Improved efficacy of SARS-CoV-2 isolation from COVID-19 clinical specimens using VeroE6 cells overexpressing TMPRSS2 and human ACE2.

The cell culture-based isolation of novel coronavirus SARS-CoV-2 from clinical specimens obtained from patients with suspected COVID-19 is important not only for laboratory diagnosis but also for obtaining live virus to characterize emerging variants. Previous studies report that monkey kidney-derived VeroE6/TMPRSS2 cells allow efficient isolation of SARS-CoV-2 from clinical specimens because these cells show stable expression of the receptor molecule monkey ACE2 and the serine-protease TMPRSS2. Here, we demonstrated that VeroE6 cells overexpressing human ACE2 and TMPRSS2 (Vero E6-TMPRSS2-T2A-ACE2 cells) are superior to VeroE6/TMPRSS2 for isolating SARS-CoV-2 from clinical specimens. These cells showed a 1.6-fold increase in efficiency in SARS-CoV-2 isolation, and were particularly effective for clinical specimens with a relatively low viral load (< 106 copies/mL). When using vesicular stomatitis virus (VSV) pseudoviruses (VSV/SARS-2pv) bearing the spike proteins of all of the tested SARS-CoV-2 strains, Vero E6-TMPRSS2-T2A-ACE2 cells showed a 2- to fourfold increase in infectivity. Furthermore, the results of virus titration and neutralization antibody assays using Vero E6-TMPRSS2-T2A-ACE2 cells were different from those using VeroE6/TMPRSS2, highlighting the importance of selecting appropriate cell culture systems to determine SARS-CoV-2 infectivity.

COVID-19 severity and corticosteroid treatment have minimal effect on specific antibody production.

BACKGROUND: Dexamethasone is currently administered for Coronavirus disease 2019(COVID-19); however, there are concerns about its effect on specific antibodies' production. The aim of this study was to evaluate whether specific antibodies were affected by COVID-19 severity and corticosteroid treatment. METHODS: Of 251 confirmed COVID-19 patients admitted to our hospital between January 26 and August 10, 2020, the early period of the pandemic, 75 patients with sera within 1 month of onset and 1 month or longer were included in the research. A total of 253 serum samples from these patients were collected. The levels of specific antibodies for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), immunoglobulin G (IgG) and M (IgM), were measured retrospectively. The results were compared separately of each COVID-19 severity, and with or without corticosteroid treatment. RESULTS: Among the 75 patients, 47, 18, and 10 had mild, moderate, and severe disease, respectively. The median age was 53.0 years and 22 (29%) were women. The most common comorbidities were hypertension and dyslipidemia. Corticosteroids were administered to 20 (27%) and 10 (53%), patients with moderate and severe disease, respectively. The positivity rates IgM increased first, and IgG was almost always positive after day 16, regardless of the severity of COVID-19. On days 6-10, both IgG and IgM positivity rates were higher in patients with moderate disease than in those with mild or severe disease. In patients with moderate disease, IgG positivity was similar over time, regardless of corticosteroid treatment. CONCLUSIONS: In COVID-19 patients, specific IgG is positive and maintained for a long period of time, even after corticosteroid treatment. The effect of corticosteroid treatment in a COVID-19 epidemiological study using specific IgG antibodies was considered minor. COVID-19 patients were more likely to receive oxygen if IgM was positive 1 week after onset, but not mechanical ventilation. IgM measurement 1 week after onset may predict COVID-19 severity.

Effectiveness of remdesivir in patients with COVID-19 and severe renal insufficiency: a nationwide cohort study in Japan.

