Air Pollution and Hospitalization for Bronchiolitis among Young Children

Perinatal exposure to traffic related air pollutants and the risk of infection in the first six months of life: a cohort study from a low-middle income country

OBJECTIVE

There is limited study from low-and-middle income countries on the effect of perinatal exposure to air pollution and the risk of infection in infant. We assessed the association between perinatal exposure to traffic related air pollution and the risk of infection in infant during their first six months of life.

METHODS

A prospective cohort study was performed in Jakarta, March 2016-September 2020 among 298 mother-infant pairs. PM2.5, soot, NOx, and NO2 concentrations were assessed using land use regression models (LUR) at individual level. Repeated interviewer-administered questionnaires were used to obtain data on infection at 1, 2, 4 and 6 months of age. The infections were categorized as upper respiratory tract (runny nose, cough, wheezing or shortness of breath), lower respiratory tract (pneumonia, bronchiolitis) or gastrointestinal tract infection. Logistic regression models adjusted for covariates were used to assess the association between perinatal exposure to air pollution and the risk of infection in the first six months of life.

RESULTS

The average concentrations of PM2.5 and NO2 were much higher than the WHO recommended levels. Upper respiratory tract infections (URTI) were much more common in the first six months of life than diagnosed lower respiratory tract or gastro-intestinal infections (35.6%, 3.5% and 5.8% respectively). Perinatal exposure to PM2.5 and soot suggested increase cumulative risk of upper respiratory tract infection (URTI) in the first 6 months of life per IQR increase with adjusted OR of 1.50 (95% CI 0.91; 2.47) and 1.14 (95% CI 0.79; 1.64), respectively. Soot was significantly associated with the risk of URTI at 4-6 months age interval (aOR of 1.45, 95%CI 1.02; 2.09). All air pollutants were also positively associated with lower respiratory tract infection, but all CIs include unity because of relatively small samples. Adjusted odds ratios for gastrointestinal infections were close to unity.

CONCLUSION

Our study adds to the evidence that perinatal exposure to fine particles is associated with respiratory tract infection in infants in a low-middle income country.

Air pollution and bronchiolitis: a case-control study in Antwerp, Belgium

This case-control study aimed to investigate the association between short-term (1 to 5 days) and medium-term (31 days) exposure to air pollutants (PM2.5, PM10, BC, NO2) at home/daycare and the risk of 'severe bronchiolitis' (defined as 'requiring hospitalization for bronchiolitis') in children under 2 years in Antwerp, Belgium. We included 118 cases and 79 controls admitted to three general hospitals from October 2020 to June 2021. Exposure levels were predicted using an interpolation model based on fixed measuring stations. We used unconditional logistic regression analysis to assess associations, with adjustment for potential confounders. There were hardly any significant differences in the day-to-day air pollution values between cases and controls. Medium-term (31 days) exposure to PM2.5, PM10, and NO2 was however significantly higher in cases than controls in univariate analysis. Logistic regression revealed an association between severe bronchiolitis and interquartile range (IQR) increases of PM2.5 and PM10 at home and in daycare, as well as IQR increases of NO2 in daycare. Controls were however overrepresented in low pollution periods. Time-adjustment reduced the odds ratios significantly at home for PM2.5 and PM10 (aOR 1.54, 95%CI 0.51-4.65; and 2.69, 95%CI 0.94-7.69 respectively), and in daycare for. PM2.5 (aOR 2.43, 95%CI 0.58-10.1). However, the association between severe bronchiolitis and medium-term air pollution was retained in daycare for IQR increases of PM10 (aOR 5.13, 95%CI 1.24-21.28) and NO2 (aOR 3.88, 95%CI 1.56-9.61) in the time-adjusted model.  Conclusion: This study suggests a possible link between severe bronchiolitis and medium-term (31 days) air pollution exposure (PM10 and NO2), particularly in daycare. Larger studies are warranted to confirm these findings. What is Known: • Bronchiolitis is a leading cause of hospitalization in infants globally and causes a yearly seasonal wave of admissions in paediatric departments worldwide. • Existing studies, mainly from the USA, show heterogeneous outcomes regarding the association between air pollution and bronchiolitis. What is New: • There is a possible link between severe bronchiolitis and medium-term (31 days) air pollution exposure (PM10 and NO2), particularly in daycare. • Larger studies are needed to validate these trends.

Bronchiolitis recovery and the use of High Efficiency Particulate Air (HEPA) Filters (The BREATHE Study): study protocol for a multi-center, parallel, double-blind, randomized controlled clinical trial

BACKGROUND

Acute viral bronchiolitis is the most common reason for hospitalization of infants in the USA. Infants hospitalized for bronchiolitis are at high risk for recurrent respiratory symptoms and wheeze in the subsequent year, and longer-term adverse respiratory outcomes such as persistent childhood asthma. There are no effective secondary prevention strategies. Multiple factors, including air pollutant exposure, contribute to risk of adverse respiratory outcomes in these infants. Improvement in indoor air quality following hospitalization for bronchiolitis may be a prevention opportunity to reduce symptom burden. Use of stand-alone high efficiency particulate air (HEPA) filtration units is a simple method to reduce particulate matter ≤ 2.5 µm in diameter (PM2.5), a common component of household air pollution that is strongly linked to health effects.

