Haplotype networks of SARS-CoV-2 infections in the Diamond Princess cruise ship outbreak.

The Diamond Princess cruise ship was put under quarantine offshore Yokohama, Japan, after a passenger who disembarked in Hong Kong was confirmed as a coronavirus disease 2019 case. We performed whole-genome sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) directly from PCR+ clinical specimens and conducted a phylogenetic analysis of the outbreak. All tested isolates exhibited a transversion at G11083T, suggesting that SARS-CoV-2 dissemination on the Diamond Princess originated from a single introduction event before the quarantine started. Although further spreading might have been prevented by quarantine, some progeny clusters could be linked to transmission through mass-gathering events in the recreational areas and direct transmission among passengers who shared cabins during the quarantine. This study demonstrates the usefulness of haplotype network/phylogeny analysis in identifying potential infection routes.

Unprecedented increase in syphilis cases among heterosexual men and women in Japan, 2021-2022.

Based on national surveillance data, we describe an unprecedented increase in syphilis case reports in Japan, with a surge in 2021-2022 reaching 10141 cases in Week 42, 2022, a 1.7-fold increase over the same period in 2021. This already represented the highest annual case count in nearly half a century; by Week 52, 2022, the number reached 12 966, far surpassing the 7978 cases in 2021. Predominantly affecting heterosexual men and young women, the proportionate increase in primary and secondary syphilis cases suggests a true increase in incidence. The syphilis surge during the pandemic poses a serious public health concern and underscores the importance of adequate testing and preventive measures.

Facilitating the deployment of Japanese human resources for responding global outbreaks of emerging and Re-emerging infectious diseases: A cross-sectional study.

INTRODUCTION: In response to global outbreaks of infectious diseases, the need for support from organizations such as the World Health Organization Global Outbreak Alert and Response Network (GOARN) is increasing. Identifying the obstacles and support needs for applicants could increase GOARN deployments from Japan. METHODS: This cross-sectional study involved a web-based, self-administered questionnaire survey targeting Japanese participants in the GOARN Tier 1.5 training workshop, held in Tokyo in December 2019. RESULTS: All 47 Japanese participants in the workshop responded to the survey. Most responders were male and in their 30s and 40s. Participants specialized in case management (42.6%), infection prevention and control (25.6%), epidemiology and surveillance (19.1%). Only two participants (4.6%) had experienced a GOARN deployment. Their motivations for joining the GOARN training workshop were "Desire to be part of an international emerging infectious disease response team" (44.6%), "Interest in making an international contribution" (19.1%), and "Interest in working for the Japanese government in the field of international infectious diseases" (14.9%). Obstacles to GOARN deployments were "Making time for deployments" (45.7%) and "Lack of required professional skills and knowledge" (40.4%). The support needs for GOARN deployments constituted "Periodic simulation training" (51.1%), "Financial support during deployments" (44.7%), and "Technical support for deployments" (40.4%). CONCLUSIONS: Our study revealed the obstacles and support needs of Japanese candidates for GOARN deployment. Making time and upskilling for GOARN deployment were the main obstacles. More practical training (like GOARN Tier 2.0) with other supports are needed. The national framework is desirable to realize these supports.

Increase in congenital syphilis cases and challenges in prevention in Japan, 2016-2017.

In Japan, the increase in congenital syphilis (CS) notifications has become a public health concern. We conducted a case series study to describe the characteristics of CS patients and their mothers. Of the 13 mothers who consented to participate, seven had regular prenatal care visits, including four who had tested negative at their first trimester syphilis screening. Only three mothers noted that their partners were tested, with all three partners being diagnosed with syphilis. Raising awareness for syphilis prevention during pregnancy, partner testing, and considering additional syphilis testing at the third trimester of pregnancy during times of increased syphilis prevalence is imperative.

Environmental Sampling for Severe Acute Respiratory Syndrome Coronavirus 2 During a COVID-19 Outbreak on the Diamond Princess Cruise Ship.

During a COVID-19 outbreak on the Diamond Princess cruise ship we sampled environmental surfaces after passengers and crew vacated cabins. SARS-CoV-2 RNA was detected in 58 of 601 samples (10%) from case cabins 1-17 days after cabins were vacated but not from noncase cabins. There was no difference in detection proportion between cabins of symptomatic (15%, 28/189; cycle quantification [Cq], 29.79-38.86) and asymptomatic cases (21%, 28/131; Cq, 26.21-38.99). No SARS-CoV-2 virus was isolated from any of the samples. Transmission risk of SARS-CoV-2 from symptomatic and asymptomatic patients may be similar and surfaces could be involved in transmission.

Severe Fever with Thrombocytopenia Syndrome, Japan, 2013-2017.

