Air quality, meteorological variability and pediatric respiratory syncytial virus infections in Singapore

Bronchiolitis: Increased severity in the post-COVID-19 era

INTRODUCTION

Acute bronchiolitis is a pressing public health concern, leading to numerous infant hospitalizations worldwide annually. The notable decrease in bronchiolitis hospitalizations during the COVID-19 pandemic sparked concerns about a potential resurgence post-pandemic. Questions also arose about the severity of post-pandemic cases compared to prepandemic ones. This study aimed to compare bronchiolitis severity before and after the COVID-19 pandemic, alongside changes in the epidemiology of bronchiolitis viral agents.

MATERIAL AND METHODS

We conducted a retrospective analysis of medical records concerning infants under 12 months hospitalized for acute bronchiolitis in our pediatric pulmonology department over a period of 5 years: 2 pre-COVID years (2018-2020), the COVID year (2020), and 2 post-COVID years (2021-2023). Clinical and laboratory data were collected using standardized forms.

RESULTS

Hospital admissions exhibited comparable rates pre- and post-COVID but witnessed a decline during the COVID period. Post-COVID, bronchiolitis severity increased, with longer hospitalization durations (p < 0.001) and increased oxygen therapy (p = 0.04), coinciding with a surge in the prevalence of RSV infections (p = 0.01). Patients testing positive for RSV were significantly younger (p = 0.005) and exhibited more severe symptoms.

DISCUSSION AND CONCLUSION

This study reveals a significant increase in bronchiolitis severity and a rise in RSV cases following the COVID pandemic. The implementation of preventive measures such as nirsevimab is crucial to alleviate the burden of respiratory illnesses in vulnerable populations. Continued vigilance and research are needed to address the evolving challenges of bronchiolitis in the post-COVID era.

A study of the correlation between meteorological factors and hospitalization for acute lower respiratory infections in children

BACKGROUND

The study focuses on the effect of temperature and relative humidity on hospitalization for acute lower respiratory tract infections (LRTI) in children, respectively.

METHODS

In this study, the Distributed Lag Nonlinear Model (DLNM) based on quasi-Poisson distribution was used to investigate the effect of temperature and relative humidity on LRTI hospitalization in children, and subgroup analyses were conducted to identify sensitive populations by gender and age.

RESULTS

A total of 43,951 children were hospitalized for LRTI from 1 January 2014 to 31 December 2019 in Lanzhou. The mean temperature during the study period was 11.34 °C and the mean relative humidity was 51.03%. With reference to the median temperature of 12.7 °C during the study period, both low (-4.1 °C) and high (25.43 °C) temperature had a detrimental effect on LRTI hospitalization, and the maximum effect was reached at lag0-10 and lag0-9, respectively, with RR values of 1.645 (95%CI: 1.533, 1.764) and 1.098 (95%CI: 1.018, 1.184). With a reference to the median relative humidity of 51.17% during the study period, both low relative humidity (26.71%) and high relative humidity (76.70%, P95) had a detrimental effect on LRTI hospitalization, and the maximum effect was reached at lag0-21 and lag21, respectively, with RR values of 1.235 (95% CI: 1.163, 1.311) and 1.044 (95% CI: 1.036, 1.051). The results of subgroup analyses showed that changes in meteorological factors had a stronger effect on Female and children aged 5-14 years.

CONCLUSIONS

The meteorological factors all have different degrees of influence on LRTI hospitalization in children. Girls and the children aged 5-14 years are more sensitive. Attention to these meteorological risks can inform targeted interventions.

Association between exposure to ambient air pollution, meteorological factors and atopic dermatitis consultations in Singapore-a stratified nationwide time-series analysis

