Infectious virus shedding duration reflects secretory IgA antibody response latency after SARS-CoV-2 infection.

Infectious virus shedding from individuals infected with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is used to estimate human-to-human transmission risk. Control of SARS-CoV-2 transmission requires identifying the immune correlates that protect infectious virus shedding. Mucosal immunity prevents infection by SARS-CoV-2, which replicates in the respiratory epithelium and spreads rapidly to other hosts. However, whether mucosal immunity prevents the shedding of the infectious virus in SARS-CoV-2-infected individuals is unknown. We examined the relationship between viral RNA shedding dynamics, duration of infectious virus shedding, and mucosal antibody responses during SARS-CoV-2 infection. Anti-spike secretory IgA antibodies (S-IgA) reduced viral RNA load and infectivity more than anti-spike IgG/IgA antibodies in infected nasopharyngeal samples. Compared with the IgG/IgA response, the anti-spike S-IgA post-infection responses affected the viral RNA shedding dynamics and predicted the duration of infectious virus shedding regardless of the immune history. These findings highlight the importance of anti-spike S-IgA responses in individuals infected with SARS-CoV-2 for preventing infectious virus shedding and SARS-CoV-2 transmission. Developing medical countermeasures to shorten S-IgA response time may help control human-to-human transmission of SARS-CoV-2 infection and prevent future respiratory virus pandemics.

The Tokyo 2020 and Beijing 2022 Olympic Games held during the COVID-19 pandemic: planning, outcomes, and lessons learnt.

The COVID-19 pandemic profoundly affected all mass gatherings for sporting and religious events, causing cancellation, postponement, or downsizing. On March 24, 2020, the Japanese Government, the Tokyo Organising Committee of the Olympic and Paralympic Games, and the International Olympic Committee decided to postpone the Tokyo 2020 Olympic and Paralympic Games until the summer of 2021. With the emergence of SARS-CoV-2, the potential creation of a superspreading event that would overwhelm the Tokyo health system was perceived as a risk. Even with a delayed start date, an extensive scale of resources, planning, risk assessment, communication, and SARS-CoV-2 testing were required for the Games to be held during the COVID-19 pandemic. The effectiveness of various mitigation and control measures, including the availability of vaccines and the expansion of effective testing options, allowed event organisers and the Japanese Government to successfully host the rescheduled 2020 Tokyo Olympic Games from July 23 to Aug 8, 2021 with robust safety plans in place. In February and March, 2022, Beijing hosted the 2022 Winter Olympic Games as scheduled, built on the lessons learnt from the Tokyo Games, and developed specific COVID-19 countermeasure plans in the context of China's national framework for the plan called Zero COVID. Results from the testing programmes at both the Tokyo and Beijing Games show that the measures put in place were effective at preventing the spread of COVID-19 within the Games, and ensured that neither event became a COVID-19-spreading event. The extensive experience from the Tokyo and Beijing Olympic Games highlights that it is possible to organise mass gatherings during a pandemic, provided that appropriate risk assessment, risk mitigation, and risk communication arrangements are in place, leaving legacies for future mass gatherings, public health, epidemic preparedness, and wider pandemic response.

Simplifying Oral health evaluation: a novel approach through single-item surveys.

