreaks that occurred in nursing homes and care facilities in Suita City. During this study, twenty-five elderly facilities in Suita City with a capacity of 40 or more individuals where an outbreak occurred during the sixth or seventh wave of infection were included. We investigated whether there was a difference in the COVID-19 incidence and the percentage of positive cases according to the type of facility. We also investigated the relationship between the facility capacity and positive case rate and that between the number of positive cases and outbreak duration. The incidence rate of COVID-19 was significantly different according to the facility type (p < 0.001). No association was found between the facility capacity and positive case rate. The outbreak duration increased as the number of positive cases increased (p = 0.004).

Trends of participants in convalescent plasma donation for COVID-19 in Japan as the pandemic evolved

Background

We aimed to investigate chronological changes in the characteristics of participants in a coronavirus disease 2019 convalescent plasma donation study that may benefit optimal collection methods in the future.

Methods

Data from a convalescent plasma donation study from April 30, 2020 to November 5, 2021 were collected and analyzed. After August 23, 2021, an interim analysis of factors linked to higher antibody titers led us to restrict our participant recruitment criteria to participants who were within 4 months of disease onset and to patients who were otherwise most likely to have sufficiently high antibody titers. Overall, 1299 samples from 1179 patients were analyzed.

Results

Over the duration of the study, 35.9% of the samples were deemed eligible for convalescent plasma collection. The overall eligibility rate initially declined, dipping to <20% after one year. During this period, the proportion of enrolled samples from patients who had severe illness also declined, and the proportion of samples from participants who were >120 days post disease onset increased. After the addition of days from onset and vaccination status to our participant recruitment criteria, the eligibility rate improved significantly.

Conclusions

As outbreaks of emerging infectious disease occur, it is desirable to construct and implement a scheme for convalescent plasma donation promptly and to monitor the eligibility rate over time. If it declines, promptly analyze and resolve the associated factors. Additionally, vaccine development and infection prevalence are likely to influence the effective recruitment of participants with high antibody titers.

Evaluation of potential rabies exposure among Japanese international travelers: A retrospective descriptive study

BACKGROUND

Although Japan has been a rabies-free country for >50 years, a few cases have been reported among people traveling abroad. This study aimed to investigate animal exposure among Japanese travelers using the Japanese Registry for Infectious Diseases from Abroad (J-RIDA).

METHOD

In this retrospective analysis, we examined Japanese overseas travelers with animal exposure, as included the J-RIDA database, reported from October 1, 2017, to October 31, 2019, with a focus on pre-exposure prophylaxis (PrEP) administration and the animals to which the patients were exposed.

RESULTS

Among the 322 cases included in the analysis, 19 (5.9%) patients received PrEP and 303 did not. The most common purpose of travel was a non-package tour (n = 175, 54.3%). Most trips (n = 213, 66.1%) were to a single country for <2 weeks. Most patients (n = 286, 87.9%) traveled to countries with a rabies risk. The majority of patients with and without PrEP were injured in rabies-risk countries [n = 270 (89.1%) for non-PrEP and n = 16 (84.2%) for PrEP]. Animals associated with injuries included dogs (55.0%), cats (25.5%), and monkeys (15.5%). Most patients were classified as World Health Organization Category II/III for contact with suspected rabid animals (39.5% and 44.1% for categories II and III, respectively) and had exposure within 5 days of travel. Southeast Asia (n = 180, 55.9%) was the most common region in which travelers were exposed to animals.

CONCLUSIONS

Japanese overseas travelers had contact with animals that could possibly transmit the rabies virus, even on short trips. Promoting pre-travel consultation and increasing awareness of the potential for rabies exposure are important for prevention of rabies among Japanese international travelers.

Aneurysm Infection Caused by Desulfovibrio desulfuricans

An 84-year-old man in Japan who had undergone endovascular aortic repair 9 years earlier had an infected aneurysm develop. We detected Desulfovibrio desulfuricans MB at the site. The patient recovered after surgical debridement, artificial vessel replacement, and appropriate antimicrobial therapy. Clinicians should suspect Desulfovibrio spp. infection in similar cases.

Efficacy of convalescent plasma therapy for COVID-19 in Japan: An open-label, randomized, controlled trial

BACKGROUND

Convalescent plasma is a potential therapeutic option for patients with coronavirus disease 2019 (COVID-19). Despite its use for treating several viral infections, we lack comprehensive data on its efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

We conducted a multicenter, open-label, randomized controlled trial of convalescent plasma therapy with high neutralizing activity against SARS-CoV-2 in high-risk patients within five days after the onset of COVID-19 symptoms. The primary endpoint was the time-weighted average change in the SARS-CoV-2 viral load in nasopharyngeal swabs from days 0-5.

RESULTS

Between February 24, 2021, and November 30, 2021, 25 patients were randomly assigned to either convalescent plasma (n = 14) or standard of care (n = 11) groups. Four patients discontinued their allocated convalescent plasma, and 21 were included in the modified intention-to-treat analysis. The median interval between the symptom onset and plasma administration was 4.5 days (interquartile range, 3-5 days). The primary outcome of the time-weighted average change in the SARS-CoV-2 viral load in nasopharyngeal swabs did not significantly differ between days 0-5 (1.2 log₁₀ copies/mL in the convalescent plasma vs. 1.2 log₁₀ copies/mL in the standard of care (effect estimate, 0.0 [95% confidence interval, -0.8-0.7]; P = 0.94)). No deaths were observed in either group.

CONCLUSIONS

The early administration of convalescent plasma with high neutralizing activity did not contribute to a decrease in the viral load within five days compared with the standard of care alone.

