Estimated effectiveness of school closure and voluntary event cancellation as COVID-19 countermeasures in Japan.

BACKGROUND: As countermeasures against the COVID-19 outbreak, sports and entertainment events were canceled (VEC) in Japan for two weeks from 26 February through 13 March. Moreover, most schools were closed (SC). OBJECTIVE: For this study, we estimated the basic reproduction number (R0) and SC and VEC effects. METHOD: After constructing a susceptible-infected-recovered model with three age classes, we used data of symptomatic patients in Japan for 14 January through 24 March. The SC and VEC effects were incorporated into the model through changes in contact patterns and contact frequencies among age classes. RESULTS: Results suggest R0 as 2.56, with 95% CI of [2.51, 2.96] before SC and VEC. The respective effects of SC and VEC were estimated as 0.4 (95% CI [0.3, 0.5]) and 0.5 (95% CI [0.3, 0.7]). CONCLUSION: The estimated R0 is similar to those found from other studies of China and Japan. Significant reduction of contact frequency has been achieved by SC and VEC. Nevertheless, its magnitude was insufficient to contain the outbreak.

Risk factors affecting the failure to complete treatment for patients with latent tuberculosis infection in Tokyo, Japan.

OBJECTIVE: The treatment completion rate for all latent tuberculosis infection (LTBI) patients in Tokyo was 83.6% in 2014: somewhat lower than the targeted goal of 85%. This study examines the association between risk factors and LTBI patients' failure to complete treatment. METHODS: We collected data related to the treatment of LTBI patients who were reported to public health centers in Tokyo from January 2014 through December 2014. Data included potential risk factors affecting treatment, treatment results, and patient characteristics. We used Fisher's exact test to evaluate risk factors affecting failure to complete treatment. The failure rate was defined as the incompletion rate of treatment. RESULTS: Of 1060 notified cases, 877 had completed treatment; 116 had not completed treatment. Of these 116 cases, failure to complete treatment in 52 cases was attributable to side effects of anti-tuberculosis drugs. Reasons other than side effects were given for 64 cases. Another 67 cases could not be followed up. In all, 941 cases were analyzed, excluding cases lost to follow-up and cases for which patients had not completed treatment because of anti-tuberculosis drug side effects. Failure rates among foreign-born patients (26.9%) were significantly much higher than those among Japan-born patients (3.9%). Statistical tests indicated no presumed potential risk factor as significant. However, "no supporter for foreign-born LTBI patients" was marginally significant. CONCLUSION: Only "no supporter for foreign-born LTBI patients" was found to be marginally significant. More data must be accumulated to assess the risk factors affecting LTBI treatment.

Syndromic surveillance using ambulance transfer data in Tokyo, Japan.

Bioterrorism attacks become more probable when important high-profile international or political events are held, such as G7 summit meetings or mass gathering events including Olympic and Paralympic games and FIFA World Cup tournaments. Outbreaks of infectious disease and widespread incidents of food poisoning are also public health concerns at such times. In Japan, the Tokyo Metropolitan Government operates Ambulance Transfer Syndromic Surveillance (ATSS), which can help monitor such incidents. The present study presents and assesses the ATSS framework. During the study period of October 2017 through November 2018, we monitored 33 areas for symptoms of 9 categories: vomiting/nausea, dizziness, palpitation, unconsciousness, breathing disorder, fever, spasm/paralysis, collapse/weakness, and bloody emesis/nasal hemorrhage. Among all symptoms, we found 9929 low-level aberrations, 2537 medium-level aberrations, and 577 high-level aberrations, with respective frequencies of 9.2%, 2.3%, and 0.5%. Of those, Tokyo Metropolitan Institute of Public Health reported the information to Tokyo Metropolitan Government 28 times during the period. Of the 28 identified clusters, Tokyo Metropolitan Government judged the necessity for investigating 7. All of those were investigated at hospitals by the jurisdictional public health center. Because ATSS covers almost the entire Tokyo metropolitan area, with about 13.8 million residents, it is definitely the largest syndromic surveillance in the world.

Higher Incidence of Syphilis among Patients with HIV Infection: Population Study using Surveillance Data of Tokyo, Japan.

