Effectiveness of feedback control and the trade-off between death by COVID-19 and costs of countermeasures.

We provided a framework of a mathematical epidemic modeling and a countermeasure against the novel coronavirus disease (COVID-19) under no vaccines and specific medicines. The fact that even asymptomatic cases are infectious plays an important role for disease transmission and control. Some patients recover without developing the disease; therefore, the actual number of infected persons is expected to be greater than the number of confirmed cases of infection. Our study distinguished between cases of confirmed infection and infected persons in public places to investigate the effect of isolation. An epidemic model was established by utilizing a modified extended Susceptible-Exposed-Infectious-Recovered model incorporating three types of infectious and isolated compartments, abbreviated as SEIIIHHHR. Assuming that the intensity of behavioral restrictions can be controlled and be divided into multiple levels, we proposed the feedback controller approach to implement behavioral restrictions based on the active number of hospitalized persons. Numerical simulations were conducted using different detection rates and symptomatic ratios of infected persons. We investigated the appropriate timing for changing the degree of behavioral restrictions and confirmed that early initiating behavioral restrictions is a reasonable measure to reduce the burden on the health care system. We also examined the trade-off between reducing the cumulative number of deaths by the COVID-19 and saving the cost to prevent the spread of the virus. We concluded that a bang-bang control of the behavioral restriction can reduce the socio-economic cost, while a control of the restrictions with multiple levels can reduce the cumulative number of deaths by infection.

Usefulness of the Legionella Score for differentiating from COVID-19 pneumonia to legionella pneumonia.

Legionella pneumophila is a major causative pathogen of community-acquired pneumonia (CAP), but recently the novel coronavirus disease 2019 (COVID-19) became the most common causative pathogen of CAP. Because L. pneumophila CAP is clinically distinct from bacterial CAPs, the Japan Society for Chemotherapy (JSC) developed a simple scoring system, the Legionella Score, using six parameters for the presumptive diagnosis of L. pneumophila pneumonia. We investigated the clinical and laboratory differences of L. pneumophila CAP and COVID-19 CAP and validated the Legionella Score in both CAP groups. We analyzed 102 patients with L. pneumophila CAP and 956 patients with COVID-19 CAP. Dyspnea and psychiatric symptoms were more frequently observed and cough was less frequently observed in patients with L. pneumophila CAP than those with COVID-19 CAP. Loss of taste and anosmia were observed in patients with COVID-19 CAP but not observed in those with L. pneumophila CAP. C-reactive protein and lactate dehydrogenase levels in L. pneumophila CAP group were significantly higher than in the COVID-19 CAP group. In contrast, sodium level in the L. pneumophila CAP group was significantly lower than in the COVID-19 CAP group. The median Legionella Score was significantly higher in the L. pneumophila CAP group than the COVID-19 CAP group (score 4 vs 2, p < 0.001). Our results demonstrated that the JSC Legionella Score had good diagnostic ability during the COVID-19 pandemic. However, physicians should consider COVID-19 CAP when loss of taste and/or anosmia are observed regardless of the Legionella Score.

COVID-19 and invasive fungal coinfections: A case series at a Brazilian referral hospital.

BACKGROUND: COVID-19 co-infections have been described with different pathogens, including filamentous and yeast fungi. METHODOLOGY: A retrospective case series study conducted from February to December 2020, at a Brazilian university hospital. Data were collected from two hospital surveillance systems: Invasive fungal infection (IFI) surveillance (Mycosis Resistance Program - MIRE) and COVID-19 surveillance. Data from both surveillance systems were cross-checked to identify individuals diagnosed with SARS-CoV-2 (by positive polymerase chain reaction (PCR)) and IFI during hospital stays within the study period. RESULTS: During the study period, 716 inpatients with COVID-19 and 55 cases of IFI were identified. Fungal co-infection with SARS-CoV-2 was observed in eight (1%) patients: three cases of aspergillosis; four candidemia and one cryptococcosis. The median age of patients was 66 years (IQR 58-71 years; range of 28-77 years) and 62.5% were men. Diagnosis of IFI occurred a median of 11.5 days (IQR 4.5-23 days) after admission and 11 days (IQR 6.5-16 days) after a positive PCR result for SARS-CoV-2. In 75% of cases, IFI was diagnosed in the intensive care unit (ICU). Cases of aspergillosis emerged earlier than those of candidemia: an average of 8.6 and 28.6 days after a positive PCR for SARS-CoV-2, respectively. All the patients with both infections ultimately died. CONCLUSION: A low rate of COVID-19 co-infection with IFI was observed, with high mortality. Most cases were diagnosed in ICU patients. Aspergillosis diagnosis is highly complex in this context and requires different criteria.

Immersive Virtual Reality Reminiscence Reduces Anxiety in the Oldest-Old Without Causing Serious Side Effects: A Single-Center, Pilot, and Randomized Crossover Study.

Background: Dementia is one the major problems of aging societies, and, novel and effective non-drug therapies are required as interventions in the oldest-old to prevent cognitive decline. Objective: This study aims to examine the efficacy and safety of reminiscence using immersive virtual reality (iVR reminiscence) focusing on anxiety that often appears with cognitive decline. The secondary objective is to reveal the preference for VR image types for reminiscence: live-action (LA) or computer graphics (CG). Methods: This was a pilot, open-label, and randomized crossover study which was conducted on January 2020 at a single nursing home. The subjects were randomly divided into two groups (A or B) in equal numbers, and they alternately viewed two types of VR images (LA and CG) themed on the mid- to late Showa era (A.D. 1955-1980) in Japan. In group A, the CG images were viewed first, and then the LA images were viewed (CG→ LA). In group B, the images were viewed in the opposite order (LA→ CG). Before VR viewing, subjects responded to Mini-Mental State Examination (MMSE) Japanese version and State-Trait Anxiety Inventory (STAI) Japanese version. After viewing the first and second VR, subjects responded to STAI and the numerical rating scale (NRS) for satisfaction and side effects (nausea, dizziness, headache, and tiredness). Results: Ten subjects participated in this study. The values of analyses are presented in the mean (SD). The age was 87.1 years (4.2), and the MMSE was 28.5 (1.8). The total STAI score before VR viewing was 36.1 (7.2), but it significantly decreased to 26.8 (4.9) after the first VR viewing (P = 0.0010), and further decreased to 23.4 (2.8) after the second VR viewing (P < 0.001). The NRS score for satisfaction tended to be higher after viewing LA in group A (CG→ LA) (CG vs. LA; 7.0 (2.3) vs. 8.6 (1.5), P = 0.0993), while in group B (LA→ CG), the score after CG was slightly lower than that after LA. There were no serious side effects. Conclusions: This study suggests that iVR reminiscence can reduce anxiety in the oldest-old without causing serious side effects. Furthermore, the impacts might be better with LA images.