Trends in the incidence and mortality of legionellosis in Japan: a nationwide observational study, 1999-2017

Analysis of water and aerosol samples of tunnel car washes operated with recycled water for Legionella with culture, qPCR and viability-qPCR

Due to the generation of large quantities of aerosol and the recycling of water, tunnel car washes are discussed as potential sources of legionellosis. Additionally, occupational health and safety aspects are important for tunnel car washes as they are often workplaces. A total of 17 different tunnel car washes were investigated for the presence of Legionella. In the process, 78 water samples and 63 air samples were taken. This comprised samples of municipal and recycled water as well as aerosol from the car wash tunnel and the workplace. The analysis for Legionella included culture method in combination with an immunochromatographic test, qPCR and viability-qPCR. Where possible, Legionella species were identified by sequencing of mip gene. Using the culture method Legionella were detected in 9 of 78 water samples (91 to 10,800 CFU/100 mL). In contrast, quantifiable concentrations of viable Legionella spp. were found in 68 of 78 water samples with viability-qPCR. The median concentration was 9.2 × 105(n = 16) and 7.2 × 105 GU/100 mL (n = 17) for the recycled water from the storage tank and the nozzles in the car wash tunnel. Viable Legionella spp. were detectable in the aerosol at the workplace in 38.1 % of the samples (n = 21). Concentration was between 155 and 3829 GU/m3 (n = 7). L. pneumophila non-serogroup 1 were quantitatively detectable in the recycled water of one car wash, using qPCR methods and culture. Aerosolisation of this species was not detected. The presence of viable Legionella spp. in most water and many aerosol samples as well as the identification of species related to infection suggests that there is a risk of legionellosis through exposure to bioaerosols released from tunnel car washes. Comparison of conventional culture method with qPCR methods showed a considerable underestimation of Legionella concentrations by culture.

Daily diurnal temperature range associated with emergency ambulance calls: a nine-year time-series study

Background

Diurnal temperature range (DTR) is associated with the increased risk of morbidity and mortality. However, the relationship between DTR and emergency ambulance calls (EACs), which more accurately and immediately reflect the health impacts of temperature changes, remains underexplored in China.

Methods

We collected daily data on EACs and meteorological factors from 2009 to 2017 in Guangzhou, China. DTR, representing the temperature range within a day, was calculated by subtracting the minimum temperature from the maximum temperature for each day. Generalized additive models were used to estimate the association between DTR and EACs for all-cause, cardiovascular diseases, and respiratory diseases. Additionally, subgroup and sensitivity analyses were conducted in our study.

Results

We found significant associations between daily DTR and EACs. The excess risks (ERs) were 0.47% (95% CI: 0.14, 0.81%) for all-cause EACs, 0.94% (95% CI: 0.46, 1.43%) for cardiovascular-related EACs, and 1.31% (95% CI: 0.76, 1.86%) for respiratory -related EACs at lag01, respectively. Subgroup analyses indicated that these associations were notably stronger among the older, males, and during the warm season. Specifically, there was an increase of 1.16% (95% CI: 0.59, 1.74%) in cardiovascular-related EACs among the older adult, compared to 0.45% (95% CI: -0.21, 1.12%) among those younger than 65 years. Among males, the increase was 1.39% (95% CI: 0.79, 1.99%), compared to 0.13% (95% CI: -0.53, 0.79%) among females. During the warm season, the increase was 1.53% (95% CI: 0.74, 2.34%), compared to 0.75% (95% CI: 0.14, 1.37%) during the cold season.

Conclusion

DTR might increase the risk of daily all-cause, cardiovascular-related, and respiratory-related EACs in Guangzhou, China. The associations were particularly strong among older adults, males, and during the warm season. Implementing public health policies is essential to mitigate the adverse health effects of DTR.

Sex and gender differences in intensive care medicine

Despite significant advancements in critical care medicine, limited attention has been given to sex and gender disparities in management and outcomes of patients admitted to the intensive care unit (ICU). While "sex" pertains to biological and physiological characteristics, such as reproductive organs, chromosomes and sex hormones, "gender" refers more to sociocultural roles and human behavior. Unfortunately, data on gender-related topics in the ICU are lacking. Consequently, data on sex and gender-related differences in admission to the ICU, clinical course, length of stay, mortality, and post-ICU burdens, are often inconsistent. Moreover, when examining specific diagnoses in the ICU, variations can be observed in epidemiology, pathophysiology, presentation, severity, and treatment response due to the distinct impact of sex hormones on the immune and cardiovascular systems. In this narrative review, we highlight the influence of sex and gender on the clinical course, management, and outcomes of the most encountered intensive care conditions, in addition to the potential co-existence of unconscious biases which may also impact critical illness. Diagnoses with a known sex predilection will be discussed within the context of underlying sex differences in physiology, anatomy, and pharmacology with the goal of identifying areas where clinical improvement is needed. To optimize patient care and outcomes, it is crucial to comprehend and address sex and gender differences in the ICU setting and personalize management accordingly to ensure equitable, patient-centered care. Future research should focus on elucidating the underlying mechanisms driving sex and gender disparities, as well as exploring targeted interventions to mitigate these disparities and improve outcomes for all critically ill patients.