BACKGROUND: This study adopts a novel approach of using single-item surveys to simplify the assessment of oral health status and behaviors among Japanese private sector employees. We aimed to establish the validity of self-reported oral health in relation to clinical dental examinations, and to elucidate the relationship between oral diseases, health behaviors, and self-assessments. A secondary aim was to explore the association of self-rated oral health with oral health behaviors. MATERIALS AND METHODS: Self-administered questionnaires and dental examinations were obtained from 2262 Japanese private sector employees. Workers self-rated their overall oral health status according to five choices: "very good," "good," "fair," "poor," or "bad." Self-reports were then compared with the results of clinical dental examinations, which included measuring the oral hygiene index (DI-S), the number of decayed teeth, periodontal status (Community Periodontal Index) and number of missing teeth. Convergent validity was also tested by examining the correlations of self-reported oral health status with oral health behaviors. RESULTS: Overall, 30.8% of workers reported their oral health as "poor" or "bad." "Poor" or "bad" oral health status was significantly correlated with missing teeth, periodontitis, and decayed teeth. However, lower correlations were found for gingivitis and the oral hygiene index. Most self-reported oral health behaviors were correlated with self-rated oral health; exceptions were "tooth brushing instructions received in a dental clinic," "having a primary-care dentist," and "habitual snacking between meals." CONCLUSIONS: Self-rated oral health provides reasonably valid data, and correlated well with clinically assessed oral health status, including dental caries, periodontal status, and tooth loss. Convergent validity was also found for oral health behaviors. TRIAL REGISTRATION: Clinical trial registration number: UMIN000023011 (UMIN-CTR). Date of clinical trial registration: 06/07/2016.

Development of a partnership between academia, community, and government in response to the 2022 mpox outbreak in Japan.

Objectives　In response to the steady rise in the number of cases of mpox in nonendemic countries, starting with an outbreak in the United Kingdom in May 2022, the World Health Organization declared a public health emergency of international concern on July 23, 2022. As of November 13, 2022, seven cases of mpox have been reported in Japan.Methods　A community engagement approach was applied to prevent the spread of mpox in Japan.Results　A tripartite partnership between academia, community, and government (ACG) was established to promote multisectoral communication between vulnerable communities, medical personnel involved in diagnosis and treatment, public health specialists at public health centers, epidemiologists at the National Institute of Infectious Diseases (NIID), and government and public administration. Through information sharing, this ACG partnership can translate accurate information into effective infection control measures.Conclusion　By developing and maintaining the ACG partnership, an environment will be created that allows an immediate response to future public health crises affecting vulnerable communities. This Practice Report describes the process of establishing an ACG partnership.

National Surveillance of Pediatric Acute Hepatitis of Unknown Etiology, Japan, October 2021-December 2022.

Pediatric acute hepatitis of unknown etiology has been reported globally since April 2022. In Japan, 139 possible cases with onset dates after October 2021 were reported as of December 2022. Three patients required liver transplants, but none died. Rates of adenovirus positivity (11/125, 9%) were lower than those for other countries.

Two Cases of Breakthrough Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infections Caused by the Omicron Variant (B.1.1.529 Lineage) in International Travelers to Japan.

In November 2021, the World Health Organization designated a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant of concern, Omicron (PANGO lineage B.1.1.529). We report on the first 2 cases of breakthrough coronavirus disease 2019 (COVID-19) caused by Omicron in Japan among international travelers returning from the country with undetected infection. The spread of infection by Omicron were considered.

Duration of Infectious Virus Shedding by SARS-CoV-2 Omicron Variant-Infected Vaccinees.

To determine virus shedding duration, we examined clinical samples collected from the upper respiratory tracts of persons infected with severe acute respiratory syndrome coronavirus 2 Omicron variant in Japan during November 29-December 18, 2021. Vaccinees with mild or asymptomatic infection shed infectious virus 6-9 days after onset or diagnosis, even after symptom resolution.

Neutralising activity and antibody titre in 10 patients with breakthrough infections of the SARS-CoV-2 Omicron variant in Japan.

The Omicron variant of severe acute respiratory syndrome coronavirus 2 has multiple amino acid mutations in its spike proteins, which may allow it to evade immunity elicited by vaccination. We examined the neutralising activity and S1-IgG titres in patients with breakthrough infections caused by the Omicron variant after two doses of vaccination. We found that neutralising activity was significantly lower for the Omicron variant than for the Wuhan strain. Two doses of vaccination might not induce sufficient neutralising activity for the Omicron variant.