In Japan, the reported cases of syphilis have been increasing since 2011 especially in large cities such as Tokyo. The objective of this study was to evaluate the risk of HIV infection for syphilis co-infection on the population of Tokyo, Japan. We analyzed data of syphilis cases obtained from additional surveillance by the Tokyo Metropolitan Government in 2018, including those with human immunodeficiency virus (HIV) infection as well as data of HIV/acquired immunodeficiency syndrome (AIDS) cases during 1985-2017. We calculated the incidence of symptomatic syphilis cases among HIV-infected or non-HIV-infected individuals. Similarly, we calculated the incidence of syphilis, including asymptomatic cases, among each population. The relative risk of HIV infection for syphilis, including or excluding asymptomatic syphilis cases, was estimated. The relative risk was calculated by dividing the incidence of syphilis in the HIV-infected population by that in the non-HIV-infected population. Of the 1,775 syphilis cases reported in 2018, 172 cases were infected with HIV, 575 cases were uninfected, and the remainder were either unknown or not reported. The cumulative number of HIV/AIDS cases during 1985-2017 in Tokyo was 9,629; among them, 172 were co-infected with syphilis. The relative risk of HIV infection for syphilis was estimated as 423.29 if asymptomatic syphilis cases were included, and 372.37 if they were excluded. These results showed an extremely high risk of HIV infection. Since many syphilis cases have unknown or unreported HIV infection status, reduction of these cases might contribute to more reliable estimation of HIV infection risk.

Association of influenza outbreak in each nursery school and community in a ward in Tokyo, Japan.

In nursery schools, influenza outbreaks have occurred every year. However, influenza characteristics of its diffusion among nursery schools, within each nursery school, and among classes of different ages in nursery schools remains unclear. This paper presents an examination of these matters using the Nursery School Absenteeism Surveillance System (NSASSy). All nursery schools in ward A in Tokyo introduced to the NSASSy in 2015. The study period was November 2015 through March 2016. The data of influenza patients were extracted from NSASSy. We examined four definitions of 'starting date of community outbreak' (SDCO) of influenza: 1) the first recorded day of influenza patients (SDCO1), 2) the last day of influenza patients recorded for two consecutive days (SDCO2), 3) three consecutive days (SDCO3), and 4) four consecutive days (SDCO4). We evaluated those four definitions by duration of the initial case at each nursery school from SDCO and evaluated the proportion of nursery schools at which the initial case occurred before SDCO. The average durations of initial cases at respective nursery schools from SDCO1-4 were 40.3, 26.3, 23.1 and 13.3 days. The respective proportions of nursery schools at which the initial case occurred before SDCO1-4 were 3.1%, 6.4%, 9.4% and 40.6%. Results demonstrate that SDCO3 is an appropriate definition of SDCO. Robustness checks for other areas, seasons, and population size constitute the next challenge for research in this area.

Association of severe abnormal behavior and acetaminophen with/without neuraminidase inhibitors.

BACKGROUND: Even though abnormal behavior related with influenza and neuraminidase inhibitors (NI) has been discussed, the risks of acetaminophen and co-administration of NI and acetaminophen have not been examined. This study assesses those risks. MATERIALS AND METHODS: All cases of patients with influenza who present with severe abnormal behavior are reported by physicians of all clinics and hospitals throughout Japan. The numbers of people diagnosed as having influenza, whether prescribed NI and acetaminophen or not, were extracted from the National Database of Electronic Medical Claims (NDBEMC). The study period was from September 2009 to March 2016. RESULTS: We found two consistent results among four combinations of age class and severity. The one was that patients who did not use NI or acetaminophen showed significantly higher incidence of abnormal behavior than zanamivir with acetaminophen, another one was that patients with oseltamivir only has higher incidence than zanamivir with acetaminophen. Concerning about acetaminophen, the use of it significantly decrease risk for severe and the most severe instances in 5-9-year-old patients with laninamivir and the severe instances in 10-19-year-old patients with zanamivir. DISCUSSION: We also demonstrated that acetaminophen alone or co-administered with NI does not seem to raise the risk of abnormal behavior in influenza patients.

Cost-effectiveness analysis of (Nursery) School Absenteeism Surveillance System.

