Reverse transcription-quantitative PCR (RT-qPCR)-based tests are widely used to diagnose coronavirus disease 2019 (COVID-19). As a result that these tests cannot be done in local clinics where ...RT-qPCR testing capability is lacking, rapid antigen tests (RATs) for COVID-19 based on lateral flow immunoassays are used for rapid diagnosis. However, their sensitivity compared with each other and with RT-qPCR and infectious virus isolation has not been examined. Here, we compared the sensitivity among four RATs by using severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolates and several types of COVID-19 patient specimens and compared their sensitivity with that of RT-qPCR and infectious virus isolation. Although the RATs read the samples containing large amounts of virus as positive, even the most sensitive RAT read the samples containing small amounts of virus as negative. Moreover, all RATs tested failed to detect viral antigens in several specimens from which the virus was isolated. The current RATs will likely miss some COVID-19 patients who are shedding infectious SARS-CoV-2.
We investigated the clinical course of individuals with 2019 novel coronavirus disease (COVID-19) who were transferred from the Diamond Princess cruise ship to 12 local hospitals. The conditions and ...clinical courses of patients with pneumonia were compared with those of patients without pneumonia. Among 70 patients (median age: 67 years) analyzed, the major symptoms were fever (64.3%), cough (54.3%), and general fatigue (24.3%). Forty-three patients (61.4%) had pneumonia. Higher body temperature, heart rate, and respiratory rate as well as higher of lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and C-reactive protein (CRP) levels and lower serum albumin level and lymphocyte count were associated with the presence of pneumonia. Ground-glass opacity was found in 97.7% of the patients with pneumonia. Patients were administered neuraminidase inhibitors (20%), lopinavir/ritonavir (32.9%), and ciclesonide inhalation (11.4%). Mechanical ventilation and veno-venous extracorporeal membrane oxygenation was performed on 14 (20%) and 2 (2.9%) patients, respectively; two patients died. The median duration of intubation was 12 days. The patients with COVID-19 transferred to local hospitals during the outbreak had severe conditions and needed close monitoring. The severity of COVID-19 depends on the presence of pneumonia. High serum LDH, AST and CRP levels and low serum albumin level and lymphocyte count were found to be predictors of pneumonia. It was challenging for local hospitals to admit and treat these patients during the outbreak of COVID-19. Assessment of severity was crucial to manage a large number of patients.
To develop an effective vaccine against a novel viral pathogen, it is important to understand the longitudinal antibody responses against its first infection. Here we performed a longitudinal study ...of antibody responses against SARS-CoV-2 in symptomatic patients.
Sequential blood samples were collected from 39 individuals at various timepoints between 0 and 154 days after onset. IgG or IgM titers to the receptor binding domain (RBD) of the S protein, the ectodomain of the S protein, and the N protein were determined by using an ELISA. Neutralizing antibody titers were measured by using a plaque reduction assay.
The IgG titers to the RBD of the S protein, the ectodomain of the S protein, and the N protein peaked at about 20 days after onset, gradually decreased thereafter, and were maintained for several months after onset. Extrapolation modeling analysis suggested that the IgG antibodies were maintained for this amount of time because the rate of reduction slowed after 30 days post-onset. IgM titers to the RBD decreased rapidly and disappeared in some individuals after 90 days post-onset. All patients, except one, possessed neutralizing antibodies against authentic SARS-CoV-2, which they retained at 90 days after onset. The highest antibody titers in patients with severe infections were higher than those in patients with mild or moderate infections, but the decrease in antibody titer in the severe infection cohort was more remarkable than that in the mild or moderate infection cohort.
Although the number of patients is limited, our results show that the antibody response against the first SARS-CoV-2 infection in symptomatic patients is typical of that observed in an acute viral infection.
The Japan Agency for Medical Research and Development and the National Institutes of Allergy and Infectious Diseases.
This report outlines the need for the development of an advanced course in mass-casualty life support (MCLS) and introduces the course content. The current problems with education on disasters ...involving chemical agents, biological agents, radiation/nuclear attacks, or explosives (CBRNE) in Japan are presented. This newly developed "MCLS-CBRNE" program was created by a Ministry of Health, Labour, and Welfare (Tokyo, Japan) research group based on these circumstances. Modifications were then made after a trial course. Training opportunities for relevant organizations to learn how to act at a CBRNE disaster site currently are lacking. The developed course covers initial responses at a disaster site. This one-day training course comprises lectures, three tabletop simulations, and practical exercises in pre-decontamination triage and post-decontamination triage. With regard to field exercises conducted to date, related organizations have experienced difficulties in understanding each other and adapting their approaches. Tabletop simulations provide an opportunity for participants to learn how organizations working on-site, including fire, police, and medical personnel, act with differing goals and guiding principles. This course appears useful as a means for relevant organizations to understand the importance of developing common guidelines. The MCLS-CBRNE training is proposed to support CBRNE disaster control measures during future events. Anan H , Otomo Y , Kondo H , Homma M , Koido Y , Morino K , Oshiro K , Harikae K , Akasaka O . Development of mass-casualty life support-CBRNE (MCLS-CBRNE) in Japan. Prehosp Disaster Med. 2016;31(5):547-550.