Proactive Engagement of the Expert Meeting in Managing the Early Phase of the COVID-19 Epidemic, Japan, February-June 2020.

To deal with the risk of emerging diseases with many unknowns, close and timely collaboration and communication between science experts and policymakers are crucial to developing and implementing an effective science-based intervention strategy. The Expert Meeting, an ad hoc medical advisory body, was established in February 2020 to advise Japan's COVID-19 Response Headquarters. The group played an important role in the policymaking process, promoting timely situation awareness and developing science-based proposals on interventions that were promptly reflected in government actions. However, this expert group may have been overly proactive in taking on the government's role in crisis management. For the next stage of managing the coronavirus disease pandemic and future pandemics, the respective roles of the government and its advisory bodies need to be clearly defined. Leadership and strategic risk communication by the government are key.

SARS-CoV-2 detection by fluorescence loop-mediated isothermal amplification with and without RNA extraction.

Rapid and simple point-of-care detection of SARS-CoV-2 is an urgent need to prevent pandemic. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) can detect SARS-CoV-2 more rapidly than RT-PCR. Saliva is non-invasive specimen suitable for mass-screening, but data comparing utility of nasopharyngeal swab (NPS) and saliva in RT-LAMP test are lacking and it remains unclear whether SARS-CoV-2 could be detected by direct processing of samples without the need for prior RNA extraction saliva. In this study, we compared utility of saliva and NPS samples for the detection of SARS-CoV-2 by a novel RT-fluorescence LAMP (RT-fLAMP). The sensitivity and specificity of the RT-fLAMP with RNA extraction were 97% and 100%, respectively, with equivalent utility of NPS and saliva. However, sensitivity was decreased to 71% and 47% in NPS and saliva samples without RNA extraction, respectively, suggesting that RNA extraction process may be critical for the virus detection by RT-fLAMP.

Severe fever with thrombocytopenia syndrome in Japan and public health communication.

A fatal case of severe fever with thrombocytopenia syndrome was reported in Japan in 2013. The ensuing process of public communication offers lessons on how to balance public health needs with patient privacy and highlights the importance of multilateral collaborations between scientific and political communities.

Public health challenges and legacies of Japan's response to the Ebola virus disease outbreak in West Africa 2014 to 2015.

The largest outbreak of Ebola virus disease occurred in West Africa in 2014 and resulted in unprecedented transmission even in distant countries. In Japan, only nine individuals were screened for Ebola and there was no confirmed case. However, the government promoted the reinforcement of response measures and interagency collaboration, with training and simulation exercises conducted country-wide. The legacies included: publication of a communication policy on case disclosure, a protocol for collaboration between public health and other agencies, and establishing an expert committee to assemble the limited available expertise. There were challenges in taking proportionate and flexible measures in the management of people identified to be at high risk at entry points to Japan, in the decentralised medical response strategy, and in the medical countermeasures preparedness. The Ebola outbreak in West Africa provided a crucial opportunity to reveal the challenges and improve the preparedness for rare but high impact emerging diseases that are prone to be neglected. Efforts to uphold the lessons learnt and maintain public health preparedness should help prepare for future emerging diseases, including bioterrorist acts and pandemics.

The first identification and retrospective study of Severe Fever with Thrombocytopenia Syndrome in Japan.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV), a novel bunyavirus reported to be endemic in central and northeastern China. This article describes the first identified patient with SFTS and a retrospective study on SFTS in Japan. METHODS: Virologic and pathologic examinations were performed on the patient's samples. Laboratory diagnosis of SFTS was made by isolation/genome amplification and/or the detection of anti-SFTSV immunoglobulin G antibody in sera. Physicians were alerted to the initial diagnosis and asked whether they had previously treated patients with symptoms similar to those of SFTS. RESULTS: A female patient who died in 2012 received a diagnosis of SFTS. Ten additional patients with SFTS were then retrospectively identified. All patients were aged ≥50 years and lived in western Japan. Six cases were fatal. The ratio of males to females was 8:3. SFTSV was isolated from 8 patients. Phylogenetic analyses indicated that all of the Japanese SFTSV isolates formed a genotype independent to those from China. Most patients showed symptoms due to hemorrhage, possibly because of disseminated intravascular coagulation and/or hemophagocytosis. CONCLUSIONS: SFTS has been endemic to Japan, and SFTSV has been circulating naturally within the country.

