Incidence of Kawasaki Disease Before and After the COVID-19 Pandemic in Japan: Results of the 26th Nationwide Survey, 2019 to 2020.

Importance: Global studies have reported that the incidence of Kawasaki disease (KD) declined during the COVID-19 pandemic. These studies suggest that the global pandemic and its accompanying mitigation measures may provide an important opportunity to explore the hypothesis of a KD pathogenesis. Objective: To compare changes in KD incidence in Japan before and after the start of the COVID-19 pandemic. Design, Setting, and Participants: This cohort study was conducted using the data set from Japan's 26th nationwide KD survey that obtained information on patients who were diagnosed with KD in Japan from January 1, 2019, through December 31, 2020. Main Outcomes and Measures: Kawasaki disease incidence rates were calculated by referring to the national population data in the vital statistics data for Japan. Results: A total of 28 520 patients were identified (16 236 male individuals [56.9%]; median [IQR] age, 26 [14-44] months). A total of 17 347 patients were diagnosed with KD in 2019 and 11 173 were diagnosed in 2020, representing a 35.6% reduction in the number of patients diagnosed in 2020 compared with the previous year. Patient distributions for days of illness at the first hospital visit were almost identical in 2019 and 2020, suggesting that the decrease in KD incidence likely was not associated with pandemic-related delays in seeking treatment. The proportion of patients diagnosed with KD who were younger than 12 months was significantly larger in 2020 than in 2019 (21.6% vs 19.4%; P < .001). Compared with KD incidence among younger patients, the incidence among those 24 months and older declined rapidly after initiation of COVID-19 special mitigation measures, with a greater percentage reduction (58.3% reduction in July), but rebounded faster after the end of the special mitigation period. By contrast, the incidence among patients younger than 12 months declined moderately after the initiation of the special mitigation period, with a lower percentage reduction (40.3% reduction in October), and rebounded at a later phase. Conclusions and Relevance: In this cohort study, the number of patients diagnosed with KD decreased by approximately one-third across Japan in 2020, with no indication that parents avoided a hospital visit. Differences in KD incidence reduction patterns before and after the initiation of COVID-19 pandemic mitigation measures were found in patients with KD aged younger than 12 months compared with those 24 months or older, suggesting a potential KD pathogenesis involving transmission among children.

Regional Differences in Kawasaki Disease Incidence Reduction Before and After the Onset of the Coronavirus Disease 2019 Pandemic.

OBJECTIVE: To assess regional differences in reduction of the incidence of Kawasaki disease during the mitigation period for the coronavirus disease 2019 pandemic, with a hypothesis that more sparsely populated regions have fewer opportunities for human-to-human contact, resulting in a greater reduction in the incidence of Kawasaki disease. STUDY DESIGN: A retrospective ecological study was conducted using data from patients hospitalized for Kawasaki disease as well as infectious diseases surveillance reports in Shiga Prefecture, Japan, during 2015-2020. We defined the periods before and after the onset of pandemic as January 2015-March 2020 and as April 2020-December 2020, respectively. We compared the reductions in the incidence of Kawasaki disease among 6 administrative regions in the prefecture according to the density of the populations. RESULTS: A total of 1290 patients with Kawasaki disease were identified. The incidence of Kawasaki disease (per 100 000 person-years) was significantly reduced after the coronavirus disease 2019 pandemic onset (period before pandemic onset, 105.6 [95% CI 99.8-111.8]; period after pandemic onset, 68.6 [95% CI 56.7-83.0]). During the period after pandemic onset, the incidence of Kawasaki disease was significantly reduced in May, compared with the corresponding period in previous years. The number of patients aged 2-4 years was significantly reduced after the pandemic onset. Notably, greater reductions in the incidence of Kawasaki disease were found in regions with lower population densities. CONCLUSIONS: Assuming that there were fewer opportunities for human-to-human contact in more sparsely populated regions during the pandemic mitigation period, our findings support the hypothesis that human-to-human contact may be associated with development of Kawasaki disease.