BACKGROUND: Our earlier report reported that the (Nursery) School Absenteeism Surveillance System ((N)SASSy) can decrease numbers of patients. This study evaluates (N)SASSy's cost-effectiveness. METHODS: A social perspective is taken for economic evaluation. For simplicity, 8,000 yen is assumed for direct medical costs. We assume the home health care duration to be 6 days, with 30 000 yen as the indirect opportunity cost of family nursing. Benefit-cost ratios are used as indicators of cost-effectiveness. RESULTS: By multiplying the disease burden per patient by the reduced number of patients, the (N)SASSy effect was estimated as 206.9 billion yen, with 95% confidence interval of [67.3,346.6] billion yen. The total cost attributable to (N)SASSy throughout Japan is expected to be 2.63 billion yen. The benefit-cost ratio is expected to be approximately 60. CONCLUSIONS: The estimated benefit-cost ratio is much higher than that for the routine immunization of children.

Determinants of Vaccination Coverage for the Second Dose of Measles-Rubella Vaccine in Tokyo, Japan.

In Japan, some measles outbreaks were initiated by a tourist from oversea and foreign workers recently. Moreover, rubella outbreak emerged since July 2018 mainly in the South Kanto, and the outbreak is currently ongoing in 2019. It is important to maintain a high measles-rubella combined vaccine (MR) coverage for measles-rubella control. Vaccination coverage for the second dose of MR (MR2) is 90.8% in Tokyo in 2016, which was the third worst among all prefectures in Japan. The purpose of this study was to clarify determinant factors of vaccination coverage for MR2 in Tokyo. Data were obtained for 49 wards and cities in Tokyo in 2016. We regressed vaccination coverage of MR2 on the times of notification by mail, the proportion of households receiving welfare payments, and the proportion of non-Japanese elementary school students. In addition to the simplest specification, five factors were included separately as explanatory variables: the proportion of public health nurses; the ratio of the number of pediatric medical facilities to the number of preschool and elementary school children; the moving-in rate; the proportion of households with a single parent; and the proportion of households with husband and wife both working. Results show that a high proportion of households receiving welfare payments, notification by two or more letters, and moving-in rate or a lower proportion of non-Japanese elementary school students improve coverage. In conclusion, the health authorities can exert efforts to reduce burden of time spent for vaccination and provide sufficient information to improve coverage.

Infection Control in Nursery Schools and Schools Using a School Absenteeism Surveillance System.

Infection control in nursery schools and schools is important for community health and the health of children. In Japan, caregivers of children or students usually report the absence due to illness to their attending nurseries or schools, including symptoms and diagnosed diseases. The (Nursery) School Absenteeism Surveillance System, (N)SASSy, covers about 60% of schools and 40% of nurseries in Japan. In this paper, we evaluated the benefits of (N)SASSy as an infection control measure by a public health center. Mito Public Health Center (MPHC) covers 58 nurseries and 186 schools, as of May 2015, and called the nurseries and/or schools to confirm the situation, in case of aberration detected through (N)SASSy. The outcome was defined as the proportion of cluster avoidance by advice from MPHC. A cluster was identified, when the number of patients at the same facility with the same symptom or diagnosed disease was greater than ten during the prior seven days. During the study period (April 2015-March 2016), MPHC advised 85 times, and clusters were avoided 82 times (96.5%). The proportion of cluster avoidance was 100% for fever, enterohemorrhagic Escherichia coli infection, respiratory syncytial virus infection, or streptococcal pharyngitis infection. The proportion of cluster avoidance for diarrhea, vomiting or gastroenteritis infection, mumps, hand-foot-mouth disease (HFMD), and influenza was 78.8, 50.0, 20.0, and 6.7%, respectively. In conclusion, advice from a public health center given by phone based on information from (N)SASSy will be helpful for reducing the number of clusters of infectious diseases, except for HFMD and influenza.

Severe abnormal behavior incidence after administration of neuraminidase inhibitors using the national database of medical claims.