BACKGROUND: The effectiveness of remdesivir in patients with coronavirus disease 2019 (COVID-19) and severe renal insufficiency remains underexplored. OBJECTIVES: To evaluate whether remdesivir reduces the risk of mortality or invasive mechanical ventilation/extracorporeal membrane oxygenation (IMV/ECMO) in this population. METHODS: This retrospective observational study utilising the COVID-19 Registry Japan (COVIREGI-JP) included noncritical patients with COVID-19 and severe renal insufficiency (defined as serum creatinine levels ≥3 mg/dL, on maintenance dialysis, or kidney transplant recipients) admitted to Japanese hospitals within 7 days of symptom onset between January 1, 2020 and May 8, 2023. Patients were classified into the remdesivir group if remdesivir was initiated within the first 2 days of admission. We estimated the multivariable-adjusted hazard ratio (HR) for mortality and initiation of IMV/ECMO using landmark analysis to address immortal time bias. RESULTS: Among the 1,449 patients included in the landmark analysis (median age, 74 years [interquartile range 62-84 years]; 992 [68.5%] were male), 272 initiated remdesivir within the first 2 days of admission. During the 28 days from the landmark timepoint, 19 (7.0%) and 136 (11.6%) patients in the remdesivir and control groups, respectively, had an outcome. The remdesivir group had a lower risk of mortality or IMV/ECMO initiation than the control group (adjusted HR, 0.44; 95% confidence interval, 0.23-0.83). CONCLUSIONS: In noncritical patients with COVID-19 and severe renal insufficiency at admission, initiating remdesivir early after disease onset, within the first 2 days of admission, led to a lower risk of mortality or IMV/ECMO initiation, compared with non-initiation of remdesivir.

Factors associated with the change of antimicrobial prescription before and after the national action plan on antimicrobial resistance: Additional analysis of a nationwide survey conducted by the Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases.

BACKGROUND: A nationwide survey conducted by the Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases in 2020 provided insights into antimicrobial prescription practices among clinic doctors. This study aimed to investigate factors influencing changes in antimicrobial prescriptions post-implementation of the National Action Plan on Antimicrobial Resistance (NAPAR) and doctors' inclination to prescribe antimicrobials for common cold cases. METHODS: In September 2020, randomly selected questionnaires were distributed to 3000 community-based medical clinics in Japan. The primary objective was to assess the reduction in antimicrobial prescriptions post-NAPAR implementation. Multivariate linear regression analysis was employed to identify associated factors. RESULTS: Analysis of 632 responses (response rate: 21.1 %) revealed determinants of decreased antimicrobial prescriptions, including familiarity with the Guide to Antimicrobial Stewardship (ß = .482, t = 3.177, p = 0.002) and awareness of NAPAR (ß = .270, t = 2.301, p = 0.022). CONCLUSION: Interventions such as the Guide to Antimicrobial Stewardship may have contributed to the reduction in antimicrobial prescriptions among Japanese physicians. However, targeted strategies are needed to address high-prescription groups. Enhancing awareness and education on appropriate antimicrobial use should be integral components of future initiatives to combat antimicrobial resistance effectively.

Successful treatment of Staphylococcus argenteus sequence type 2198 uncomplicated bacteremia with a 2-week antibiotic course.

There is a paucity of data on the clinical course and treatment of Staphylococcus argenteus. Herein, we describe a successfully treated case of S. argenteus bacteremia. A 76-year-old man with lung adenocarcinoma developed bacteremia caused by penicillin-resistant, oxacillin-susceptible S. argenteus, which was identified through mass spectrometry and nuc gene sequencing. He was diagnosed with a peripheral line-associated bloodstream infection and successfully treated with a 2-week course of cefepime, followed by cefazolin, concurrent with intravenous catheter removal. The isolate was positive for blaZ and negative for mecA. It was assigned to sequence type 2198 using multilocus sequence typing. Formerly classified as Staphylococcus aureus clonal complex 75, S. argenteus became a distinct species in 2015. Its identification has increased owing to widespread mass spectrometer use. Most East and Southeast Asian S. argenteus isolates reported to date are methicillin-susceptible, consistent with the susceptibility pattern of the isolate in our study. Given the potential equivalence in virulence between S. argenteus and S. aureus, we recommend treating S. argenteus with the same rigor as S. aureus until further clinical data becomes available.