Change in the Acceptance of Telemedicine Use Among Older Patients with Knee Osteoarthritis During the Coronavirus Disease 2019 Pandemic.

Background: Hospital-related coronavirus disease 2019 (COVID-19) infection is of utmost concern among patients and health care workers. Expanding the use of telemedicine may be required in daily outpatient practice; however, the acceptance of telemedicine use is still low, especially among older patients. In an orthopedic practice, no studies have investigated potential factors that can contribute to changes in the acceptance of using telemedicine. Focusing on older outpatients with knee osteoarthritis (KOA), we hypothesized that a drastic surge in the number of patients with COVID-19 could trigger changes in attitudes regarding the acceptance of telemedicine use. Methods: A baseline survey was conducted after the first wave of the COVID-19 pandemic in Japan to obtain information on the willingness to use telemedicine among patients aged ≥70 years who regularly consulted an orthopedic surgeon for KOA. A follow-up survey was subsequently conducted during the third wave of the pandemic period to assess changes in the acceptance of telemedicine use in response to the rapidly increasing number of patients with COVID-19. We compared the difference in acceptance of telemedicine use and knee pain status between the baseline and follow-up surveys. Results: In the baseline survey, 11 of 43 patients (25.6%) responded that they would be willing to use telemedicine. In the follow-up survey, patients' acceptance of telemedicine did not change, with the exact same number and percentage of patients who were willing to use telemedicine as in the baseline survey, despite that ∼20% of patients reported improvement in their knee pain status. Discussion: Our findings indicate that older outpatients with KOA did not change their willingness to accept use of telemedicine, even with a drastically increased risk of hospital-related transmission of a potentially fatal infectious disease when visiting a hospital. The acceptance of telemedicine use among older patients might not be less sensitive to external environmental factors but instead might be more sensitive to patients' personal factors, such as anxiety for information technology and resistance to changes in their lifestyle.

Human Mobility and Droplet-Transmissible Pediatric Infectious Diseases during the COVID-19 Pandemic.

The study tested the hypothesis that human mobility may be a potential factor affecting reductions in droplet-transmissible pediatric infectious diseases (PIDs) during the coronavirus disease-2019 (COVID-19) pandemic mitigation period in 2020. An ecological study was conducted using two publicly available datasets: surveillance on infectious diseases collected by the Japanese government and COVID-19 community mobility reports presented by Google. The COVID-19 community mobility reports demonstrated percentage reductions in the movement of people over time in groceries and pharmacies, parks, and transit stations. We compared the weekly trends in the number of patients with droplet-transmissible PIDs identified in 2020 with those identified in the previous years (2015-2019) and assessed the correlations between the numbers of patients and percentage decreases in human mobility during 2020. Despite experiencing their peak seasons, dramatic reductions were found in the numbers of patients with pharyngoconjunctival fever (PCF) and group A streptococcal (GAS) pharyngitis after the tenth week of 2020. Beyond the 20th week, no seasonal peaks were observed in the number of patients with all PIDs identified in 2020. Significant correlations were found between the percentage decreases in human mobility in transit stations and the number of patients with hand-foot-and-mouth disease (Pearson correlation coefficient [95% confidence interval]: 0.65 [0.44-0.79]), PCF (0.47 [0.21-0.67]), respiratory syncytial virus infection (0.45 [0.19-0.66]), and GAS pharyngitis (0.34 [0.06-0.58]). The highest correlations were found in places underlying potential human-to-human contacts among adults. These findings suggest that reductions in human mobility for adults might contribute to decreases in the number of children with droplet-transmissible PIDs by the potential prevention of adult-to-child transmission.

Influenza Outbreak and a Group Meal in a Geriatric Long-term Care Facility in Japan.