Association between SARS-CoV-2 anti-spike antibody titers and the development of post-COVID conditions: A retrospective observational study

The symptoms that persist after an acute coronavirus disease 2019 (COVID-19) are referred to as post- COVID conditions. Although the cause of post-COVID conditions remains unclear, the host immune response to SARS-CoV-2 may be involved. Hence, we aimed to investigate the effect of serum antibody titers against SARS-CoV-2 on the development of post-COVID conditions. We conducted a retrospective observational study of COVID-19-recovered individuals who attended the clinic at the National Center for Global Health and Medicine between January 2020 and April 2021. Serum SARS-CoV-2 anti-spike antibody titers were measured and a questionnaire survey was used to collect information on the presence of post-COVID conditions and demographic characteristics of the participants. Participants were then divided into two groups: high peak antibody titer group [≥ 0.759 OD450 value], and low peak antibody titer group [< 0.759 OD450 value] and compared their frequency of post-COVID conditions. Of 526 individuals attending the clinic, 457 (86.9%) responded to the questionnaire. We analyzed the data of 227 (49.7%) participants with measurements of serum antibody titers during the peak period. The incidence of depressed mood was significantly higher in the group with higher antibody titers (odds ratio: 2.34, 95% CI: 1.17-4.67, p = 0.016). There was no significant difference in the frequency of the remaining symptoms between the two groups. Among post-COVID conditions, the depressed mood was more frequent in the group with high serum antibody titers which suggests a difference in pathogenesis between depressive mood and other post-COVID conditions that requires further investigation.

The safety of plasma apheresis from donors recovering from COVID-19 infection in Japan

PURPOSE

Since 2020, the novel coronavirus infection (COVID-19) has spread globally. A few studies have investigated the safety of COVID-19 convalescent plasma (CCP) apheresis from COVID-19. This study was the first retrospective observational study of CCP in Japan.

METHODS

We recruit donors from April 2020 to November 2021 and plasmapheresis in our center (NCGM: national center for global health and medicine). We set the primary endpoint as the Donors Adverse Event (DAE) occurrence at the time of the CCP collection. Variable selection was used to explore the determinants of DAE.

RESULTS

Mean and SD age was 50.5 (10.6) years old. Seventy-three (42.2 %) were female, and 87 (33.3 %) were multiple-times donors. Twelve (6.97 % by donors and 4.6 % in total collections) adverse events occurred. The DAEs were VVR (Vaso Vagal Reaction), paresthesia, hypotension, agitation, dizziness, malaise, and hearing impairment/paresthesia. Half of them were VVR during apheresis. DAE occurred only in first-time donors and more in severe illnesses such as using ventilation and ECMO. From the donor characteristics and variable selection, the risk factors are as follows: younger age, female, the severity of disease at the time of the disease, and lower SBP before initiation. Our DAE incidence did not differ from previous studies. DAEs were more likely to occur in CCP apheresis than in healthy donors.

CONCLUSION

We confirm the safety of CCP apheresis in this study, although DAEs were more than healthy donors. More caution should be exercised in the plasma collection for future outbreaks of emerging infectious diseases.

Comparison of the clinical characteristics and outcomes of Japanese patients with COVID-19 treated in primary, secondary, and tertiary care facilities

AIM

To compare the characteristics and clinical course of patients with coronavirus disease (COVID-19) according to the healthcare level of the admitted hospital, to provide an insight into determining the appropriate level of care for each patient.

METHODS

This retrospective, observational study utilized data from the COVID-19 Registry Japan (COVIREGI-JP), the largest Japanese registry of hospitalized patients with COVID-19. Datasets were obtained from reports filed as of May 31, 2022.

RESULTS

A total of 59,707 patients (2004 in the primary care group, 41,420 in the secondary care group, and 16,283 in the tertiary care group) from 585 facilities were included in the analysis. Patients with established risk factors for severe disease, such as old age and the presence of comorbidities, were treated at higher care facilities and had poorer initial conditions and in-hospital clinical course, as well as higher mortality. Analysis of the fatality rates for each complication suggested that patients with complications requiring procedures (e.g. pleural effusions, myocardial ischemia, and arrhythmia) may have better survival rates in facilities with specialist availability. The number of deaths and severe COVID-19 cases in this study were notably less than those reported overseas.

CONCLUSION

Our results showed that more difficult COVID-19 cases with poor outcomes were treated at higher care level facilities in Japan. Attending to possible complications may be useful for selecting an appropriate treatment hospital. Healthcare providers need to maintain a broad perspective on the distribution of medical resources.

Steroid pulse therapy for severe fever with thrombocytopenia syndrome patients may not improve prognosis: Retrospective analysis with overlap weighting using a national inpatient database

BACKGROUND

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease caused by the SFTS virus. Effective treatment for SFTS has not been established, but steroid pulse therapy is often used. This study aimed to verify whether steroid pulse therapy for SFTS improves prognosis or not.

METHODS

Data of SFTS patients were obtained from the Japanese Diagnosis Procedure Combination Database from April 2013 to March 2021. Patients treated with steroid pulse therapy were compared with untreated patients, using overlap weighting and traditional multivariable regression analysis to evaluate the impact of steroid pulse therapy on prognosis.

RESULTS

412 SFTS patients were included in this study, and 66 (16%) underwent steroid pulse therapy within 3 days of admission and were allocated to the steroid pulse therapy group. After overlap weighting, patients in the steroid pulse therapy group had a significantly higher in-hospital mortality rate than patients in the control group (31.1% vs. 20.5%; difference: +10.6%; 95% confidence interval: +2.2% to +19.0%). There were no statistically significant differences in hospitalization cost and length of hospital stay between the two groups. The results of the sensitivity analysis using traditional multivariable regression were similar to those of the main analysis.

CONCLUSION

In the analysis of SFTS patients using the Japanese Diagnosis Procedure Combination inpatient data, steroid pulse therapy did not improve patient prognosis. The evidence does not support the universal use of steroid pulse therapy in patients with severe SFTS.