Protection of Omicron Bivalent Vaccine, Previous Infection, and Their Induced Neutralizing Antibodies Against Symptomatic Infection With Omicron XBB.1.16 and EG.5.1.

Background: Data are limited on the protective role of the Omicron BA bivalent vaccine, previous infection, and their induced neutralizing antibodies against Omicron XBB.1.16 and EG.5.1 infection. Methods: We conducted a nested case-control analysis among tertiary hospital staff in Tokyo who had received ≥3 doses of COVID-19 vaccines and donated blood samples in June 2023 (1 month before the Omicron XBB.1.16 and EG.5.1 wave). We identified 206 symptomatic cases between June and September 2023 and selected their controls with 1:1 propensity score matching. We examined the association of vaccination, previous infection, and preinfection live virus neutralizing antibody titers against Omicron XBB.1.16 and EG.5.1 with the risk of COVID-19 infection. Results: Previous infection during the Omicron BA- or XBB-dominant phase was associated with a significantly lower infection risk during the XBB.1.16 and EG.5.1-dominant phase than infection-naive status, with 70% and 100% protection, respectively, whereas Omicron BA bivalent vaccination showed no association. Preinfection neutralizing titers against XBB.1.16 and EG.5.1 were 39% (95% CI, 8%-60%) and 28% (95% CI, 8%-44%) lower in cases than matched controls. Neutralizing activity against XBB.1.16 and EG.5.1 was somewhat detectable in the sera of individuals with previous infection but barely detectable in those who were infection naive and received the Omicron bivalent vaccine. Conclusions: In the era when the Omicron XBB vaccine was unavailable, the Omicron BA bivalent vaccine did not confer the neutralizing activity and protection against Omicron XBB.1.16 and EG.5.1 symptomatic infection. The previous infection afforded neutralizing titers and protection against symptomatic infection with these variants.

Comparison of clinical characteristics and severity of COVID-19 with or without viral co-infection in hospitalized children.

BACKGROUND: Co-infection with other pathogens can alter the severity and clinical outcomes of viral infections. However, the information regarding viral co-infections in pediatric coronavirus disease 2019 (COVID-19) cases is still limited. METHODS: This is a nationwide, retrospective cohort study using the data from the COVID-19 Registry Japan. The pediatric (<18 years), laboratory confirmed, hospitalized COVID-19 patients in the Omicron variant of concern predominant period (January 2022 to January 2024) were included. Co-infection was investigated by multiplex PCR. We compared clinical characteristics, symptoms, severity, and outcomes between children with and without co-infection. RESULTS: Among 245 hospitalized pediatric COVID-19 patients, 78 (31.8 %) had co-infections. The patient backgrounds of the "co-infection" and "SARS-CoV-2 alone" groups were similar, although age distribution was different, with a lower number of patients over 12 years in the co-infection group (n = 2, 2.6 % vs. n = 29, 17.4 %; P < 0.001). Among the patients with co-infection, the most common pathogen was enterovirus/rhinovirus (51.3 %), followed by parainfluenza virus (23.1 %) and adenovirus (12.8 %). Patients with co-infection more commonly had respiratory symptoms, including SpO2 < 96 %, shortness of breath, runny nose, and wheezing. Requirement of non-invasive oxygen support was higher in the co-infection group (n = 27, 34.6 % vs. n = 28, 16.8 %, P = 0.006). By multivariable logistic regression analysis, co-infection and presence of any comorbidity were identified as significant risk factors for necessity of oxygen therapy (odds ratio [95 % confidence interval] 2.44 [1.29-4.63] and 3.99 [2.07-7.82], respectively). CONCLUSIONS: Viral co-infection may increase the risk of respiratory distress in pediatric COVID-19 patients.

Characteristics of Streptococcal Toxic Shock Syndrome Caused by Different Beta-hemolytic Streptococci Species: A Single-center Retrospective Study.

