Objective: This study was aimed at clarifying the clinical characteristics and prognosis of patients hospitalized with COVID-19 and the treatment strategies for COVID-19 in each surge of the COVID-19 pandemic.

Subjects and methods: We retrospectively examined the data of 358 patients with confirmed COVID-19 (116 in surge 3, 137 in surge 4, and 105 in surge 5) who were admitted to the Yoshijima Hospital.

Results: As compared with the findings in surges 3 and 4, inpatients were younger in surge 5, when COVID-19 vaccination had expanded in Japan. favipiravir was used more often in surge 3. Use of remdesivir, baricitinib, and anticoagulant drugs increased on and after surge 4. The frequency with which moderate COVID-19 patients worsened to severe/critical or critical after admission decreased during surge 4 and surge 5 as compared with that during surge 3. An additional analysis revealed that 42 patients developed severe hypoxia, the frequency of high-flow nasal cannula (HFNC) use increased, and the frequency of cases requiring admission to the intensive care unit and tracheal intubation decreased on and after surge 4.

Conclusion: Establishment of treatment strategies, active use of HFNC, and decrease in the number of elderly patients that occurred with the expansion of the COVID-19 vaccination drive may have contributed to the improvement in the clinical outcomes of hospitalized patients with COVID-19.

Background: Randomized phase III clinical trials suggest that the antibody cocktail containing casirivimab and imdevimab reduces the risk of hospitalization/death in high-risk COVID-19 patients. However, the efficacy of the cocktail in daily clinical practice remains unknown.

Methods: We administered the antibody cocktail to consecutive febrile high-risk COVID-19 patients hospitalized at our institute from late July 2021 through early September 2021. During the time, the delta variant was the dominant variant in our community. Primary efficacy was defined as reduction of fever to below 37°C and absence of need for additional medical interventions after the cocktail therapy. In addition, several laboratory data were examined to detect the cutoff values for favorable clinical outcomes by ROC curve analysis.

Results: The cocktail was given to 55 febrile high-risk COVID-19 patients, 38 (69.1%) out of which were male. The median values (and ranges) of the age, SpO₂, and number of comorbidities were 51 (20-94) years; 97% (93%-99%), and 2 (1-5), respectively. 43.6% of the patients showed evidence of pneumonia. The cocktail therapy showed 74.5% efficacy in the 55 patients who received the therapy. The median value and range of the duration (day) of fever after the cocktail therapy was 1.5 (1-4), respectively. The cocktail infusion was administered a median of 4 days from disease onset, and the median duration of fever from disease onset was 5.4 days. The median observation period after the cocktail infusion was 6 days. The cutoff values of the age, SpO₂, serum CRP, and serum LDH were ≤72 years old, ≥96%, <2.64mg/dL, and <220U/L, respectively (odds ratios=12.2, 27.8, 11.6, and 17.2, respectively).

Conclusions: The antibody cocktail therapy was associated with a speedy recovery from COVID-19-related fever, and the efficacy is likely affected by the age, SpO₂, serum CRP, and serum LDH values.

Background: The importance of the antimicrobial stewardship program (ASP) is globally acknowledged. Although there have been previous reports on the efficacy of the ASP in a pediatric setting, few studies have been conducted at university hospitals in rural areas. Hence, this study was aimed at evaluating the efficacy of a pediatric ASP at the pediatrics department of Fukushima Medical University Hospital (FMUH).

Methods: The study included patients who were hospitalized and administered intravenous antibiotics in 2016, before the introduction of the ASP at the department of pediatrics of FMUH, as well as patients admitted to the hospital from 2017 to 2019, after the introduction of the ASP at the hospital. The efficacy of the ASP was evaluated by assessing the antibiotic use density (AUD) of the antimicrobial agents, drug susceptibility of Pseudomonas aeruginosa, and the annual detection rate of drug-resistant organisms.

Results: The number of times intravenous antibiotics were administered in 2016, 2017, 2018, and 2019 were 279, 380, 428, and 350, respectively. The AUD values decreased significantly over time from 3.12 in 2016 to 0.93 in 2019 (p<0.05). A significant difference was reported in the proportion of Pseudomonas aeruginosa isolates susceptible to meropenem in 2016 (50%) and after 2017 (>80%), following the introduction of the pediatric ASP (p<0.01). Although the AUD of vancomycin increased with an increase in the number of patients admitted to the PICU, no vancomycin-resistant strains were detected.

Conclusion: Practicing and promoting a pediatric ASP at a medical university hospital is effective.