Deprescribing antacids after the diagnosis of Clostridioides difficile infection: A single-center observational study

Overuse of antacids is associated with the development and recurrence of Clostridioides difficile infection (CDI). Discontinuation of unnecessary antacids for CDI management is advocated; however, the clinical pervasiveness on the discontinuation of antacids remains unclear. We conducted a single-center retrospective observational study to determine the rate of antacid discontinuation following CDI diagnosis. Among 51 patients (58 infections; median age 76.5 years, range 69-82; 53.5% women) treated with antimicrobials against C. difficile, 41 had been treated with antacids, and of these, 18 exhibited no indication for antacid administration. However, none had discontinued antacid use. While CDI provides an opportunity for antacid stewardship, it is not implemented in clinical practice. In addition to the efforts of individual clinicians, the dissemination of knowledge of the indications and side effects of antacids, establishment of a multidisciplinary support system, and creation and implementation of a clinical stewardship pathway are necessary to increase the deprescription of antacids in patients with CDI.

Nationwide Descriptive Epidemiological Study of Patients with COVID-19 Evacuated from Wuhan, China to Japan from January to February, 2020

We investigated the epidemiological findings regarding the route of coronavirus disease 2019 (COVID-19) and infection prevention and control (IPC) measures among returnees in the emergency evacuation from Wuhan, China to Japan during the COVID-19 outbreak in 2020. A total of 12 of the 14 returnees (median age [range]: 49.5 years [29-65 years]; 9 men [75%]) had confirmed COVID-19. The proportion of returnees with COVID-19 was 12/566 (2.1%) in Flights 1-3 and 2/263 (0.8%) in Flights 4 and 5. Six patients were asymptomatic on admission, while 3 patients developed symptoms thereafter. None of the participants reported a specific history of contact with animals, going to seafood markets, or visiting medical facilities. Two patients were in contact with an individual who was confirmed or suspected of having COVID-19. Most patients resided in hotels in the center of Wuhan City, taking taxis and trains for commute. Patients relatively adhered to IPC measures such as wearing a mask and hand hygiene. However, emphasis on IPC measures such as universal masking and more rigorous avoidance of exposure risk might have been necessary to prevent infection. In addition, forced social distancing due to lockdown might have contributed to the lower infection rates in Flights 4 and 5, compared to Flights 1-3.

Analysis of cross-reactivity among flaviviruses using sera of patients with dengue showed the importance of neutralization tests with paired serum samples for the correct interpretations of serological test results for dengue

Dengue is a febrile illness caused by the dengue virus (DENV) that belongs to the genus Flavivirus in the family Flaviviridae. Cross-reactivity between flaviviruses poses a challenge while interpreting serological test results. In the present study, the cross-reactivity of sera of the patients with dengue, who traveled from Japan to DENV-endemic countries, was analyzed by using an enzyme-linked immunosorbent assay (ELISA) and neutralization test (NT). Sixteen serum samples were collected from patients with dengue and were tested for: i) IgM antibodies against Zika virus (ZIKV), West Nile virus (WNV), Japanese encephalitis virus (JEV), and tick-borne encephalitis virus (TBEV) using IgM ELISA, ii) IgG antibody against TBEV using IgG ELISA, and iii) neutralizing antibody against ZIKV, WNV, TBEV, and JEV. Among the 16 samples tested using ELISA, seven samples were IgM-positive for at least one of the other flaviviruses, and nine samples were IgG-positive for TBEV. Neutralizing antibody titers (NATs) against ZIKV, WNV, and TBEV were one-fourth or lower than those against the causative DENV in all samples. The NATs against JEV were one-fourth or lower than those against the causative DENV in six convalescent-phase serum sample among the seven convalescent-phase serum samples. The NAT against DENV of the residual one convalescent-phase serum was similar to that against JEV and that against JEV of its relevant acute-phase serum sample. These results showed that NTs with paired serum samples are important to correctly interpret the serological test results for DENV.

Neutralization activity of IgG antibody in COVID‑19‑convalescent plasma against SARS-CoV-2 variants

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated the anti-SARS-CoV-2 antibody levels, anti-spike (S)-immunoglobulin G (IgG) and anti-nucleocapsid (N)-IgG, and the neutralization activity of IgG antibody in COVID‑19‑convalescent plasma against variants of SARS-CoV-2, alpha, beta, gamma, delta, kappa, omicron and R.1 strains. The study included 30 patients with clinically diagnosed COVID-19. The anti-S-IgG and anti-N-IgG levels ranged from 30.0 to 555.1 and from 10.1 to 752.6, respectively. The neutralization activity (50% inhibition concentration: IC50) for the wild-type Wuhan strain ranged from < 6.3 to 81.5 µg/ml. IgG antibodies were > 100 µg/ml in 18 of 30 (60%) subjects infected with the beta variant. The IC50 values for wild-type and beta variants correlated inversely with anti-S-IgG levels (p < 0.05), but no such correlation was noted with anti-N-IgG. IgG antibodies prevented infectivity and cytopathic effects of six different variants of concern in the cell-based assays of wild-type, alpha, gamma, delta, kappa and R.1 strains, but not that of the beta and omicron strains. IgG is considered the main neutralizing activity in the blood, although other factors may be important in other body tissues.

We Should Pay More Attention to Sex Differences to Predict the Risk of Severe COVID-19: Men Have the Same Risk of Worse Prognosis as Women More Than 10 Years Older

BACKGROUND

Prioritization for novel coronavirus disease 2019 (COVID-19)-related health policies usually considers age and certain other characteristics, but sex is rarely included, despite the higher risk of severe disease in men. The aim of this study was to compare the impact of sex and age on the severity of COVID-19 by estimating the age difference in years for which the risk for men versus women is the same.