We conducted an epidemiologic study of severe fever with thrombocytopenia syndrome (SFTS) in Japan during 2013-2017. Of 303 cases reported during that period, 133 (44%) were included in this study. The median time between onset of illness and diagnosis of SFTS shortened, from 11.5 to 3.0 days, but the case-fatality rate remained high, at 27%. In 64 patients (48%), a close contact with companion animals was reported within 2 weeks of disease onset. Of these 64 patients, 40 were surveyed further, and we confirmed that 3 had direct contact with body fluids of ill companion animals; 2 had direct contact with the saliva of an ill feral cat or pet dog. These patients reported no history of tick bite, suggesting that ill companion animals might be a source of SFTS virus transmission. Direct contact with the body fluids of ill companion animals should be avoided.

Initial Investigation of Transmission of COVID-19 Among Crew Members During Quarantine of a Cruise Ship - Yokohama, Japan, February 2020.

An outbreak of coronavirus disease 2019 (COVID-19) among passengers and crew on a cruise ship led to quarantine of approximately 3,700 passengers and crew that began on February 3, 2020, and lasted for nearly 4 weeks at the Port of Yokohama, Japan (1). By February 9, 20 cases had occurred among the ship's crew members. By the end of quarantine, approximately 700 cases of COVID-19 had been laboratory-confirmed among passengers and crew. This report describes findings from the initial phase of the cruise ship investigation into COVID-19 cases among crew members during February 4-12, 2020.

Descriptive study of COVID-19 outbreak among passengers and crew on Diamond Princess cruise ship, Yokohama Port, Japan, 20 January to 9 February 2020.

An outbreak of coronavirus disease (COVID-19) occurred on the Diamond Princess cruise ship making an international journey, which led to quarantine of the ship at Yokohama Port, Japan. A suspected COVID-19 case was defined as a passenger or crew member who developed a fever or respiratory symptoms, and a confirmed COVID-19 case had laboratory-confirmation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Between 3 and 9 February 2020, 490 individuals were tested for SARS-CoV-2 and 172 were positive (152 passengers (median age: 70 years; interquartile range (IQR): 64-75; males: 45%) and 20 crew (median age: 40 years; IQR: 35-48.5; males: 80%). Other than the Hong Kong-related index case, symptom onset for the earliest confirmed case was 22 January, 2 days after the cruise ship left port. Attack rates among passengers were similar across the decks, while beverage (3.3%, 2/61) and food service staff (5.7%, 14/245) were most affected. Attack rates tended to increase with age. A comprehensive outbreak response was implemented, including surveillance, provision of essential medical care, food and medicine delivery, isolation, infection prevention and control, sampling and disembarkation.

Rapid Increase in Reports of Syphilis Associated With Men Who Have Sex With Women and Women Who Have Sex With Men, Japan, 2012 to 2016.

BACKGROUND: In Japan, syphilis reports have recently increased rapidly. However, unlike other developed countries where men who have sex with men (MSM) were associated with the rise, the increase in Japan has been attributed more to men who have sex with women (MSW) and women who have sex with men (WSM). We report on this increase based on surveillance data. METHODS: Syphilis is a notifiable disease requiring all laboratory-confirmed cases to be reported; stage and sex of the sex partner(s) suspected as the infection source are also reported. Focusing on primary and secondary (P&S) cases, we describe the temporal, demographic, and geographic distributions of reported cases in 2012 through 2016. RESULTS: A total of 7040 (64.0%) of 10,997 cases were P&S; the annual rate of increase was greatest for P&S and the proportion of P&S increased over time. Among P&S cases (1609 MSM, 2768 MSW, and 1323 WSM), MSW and WSM each surpassed MSM cases in 2016. Men were older with a wider age distribution (median, 37 years; interquartile range, 28-46 years) relative to women (median, 26 years; interquartile range, 21-34 years). Among women, 20- to 24-year-olds consistently had the highest reporting rate, reaching 9.0 per 100,000 in 2016. Congenital syphilis reports increased from 0.4 in 2012 to 1.4 per 100,000 live births in 2016. Although Tokyo prefecture had the highest reporting rate (3.98 per 100,000 person-years), the proportionate contribution from Tokyo decreased in 2016. CONCLUSIONS: Reports on P&S syphilis increased yearly among MSW and WSM. Young women seem to be at particular risk, and with increased reports of congenital syphilis, syphilis prevention and control is currently a public health priority in Japan.

Sociodemographic characteristics and clinical description of congenital syphilis patients and their mothers in Japan: a qualitative study, 2016.

