Effect of the COVID-19 pandemic and state of emergency declarations on the relative incidence of legionellosis and invasive pneumococcal disease in Japan

Introduction: During the COVID-19 pandemic, the incidence of many droplet-transmitted infections decreased due to increased mask-wearing and social distancing. Contrastingly, there has been concern that COVID-19 countermeasures, such as lockdowns, may increase legionellosis incidence via water stagnation. During the pandemic in Japan, four state of emergency declarations were imposed between 2020 and 2021, which makes it particularly suitable to test this hypothesis. Methods: We use country-level surveillance data from the National Institute of Infectious Diseases to track the relative incidence of legionellosis compared to invasive pneumococcal disease (IPD) during the COVID-19 pandemic in Japan, with a focus on the periods just after state of emergency declarations were lifted. Results: The absolute number of legionellosis and IPD cases decreased in 2020 and 2021 compared to previous years. The average relative incidence of legionellosis as well as the variance of the relative incidence significantly increased during the pandemic compared to previous years. There were no increases in the relative incidence of legionellosis during the periods immediately following emergency declaration liftings, but the relative incidence did increase considerably during the first two states of emergency. Conclusions: COVID-19 countermeasures appear more effective at decreasing the incidence of human-to-human transmitted infections, such as IPD, compared to environmentally-transmitted infections, such as legionellosis. Though no evidence was found to suggest that legionellosis cases increased after state of emergency declarations, public health efforts should continue to emphasize the importance of routine sanitation and water system maintenance to prevent water stagnation and Legionella spp. contamination. © 2022 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases

Retrospective study evaluating the cytokine dynamics in COVID-19 patients who were treated with casirivimab/imdevimab

Background. Neutralizing antibody therapy such as casirivimab/imdevimab is known to significantly reduce the viral load of SARS-CoV-2, but there is limited study on the clinical prognosis of neutralizing antibody therapy, especially in Asia, and the dynamics of cytokines is unknown worldwide. Several cytokines have been investigated as biomarkers to predict oxygen demand, among which CCL17 and INF3 have received approved and covered by the national health insurance in Japan. Methods. Between July 2021 - December 2021, patient's demographic, laboratory, radiological findings, prognosis, and cytokine kinetics (IFN-gamma3, CCL17) at National Center for Global Health and Medicine, Tokyo, Japan, were analyzed using medical charts and serum samples. Univariate analysis was performed using Fisher's exact probability test and Mann-Whitney U test to evaluate the clinical characteristics of the group with oxygen demand compared with those of the group without oxygen demand. Results. Thirty-four patients were analyzed. The median age of the cohort was 57.5 years (IQR 52.8-67.3), and 25 (73.5%) were male. Eight patients (23.5%) had been fully vaccinated and three patients (8.8%) had been vaccinated once. The severity of disease before casirivimab/imdevimab was asymptomatic in two (5.9%), mild in 12 (35.3%), moderate in 20 (58.8%) cases. Of the 17 cases in which mutant strains were identified, 16 were delta strains. The IFN-gamma3 level (pg/mL) before casirivimab/imdevimab was significantly higher (7.6 vs. 17.2, p = 0.005), while the CCL17 level (pg/mL) was significantly lower (148.8 vs. 64.2, p = 0.036) in the group with oxygen demand during the therapeutic course compared to those in the group without oxygen demand. After casirivimab/imdevimab was administered, the IFN-gamma3 level decreased to a median of 0.0 (IQR 0.0-0.3), while the CCL17 level increased to median of 220.3 (IQR 135.8-304.8), with no statistically significant differences between both groups (Figure 1). None of the patients became seriously ill. Figure 1A and 1B show the changing of the cytokine dynamics in COVID-19 patients who were treated with casirivimab/imdevimab on IFN-gamma3 level and CCL17 level, respectively. Conclusion. There was a statistically significant difference between IFN-gamma3 and CCL17 levels before casirivimab/imdevimab in both groups. Our results suggest that casirivimab/immudevimab may improve the clinical prognosis for COVID-19 patients with delta strains.

Effect of the COVID-19 Pandemic and State of Emergency Declarations on the Relative Incidence of Legionellosis and Invasive Pneumococcal Disease in Japan