METHODS

We analyzed 23,414 Japanese COVID-19 inpatients aged 20-89 years (13,360 men and 10,054 women). We graded the severity of COVID-19 (0 to 5) according to the most intensive treatment required during hospitalization. The risk of grade 2/3/4/5 (non-invasive positive pressure ventilation/invasive mechanical ventilation/extracorporeal membrane oxygenation/death), grade 3/4/5, and separately grade 5 was analyzed using a multiple logistic regression model.

RESULTS

The odds ratio (OR) of grades 2/3/4/5, 3/4/5 (primary outcome), and 5 for men relative to women was 2.76 (95% CI, 2.44-3.12), 2.78 (95% CI, 2.42-3.19), and 2.60 (95% CI, 2.23-3.03), respectively, after adjustment for age and date of admission. These risks for men were equivalent to those for women 14.1 (95% CI, 12.3-15.8), 11.2 (95% CI, 9.7-12.8), and 7.5 (95% CI, 6.3-8.7) years older, respectively.

CONCLUSION

The risks of worse COVID-19 prognosis (grades 3/4/5) in men were equivalent to those of women 11.2 years older. Reanalyzing data extracted from four previous studies also revealed a large impact of sex difference on the severity of COVID-19. We should pay more attention to sex differences to predict the risk of COVID-19 severity and to formulate public health policy accordingly.

[Cerebral toxoplasmosis developed after unrelated bone marrow transplantation for acute myeloid leukemia]

A 16-year-old boy received an unrelated bone marrow transplant while in second remission of acute myeloid leukemia. He suffered from severe oral mucosal complications and had difficulty taking oral drugs such as sulfamethoxazole/trimethoprim (ST). Engraftment was obtained on transplant day 35, and blurred vision and headache appeared around transplant day 60. Funduscopy revealed retinal hemorrhage and macular edema, and an MRI scan of the head revealed a nodular lesion in the left putamen. Toxoplasma gondii was detected by CSF PCR, and cerebral toxoplasmosis was diagnosed. Following therapy with ST and clindamycin, the patient was administered pyrimethamine, sulfadiazine, and leucovorin. Symptoms improved promptly, and CSF PCR was negative 45 days after the start of treatment. Since the prevalence of toxoplasma antibodies increases with age, it is crucial to avoid toxoplasma reactivation by ST after hematopoietic cell transplantation in postpubescent patients.

Establishment and clinical application of SARS-CoV-2 catch column

BACKGROUND

A certain number of patients with coronavirus disease 2019 (COVID-19), particularly those who test positive for SARS-CoV-2 in the serum, are hospitalized. Further, some even die. We examined the effect of blood adsorption therapy using columns that can eliminate SARS-CoV-2 on the improvement of the prognosis of severe COVID-19 patients.

METHODS

This study enrolled seven patients receiving mechanical ventilation. The patients received viral adsorption therapy using SARS-catch column for 3 days. The SARS-catch column was developed by immobilizing a specific peptide, designed based on the sequence of human angiotensin-converting enzyme 2 (hACE2), to an endotoxin adsorption column (PMX). In total, eight types of SARS-CoV-2-catch (SCC) candidate peptides were developed. Then, a clinical study on the effects of blood adsorption therapy using the SARS-catch column in patients with severe COVID-19 was performed, and the data in the present study were compared with historical data of severe COVID-19 patients.

RESULTS

Among all SCC candidate peptides, SCC-4N had the best adsorption activity against SARS-CoV-2. The SARS-catch column using SCC-4N removed 65% more SARS-CoV-2 than PMX. Compared with historical data, the weaning time from mechanical ventilation was faster in the present study. In addition, the rate of negative blood viral load in the present study was higher than that in the historical data.

CONCLUSION

The timely treatment with virus adsorption therapy may eliminate serum SARS-CoV-2 and improve the prognosis of patients with severe COVID-19. However, large-scale studies must be performed in the future to further assess the finding of this study (jRCTs052200134).

Preserved SARS-CoV-2 neutralizing IgG activity of in-house manufactured COVID-19 convalescent plasma

PURPOSE

In the current study, we aimed to evaluate the neutralizing IgG activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as the coagulation factors of convalescent plasmas which we manufactured in-house without a fast-freezing technique.

METHODS

We collected plasmas from eligible participants who had confirmed certain titers of neutralizing antibodies. The plasmas were frozen and stored in the ordinary biofreezer without a fast-freezing function. The purified-IgG neutralizing activity of 20 samples from 19 participants and the coagulation factors of 49 samples from 40 participants were evaluated before and after freezing.

RESULTS

Purified-IgG maintained its neutralizing activities, with the median 50 % inhibitory concentration (IC50) of 10.11 mg/ml (IQR 6.53-18.19) before freezing and 8.90 m g/ml (IQR 6.92-28.27) after thawing (p = 0.956). On the contrary, fibrinogen and factor Ⅷ decreased significantly after freezing and thawing in our environment. No significant temperature deviation was observed during the storage period.

CONCLUSION

Neutralizing IgG activity, which largely contributes to the antiviral activity of convalescent plasma, did not change through our in-house manufacturing, without fastfreezing and storage conditions for more than 200 days. Ordinary freezers without the fast-freezing function are suitable enough to manufacture and store convalescent plasmas. Hospitals or facilities without specified resources could easily collect and store convalescent plasmas in case of upcoming emerging or re-emerging infectious diseases on-demand with appropriate neutralizing antibody levels measurements.

Characteristics and potential quality indicators for evaluating pre-travel consultations in Japan hospitals: the Japan Pretravel consultation registry (J-PRECOR)

Background

Awareness of pre-travel consultations (PTCs) and prevention methods for overseas travel-related diseases, and the understanding of PTCs among Japanese travelers and medical professionals remains low in Japan. A multicenter registry was established to examine PTCs in Japan. This study assessed the PTC implementation rate and examined the indicators of PTCs that can be used as criteria for evaluating quality.