Aim
Transporting critically ill patients outside of disaster‐affected areas for treatment is an important activity of Japan Disaster Medical Assistance Teams (DMATs). We investigated whether this ...activity is possible after possible catastrophic damage from a Nankai Trough earthquake.
Methods
Japan was divided into three areas based on the level of predicted damage (definitely, possibly, and non‐affected areas). A survey of DMATs and the locations of emergency base hospitals and intensive care units (ICUs) in each area was carried out, and the ability to support disaster areas was investigated. Next, a survey of wide‐area medical transport by Self‐Defense Force aircraft and the medical transport abilities of helicopter ambulances was carried out. The numbers of ICU beds in each area were compared, and the capacity to accept patients was investigated. Finally, subjects for further study were examined.
Results
The number of DMATs that could be sent from non‐affected areas was insufficient. The number of patients that can be transported by Self‐Defense Force aircraft and helicopter ambulance during the first 3 days was determined to be 1,443. The number of patients that can be accepted by ICUs in non‐affected areas was insufficient. A system needs to be developed to provide medical treatment for critically ill patients within disaster areas during the acute phase. This will require DMAT operational reforms and the creation of logistics systems such as the supply of resources for earthquake‐reinforced hospitals.
Conclusion
In addition to patient transport, systems to provide medical care inside disaster‐affected areas are needed.
We investigated the specific medical response capabilities and considered Japan Disaster Medical Assistance Team activity guidelines that should be changed assuming a Nankai Trough earthquake. The investigations indicate an overwhelming shortage in the number of responding Disaster Medical Assistance Teams, aircraft transport capacity, and the number of intensive care unit beds that can accept critically ill patients estimated to need transport out of the affected areas.
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•A cyclone prefilter developed to mitigate clogging in HEPA filters.•The prefilter installed a blade and vents for self-cleaning of collected particles.•>50 % PM2.5 collection ...efficiency was achieved with < 10 Pa pressure drop.•CFD simulations highlighted the impact of radial velocity on particle collection.•Particle loading tests demonstrated for > 10 years of continuous operation.
Owing to the biological and environmental impacts of fine particles in gas such as PM2.5, improvement of air purifier technologies is needed, as traditional High-Efficiency Particulate Air (HEPA) filters struggle with pressure increases and clogging from particle accumulation. This study explores the potential usage of centrifugal force in designing a novel particle collection device as a pre-filter for air cleaning systems. This prefilter consists of a cylinder for housing, a rotating blade for generating swirling flow, and sidewall square vents installed to exhaust the collected particles, leading to a reduction in the accumulation of particles in the particle collector and suppression of the pressure drop increment. We evaluated the initial collection performance across three different blade structures. Two of these designs achieved a collection efficiency of over 50 % for PM2.5 particles when the rotation speed was > 2000 rpm, while maintaining a pressure drop of < 10 Pa. Furthermore, we employed computational fluid dynamics to access the detailed flow profiles in the device and the analysis indicated that the radial velocity significantly impacts the particle collection performance. Finally, the influence of prolonged usage on collector performance dust loading test was performed. Installation of sidewall vents was found to be effective in reducing the accumulation of particles in the collector, suggesting the continuous long-term use of the device without maintenance.
The objective of this study was to draft a new Japanese Disaster Medical Assistance Team (DMAT) training program based on the responses to the Great East Japan Earthquake.
Working group members of ...the Japan DMAT Investigative Commission, Ministry of Health, Labour and Welfare, reviewed reports and academic papers on DMAT activities after the disaster and identified items in the current Japanese DMAT training program that should be changed. A new program was proposed that incorporates these changes.
New topics that were identified to be added to the DMAT training program were hospital evacuation, preparations to receive DMATs at damaged hospitals, coordination when DMAT activities are prolonged, and safety management and communication when on board small helicopters. The use of wide-area transport was reviewed and changes were made to cover selection of various transport means including helicopter ambulances. Content related to confined space medicine was removed. The time spent on emergency medical information system (EMIS) practical training was increased. Redundant or similar content was combined and reorganized, and a revised DMAT training program that did not increase the overall training time was designed.
The revised DMAT training program will provide practical training better suited to the present circumstances in Japan.