Background: Streptococcal toxic shock syndrome (STSS) is a life-threatening condition caused by beta-hemolytic streptococci (BHS). Streptococcus pyogenes is the main causative agent of this disease; other BHS such as Streptococcus agalactiae or Streptococcus dysgalactiae could also cause STSS. However, the clinical characteristics of STSS caused by other types of BHS remain poorly understood. In this study, we evaluated the likelihood of STSS development in various streptococcal species. Methods: We conducted a retrospective observational study using adult medical records of patients with invasive BHS in a tertiary care institution from 2002 to 2022 and classified them into STSS or non-STSS groups. Multivariable analysis of bacterial species adjusted for age and diabetes mellitus was conducted. S pyogenes cases were propensity-matched (1:4) to non-pyogenes BHS cases. Results: A total of 43 STSS and 285 non-STSS cases were identified. S pyogenes, S agalactiae, and S dysgalactiae accounted for 17, 13, and 13 STSS cases, respectively. The crude mortality of STSS was approximately 35% in all groups. A multivariable analysis suggested that STSS was less frequent in S agalactiae and S dysgalactiae cases with odds ratio 0.24 (95% confidence interval [CI], 0.10-0.54; P < .001) and 0.23 (95% CI, .10-.55; P < .001), respectively. Propensity score matching showed that S pyogenes caused STSS more frequently than other BHS cases with an odds ratio of 3.28 (95% CI 1.21-8.77; P = .010). Conclusions: This study described and compared the clinical characteristics of STSS caused by different BHS. We demonstrated that S pyogenes caused STSS more often than other BHS.

Travel-associated sexually transmitted infections in Japan: An observational study using imported infectious disease registry data.

International travel is a risk factor for acquiring sexually transmitted infections (STIs) owing to factors such as increased sexual opportunities, a sense of freedom, and the allure of the sex industry. We investigated the incidence of travel-associated STIs in Japan using data from the Japan Registry for Infectious Diseases from Abroad (J-RIDA) reported by 17 participating medical institutions between October 2017 and December 2022. Data were collected on the patients' age, sex, nationality, chief complaint, whether they had visited a travel clinic before travel, travel history, and final diagnosis. Of 4545 cases of travel-associated illness reported, 52 (1.1%) were STIs. Most patients with STIs were male (81%) with a median age of 31 years. HIV (17%), genital herpes (13%), syphilis (13%), and gonorrhea (12%) were the most frequently reported STIs. Only one patient had visited a travel clinic before travel. Promoting awareness and vaccination is crucial for preventing travel-associated STIs.

Correlates of Nucleocapsid Antibodies and a Combination of Spike and Nucleocapsid Antibodies Against Protection of SARS-CoV-2 Infection During the Omicron XBB.1.16/EG.5-Predominant Wave.

Background: We aimed to examine the association among nucleocapsid (N) antibodies, a combination of N and spike (S) antibodies, and protection against SARS-CoV-2 reinfection. Methods: We conducted a prospective cohort study among staff at a national medical research center in Tokyo and followed them for the incidence of SARS-CoV-2 infection between June and September 2023 (Omicron XBB.1.16/EG.5 wave). At baseline, participants donated blood samples to measure N- and S-specific antibodies. Cox regression was used to estimate the hazard ratio and protection ([1 - hazard ratio] × 100) against subsequent SARS-CoV-2 infection across these antibody levels. Results: Among participants with previous infection, higher pre-reinfection N antibodies were associated with a lower risk of reinfection, even after adjusting S antibody levels (P < .01 for trend). Estimation of the protection matrix for N and S antibodies revealed that high levels in N and S antibodies conferred robust protection (>90%) against subsequent infection. In addition, a pattern of low pre-reinfection N antibodies but high vaccine-enhanced S antibodies showed high protection (>80%). Conclusions: Pre-reinfection N antibody levels correlated with protection against reinfection, independent of S antibodies. If the N antibodies were low, vaccine-boosted S antibodies might enhance the reinfection protection.