Impact of the COVID-19 pandemic on the epidemiology of other communicable diseases in Japan

OBJECTIVES

To elucidate the impact of the COVID-19 pandemic on the epidemiology of other infectious diseases.

DESIGN

We investigated the epidemiology of 36 communicable diseases during 2015-2021 in Japan and compared the number of cases in each disease between the prepandemic (2015-2019) and intrapandemic (2020-2021) periods. Relationships between the incidence of the infectious diseases and the COVID-19 pandemic were also investigated.

RESULTS

Of 36 communicable diseases, the number of cases in the 27 diseases (75%) mainly caused by pathogens transmitted by droplet or contact was lower intrapandemic than prepandemic, and the cases of 21 diseases (58%) continued to decrease intrapandemic. The number of cases of six diseases (17%) was higher intrapandemic than prepandemic, and the cases of two diseases (5.6%), Japanese spotted fever and syphilis, continued to increase intrapandemic. Time trend analyses revealed a positive correlation between case numbers of communicable diseases and the COVID-19 pandemic, whereas the case numbers of hand-foot-and-mouth disease and respiratory syncytial virus infection rebounded in 2021 after decreasing in 2020.

CONCLUSION

The COVID-19 pandemic has greatly impacted the epidemiology of communicable diseases, suggesting that countermeasures against COVID-19 and lifestyle changes might be involved in these epidemiological changes.

Temporal trends in legionellosis national notification data and the effect of COVID-19, Switzerland, 2000-2020

The notification rate of legionellosis in Switzerland and other European countries has markedly increased over the last 20 years. Here, we investigated the Swiss notification data on legionellosis from 2000 to 2020 in regards of overall time trend, content and data quality. We further explored the impact of the COVID-19 pandemic on the reported case numbers using an interrupted time series approach. Between 2000 and 2020, 5980 cases were included in our analysis. The annual crude notification rate for legionellosis cases increased from 1.1/100,000 population (CI: 0.9-1.4) in 2000 to 5.6/100,000 population (CI: 5.1-6.1) in 2020. In recent years, the summer peaks have been more pronounced and some shifted earlier in the year. The highest notification rate was recorded in 2018 with 6.7/100,000 population (CI: 6.2-7.3). The hospitalisation rate for notified cases remained high across all study years (89.9%), while the case fatality rate slightly decreased (from 7.7% to 3.6%). COVID-19 containment measures, such as travel restrictions and/or related behavioural changes, are associated with a temporary decline in cases of 35%. Overall, the quality of the notification data was good. Clinical data were more susceptible to interferences than data from laboratory reporting, which could be observed most clearly in the decline of clinical reports by 4.3 percentage points in 2020. As the case classification for Legionnaires' disease includes pneumonia symptoms, this decline could lead to an underestimation of Legionnaires' disease cases, yet the continuous reporting though the diagnostic laboratories suggested a robust surveillance system for legionellosis in Switzerland.

Incidence and risk factors associated with progression to severe pneumonia among adults with non-severe Legionella pneumonia

BACKGROUND

Legionella species are important causative organisms of severe pneumonia. However, data are limited on predictors of progression to severe Legionella pneumonia (LP). Therefore, the risk factors for LP progression from non-severe to the severe form were investigated in the present study.

METHODS

This was a retrospective cohort study that included adult LP patients admitted to a 2,700-bed referral center between January 2005 and December 2019.

RESULTS

A total of 155 patients were identified during the study period; 58 patients (37.4%) initially presented with severe pneumonia and 97 (62.6%) patients with non-severe pneumonia. Among the 97 patients, 28 (28.9%) developed severe pneumonia during hospitalization and 69 patients (71.1%) recovered without progression to severe pneumonia. Multivariate logistic regression analysis showed platelet count ≤150,000/mm3 (odds ratio [OR], 2.923; 95% confidence interval [CI], 1.100-8.105; P=0.034) and delayed antibiotic treatment >1 day (OR, 3.092; 95% CI, 1.167-8.727; P=0.026) were significant independent factors associated with progression to severe pneumonia.

CONCLUSIONS

A low platelet count and delayed antibiotic treatment were significantly associated with the progression of non-severe LP to severe LP.