Influenza outbreaks at geriatric long-term care facilities (g-LTCFs) can be deadly and their prevention is important. However, the factors influencing disease transmission in g-LTCFs remain controversial. In this descriptive study, we tried to identify the potential risk factors influencing influenza outbreaks that occurred in different influenza seasons within a single g-LTCF with 100 residents in Gunma Prefecture. We reviewed the detailed facility records for all influenza cases in both residents and staff between January 2012 and June 2020. Facility preventive measures were also reviewed. We found that community meals may have been a potential source of transmission leading to the outbreaks. When influenza infection is noted, implementation of strict preventive measures and restriction of meal provision to resident rooms may help to prevent disease transmission and the development of an outbreak. Such measures may also be useful to prevent the transmission of other serious droplet-borne diseases within g-LTCFs.

Kawasaki Disease and Pediatric Infectious Diseases During the Coronavirus Disease 2019 Pandemic.

OBJECTIVE: To assess the epidemiologic association between Kawasaki disease and common pediatric infectious diseases (PIDs) identified during the coronavirus disease 2019 (COVID-19) pandemic period to confirm whether the infection-triggered theory is a plausible hypothesis for the pathogenesis of Kawasaki disease. STUDY DESIGN: A retrospective epidemiologic study was conducted using datasets obtained from Web-based surveillance of Kawasaki disease and PIDs in Japan. We compared weekly numbers of patients who developed Kawasaki disease and specific PIDs between 2020 and 2017-2019 and evaluated the association between the percent reduction in the number of patients with these diseases. RESULTS: A total of 868 patients developed Kawasaki disease in 2020. During the social distancing period in 2020, the number of patients with Kawasaki disease was approximately 35% lower than in 2017-2019. Time from the onset of Kawasaki disease until the first hospital visit did not differ significantly among the examined years. The proportion of older children with Kawasaki disease decreased more than that of infants with Kawasaki disease (age <1 year), resulting in a significant difference in the proportion of infant patients between 2020 and 2017-2019 (24% vs 19%; P < .01). The number of patients with incomplete Kawasaki disease was unchanged from that of previous years. The weekly percent reduction in patient numbers differed between Kawasaki disease and PIDs during 2020, with no strong correlation between the 2 diseases. CONCLUSIONS: Our data indicate that parents of patients with Kawasaki disease did not avoid hospital visits during the COVID-19 pandemic period. The findings indicate the possibility that triggering Kawasaki disease might be associated with presently unidentified respiratory pathogen(s) that potentially might be acquired from both within and outside the household.

Willingness of Patients With Knee Osteoarthritis to Use Telemedicine Amid Sars-CoV-2 Outbreak.

BACKGROUND: There is no report yet on the application of telemedicine in orthopedic practice in Japan. With a focus on patients with KOA, we investigated the willingness of patients to use telemedicine by assessing factors such as the patient's age, smartphone possession, hospital visiting time, and severity of KOA. METHODS: Data of patients who regularly consulted orthopedic surgeons at our institutions from April 2020 to June 2020 were retrospectively analyzed using an electronic medical database. The patients were diagnosed with KOA according to clinical and radiological findings, according to the Kellgren-Lawrence (KL) classification. included were patients with KOA with KL classification above grade 2. All patients were asked: 1) whether they were willing to use telemedicine (Yes or No), 2) the reason why they answered Yes, 3) the reason why they answered No, 4) if they possessed a smartphone, 5) their numeric rating scale for pain at their last outpatient visit after the Sars-CoV-2 epidemic emerged, and 6) the time required for visiting hospital from their house. Patients were stratified into 2 groups depending on whether they answered Yes (Group Y) or No (group N). Comparisons between the groups concerning smartphone possession, NRS pain, hospital visiting times, and distribution of KL grade were made. RESULTS: Only 36.7% of the patients with KOA said they were willing to use telemedicine. The average age of group Y was significantly younger than that of group N (67.9 ± 9.1 vs 73.1 ± 8.0, P = 0.0026) and the cutoff age was 70.0 years. In addition, the rate of smartphone possession was significantly higher in group Y than in group N (82.5% vs 34.5%, P < 0.001). Hospital visit times and the severity of KOA did not differ between the groups. CONCLUSION: Age is a barrier to the adoption of telemedicine.