Tocilizumab in combination with standard of care in patients with severe COVID-19 pneumonia: Efficacy and safety from a phase 3 clinical trial in Japan.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is characterized by high interleukin-6 levels. Clinical data supporting tocilizumab, a monoclonal antibody that targets interleukin-6 receptor-alpha, for treating Japanese patients with severe COVID-19 pneumonia are needed. METHODS: This single-arm phase 3 study investigated tocilizumab (8 mg/kg) plus standard of care (SOC) in Japanese patients hospitalized with severe COVID-19 pneumonia. Clinical status was assessed using a 7-category ordinal scale on day 28 (primary endpoint) and day 14 (secondary endpoint). Other secondary endpoints were time to improvement (≥2 category improvement) and time to hospital discharge. Safety was assessed as the incidence of adverse events (AEs). RESULTS: Among 48 patients enrolled, 44 (91.7 %) scored ≥3 on the 7-category ordinal scale at baseline. At day 28, 35 patients (72.9 %) scored 1 and 5 (10.4 %) scored 7 on the 7-category ordinal scale; 36 (75.0 %, 95 % confidence interval [CI]: 60.40 %-86.36 %) and 39 (81.3 %, 95 % CI: 67.37 %-91.05 %) patients achieved ≥2- and ≥1-category improvement, respectively; 6 patients (12.5 %, 95 % CI: 4.73 %-25.25 %) demonstrated ≥1-category worsening. At day 14, 25 (52.1 %, 95 % CI: 37.19 %-66.71 %) and 33 patients (68.8 %, 95 % CI: 53.75 %-81.34 %) achieved ≥2- and ≥1-category improvement, respectively; 5 patients (10.4 %, 95 % CI: 3.47 %-22.66 %) demonstrated ≥1-category worsening. Median times (95 % CI) to improvement and hospital discharge were 11 (9-15) and 15 (11-18) days, respectively. Forty patients (83.3 %) experienced AEs; the incidence of ≥grade 3 AEs was 25 %. CONCLUSION: Tocilizumab plus SOC may provide improved clinical status in Japanese patients with severe COVID-19 pneumonia; no new safety signals were identified.

Modelling the effectiveness of an isolation strategy for managing mpox outbreaks with variable infectiousness profiles.

The global outbreak of mpox in 2022 and subsequent sporadic outbreaks in 2023 highlighted the importance of nonpharmaceutical interventions such as case isolation. Individual variations in viral shedding dynamics may lead to either premature ending of isolation for infectious individuals, or unnecessarily prolonged isolation for those who are no longer infectious. Here, we developed a modeling framework to characterize heterogeneous mpox infectiousness profiles - specifically, when infected individuals cease to be infectious - based on viral load data. We examined the potential effectiveness of three different isolation rules: a symptom-based rule (the current guideline in many countries) and rules permitting individuals to stop isolating after either a fixed duration or following tests that indicate that they are no longer likely to be infectious. Our analysis suggests that the duration of viral shedding ranges from 23 to 50 days between individuals. The risk of infected individuals ending isolation too early was estimated to be 8.8% (95% CI: 6.7-10.5) after symptom clearance and 5.4% (95% CI: 4.1-6.7) after 3 weeks of isolation. While these results suggest that the current standard practice for ending isolation is effective, we found that unnecessary isolation following the infectious period could be reduced by adopting a testing-based rule.

Cost-effectiveness analysis of NVX-CoV2373 COVID-19 vaccination for elderly people in Japan.