An earlier study using the number of abnormal behaviors reported to the study group as the numerator and the number of influenza patient prescribed each neuraminidase inhibitor (NI) estimated by respective pharmaceutical companies found no significant difference among incidence rates of the most severe abnormal behaviors by type of NI throughout Japan. However, the dataset for the denominator used in that earlier study was the estimated number of prescriptions. In the present study, to compare the incidence rates of abnormal behavior more precisely among influenza patients administered several sorts of NI or administered no NI, we used data obtained from the National Database of Electronic Medical Claims (NDBEMC) as the denominator to reach a definitive conclusion. Results show that patients not administered any NI (hereinafter un-administered) or those administered peramivir sometimes showed higher risk of abnormal behavior than those administered oseltamivir, zanamivir, or laninamivir. However, the un-administered or peramivir patients were fewer than those taking other NI. Therefore, accumulation of data through continued research is expected to be necessary to reach a definitive conclusion about the relation between abnormal behavior and NI in influenza patients. Since severe abnormal behaviors with all types of NI or of un-administered patients have been reported, there are some risks in the administration of NI or even in un-administered cases. Therefore, we infer that the policy mandating package inserts in all types of NI.

Case study of early detection and intervention of infectious disease outbreaks in an institution using Nursery School Absenteeism Surveillance Systems (NSASSy) of the Public Health Center.

Objectives Detecting outbreaks early and then activating countermeasures based on such information is extremely important for infection control at childcare facilities. The Sumida ward began operating the Nursery School Absenteeism Surveillance System (NSASSy) in August 2013, and has since conducted real-time monitoring at nursery schools. The Public Health Center can detect outbreaks early and support appropriate intervention. This paper describes the experiences of Sumida Public Health Center related to early detection and intervention since the initiation of the system.Methods In this study, we investigated infectious disease outbreaks detected at 62 nursery schools in the Sumida ward, which were equipped with NSASSy from early November 2013 through late March 2015. We classified the information sources of the detected outbreak and responses of the public health center. The sources were (1) direct contact from some nursery schools, (2) messages from public officers with jurisdiction over nursery schools, (3) automatic detection by NSASSy, and (4) manual detection by public health center officers using NSASSy. The responses made by the health center were described and classified into 11 categories including verification of outbreak and advice for caregivers.Results The number of outbreaks detected by the aforementioned four information sources was zero, 25, 15, and 7 events, respectively, during the first 5 months after beginning NSASSy. These numbers became 5, 7, 53, and 25 events, respectively, during the subsequent 12 months. The number of outbreaks detected increased by 47% during the first 5 months, and by 87% in the following 12 months. The responses were primarily confirming the situation and offering advice to caregivers.Conclusion The Sumida Public Health Center ward could achieve early detection with automatic or manual detection of NSASSy. This system recently has become an important detection resource, and has contributed greatly to early detection. Because the Public Health Center can use it to achieve real-time monitoring, they can recognize emergent situations and intervene earlier, and thereby give feedback to the nursery schools. The system can contribute to providing effective countermeasures in these settings.

Early detection and response for measles and rubella cases through the (Nursery) School Absenteeism Surveillance System in Ibaraki Prefecture.

Objectives In Ibaraki Prefecture, all (nursery) schools have joined the (Nursery) School Absenteeism Surveillance System (hereafter denoted as (N)SASSy), which is operated by the Japan School Health Association to monitor the prevalence of infectious diseases, the early detection and response for outbreaks, and prevention of large outbreaks. Prefectural government officers also utilize it as a control measure for infectious diseases. In particular, when cases of measles or rubella are registered, (N)SASSy sends e-mails automatically to prefectural government officers to activate control measures. This paper summarizes administrative responses by prefectural government officers for measles or rubella cases using (N)SASSy and discusses the future challenges.Methods We summarized registration, detection, and first response data for measles or rubella cases in (N)SASSy and compared the number of detected and reported cases enforced by the Infectious Diseases Control Law from January 1, 2013 to December 31, 2014.Results The public health center questioned hospitals/clinics and (nursery) schools about all registered measles or rubella cases in (N)SASSy on the same day to check the entered information. In the past 2 years, there were 5 measles and 56 rubella cases in 2013 and 1 measles and 19 rubella cases in 2014 registered with (N)SASSy. All cases were checked and investigated by the public health center. Of all cases detected by (N)SASSy, 7 rubella cases in 2013 and 1 rubella case in 2014 were reported based on the law. No measles cases were reported in the 2 years. The results of investigations and laboratory tests were given as feedback to the (nursery) schools. If the case did not case definition determined by the law, we changed the status in (N)SASSy to suspected or discarded cases.Conclusion Since (N)SASSy assists prefectural government officers with earlier detection of and response for infectious diseases, it definitely contributes to infection control. Immediate feedback of the laboratory test results to the (nursery) schools was also useful to confirm cases of measles or rubella. As data entry in (nursery) schools is needed for stable operation and utilization of (N)SASSy, it is important that workshops for (N)SASSy are held for (nursery) school teachers every year to maintain accuracy. Our future challenges include the coordination among (nursery) schools, hospitals/clinics, and prefectural government and their applications for infection control.