Methods

Clients who presented for their PTCs at 17 facilities and were registered between February 1, 2018, and May 31, 2020, were included. Medical information was extracted retrospectively via a web-based system. Correlations between vaccination risk categories and advice/intervention proportions by the facility were evaluated using Spearman’s ordered phase relations (α = 0.05).

Results

Of the 9700 eligible clients (median age, 32 years; 880 [9.1%] aged < 16 years and 549 [5.7%] aged ≥65 years), the most common travel duration was ≥181 days (35.8%); higher among younger clients. The most common reason for travel was business (40.5%); the US (1118 [11.5%]) and Asia (4008 [41.3%]) were the most common destinations and continents, respectively. The vaccine number (median three per person) increased after the PTCs except for the tetanus toxoid. Only 60.8% of the clients recommended for malaria prophylaxis received anti-malarial agents. The gross national income; the incidence of human rabies, typhoid fever, falciparum malaria; and dengue risk category were associated with the percentage of hepatitis-A vaccines; explaining rabies post-exposure prophylaxis, typhoid-fever vaccinations, malaria-prophylaxis prescriptions; and mosquito repellants, respectively.

Conclusions

Although the characteristics of the travelers differed, the quality of the PTCs should be improved to address, for example, the lower rate of acceptance of malaria prophylaxis in Japan.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40794-021-00160-4.

Surveillance and risk assessment of health screening for vaccine-preventable diseases among international students in Japan: A cross-sectional study in 2020

We conducted a cross-sectional study using a structured questionnaire in three major Japanese cities from August 03 to 24, 2020 to clarify the current situation of health checkups, including vaccine-preventable diseases (VPDs), among international students at Japanese universities (JUs) and Japanese language schools (JLSs). The total response rate was 36%: 69 JUs (31%) and 137 JLSs (39%). Over 90% of these institutions conducted chest X-ray screening for tuberculosis among their students, whereas only 24.6% of JUs and 15.3% of JLSs performed general blood tests for health screening. Only 14.5% and 2.2% of the JUs and JLSs, respectively, required the submission of vaccination or antibody certificates for admission. The difficulties in requesting vaccination certificates from international students are due to poor legal requirements and concerns about rising costs for schools. From 2017 to 2019, 183 international students, principally from East Asia and Southeast Asia, were infected with VPDs, particularly tuberculosis (99 cases) and varicella (71 cases). Whereas the majority of Japanese educational institutions screen international students for tuberculosis (TB) at admission, only a few institutions request proof of antibody testing relating to other VPDs or of vaccination. These findings will help formulate guidelines for checkups related to vaccination for international students required to protect the educational institutions in Japan from the spread of VPDs. In addition, providing multifaceted social support, including financial compensation for institutions and enhanced international students' health issues, would be helpful.

Delayed Tetracycline Initiation Increases Mortality Risk in Patients With Japanese Spotted Fever: Retrospective Analysis Using a National Inpatient Database

Background

This study aimed to determine the relationship between time to tetracycline therapy initiation and disease outcome in patients hospitalized with Japanese spotted fever (JSF).

Methods

Patients with JSF enrolled in the Japanese Diagnosis Procedure Combination database from July 2010 to March 2021 were included in the analysis. Patients who received tetracycline on the day of admission were compared with those who received tetracycline later during their hospital stay using inverse probability of treatment weighting. The primary outcome was in-hospital mortality. Secondary outcomes were total hospitalization cost and length of hospital stay.

Results

A total of 1360 patients were included, of whom 1060 (78%) received tetracycline on the day of admission (early tetracycline group), and 300 (22%) received tetracycline later (delayed tetracycline group). Patients in the delayed tetracycline group had significantly higher in-hospital mortality than those in the early tetracycline group (3.9% vs 1.4%; odds ratio, 2.94; 95% CI, 1.34–6.47), significantly higher hospitalization costs, and longer hospital stays than those in the early tetracycline group.

Conclusions

The prognosis of patients with JSF is worse if tetracycline administration is delayed; therefore, physicians should initiate tetracycline on admission if JSF is suspected as a possible diagnosis.

Physical oral care prevents ventilator-associated pneumonia in Vietnam: A prospective interventional study

BACKGROUND

Ventilator-associated pneumonia (VAP) has emerged as a critical issue in the intensive care unit (ICU) because of its high burden on patients and medical staff. Here, we examined the potential for reducing VAP incidence through physical oral care interventions without any medication.

METHODS

This prospective interventional study compared VAP incidence during an 8-month baseline period (usual oral care) and a 9-month intervention period (physical oral care with sponge brush) among patients who received mechanical ventilation for >48 h in a tertiary care hospital in Vietnam from 2017 to 2019. Physical oral care was provided by general ICU nurses who had been trained by dentists and infection control nurses. VAP was diagnosed using the Clinical Pulmonary Infection Score.

RESULTS

In total, 423 patients were enrolled in the baseline group and 454 patients were enrolled in the intervention group; 303 and 300 patients, respectively, were included in the analysis. Two hundred thirty-eight VAP episodes were identified: 135 (44.6%) during the baseline period and 103 (34.3%) during the intervention period. Univariate analysis revealed significant reduction of VAP occurrence in the intervention period (odds ratio = 0.65; 95% confidence interval = 0.47-0.90; P = 0.010). The incidences of VAP per 1000 ventilator-days were 63.4 (135/2128) during the baseline period and 48.4 (103/2128) during the intervention period (P = 0.038).

CONCLUSIONS

Physical oral care without any medication (e.g., chlorhexidine) reduced VAP incidence in the ICU. This method could be used to reduce VAP incidence, particularly in countries with limited medical resources.