Background: NVX-CoV2373 is one of the vaccines marketed for COVID-19 prevention in Japan. Information on its cost-effectiveness is important for making well-informed decisions on the future of Japan's COVID-19 vaccination programme from the public healthcare payer's perspective. The aim of this study was to evaluate the cost-effectiveness of NVX-CoV2373 vaccination in the elderly Japanese population. Methods: Two analysis populations that included elderly Japanese individuals (aged ≥ 65 years) were defined in this study: those who had not received a COVID-19 vaccine or had not completed a primary vaccination series (i.e., first two vaccinations) with an approved COVID-19 vaccine (analysis population 1), and those who had received two primary vaccinations with an approved COVID-19 vaccine (analysis population 2). A literature-informed Markov model for each analysis population was developed to evaluate the cost-effectiveness of vaccination with NVX-CoV2373 against no vaccination with NVX-CoV2373 from the public healthcare payer's perspective as a base-case analysis and from the societal perspective as a scenario analysis. Vaccine efficacy was estimated from a phase 3 study of NVX-CoV2373 (EudraCT number: 2020-004123-16). Cost-effectiveness was assessed using a willingness-to-pay threshold of Japanese yen (JPY) 5 million per quality-adjusted life-year (QALY). Deterministic and probabilistic sensitivity analyses were also performed. Results: For analysis population 1, NVX-CoV2373 primary and booster vaccinations would reduce costs by JPY 37,647 and prolong QALYs by 0.01601. Therefore, NVX-CoV2373 primary and booster vaccinations were considered to be dominant over no vaccination. For analysis population 2, an NVX-CoV2373 booster vaccination would increase costs by JPY 5010 and prolong QALYs by 0.00550, with the incremental cost-effectiveness ratio of JPY 910,566 per QALY gained. Conclusions: Our analyses suggest that a vaccination strategy with NVX-CoV2373 is cost-effective in the elderly population (aged ≥ 65 years) of Japan.

Prevention of post COVID-19 condition by early treatment with ensitrelvir in the phase 3 SCORPIO-SR trial.

This exploratory analysis of the double-blind, phase 3, SCORPIO-SR trial assessed the effect of ensitrelvir in preventing post coronavirus disease 2019 (COVID-19) condition (PCC). Patients with mild-to-moderate COVID-19 were randomized (1:1:1) within 120 h of symptom onset; received 5-day oral ensitrelvir 125 mg (375 mg on day 1), 250 mg (750 mg on day 1), or a matching placebo once daily; and were assessed for the severity of typical PCC symptoms using a self-administered questionnaire. In total, 341, 317, and 333 patients were assessed in the ensitrelvir 125-mg, ensitrelvir 250-mg, and placebo groups, respectively (mean age, 35.6-36.5 years; men, 53.3%-58.3%). On days 85, 169, and 337, ensitrelvir 125-mg treatment showed 32.7% (95% confidence interval [CI]: -30.6, 66.1), 21.5% (95% CI: -37.3, 55.6), and 24.6% (95% CI: -43.7, 60.9) reductions versus placebo, respectively, in the risk of any of the 14 acute-phase COVID-19 symptoms (at least one mild, moderate, or severe symptom with general health not returning to the usual level). Ensitrelvir 250-mg treatment showed 10.9% (95% CI: -67.0, 52.8), 9.5% (95% CI: -56.6, 48.0), and 30.6% (95% CI: -36.2, 65.5) risk reductions versus placebo on days 85, 169, and 337, respectively. Risk reductions were observed in any of the 4 neurological symptoms and were more pronounced among patients with high acute-phase symptom scores at baseline and among those with a baseline body mass index ≥25 kg/m2. Ensitrelvir treatment in the acute phase of COVID-19 may reduce the risk of various symptoms associated with PCC. TRIAL REGISTRATION NUMBER: jRCT2031210350.

Time from admission to the onset of methicillin-resistant Staphylococcus aureus bacteremia in a single acute care hospital in Japan.