Association between first airborne cedar pollen level peak and pollinosis symptom onset: a web-based survey.

Cedar pollinosis in Japan affects nearly 25 % of Japanese citizens. To develop a treatment for cedar pollinosis, it is necessary to understand the relationship between the time of its occurrence and the amount of airborne cedar pollen. In the spring of 2009, we conducted daily Internet-based epidemiologic surveys, which included 1453 individuals. We examined the relationship between initial date of onset of pollinosis symptoms and daily amount of airborne cedar pollen to which subjects were exposed. Approximately 35.2 % of the subjects experienced the onset of pollinosis during a one-week interval in which the middle day coincided with the peak pollen count. The odds ratio for this one-week time interval was 4.03 (95 % confidence interval: 3.34-4.86). The predicted date of the cedar pollen peak can be used to determine the appropriate date for initiation of self-medication with anti-allergy drugs and thus avoid development of sustained and severe pollinosis.

Abnormal behavior during influenza in Japan during the last seven seasons: 2006-2007 to 2012-2013.

A few mortalities and cases of severe abnormal behavior have been reported after oseltamivir administration for influenza, thus increasing medical and public concerns regarding the drug's safety. We investigated the association between oseltamivir and abnormal behavior for seven years. All outpatient clinics and hospitals all over the country were requested to report severe abnormal behavior that could have resulted in a fatality if nobody intervened, such as abrupt running outside the home or intention of jumping off a building. The survey was performed prospectively between the 2007-2008 and 2012-2013 seasons, and retrospectively for the 2006-2007 season. As the result of the investigation, eight-hundred fifty-eight cases were reported and among of them 95.7% were positive by the influenza rapid diagnosis test. The epidemic curve of severe abnormal behavior showed a pattern similar to influenza-like illness. The same pattern was observed regardless of age group, gender, or timing of the incidents after waking. Consequently, specific association between the types of medications used or the types of antiviral and abnormal behavior was not observed clearly. The reported abnormal behaviors include fatal cases that would have died if nobody had stopped. This suggested that patients with influenza should be observed with caution for possible abnormal behavior whether taking oseltamivir or other neuraminidase inhibitor anti-influenza drugs.

Online reporting system for transfusion-related adverse events to enhance recipient haemovigilance in Japan: a pilot study.

BACKGROUND: A surveillance system for transfusion-related adverse reactions and infectious diseases in Japan was started at a national level in 1993, but current reporting of events in recipients is performed on a voluntary basis. A reporting system which can collect information on all transfusion-related events in recipients is required in Japan. METHODS: We have developed an online reporting system for transfusion-related events and performed a pilot study in 12 hospitals from 2007 to 2010. RESULTS: The overall incidence of adverse events per transfusion bag was 1.47%. Platelet concentrates gave rise to statistically more adverse events (4.16%) than red blood cells (0.66%) and fresh-frozen plasma (0.93%). In addition, we found that the incidence of adverse events varied between hospitals according to their size and patient characteristics. CONCLUSION: This online reporting system is useful for collection and analysis of actual adverse events in recipients of blood transfusions and may contribute to enhancement of the existing surveillance system for recipients in Japan.

Internet survey of the influence of environmental factors on human health: environmental epidemiologic investigation using the web-based daily questionnaire for health.

With increasing Internet coverage, the use of a web-based survey for epidemiological study is a possibility. We performed an investigation in Japan in winter 2008 using the web-based daily questionnaire for health (WDQH). The WDQH is a web-based questionnaire survey formulated to obtain information about the daily physical condition of the general public on a real-time basis, in order to study correlations between changes in physical health and changes in environmental factors. Respondents were asked whether they felt ill and had specific symptoms including fever. We analysed the environmental factors along with the health conditions obtained from the WDQH. Four factors were found to influence health: minimum temperature, hours of sunlight, median humidity and weekday or holiday. The WDQH allowed a daily health survey in the general population in real time via the Internet.