Sex and Gender Differences in Bacterial Infections

There is a growing awareness of the importance of sex and gender in medicine and research. Women typically have stronger immune responses to self and foreign antigens than men, resulting in sex-based differences in autoimmunity and infectious diseases. In both animals and humans, males are generally more susceptible than females to bacterial infections. At the same time, gender differences in health-seeking behavior, quality of health care, and adherence to treatment recommendations have been reported. This review explores our current understanding of differences between males and females in bacterial diseases. We describe how genetic, immunological, hormonal, and anatomical factors interact to influence sex-based differences in pathophysiology, epidemiology, clinical presentation, disease severity, and prognosis, and how gender roles affect the behavior of patients and providers in the health care system.

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.

Factors That Affect Legionella Positivity in Healthcare Building Water Systems from a Large, National Environmental Surveillance Initiative

Legionella growth in healthcare building water systems can result in legionellosis, making water management programs (WMPs) important for patient safety. However, knowledge is limited on Legionella prevalence in healthcare buildings. A dataset of quarterly water testing in Veterans Health Administration (VHA) healthcare buildings was used to examine national environmental Legionella prevalence from 2015 to 2018. Bayesian hierarchical logistic regression modeling assessed factors influencing Legionella positivity. The master dataset included 201,146 water samples from 814 buildings at 168 VHA campuses. Overall Legionella positivity over the 4 years decreased from 7.2 to 5.1%, with the odds of a Legionella-positive sample being 0.94 (0.90-0.97) times the odds of a positive sample in the previous quarter for the 16 quarters of the 4 year period. Positivity varied considerably more at the medical center campus level compared to regional levels or to the building level where controls are typically applied. We found higher odds of Legionella detection in older buildings (OR 0.92 [0.86-0.98] for each more recent decade of construction), in taller buildings (OR 1.20 [1.13-1.27] for each additional floor), in hot water samples (O.R. 1.21 [1.16-1.27]), and in samples with lower residual biocide concentrations. This comprehensive healthcare building review showed reduced Legionella detection in the VHA healthcare system over time. Insights into factors associated with Legionella positivity provide information for healthcare systems implementing WMPs and for organizations setting standards and regulations.

Severe pneumonia caused by Legionella pneumophila detected by a multiplex polymerase chain reaction assay and confirmed by serology

Legionella pneumophila is a rarely diagnosed microorganism in Serbia. It causes legionellosis, usually a mild respiratory infection. However, in some cases it can be severe and even life threatening. In June 2020, during the COVID-19 pandemic, a patient with symptoms of the aforesaid infection, namely severe pneumonia and acute respiratory distress syndrome, was admitted to the hospital. The multiplex polymerase chain reaction (PCR) test (The BioFire FilmArray Pneumonia Panel plus) detected the presence of L. pneumophila in the patient’s bronchial secretions. The specific culture for the detection of that organism, however, remained sterile. The patient’s paired sera had been sent for serology and the results in both of them came back positive for Legionella spp. 1–6, while the assays specific for each one of the 10 serogroups detected more than a fourfold increase of antibody titers in an uncommon serogroup 2 only. The patient was treated with moxifloxacin; he recovered well and was discharged after 26 days of hospitalization. Having being diagnosed with the L. pneumophila infection correctly through the multiplex PCR test, the patient was given the right therapy with moxifloxacin. The serologic assays corroborated this result and revealed the uncommon group 2, thus confirming the necessity of carrying out all the tests available to attain the exact diagnosis of legionellosis.

Infectious disease activity during the COVID-19 epidemic in Japan: Lessons learned from prevention and control measures

In Japan, the Law Concerning the Prevention of Infectious Diseases and Medical Care for Patients with Infectious Diseases (the "Infectious Diseases Control Law") classifies infectious diseases as category I-V infectious diseases, pandemic influenza, and designated infectious diseases based on their infectivity, severity, and impact on public health. COVID-19 was designated as a designated infectious disease as of February 1, 2020 and then classified under pandemic influenza as of February 13, 2021. According to national reports from sentinel surveillance, some infectious diseases transmitted by droplets, contact, or orally declined during the COVID-19 epidemic in Japan. As of week 22 (June 6, 2021), there were 704 cumulative cases of seasonal influenza, 8,144 cumulative cases of chickenpox, 356 cumulative cases of mycoplasma pneumonia, and 45 cumulative cases of rotavirus gastroenteritis; these numbers were significantly lower than those last year, with 563,487 cumulative cases of seasonal influenza, 31,785 cumulative cases of chickenpox, 3,518 cumulative cases of mycoplasma pneumonia, and 250 cumulative cases of rotavirus gastroenteritis. Similarly, many infectious diseases transmitted by droplets or contact declined in other countries and areas during the COVID-19 pandemic. One can reasonably assume that various measures adopted to control the transmission of COVID-19 have played a role in reducing the spread of other infectious diseases, and especially those transmitted by droplets or contact. Extensive and thorough implementation of personal protective measures and behavioral changes may serve as a valuable reference when identifying ways to reduce the spread of infectious diseases transmitted by droplets or contact in the future.