Background In Japan, congenital syphilis (CS) notifications have increased recently. However, little is known about the CS cases or the clinical and sociodemographic characteristics of the patients' mothers. METHODS: Twelve cases of CS were reported through national surveillance in the period March-December 2016, and the mothers of seven patients were included in this study. The patients' mothers and physicians completed a self-administered questionnaire, providing sociodemographic and clinical information of the patients and their mothers. In addition, we explored the awareness and knowledge of, attitudes towards and practices regarding CS occurrence through semistructured interviews with the mothers. RESULTS: Of the seven CS patients, three were asymptomatic, with a range of non-specific clinical manifestations in the rest. The mothers tended to be of young age, unmarried and to have a history of commercial sex work, other sexually transmissible infections (STIs) and no or irregular prenatal care visits during pregnancy. Of the four mothers who had had regular prenatal care visits, two had tested negative for syphilis at the first trimester antenatal screening. Themes emerged that indicated challenges in preventing CS, including a lack of guidance or guidelines for physicians to consider testing for syphilis after the first trimester, lack of physicians' awareness or experience of syphilis or CS and a lack of awareness or knowledge in pregnant women regarding STIs. CONCLUSIONS: Key characteristics of recent CS patients and their mothers in Japan were revealed, identifying previously reported factors as well as new challenges. A holistic approach, designed to address challenges at the level of the healthcare system, healthcare provider and the pregnant woman and her partner will be important in preventing CS.

Seasonal influenza vaccine (A/New York/39/2012) effectiveness against influenza A virus of health care workers in a long term care facility attached with the hospital, Japan, 2014/15: A cohort study.

The 2014/15 influenza season started earlier than usual, and intense activity was reflection of circulation of antigenically-drifted and vaccine-mismatched dominant A(H3N2) viruses. Although inpatients and health-care workers (HCWs) had a high influenza vaccination coverage rate well prior to the beginning of influenza season, numerous outbreaks of influenza A(H3N2) infection with fatal cases were reported in long-term care facilities (LTCFs) in Japan during 2014/15 influenza season. In January 2015, we were given opportunity to conduct outbreak investigation of influenza A at facility A (LTCF attached with hospital) in Western part of Japan. We evaluated overall and occupation-stratified influenza vaccine effectiveness (VE) among HCWs at facility A using a retrospective cohort design. Overall VE, occupation-stratified VE and adjusted VE (AVE) with 95% confidence intervals (CIs) were estimated using the following formula: (1-relative risks (RR) or 1-adjusted RR) × 100%. Overall vaccine coverage rate among HCWs was 85%. Overall VE for HCWs was 28% (95% CI: -70 to 67) and overall AVE was 3% (95% CI: -34 to 30). Although there was no severe cases, our results indicated that even with high vaccination coverage rate with appropriate vaccination timing, the VE was low for HCWs, which echoes with previously reported VE from other northern hemisphere countries. However, rehabilitation group who had high awareness against influenza as a group and carried out intensive precautions from early influenza season had no cases. We conclude that multiple preventive measures in addition to high vaccination rate is necessary for preventing influenza of HCWs working at LCTFs.

[Response to Ebola Virus Disease Outbreak: Experience in Field Epidemiology in Sierra Leone].

The Ebola virus disease (EVD) outbreak that occurred in West Africa in 2014 was the largest ever in the world. In Sierra Leone, the number of cases reported peaked in December 2014 and gradually declined. However, the outbreak was not immediately terminated. To support the response of the World Health Organization (WHO) to EVD, the WHO Western Pacific Regional Office established the Western Pacific Ebola Support Team (WEST) with the aim of eliminating EVD in Port Loko District, where a certain number of new cases were still being reported in March 2015. We were dispatched to join WEST as WHO short term consultants in epidemiology for about six weeks from March to June 2015. Here, we describe our activities in the field as epidemiologists to show how Japan can contribute in the area of epidemiology during infectious disease outbreaks of international concern. The analysis suggested that the surveillance data for all the deaths and suspected EVD cases were underreporting the actual number of EVD cases in Port Loko District. Although contact tracing was conducted, new EVD cases were often found among untraced contacts because of inadequate information from residents or insufficient investigation by the contact tracing team. In addition, incomplete monitoring of the health status of close contacts resulted in secondary transmission of the disease. Data managers established a database by centralizing data from the surveillance and contact tracing teams, laboratories, and healthcare facilities. The number of deaths per week recorded by these data sources was lower than the number of deaths per week that would be expected from the national mortality statistics. The team strengthened surveillance and social mobilization in the regions with wide disparities between the actual and reported numbers of deaths. For the on-the-ground activities, the field coordinator, epidemiologists, and social mobilizers, as well as the logistic and administrative support personnel, were all indispensable in supporting the field investigation of these infectious disease outbreaks of public health concern. A field coordinator, in particular, requires outstanding knowledge, experience and skills to lead team operations in liaison with international and local partners and to build confidence among local residents. The development of these human resources and the maintenance of a response team are required for potential future outbreaks, and this is an important area that Japan could prepare for and then contribute to future outbreaks. This report does not represent an official view of the WHO or our affiliates.