The spread of antimicrobial-resistant organisms (AROs) poses a major threat to animal and human health. In Japan, the estimated disability-adjusted life years (DALYs) due to infections with AROs is 137.9 per 100,000 persons, with methicillin-resistant Staphylococcus aureus (MRSA) being the main contributor. The factors that can contribute to DALYs in Japan include younger age and a higher number of deaths in patients with MRSA bacteremia. Moreover, longer hospital stays may contribute to higher rates of MRSA bacteremia in Japan than in Western countries. We reviewed diagnosis procedure combination data collected from January 1, 2016, to December 31, 2020, in an acute care hospital in Tokyo, Japan. We found that the median time from admission to MRSA bacteremia onset was 26 days, which is longer than that in Western countries but similar to that in South Korea. Further, our cohort was older than that in the United States and South Korea, potentially contributing to the higher number of years of life lost in Japan. These results underscore the need to develop strategies to reduce hospitalization in Japan. Larger multicenter studies are needed to comprehensively evaluate the economic and health burden of MRSA bacteremia in Japan.

Multi-year analysis of the global preclinical antibacterial pipeline: trends and gaps.

Antimicrobial resistance (AMR) is a major global health threat estimated to have caused the deaths of 1.27 million people in 2019, which is more than HIV/AIDS and malaria deaths combined. AMR also has significant consequences on the global economy. If not properly addressed, AMR could immensely impact the world's economy, further increasing the poverty burden in low- and middle-income countries. To mitigate the risk of a post-antibiotic society, where the ability to effectively treat common bacterial infections is being severely threatened, it is necessary to establish a continuous supply of new and novel antibacterial medicines. However, there are gaps in the current pipeline that will prove difficult to address, given the time required to develop new agents. To understand the status of upstream antibiotic development and the challenges faced by drug developers in the early development stage, the World Health Organization has regularly assessed the preclinical and clinical antibacterial development pipeline. The review identifies potential new classes of antibiotics or novel mechanisms of action that can better address resistant bacterial strains. This proactive approach is necessary to stay ahead of evolving resistance patterns and to support the availability of effective treatment options. This review examines the trends in preclinical development and attempts to identify gaps and potential opportunities to overcome the numerous hurdles in the early stages of the antibacterial research and development space.

Association between post-COVID-19 conditions and male semen quality in Japan: A descriptive investigation.

Some reports suggest that coronavirus disease 2019 (COVID-19) may affect male reproductive function. There is also concern in Japan that COVID-19 may contribute to the pre-existing decline in male fertility; however, no studies have investigated the effects of COVID-19 on male reproductive function. In this study, we aimed to analyze the semen quality of men who had recovered from COVID-19. Male patients who had recovered from COVID-19 between February 2020 and September 2021 were recruited for this study. Participants were sent a semen collection kit; they were asked to collect semen at home and deliver it to a laboratory at Osaka University. We used these samples to analyze sperm concentration, total sperm count, and semen volume. In total, 125 participants were included in this study. The median age of all patients was 46 years (interquartile range (IQR): 38-52 years). The severity of COVID-19 was mild in 80 patients; 19 were moderate I, 22 were moderate II, and four were severe. The median semen volume was 2.5 mL (IQR: 1.8-3.1), the median sperm concentration was 98.9 million/mL (IQR: 43.8-162.2), and the median total sperm count was 212.1 million (IQR: 89.7-368.2). In a previous study in Japan, the median sperm count in adult men was reported to be 201 million. Participants in our study did not have lower sperm counts than this, despite their older age. Our results suggest that the long-term effects of COVID-19 on spermatogenesis are minimal.

Comparison of the effects of cefmetazole and meropenem on microbiome: A pilot study.