Infection control and COVID-19 outbreak training at elderly care facilities.

Fatalities caused by pneumonia and underlying diseases from COVID-19 infection show the highest relative frequency among elderly people. Long-term care facilities for elderly people have continued to be the areas most vulnerable to COVID-19. We examined the effectiveness of training for infection control and COVID-19 at elderly care facilities. After sending questionnaires to all long-term elderly care facilities in Ibaraki prefecture, Japan during January 18-29, 2022, we received useful responses from 98 facilities. Using logistic regression, we regressed a dummy variable for outbreak experience to dummy variables representing routine but partial training, routine training for all staff members, long-term care facilities for elderly people, numbers of nurses, and numbers of residents. Outbreak experiences of two types were inferred, as represented by a dummy variable for a COVID-19 outbreak at the facility, and by a dummy variable for outbreak experience at the facility before COVID-19 was found. Multivariate analysis indicated routine training for all staff members as the most effective, in fact the only effective, countermeasure against COVID-19 outbreak.

Real-time prescription surveillance and its application to monitoring seasonal influenza activity in Japan.

BACKGROUND: Real-time surveillance is fundamental for effective control of disease outbreaks, but the official sentinel surveillance in Japan collects information related to disease activity only weekly and updates it with a 1-week time lag. OBJECTIVE: To report on a prescription surveillance system using electronic records related to prescription drugs that was started in 2008 in Japan, and to evaluate the surveillance system for monitoring influenza activity during the 2009-2010 and 2010-2011 influenza seasons. METHODS: We developed an automatic surveillance system using electronic records of prescription drug purchases collected from 5275 pharmacies through the application service provider's medical claims service. We then applied the system to monitoring influenza activity during the 2009-2010 and 2010-2011 influenza seasons. The surveillance system collected information related to drugs and patients directly and automatically from the electronic prescription record system, and estimated the number of influenza cases based on the number of prescriptions of anti-influenza virus medication. Then it shared the information related to influenza activity through the Internet with the public on a daily basis. RESULTS: During the 2009-2010 influenza season, the number of influenza patients estimated by the prescription surveillance system between the 28th week of 2009 and the 12th week of 2010 was 9,234,289. In the 2010-2011 influenza season, the number of influenza patients between the 36th week of 2010 and the 12th week of 2011 was 7,153,437. The estimated number of influenza cases was highly correlated with that predicted by the official sentinel surveillance (r = .992, P < .001 for 2009-2010; r = .972, P < .001 for 2010-2011), indicating that the prescription surveillance system produced a good approximation of activity patterns. CONCLUSIONS: Our prescription surveillance system presents great potential for monitoring influenza activity and for providing early detection of infectious disease outbreaks.

[The possibility of outbreak control by real-time surveillance with PCR method perfomed immediately--a case study of hand foot and mouth disease outbreak in a day care facility for children].

OBJECT: We examined the relationship between syndromic surveillance and laboratory confirmation, at an early stage of an outbreak of hand foot and mouth disease and RS virus infection. METHOD: We observed the epidemiological situation from a surveillance system at a day care facility for young children in Tokyo from one week before onset of the indicator until one month thereafter. For laboratory diagnosis, we collected a rectal swab or a nasal swab from one patient in the early stage of the outbreak. RESULT: A total of 20 patients, comprising 12 1-year-old, 5 2-year-old and 3 3-year-old children, were found to have hand foot and mouth disease on August 1st, 2011. From a rectal swab from one HFMD patient, enterovirus genome was detected and identified as coxsackievirus type A6 (CA6) with PCR sequencing. The CA6 had 99% identity to CA6 (Genbank No AB663318) in the VP4 coding region. RS virus also was detected from a nasal swab. DISCUSSION: The establishment of a surveillance system at day care facilities for children can monitor infectious diseases among young children promptly. Laboratory confirmation, even though from only one patient as shown in this study, can provide critical information regarding the causative agent of the outbreak. This method is easy to conduct and could be used for activating appropriate countermeasures. CONCLUSION: We believe that the combination of the timeliness of a surveillance system at day care facility for children and the convenience of laboratory diagnosis of even one patient can detect the causative pathogen, and thus enable the activation of countermeasures before an outbreak become widespread.