Atopic dermatitis (AD) is a chronic inflammatory skin disease affecting approximately 20% of children globally. While studies have been conducted elsewhere, air pollution and weather variability is not well studied in the tropics. This time-series study examines the association between air pollution and meteorological factors with the incidence of outpatient visits for AD obtained from the National Skin Centre (NSC) in Singapore. The total number of 1,440,844 consultation visits from the NSC from 2009 to 2019 was analysed. Using the distributed lag non-linear model and assuming a negative binomial distribution, the short-term temporal association between outpatient visits for AD and air quality and meteorological variability on a weekly time-scale were examined, while adjusting for long-term trends, seasonality and autocorrelation. The analysis was also stratified by gender and age to assess potential effect modification. The risk of AD consultation visits was 14% lower (RR10th percentile: 0.86, 95% CI 0.78-0.96) at the 10th percentile (11.9 µg/m3) of PM2.5 and 10% higher (RR90th percentile: 1.10, 95% CI 1.01-1.19) at the 90th percentile (24.4 µg/m3) compared to the median value (16.1 µg/m3). Similar results were observed for PM10 with lower risk at the 10th percentile and higher risk at the 90th percentile (RR10th percentile: 0.86, 95% CI 0.78-0.95, RR90th percentile: 1.10, 95% CI 1.01-1.19). For rainfall for values above the median, the risk of consultation visits was higher up to 7.4 mm in the PM2.5 model (RR74th percentile: 1.07, 95% CI 1.00-1.14) and up to 9 mm in the PM10 model (RR80th percentile: 1.12, 95% CI 1.00-1.25). This study found a close association between outpatient visits for AD with ambient particulate matter concentrations and rainfall. Seasonal variations in particulate matter and rainfall may be used to alert healthcare providers on the anticipated rise in AD cases and to time preventive measures to reduce the associated health burden.

Impact of climate change on paediatric respiratory health: pollutants and aeroallergens

Paediatric populations are particularly vulnerable to respiratory diseases caused and exacerbated by aeroallergens, pollutants and infectious agents. Worsening climate change is expected to increase the prevalence of pollutants and aeroallergens while amplifying disease severity and causing disproportionate effects in under-resourced areas. The purpose of this narrative review is to summarise the role of anthropogenic climate change in the literature examining the future impact of aeroallergens, pollutants and infectious agents on paediatric respiratory diseases with a focus on equitable disease mitigation. The aeroallergens selected for discussion include pollen, dust mites and mould as these are prevalent triggers of paediatric asthma worldwide. Human rhinovirus and respiratory syncytial virus are key viruses interacting with climate change and pollution and are primary causal agents of viral respiratory disease. Within this review, we present the propensity for aeroallergens, climate change and pollution to synergistically exacerbate paediatric respiratory disease and outline measures that can ameliorate the expected increase in morbidity and severity of disease through a health equity lens. We support shifting from fossil fuels to renewable energy worldwide, across sectors, as a primary means of reducing increases in morbidity.

Epidemiology and burden of respiratory syncytial virus in Italian adults: A systematic review and meta-analysis

OBJECTIVE

Respiratory syncytial virus (RSV) is a common respiratory pathogen not only in children, but also in adults. In view of a recent authorization of adult RSV vaccines in Italy, our research question was to quantify the epidemiology and burden of RSV in Italian adults.

METHODS

Observational studies on the epidemiology and clinical burden of laboratory-confirmed or record-coded RSV infection in Italian adults of any age were eligible. Studies with no separate data for Italian adults, modeling and other secondary publications were excluded. A literature search was performed in MEDLINE, Biological Abstracts, Global Health, Scopus and Web of Science on 22 November 2023. Critical appraisal was performed by means of a Joanna Briggs Institute checklist. Random-effects (RE) meta-analysis was performed to obtain pooled estimates and the observed heterogeneity was investigated by subgroup and meta-regression analyses. The protocol was prospectively registered (doi.org/10.17504/protocols.io.5qpvo32odv4o/v1).

RESULTS

Thirty-five studies were identified, most of which had at least one possible quality concern. RSV seasonal attack rates ranged from 0.8 ‰ in community-dwelling older adults to 10.9% in hematological outpatients. In the RE model, 4.5% (95% CI: 3.2-5.9%) of respiratory samples tested positive for RSV. This positivity prevalence was higher in older adults (4.4%) than in working-age adults (3.5%) and in outpatient (4.9%) than inpatient (2.9%) settings. According to the meta-regression, study location and sample size were also significant predictors of RSV detection frequency. The pooled estimate of in-hospital mortality was as high as 7.2% (95% CI: 4.7-10.3%). Data on other indicators of the diseases burden, such as complication and hospitalization rates, were unavailable.

CONCLUSION

RSV poses a measurable burden on Italian adults, especially those of older age and with some co-morbidities. However, several data on the natural history of RSV disease are missing and should be established by future large-scale studies.