Effectiveness of fluoroquinolone antimicrobials in addition to tetracyclines for Japanese spotted fever: A retrospective analysis using a national inpatient database

OBJECTIVES

This study aim to evaluate the effectiveness of fluoroquinolone (FQ) antimicrobial therapy in combination with tetracyclines (TCs) in patients with Japanese spotted fever (JSF) using a nationwide inpatient database in Japan.

METHODS

We identified hospitalized patients diagnosed with JSF who were enrolled in the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2021. Patients who received FQ plus TC on the day of admission were compared with patients who received TC alone on the day of admission, using inverse probability of treatment weighting. The primary outcome was in-hospital mortality. Secondary outcomes were in-hospital complications, total hospitalization costs, and length of hospital stay.

RESULTS

We identified 1060 eligible patients. Of these, 434 (41%) received FQ plus TC on the day of admission and 626 (59%) received TC alone on the day of admission. Inverse probability of treatment weighting showed no statistically significant differences between the groups in in-hospital mortality, in-hospital complications, total hospitalization costs, and length of hospital stay.

CONCLUSION

This study did not show any significantly improved effectiveness using FQ antimicrobials in combination with TCs for treating JSF. Clinicians may need to be cautious in administering FQ and TC antimicrobials concomitantly in routine practice.

Bacillus subtilis variant natto Bacteremia of Gastrointestinal Origin, Japan

We report a case of bacteremia caused by Bacillus subtilis variant natto after a gastrointestinal perforation in a patient in Japan. Genotypic and phenotypic studies of biotin identified B. subtilis var. natto. This case and 3 others in Japan may have been caused by consuming natto (fermented soybeans).

Clinical performance testing of the automated haematology analyzer XN-31 prototype using whole blood samples from patients with imported malaria in Japan

Background

The automated haematology analyzer XN-31 prototype (XN-31p) is a new flow cytometry-based device developed to measure the number and the ratio of malaria-infected red blood cells (MI-RBC) with a complete blood count (CBC). The XN-31p can provide results in about one minute and also can simultaneously provide information on the malaria parasite (Plasmodium) species. In this study, clinical testing of the XN-31p was performed using blood samples from patients with imported malaria in Japan.

Methods

Blood samples were collected from 80 patients who visited the hospital of the National Center for Global Health and Medicine, Tokyo, Japan, for malaria diagnosis from January 2017 to January 2019. The test results by the XN-31p were compared with those by other standard methods, such as microscopic observation, rapid diagnostic tests and the nested PCR.

Results

Thirty-three patients were diagnosed by the nested PCR as being malaria positive (28 Plasmodium falciparum, 2 Plasmodium vivax, 1 Plasmodium knowlesi, 1 mixed infection of P. falciparum and Plasmodium malariae, and 1 mixed infection of P. falciparum and Plasmodium ovale), and the other 47 were negative. The XN-31p detected 32 patients as “MI-RBC positive”, which almost matched the results by the nested PCR and, in fact, completely matched with the microscopic observations. The ratio of RBCs infected with malaria parasites as determined by the XN-31p showed a high correlation coefficient of more than 0.99 with the parasitaemia counted under microscopic observation. The XN-31p can analyse the size and nucleic acid contents of each cell, and the results were visualized on a two-dimensional cytogram termed the “M scattergram”. Information on species and developmental stages of the parasites could also be predicted from the patterns visualized in the M scattergrams. The XN-31p showed a positive coincidence rate of 0.848 with the nested PCR in discriminating P. falciparum from the other species.

Conclusions

The XN-31p could rapidly provide instructive information on the ratio of MI-RBC and the infecting Plasmodium species. It was regarded to be of great help for the clinical diagnosis of malaria.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04247-x.

Safety evaluation of MA-T after ingestion in mice

MA-T (Matching Transformation System®) is a proprietary chemical mixture for on-demand production of aqueous chlorine dioxide that is used for the treatment of oral malodor. MA-T is also an effective disinfectant against at least 39 pathological microorganisms, including severe acute respiratory syndrome coronavirus 2, and therefore may be useful as a disinfectant mouthwash to prevent the spread of infection. Accidental ingestion is the putative worst hazard scenario associated with mouthwash use; therefore, here we investigated the safety of MA-T ingestion in mice. Mice were provided drinking water containing 0-3000 μg/ml MA-T for 7 days followed by non-spiked drinking water for an additional 14 days. At day 7, mice ingesting 1000 or 3000 μg/ml MA-T showed significantly decreased body weight and significantly increased liver, kidney, and heart tissue injury biomarkers compared with control. However, at 14 days after stopping MA-T ingestion, body weight and tissue injury biomarkers had returned to normal. Histological analysis revealed that MA-T-induced injuries in liver, kidney, spleen, stomach, duodenum, colon, and rectum had also recovered at 14 days after stopping MA-T ingestion; however, mild vascular endothelial injuries remained in heart, jejunum, and ileum in the worst-case scenario. Taken together, MA-T may be potentially safety for further development as a disinfectant mouthwash by risk management, such as placing a caution of the label and adding a distinctive flavor.