BACKGROUND: Cefmetazole (CMZ) is a carbapenem-sparing option in the treatment of extended-spectrum beta-lactamase (ESBL)-producing bacterial infection. In this pilot study, we aimed to compare the effects of antimicrobial treatment (meropenem [MP] and CMZ) with those of no antimicrobial treatment (control group) on the microbiome. METHODS: The study was a multicenter, prospective, observational pilot study conducted from October 2020 to October 2022. Feces and saliva samples were collected for microbiome analyses at two time points (early-period: days 1-3; and late-period: days 4-30) for the antimicrobial treatment group, and at one time point for the control group. RESULTS: Five feces (MP-F and CMZ-F) and five saliva (MP-S and CMZ-S) samples were included in the MP and the CMZ groups. Ten feces (C-F) and saliva (C-S) samples were included in the control group. Group α diversity was notably lower in the late-period MP-F group than the control group as determined with the Shannon richness index. ß diversity analysis of the feces samples based on weighted and unweighted UniFrac distances revealed distinctions in both the late-period CMZ-F and MP-F groups compared with the control group. Weighted UniFrac analysis showed that only the early-period MP-F group differed from the control group. In the saliva samples, weighted and unweighted UniFrac analyses showed significant differences between the control group and the early CMZ, late CMZ, and late MP groups. CONCLUSIONS: MP treatment may cause larger impact on the feces microbiome than CMZ in Japanese patients.

Efficacy and Safety of Ensitrelvir for Asymptomatic or Mild COVID-19: An Exploratory Analysis of a Multicenter, Randomized, Phase 2b/3 Clinical Trial.

BACKGROUND: This phase 2b/3, randomized, placebo-controlled trial explored the efficacy and evaluated the safety of ensitrelvir. This trial involved individuals with asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and patients with mild symptoms of coronavirus disease 2019 (COVID-19). METHODS: The trial was conducted at 57 medical institutions in Japan, South Korea, and Vietnam (study period: January 6-August 14, 2022). Eligible participants were randomized (1:1:1) to the ensitrelvir 125-mg, ensitrelvir 250-mg, or placebo group, received the allocated intervention orally, and were followed up until Day 28. Participants self-rated the severity of 14 typical COVID-19 symptoms and recorded the data in an electronic diary. RESULTS: In total, 572 participants (194, 189, and 189 in the ensitrelvir 125-mg, ensitrelvir 250-mg, and placebo groups, respectively) were included in the intention-to-treat population. Ensitrelvir 125-mg group observed a 77% reduction in the risk of developing any of the 14 COVID-19 symptoms or fever and a 29% reduction in the risk of worsening of such symptoms or fever versus placebo (statistically nonsignificant). The viral RNA, viral titer, and time to infectious viral clearance observed a statistically significant decrease versus placebo. Most treatment-related adverse events (TEAEs) were mild to moderate in severity, and the most common TEAE observed across groups was a decrease in high-density lipoprotein. CONCLUSIONS: Our exploratory results suggest a potential reduction in the risk of development or worsening of COVID-19 symptoms with ensitrelvir. Ensitrelvir showed antiviral efficacy and was well tolerated. TRIAL REGISTRATION: Japan Registry of Clinical Trials identifier: jRCT2031210350.

Status of COVID-19 Patients Treated With Extracorporeal Membrane Oxygenation in Japan: Nationwide Database Analysis.

Background The report of epidemiological data on coronavirus disease 2019 (COVID-19) patients treated using extracorporeal membrane oxygenation (ECMO) in Japan has been limited. Our study seeks to fill the existing gap in knowledge by providing an in-depth analysis of the clinical epidemiological characteristics and diverse medical outcomes of COVID-19 patients treated with ECMO in Japan. Methods This study used the COVID-19 Registry Japan nationwide database. We included patients aged 18 years or older enrolled between March 17, 2020, and February 1, 2022, with traceable ECMO data. The items on clinical epidemiological characteristics and various medical outcomes were collected. Statistical analysis included a median and interquartile range (IQR) for continuous variables and frequencies for categorical variables. Results The number of participating hospitals was 731, and the number of patients enrolled for analysis was 49,590. Of these, 196 (0.4%) patients received ECMO. Hospital mortality was 33.2%, and discharge to home was 23.0% in the ECMO group. The complications during hospitalization included pneumothorax (9.7%), seizures (4.1%), stroke (4.6%), and pulmonary thromboembolism (2.0%). At discharge, 38.3% had worsened self-care ability, and 38.8% had worsened ambulatory function. Conclusions The results of ECMO treatment in Japan showed that the mortality and complication rates were well-controlled compared with those worldwide.