Response to Ebola virus disease outbreak in West Africa by the Ministry of Health, Labour and Welfare of Japan in 2014-2015.

Ebola Virus Disease (EVD) is categorized in the Category 1 Infectious Disease under the Act on Infectious Disease Control. Since the Act came into effect in 1999, no confirmed case of viral hemorrhagic fevers (VHF) has been reported, though some clinical samples have been tested for VHF in the National Institute of Infectious Diseases of Japan. Ministry of Health, Labour and Welfare has monitored the situation of the EVD outbreak in West Africa since the first report from Guinea in March 2014 and reinforced quarantine and public health preparedness in August. The whole-of-government response was activated at the end of October, establishing the Ministerial meeting on the Response to the EVD presided by the Prime Minister. The responses have raised the level of preparedness for such a rare import disease like VHF; however elicited many lessons. Even if the current VHF outbreak is over, the risk of the global infectious diseases outbreak will be unchanged. The maintenance and improvement of preparedness and response for infectious diseases emergency such as the Category 1 Infectious Disease outbreak by the improvement of manuals and continuous exercises are crucial for a future domestic response. In addition, human resource development is essential for contributing to global response efforts.

Crisis management for the future: Building a platform to provide information on emerging and re-emerging infectious diseases from normal times in Japan.

At the beginning of the mpox (disease caused by monkey pox) epidemic, there was no platform in Japan to provide appropriate information on emerging and re-emerging infectious diseases (EIDs), and the number of accesses to bioterrorism-related information sites increased rapidly. Even though the interest in mpox was much smaller than in coronavirus infectious disease, emerged in late 2019 (COVID-19), the increase in the number of views were much greater than during the COVID-19 epidemic. This may not be because mpox is bioterrorism-related as an analog of smallpox, but rather because there were no other websites providing information on mpox. For future crisis management, there should be a platform to provide information on possible epidemics of EIDs from normal times in Japan.

The First Case of a Child Infected with SARS-CoV-2 Omicron Variant in Japan, December 2021.

We report the first pediatric patient infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Japan. The patient was a one-year-old boy who resided in Japan. He went abroad with his parents from November 12, 2021 to November 28, 2021 and had no known contact with coronavirus disease (COVID-19) patients there. Upon arrival at the Narita International Airport on November 28, 2021, his father tested positive for SARS-CoV-2 via a quantitative antigen test. Because the boy and his mother tested negative for SARS-CoV-2, they quarantined together at a hotel separately from his father. On December 4, 2021, the boy tested positive by reverse-transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2, without symptoms, and was hospitalized with his mother; he and his father were both found to be infected with the SARS-CoV-2 Omicron variant. The boy was not vaccinated against COVID-19. RT-PCR results were negative starting on December 20, 2021. The incubation period and required period for negative conversion of SARS-CoV-2 RNA of the Omicron variant case were similar to those of the cases of conventional strains. We should carefully consider the potential of the SARS-CoV-2 Omicron variant to spread widely among unvaccinated children.

Pandemic influenza virus surveillance, Izu-Oshima Island, Japan.

A population-based influenza surveillance study (using PCR virus subtyping) on Izu-Oshima Island, Japan, found that the cumulative incidence of influenza A(H1N1)pdm09 virus infections 2 seasons after the pandemic was highest for those 10-14 years of age (43.1%). No postpandemic A(H1N1)pdm09 case-patients had been infected with A(H1N1)pdm09 virus during the pandemic season.