A Multi-Center, Open-Label, Randomized Controlled Trial to Evaluate the Efficacy of Convalescent Plasma Therapy for Coronavirus Disease 2019: A Trial Protocol (COVIPLA-RCT)

Background: Coronavirus disease 2019 is a global public health concern. As of December 2020, the therapeutic agents approved for coronavirus disease 2019 in Japan were limited to two drugs: remdesivir, an antiviral drug, granted a Special Approval for Emergency on 7 May 2020, and dexamethasone, which has an anti-inflammatory effect. The aim of this study is to evaluate the efficacy of convalescent plasma collected from donors who recovered from coronavirus disease 2019. Methods: This is an open-label, randomized controlled trial comprising two groups: a convalescent plasma and a standard-of-care group. Plasma administered to patients with coronavirus disease 2019 randomized in the convalescent plasma group of this trial will be plasma that has been collected and stored in an associated study. Patients with a diagnosis of mild coronavirus disease 2019 will be included in this trial. The efficacy of convalescent plasma transfusion will be evaluated by comparing the convalescent plasma group to the standard-of-care group (without convalescent plasma transfusion) with respect to changes in the viral load and other measures. The primary endpoint will be time-weighted average changes in the SARS-CoV-2 virus load in nasopharyngeal swabs from day 0 to days 3 and 5. It is hypothesized that the intervention should result in a decrease in the viral load in the convalescent plasma group until day 5. This endpoint has been used as a change in viral load has and been used as an index of therapeutic effect in several previous studies. Discussion: The proposed trial has the potential to prevent patients with mild COVID-19 from developing a more severe illness. Several RCTs of convalescent plasma therapy have already been conducted in countries outside of Japan, but no conclusion has been reached with respect to the efficacy of convalescent plasma therapy, which is likely in part because of the heterogeneity of the types of target patients, interventions, and endpoints among trials. Actually, previous clinical trials on plasma therapy have shown inconsistent efficacy and are sometimes ineffective in COVID-19 patients with severe disease, which is due to unmeasured neutralizing antibody titer in the COVID-19 convalescent plasma. To improve this issue, in this study, we measure neutralizing activity of convalescent plasma before administration and provide the plasma with high neutralizing activity to the subjects. It is hoped that this study will further evidence to support the role of convalescent plasma therapy in COVID-19.

Factors associated with development and persistence of post-COVID conditions: A cross-sectional study

INTRODUCTION

The post-COVID condition has become a social concern. Although the patient characteristics associated with the development of this condition are partially known, those associated with its persistence have not been identified.

METHODS

We conducted a cross-sectional questionnaire-based survey among patients who had recovered from COVID-19 and visited the National Center for Global Health and Medicine between February 2021 and March 2021. Demographic and clinical data, and data regarding the presence and duration of post-COVID conditions were obtained. We identified factors associated with the development and persistence of post-COVID conditions using multivariate logistic and linear regression analyses, respectively.

RESULTS

We analyzed 457 of 526 responses (response rate, 86.9%). The median patient age was 47 years. Of these, 378 patients (84.4%) had mild disease in the acute phase. The number of patients with symptoms at 6 and 12 months after onset or diagnosis was 120 (26.3%) and 40 (8.8%), respectively. Women were at risk of developing fatigue (odds ratio [OR]: 2.03, 95% confidence interval [CI]: 1.31-3.14), dysosmia (OR: 1.91, 95%CI: 1.24-2.93), dysgeusia (OR: 1.56, 95%CI: 1.02-2.39), hair loss (OR: 3.00, 95%CI: 1.77-5.09), and persistence of any symptoms (coefficient: 38.0, 95%CI: 13.3-62.8). Younger age and low body mass index were factors for developing dysosmia (OR: 0.96, 95%CI: 0.94-0.98 and OR: 0.94, 95%CI: 0.89-0.99, respectively) and dysgeusia (OR: 0.98, 95%CI: 0.96-1.00 and OR: 0.93, 95%CI: 0.88-0.98, respectively).

CONCLUSION

We identified factors involved in the development and persistence of post-COVID conditions. Many patients, even those with mild conditions, experience long-term residual symptoms.

Case Report: Leptospirosis by Wild Rat Bite in Winter in Tokyo Metropolitan Area, Japan

We report a case of leptospirosis in Tokyo in winter due to a rat bite, an uncommon cause of Leptospira infection. In Japan, many cases due to exposure to fresh water have been reported from domestic southwest islands in summer. However, a previous report on leptospirosis in Tokyo documented several cases occurring in winter. The main route of infection in the Tokyo metropolitan area during winter was attributed to the increased chance of direct rat exposure. Rapid and feasible diagnostic methods are needed to elucidate its epidemiology and provide prompt treatment.

Streptobacillus notomytis Bacteremia after Exposure to Rat Feces

To determine the source of Streptobacillus notomytis bacteremia in a woman in Japan with signs of rat-bite fever, we examined rat feces from her home. After culture and PCR failed to identify the causative organism in the feces, next-generation sequencing detected Streptobacillus spp., illustrating this procedure’s value for identifying causative environmental organisms.

Antibody responses after two doses of SARS-CoV-2 mRNA-1273 vaccine in an individual with history of COVID-19 re-infection

We present a case of a 58-year-old Japanese man with a history of 2 previous COVID-19 infections, who received 2 doses of mRNA-1273 vaccine. We are not aware of any previous study regarding antibody tendency after 2 infections and 2 vaccinations. We evaluated his IgG titer of antispike protein and neutralizing activity from the first infection before and after 2 doses of vaccine. Both antispike IgG titer and neutralizing activity showed a tendency to decline almost 1 year after initial infection; they rapidly increased after the first vaccination, and they remained high after the second vaccination. Although this is a single case report, it seems to have generalizability because the findings are consistent with previous reports regarding single infections or 3 doses of vaccination. Our findings suggest that a single booster shot may provide sufficient protection and aid the understanding of immunologic responses of vaccination in patients with COVID-19 with history of re-infection.

Interleukin-6 is upregulated and may be associated with myocardial injury in some patients who have recovered from COVID-19

Coronavirus disease (COVID-19) causes myocardial injury by inducing a cytokine storm in severe cases. Studies have reported that myocardial injury persists for a prolonged period during COVID-19 recovery, and cardiac troponin is a useful indicator of myocardial injury. The interleukin-6 (IL-6) level is known to be associated with the morbidity and mortality of COVID-19, but this association has not been studied during recovery. The current study examined the association between IL-6 levels and myocardial damage during COVID-19 recovery. Four of 209 patients (1.9%) who recovered from COVID-19 had elevated IL-6 levels. All 4 patients tested positive for high-sensitivity troponin T, and 3 patients had subclinical left ventricular (LV) dysfunction according to echocardiography. Positivity for IL-6 during COVID-19 recovery suggests ongoing myocardial damage due to inflammation.