INTRODUCTION: During the COVID-19 pandemic, the incidence of many droplet-transmitted infections decreased due to increased mask-wearing and social distancing. Contrastingly, there has been concern that COVID-19 countermeasures, such as lockdowns, may increase legionellosis incidence via water stagnation. During the pandemic in Japan, four state of emergency declarations were imposed between 2020-2021, which makes it particularly suitable to test this hypothesis. METHODS: We use country-level surveillance data from the National Institute of Infectious Diseases to track the relative incidence of legionellosis compared to invasive pneumococcal disease (IPD) during the COVID-19 pandemic in Japan, with a focus on the periods just after state of emergency declarations were lifted. RESULTS: The absolute number of legionellosis and IPD cases decreased in 2020 and 2021 compared to previous years. The average relative incidence of legionellosis as well as the variance of the relative incidence significantly increased during the pandemic compared to previous years. There were no increases in the relative incidence of legionellosis during the periods immediately following emergency declaration liftings, but the relative incidence did increase considerably during the first two states of emergency. CONCLUSIONS: COVID-19 countermeasures appear more effective at decreasing the incidence of human-to-human transmitted infections, such as IPD, compared to environmentally-transmitted infections, such as legionellosis. Though no evidence was found to suggest that legionellosis cases increased after state of emergency declarations, public health efforts should continue to emphasize the importance of routine sanitation and water system maintenance to prevent water stagnation and Legionellaspp. contamination.

Positive Ratio of Polymerase Chain Reaction (PCR) and Validity of Pre-Screening Criteria at an Outpatient Screening Center during the Early Phase of the COVID-19 Epidemic in Japan

Despite the increase in COVID-19 cases globally, the number of cases in Japan has been relatively low, and an explosive surge in the prevalence has not occurred. In March 2020, the Ministry of Health, Labour and Welfare (MHLW) in Japan recommended the original criteria for polymerase chain reaction (PCR) testing, although there was a lack of evidence for appropriate targets for COVID-19 testing. This study aimed to evaluate the COVID-19 positive ratio and pre-screening criteria in Tokyo immediately after the insurance-covered SARS-CoV-2 PCR testing became available in Japan. We subjected 277 individuals with mild symptoms in metropolitan Tokyo (positive: 9.0%) from March 9 to 29, 2020, to SARS-CoV-2 PCR testing. The results revealed that 25 (9.0%) of them were PCR-positive. The sensitivity and specificity of the MHLW criteria were 100% and 10.7%, respectively. When the criteria excluded nonspecific symptoms, fatigue, and dyspnea, the sensitivity slightly decreased to 92%, and the specificity increased to 22.2%. The specificity was highest when the fever criterion was >= 37.5 degrees C for >= 4 days, and exposure/travel history, including age and underlying comorbidities, was considered. Our findings suggest that the MHLW criteria, including the symptoms and exposure/travel history, may be useful for COVID-19 pre-screening.

Can urine biomarkers predict severity of COVID-19? A preliminary study

Background: Early detection of coronavirus disease (COVID-19) in patients likely to develop severe manifestations enables appropriate interventions, including rapid intensive care unit admission. This study was conducted to determine whether noninvasive urine biomarkers can predict the clinical severity of COVID-19. Methods: Design A retrospective case series. Setting Single-center study, national center hospital designated for infectious disease. Patients Fifty-eight patients who tested positive for SARS-CoV-2 in respiratory specimens through real-time reverse transcription-polymerase chain reaction (RT-PCR) were retrospectively studied. Measurements and main results Urinary β2-microglobulin (β2MG), liver-type fatty acid-binding protein (L-FABP) were serially measured. Serum interferon γ and monocyte chemotactic protein-1 were also evaluated. Results: The 58 patients were assigned into three groups. Patients requiring intensive care were assigned to the severe group (N = 12). Patients treated with oxygen were assigned to the moderate group (N = 13). Other patients were assigned to the mild group (N = 33). Urine tests revealed that low β2MG and L-FABP levels on admission were associated with mild disease, whereas high levels were associated with severe disease. In severe cases, L-FABP tended to be persistently high. The resulting cutoff values were β2MG;Severe vs. Moderate+Mild: 2457 μg/dL (Specificity 76.9% and Sensitivity 90.0%, AUC 85.9%), L-FABP;Severe vs. Moderate+Mild: 22.0 μg/gCre (Specificity 84.6% and Sensitivity 90%, AUC 91.8%). Urinary β2MG and serum IFN-γ/MCP-1 showed a similar trend. Conclusions: Evaluating urinary biomarkers such as β2MG and L-FABP may allow determination of COVID-19 patients with active cytokines and recognition of patients likely to become critically ill and requiring careful observation and early intervention.

Nightlife clusters of coronavirus disease in Tokyo between March and April 2020.

We analysed associations between exposure to nightlife businesses and severe acute respiratory syndrome coronavirus 2 PCR test results at a tertiary hospital in Tokyo between March and April 2020. A nightlife group was defined as those who had worked at or visited the businesses. We included 1517 individuals; 196 (12.9%) were categorised as the nightlife group. After propensity score matching, the proportion of positive PCR tests in the nightlife group was significantly higher than that in the non-nightlife group (nightlife, 63.8%; non-nightlife, 23.0%; P < 0.001). An inclusive approach to mitigate risks related to the businesses needs to be identified.