Airborne aerosols were collected in six size classes (PM<0.1, PM0.1–0.5, PM0.5–1, PM1–2.5, PM2.5–10 and PM>10) to investigate aerosol health risks in remote and industrial areas in Japan. We focused ...on heavy metals and their water-dispersed fractions. The average concentration of heavy metals was 18 ± 25–86 ± 48 ngm−3 for PM<0.1, 46 ± 19–154 ± 80 for PM0.5–1 ngm−3, 98 ± 49–422 ± 186 ngm−3 for PM1–2.5, 321 ± 305–1288 ± 727 ngm−3 for PM2.5–10 and 65 ± 52–914 ± 339 ngm−3 or PM>10, and these concentrations were higher in industrial areas. Heavy metals emitted from domestic anthropogenic sources were added to the long-range transport component of the aerosols. The water-dispersed fraction of heavy metals contained 3.3–40.1% of the total heavy metals in each size class. The relative contribution of Zn and other species (As, Cd, Cr, Ni, Pb, Mn, V and Cu) increased in the water-dispersed fraction. Smaller particles contained greater proportions of the water-dispersed heavy metal fraction. Carcinogenic risk (CR) and the hazard index (HI) were estimated for each size class. The CR of carcinogens was at acceptable levels (<1 ×10−6) for five particle size fractions. The HI values for carcinogens and noncarcinogens were also below acceptable levels (<1) for the same five size fractions. The estimated CR and HI values were dominated by contributions from the inhalation process.
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•Composition of water dispersed heavy metals in ultrafine particles are cleared.•Water dispersed heavy metals in ultrafine particles were measured.•Inhalation process are major process to CR and HI risk in Japan.•Domestic emissions are large influence to the industrial cities than those in remote.•CR and HI levels are safe levels in remote and industrial region in Japan.
Significance
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants are of concern, with the P.1 variants dominating in Brazil. Brazil is now seeing a record number of deaths. Here, we ...report that the pathogenicity in hamsters of a P.1 variant is similar to that of nonvariant SARS-CoV-2. However, it has an expanded host range as shown by its replication in mice. Prior infection with nonvariant SARS-CoV-2 strains efficiently prevented replication of the P.1 variant in the lower respiratory tract of hamsters upon reinfection. Convalescent sera from patients infected with nonvariants or sera from messenger RNA vaccinees showed comparable neutralization titers among the P.1 and previously circulating strains. These results suggest that previous SARS-CoV-2 infection and vaccines based on the original SARS-CoV-2 will provide some protection against P.1 infection.
The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays a key role in viral infectivity. It is also the major antigen stimulating the host's protective immune response, specifically, the production of neutralizing antibodies. Recently, a new variant of SARS-CoV-2 possessing multiple mutations in the S protein, designated P.1, emerged in Brazil. Here, we characterized a P.1 variant isolated in Japan by using Syrian hamsters, a well-established small animal model for the study of SARS-CoV-2 disease (COVID-19). In hamsters, the variant showed replicative abilities and pathogenicity similar to those of early and contemporary strains (i.e., SARS-CoV-2 bearing aspartic acid D or glycine G at position 614 of the S protein). Sera and/or plasma from convalescent patients and BNT162b2 messenger RNA vaccinees showed comparable neutralization titers across the P.1 variant, S-614D, and S-614G strains. In contrast, the S-614D and S-614G strains were less well recognized than the P.1 variant by serum from a P.1-infected patient. Prior infection with S-614D or S-614G strains efficiently prevented the replication of the P.1 variant in the lower respiratory tract of hamsters upon reinfection. In addition, passive transfer of neutralizing antibodies to hamsters infected with the P.1 variant or the S-614G strain led to reduced virus replication in the lower respiratory tract. However, the effect was less pronounced against the P.1 variant than the S-614G strain. These findings suggest that the P.1 variant may be somewhat antigenically different from the early and contemporary strains of SARS-CoV-2.
The Diamond Princess cruise ship, carrying 3711 passengers and crew members, docked at Yokohama Port in Japan on February 3, 2020. A quarantine was immediately instituted because 1 passenger who had ...disembarked in Hong Kong was confirmed to have tested positive for coronavirus disease 2019 (COVID-19). After the quarantine began, all passengers and crew were tested using the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) polymerase chain reaction assay on the ship, 696 of whom tested positive. In total, 769 patients, including 696 with COVID-19, required transport to a hospital. The Japan Disaster Medical Assistance Team (DMAT) successfully picked up and safely transported the COVID-19 patients using a novel classification system to prioritize patients. The Japan DMAT transported 203 patients to hospitals in Kanagawa and another 566 patients to hospitals in 15 different prefectures.
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