Climate change and population health in Singapore: a systematic review

Gaseous emissions have contributed to global warming, an increase in the frequency of extreme weather events and poorer air quality. The associated health impacts have been well reported in temperate regions. In Singapore, key climate change adaptation measures and activities include coastal and flood protection, and mitigating heat impacts. We systematically reviewed studies examining climate variability and air quality with population health in Singapore, a tropical city-state in South-East Asia (SEA), with the aim to identify evidence gaps for policymakers. We included 14 studies with respiratory illnesses, cardiovascular outcomes, foodborne disease and dengue. Absolute humidity (3 studies) and rainfall (2 studies) were positively associated with adverse health. Extreme heat (2 studies) was inversely associated with adverse health. The effects of mean ambient temperature and relative humidity on adverse health were inconsistent. Nitrogen dioxide and ozone were positively associated with adverse health. Climate variability and air quality may have disease-specific, differing directions of effect in Singapore. Additional high quality studies are required to strengthen the evidence for policymaking. Research on effective climate action advocacy and adaptation measures for community activities should be strengthened.

Funding

There was no funding source for this study.

Multilevel analysis identifying the factors associated with RSV detection in infants admitted for viral bronchiolitis in the era of the COVID-19 pandemic

OBJECTIVES

To identify factors independently associated with respiratory syncytial virus (RSV) detection in infants admitted for viral bronchiolitis during 3 consecutive years, before and during the COVID-19 pandemic, in Bogota, Colombia, a middle-income country with a subtropical highland climate.

METHODS

An analytical cross-sectional study was conducted before and during the COVID-19 pandemic, including patients with a diagnosis of viral bronchiolitis admitted to all the hospitals of the city between January 2019 and November 2021. We evaluated a set of a priori-selected predictor variables that included individual, healthcare system, meteorological, air pollutant, and COVID-19 variables. Since the variables analyzed are hierarchical in nature, multilevel modeling was used to identify factors independently associated with detection of RSV as the causative agent of viral bronchiolitis.

RESULTS

A total of 13,177 patients were included in the study. After controlling for potential confounders, it was found that age (odds ratio [OR] 0.86; 95% confidence interval [CI] 0.76-0.97), a third level of medical care institution (OR 3.05; 95% CI 1.61-5.76), temperature (OR 1.60; 95% CI 1.24-2.07), rainfall (OR 1.003, 95% CI 1.001, 1.005), NO2 (OR 0.97; 95% CI 0.95-0.99), CO (OR 0.99; 95% CI 0.99-0.99), and COVID-19 pandemic period (OR 0.84, 95% CI 0.71-0.99) were independently associated with RSV detection in our sample of patients.

CONCLUSIONS

The identified factors associated with RSV detection provide additional scientific evidence that may be useful in the development of specific interventions aimed at ameliorating or preventing the impact of RSV in Bogota and probably other similar low- to middle-income countries in high-risk infants.

Nonlinear and Multidelayed Effects of Meteorological Drivers on Human Respiratory Syncytial Virus Infection in Japan

In this study, we aimed to characterize the nonlinear and multidelayed effects of multiple meteorological drivers on human respiratory syncytial virus (HRSV) infection epidemics in Japan. The prefecture-specific weekly time-series of the number of newly confirmed HRSV infection cases and multiple meteorological variables were collected for 47 Japanese prefectures from 1 January 2014 to 31 December 2019. We combined standard time-series generalized linear models with distributed lag nonlinear models to determine the exposure-lag-response association between the incidence relative risks (IRRs) of HRSV infection and its meteorological drivers. Pooling the 2-week cumulative estimates showed that overall high ambient temperatures (22.7 °C at the 75th percentile compared to 16.3 °C) and high relative humidity (76.4% at the 75th percentile compared to 70.4%) were associated with higher HRSV infection incidence (IRR for ambient temperature 1.068, 95% confidence interval [CI], 1.056-1.079; IRR for relative humidity 1.045, 95% CI, 1.032-1.059). Precipitation revealed a positive association trend, and for wind speed, clear evidence of a negative association was found. Our findings provide a basic picture of the seasonality of HRSV transmission and its nonlinear association with multiple meteorological drivers in the pre-HRSV-vaccination and pre-coronavirus disease 2019 (COVID-19) era in Japan.