Evaluation of the QIAstat-Dx Respiratory SARS-CoV-2 pPanel, a rRapid mMultiplex PCR mMethod for the dDiagnosis of COVID-19

Introduction

Rapid, simple, and accurate methods are required to diagnose coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to evaluate the performance of the QIAstat-Dx Respiratory SARS-CoV-2 Panel (QIAstat-SARS-CoV-2), a rapid multiplex PCR assay for SARS-CoV-2 detection.

Methods

Nasopharyngeal swabs (NPS) that were obtained from patients with COVID-19 who were diagnosed at the National Center for Global Health and Medicine were used in this study. When the NPS samples were found to be negative for SARS-CoV-2 after treatment, they were used as negative samples. We evaluated the performance of the QIAstat-SARS-CoV-2 comparing SARS-CoV-2 detection with the National Institute of Infectious Diseases in Japan-recommended real-time polymerase chain reaction (RT-PCR) method (NIID-RT-PCR).

Results

In total, 45 NPS samples were analyzed. The proportion of overall agreement between QIAstat-SARS-CoV-2 and NIID-RT-PCR on 45 samples was 91.0% with a sensitivity of 84.0% (21/25), specificity at 100% (20/20), negative predictive value at 83.3% (20/24), and positive predictive value at 100% (21/21). There were no patients with co-infections with pathogens other than SARS-CoV-2.

Conclusions

QIAstat-SARS-CoV-2 showed a high agreement in comparison with the NIID-RT-PCR for the detection of SARS-CoV-2. The QIAstat-SARS-CoV-2 also provided a rapid and accurate diagnosis for COVID-19, even when the concurrent detection of other respiratory pathogens was desired, and therefore, has the potential to direct appropriate therapy and infection control precautions.

Factors Associated With Prolonged Psychological Distress Among Nurses and Physicians Engaged in COVID-19 Patient Care in Singapore and Japan

This study explores the factors contributing to the prolonged psychological distress of frontline nurses and physicians caring for COVID-19 patients in hospitals in Singapore and Japan. A cross-sectional survey between September and December 2020 yielded 1,644 responses (23.8%), from 62 nurses and 64 physicians in Singapore and 1,280 nurses and 238 physicians in Japan. Multivariate logistic regression analysis revealed that significant risk factors for prolonged psychological distress included being a frontline nurse [adjusted odds ratio (aOR) = 2.40, 95% confidence interval (CI): 1.24-4.66], having an underlying medical condition (aOR = 1.74, 95% CI: 1.22-2.46), experiencing prejudice because they undertook COVID-19 patient care (aOR = 3.05, 95% CI: 2.23-4.18), having trouble dealing with panicked or uncooperative patients (aOR = 2.36, 95% CI: 1.71-3.25), and experiencing an outbreak of COVID-19 in the hospital (aOR = 2.05, 95% CI: 1.38-3.04). Factors inversely associated with psychological distress included age (OR = 0.98, 95% CI: 0.97-1.00), number of beds in the hospital (aOR = 0.73, 95% CI: 0.57-0.94), clinical practice of carefully putting on and taking off personal protective equipment in daily COVID-19 patient care (aOR = 0.52, 95% CI: 0.37-0.73), and knowledge on COVID-19 (aOR = 0.82, 95% CI: 0.72-0.94). These results could help us identify vulnerable healthcare providers who need urgent mental care during the COVID-19 pandemic. Measures that may reduce psychological strain include adequate supply of medical resources, education on precautionary measures, and communication strategies to combat discrimination against frontline healthcare providers.

Imported African Tick Bite Fever in Japan: A Literature Review and Report of Three Cases

African tick bite fever (ATBF) is an acute febrile illness caused by Rickettsia africae. ATBF is an important differential diagnosis of acute febrile illness among returned travelers. However, little information is available on ATBF cases imported to Japan, as only seven have been reported to date. To characterize the epidemiological and clinical profiles of patients diagnosed with ATBF in Japan, we reported three new ATBF cases at our hospital between May 2015 and April 2018 and conducted a literature review.

Regional antimicrobial stewardship program in a provincial medical zone in Japan: A multifaceted approach

Antimicrobial resistance (AMR) is a threat to patient health. However, there is a lack of data for optimizing antimicrobial use. Furthermore, reducing antibiotic use raises concerns regarding patient safety; there is controversy regarding its effectiveness in reducing AMR prevalence. Researchers at the Japanese Red Cross Ishinomaki Hospital (JRCIH), the only tertiary care hospital in the medical zone, along with local medical and pharmacy associations and public health centers, has been leading the AMR control program since 2018. The program involves lectures aimed at optimizing antimicrobial use, regular publication of surveillance data of drug-resistant strains at the JRCIH, and presentation of first-line treatments for community-acquired infections. Delivery of oral antimicrobials across the region in 2020 was 28.7% lower than that in 2013, with delivery of cephalosporins, quinolones, and macrolides dropping by 34.8%, 46.8%, and 56.0%, respectively. Despite these reductions, there has been no associated increase in the number of patients with severe infectious diseases admitted to the JRCIH. The rates of representative drug-resistant strains bacteremia, such as extended-spectrum beta-lactamase-producing Escherichia coli and methicillin-resistant Staphylococcus aureus, reduced by half. Herein, we demonstrated the potential of collaborative efforts to optimize antimicrobial agent use and reduce AMR prevalence without compromising patient safety.