Legionellosis is an infectious disease caused by Legionella spp., whose incidence has been increasing each year in Japan; however, in most cases, the source of infection cannot be detected. In this study, we attempted to clarify the genetic distribution of Legionella isolates from patients. From 2014 to 2019, we collected 73 sputum specimens and isolated Legionella spp. in 6 cases. Twenty-two of the 73 cases were Legionella culture-positive, corresponding to a detection rate of 30.1%. Legionella pneumophila serogroup 1 (SG1) was isolated in 21 of the 22 cases, and both L. pneumophila SG1 and SG7 isolates were detected in 1 case. All the 6 strains isolated on culture were identified as L. pneumophila SG1. A total of 28 strains of L. pneumophila SG1 were analyzed by sequence-based typing (SBT). Of the 28 strains, 19 were of different sequence types (STs), 5 were ST1346, and 2 each were ST89, ST92, and ST142. In addition, 6 Legionella DNA-positive, but culture-negative sputa were analyzed by nested-SBT and 3 of them were demonstrated to be of a single ST. ST1346 was the most commonly isolated strain. Four of the 5 strains were isolated within a short period of time in November 2016, and the 5th strain was isolated 11 months later. Whole genome analysis was performed on the 5 strains of ST1346 and 3-6 pairwise single-nucleotide variant (SNV) differences were identified among the isolates, indicating that the isolates were closely related, and that these were consecutive cases of legionellosis due to an unrecognized common source of infection. Performing more detailed and accurate surveys by conducting SBT analysis quickly and reflecting it in the epidemiological investigation can lead to earlier detection of outbreaks.

Typhoid fever is common in developing countries. Even in developed countries, however, small epidemics could occur, caused not only by overseas travelers, but also by chronic carriers. Detection of chronic carriers is difficult. A small number of patients become chronic carriers and act as a source of infection if only usual treatment is given, and not complete treatment. We report two cases of typhoid fever that occurred 30 months apart in members of a family with no history of overseas travel. We examined the molecular epidemiology and identified a chronic carrier in one of the family members with gallbladder stones, and treated the carrier with antibiotics and cholecystectomy. No case of typhoid fever has occurred in the family since. No guidelines recommend examination of the gallbladder for chronic carriers, although many reports indicate gallbladder abnormalities. The above suggests that follow-up examination of typhoid fever patients should include gallbladder examination for abnormalities, especially in non-epidemic countries.

In December 2019, an outbreak of pneumonia caused by a new type of coronavirus (SARS-CoV-2) infection was reported from Wuhan, Hubei Province, China, and the infection later came to be named as COVID-19. The virus spread rapidly around the world, ultimately infecting more than 200 million people, including more than one million people in Japan. Analysis of the data of accumulated cases showed that older people and people with underlying diseases tended to have more severe disease, providing some insight into the pathogenesis of COVID-19. With the widespread vaccination drive against COVID-19 starting from February 2021, the number of severely affected older people declined in Japan. However, emergence of the δ variant strain and issues with vaccine penetration in young people caused the number of infections and severe illness to increase in people aged 60 years or under. As of October 2021, however, the number of new cases was trending downward. Screening by antigen testing, polymerase chain reaction (PCR), and chest computed tomography (CT) are the main diagnostic methods for COVID-19. It is important to recognize that mild interstitial pneumonia-like opacities could appear on the chest CT even in younger patients. In this report, we describe a non-COVID-19-vaccinated patient admitted with asthma, who had tested negative twice for SARS-CoV-2 by PCR examination of a saliva specimen. Later, after visiting our hospital, the patient tested positive for COVID-19 antibodies.

We report the case of a 31-year-old man who was admitted with a 7-day history of cough and dyspnea and had a fever of 38.0°C the following day. He had taken antipyretics and lascufloxacin 75mg/day for 4 days, but his symptoms did not improve, and he was diagnosed as having mild COVID-19 and received home care. On the morning of the admission, he developed left scrotal pain and difficulty in walking, and visited our hospital. He had tenderness in the left epididymis and was diagnosed as having epididymitis associated with COVID-19, since no other cause of epididymitis could be identified. Chest CT revealed evidence of pneumonia, so that the patient was started on remdesivir. He had a fever of 37.9°C on day 1, but it resolved later and the respiratory symptoms improved. The left scrotal pain gradually resolved, and the patient was discharged on day 5. Semen analysis showed a low sperm count and motile sperm count on day 14. MRI showed enlargement and hyperintensity of the left epididymis. Although epididymitis is not usually associated with a reduction of the sperm count, COVID-19 infection affects the reproductive function, even in the absence of the symptoms of orchitis, because SARS-CoV-2 binds the angiotensin-converting enzyme 2 (ACE2) receptors in the testes and epididymises. A fertility test had been performed 2 months prior to the onset of COVID-19 in this patient, and it was possible to compare the semen findings before and after the infection.

Herein, we report the case of a 69-year-old Japanese woman who was admitted to our hospital with dyspnea and severe hypoxia. She was diagnosed as having COVID-19 with ARDS. At the same time, her HIV screening test result also returned positive. However, the results of confirmatory tests for HIV, including Western blot analysis and RNA PCR were negative. Finally, the patient was diagnosed as having a false-positive result of the HIV screening test due to cross-reactivity between HIV gp41 antigen and SARS-CoV-2 antibody; similarity between HIV and SARS-CoV-2 spike proteins could yield false-positive results of HIV screening. Our case implies the importance of recognizing the possibility of a false-positive result of HIV screening in patients with COVID-19.