Phylogenetic and Geographic Relationships of Severe Fever With Thrombocytopenia Syndrome Virus in China, South Korea, and Japan.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne acute infectious disease caused by the SFTS virus (SFTSV). SFTS has been reported in China, South Korea, and Japan as a novel Bunyavirus. Although several molecular epidemiology and phylogenetic studies have been performed, the information obtained was limited, because the analyses included no or only a small number of SFTSV strains from Japan. METHODS: The nucleotide sequences of 75 SFTSV samples in Japan were newly determined directly from the patients' serum samples. In addition, the sequences of 7 strains isolated in vitro were determined and compared with those in the patients' serum samples. More than 90 strains that were identified in China, 1 strain in South Korea, and 50 strains in Japan were phylogenetically analyzed. RESULTS: The viruses were clustered into 2 clades, which were consistent with the geographic distribution. Three strains identified in Japan were clustered in the Chinese clade, and 4 strains identified in China and 26 in South Korea were clustered in the Japanese clade. CONCLUSIONS: Two clades of SFTSV may have evolved separately over time. On rare occasions, the viruses were transmitted overseas to the region in which viruses of the other clade were prevalent.

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.

Sensitive and specific PCR systems for detection of both Chinese and Japanese severe fever with thrombocytopenia syndrome virus strains and prediction of patient survival based on viral load.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with a high case fatality risk and is caused by the SFTS virus (SFTSV). A retrospective study conducted after the first identification of an SFTS patient in Japan revealed that SFTS is endemic to the region, and the virus exists indigenously in Japan. Since the nucleotide sequence of Japanese SFTSV strains contains considerable differences compared with that of Chinese strains, there is an urgent need to establish a sensitive and specific method capable of detecting the Chinese and Japanese strains of SFTSV. A conventional one-step reverse transcription-PCR (RT-PCR) (cvPCR) method and a quantitative one-step RT-PCR (qPCR) method were developed to detect the SFTSV genome. Both cvPCR and qPCR detected a Chinese SFTSV strain. Forty-one of 108 Japanese patients suspected of having SFTS showed a positive reaction by cvPCR. The results from the samples of 108 Japanese patients determined by the qPCR method were in almost complete agreement with those determined by cvPCR. The analyses of the viral copy number level in the patient blood samples at the acute phase determined by qPCR in association with the patient outcome confirmed that the SFTSV RNA load in the blood of the nonsurviving patients was significantly higher than that of the surviving patients. Therefore, the cvPCR and qPCR methods developed in this study can provide a powerful means for diagnosing SFTS. In addition, the detection of the SFTSV genome level by qPCR in the blood of the patients at the acute phase may serve as an indicator to predict the outcome of SFTS.

[An outbreak of Streptococcus pneumoniae serotype 11A pneumonia at a nursing home, Tokyo, 2009].

This is a report of an outbreak of Pneumococcal pneumonia among nursing home residents in Tokyo, 2009. A total of 15 cases were identified, and their sputum culture grew Streptococcus pneumoniae, all of which were confirmed as serotype 11A and ST116. This outbreak ended through the implementation of strict contact precautions, education regarding the standard precautions among the staff, administration of prophylactic antibiotics to other asymptomatic residents, and vaccination. The fact that many cases were unvaccinated in this outbreak implies the importance of vaccination against S. pneumoniae among nursing home residents.

Association of a promotional campaign for local dining facilities with the occurrence of COVID-19 in Asahikawa City, Japan, in November 2021.

Objectives: As social restrictions of COVID-19 are being eased worldwide, preventing SARS-CoV-2 transmission among staff members and customers in dining facilities is essential to continuously running business because restaurants and bars are high-risk locations for COVID-19 outbreaks. In 2021, COVID-19 outbreaks occurred at restaurants or bars in Asahikawa city, Japan two weeks after the launch of a promotional campaign for local dining facilities. We investigated this event to assess the association between the promotional campaign and the occurrence of SARS-CoV-2 infection. Study design: Cohort study. Methods: We assessed the association between the occurrence of COVID-19 cases in the restaurants and bars and their participation in the campaign by calculating risk ratio and 95% confidence interval. Results: Cases were identified among workers or customers in 4.0% (4/101) of the participating restaurants or bars and in 1.2% (39/3257) of the non-participating restaurants or bars. The risk ratio was 3.3 (95% confidence interval 1.2-9.0). Conclusion: The association between the occurrence of SARS-CoV-2 infection in the restaurants or bars and participation in the campaign is undeniable. Promotional campaigns to vitalize dining facilities should be accompanied by enhanced infection prevention measures, especially ventilation.