METHODS

BREATHE is a multi-center, parallel, double-blind, randomized controlled clinical trial. Two hundred twenty-eight children < 12 months of age hospitalized for the first time with bronchiolitis will participate. Children will be randomized 1:1 to receive a 24-week home intervention with filtration units containing HEPA and carbon filters (in the child's sleep space and a common room) or to a control group with units that do not contain HEPA and carbon filters. The primary objective is to determine if use of HEPA filtration units reduces respiratory symptom burden for 24 weeks compared to use of control units. Secondary objectives are to assess the efficacy of the HEPA intervention relative to control on (1) number of unscheduled healthcare visits for respiratory complaints, (2) child quality of life, and (3) average PM2.5 levels in the home.

DISCUSSION

We propose to test the use of HEPA filtration to improve indoor air quality as a strategy to reduce post-bronchiolitis respiratory symptom burden in at-risk infants with severe bronchiolitis. If the intervention proves successful, this trial will support use of HEPA filtration for children with bronchiolitis to reduce respiratory symptom burden following hospitalization.

TRIAL REGISTRATION

NCT05615870. Registered on November 14, 2022.

RSV Burden and Its Impact on Pediatric Inpatient Bed Occupancy in Belgium: An Analysis of National Hospital Claims Data

BACKGROUND

Respiratory syncytial virus (RSV) infections represent a substantial burden on pediatric services during winter. While the morbidity and financial burden of RSV are well studied, less is known about the organizational impact on hospital services (ie, impact on bed capacity and overcrowding and variation across hospitals).

METHODS

Retrospective analysis of the population-wide Belgian Hospital Discharge Data Set for the years 2017 and 2018 (including all hospital sites with pediatric inpatient services), covering all RSV-associated (RSV-related International Classification of Diseases, 10th Version, Clinical Modification diagnoses) inpatient hospitalization by children under 5 years old as well as all-cause acute hospitalizations in pediatric wards.

RESULTS

RSV hospitalizations amount to 68.3 hospitalizations per 1000 children less than 1 year and 5.0 per 1000 children 1-4 years of age and are responsible for 20%-40% of occupied beds during the peak period (November-December). The mean bed occupancy rate over the entire year (2018) varies across hospitals from 22.8% to 85.1% and from 30.4% to 95.1% during the peak period. Small-scale pediatric services (<25 beds) are more vulnerable to the volatility of occupancy rates. Forty-six hospital sites have daily occupancy rates above 100% (median of 9 days). Only in 1 of 23 geographically defined hospital networks these high occupancy rates are on the same calendar days.

CONCLUSIONS

Pediatric services tend to be over-dimensioned to deal with peak activity mainly attributable to RSV. RSV immunization can substantially reduce pediatric capacity requirements. Enhanced collaboration in regional networks is an alternative strategy to deal with peaks and reduce capacity needs.

Exposure to outdoor air pollution and risk of hospitalization for bronchiolitis in an urban environment: A 9-year observational study

BACKGROUND

Outdoor air pollution is supposed to influence the course of bronchiolitis, but the evidence is limited. The present study aimed at evaluating the role of outdoor air pollutants on hospitalization for bronchiolitis.

METHODS

Infants aged ≤12 months referred for bronchiolitis to our Pediatric Emergency Department in Bologna, Italy, from 1 October 2011 to 16 March 2020 (nine epidemic seasons) were retrospectively included. Daily concentrations of benzene (C6 H6 ), nitrogen dioxide (NO2 ), particulate matter ≤2.5 μm (PM2.5 ), and ≤10 μm (PM10 ), and the mean values of individual patient exposure in the week and the 4 weeks before hospital access were calculated. The association between air pollutants exposure and hospitalization was evaluated through logistic regression analysis.

RESULTS

A total of 2902 patients were enrolled (59.9% males; 38.7% hospitalized). Exposure to PM2.5 in the 4 weeks preceding bronchiolitis was identified as the main parameter significantly driving the risk of hospitalization (odds ratio [95% confidence interval]: 1.055 [1.010-1.102]). After stratifying by season, higher values of other outdoor air pollutants were found to significantly affect hospitalization: 4-week exposure to C6 H6 (Season 2011-2012, 4.090 [1.184-14.130]) and PM2.5 (Season 2017-2018, 1.282 [1.032-1.593]), and 1-week exposure to C6 H6 (Season 2012-2013, 6.193 [1.552-24.710]), NO2 (Season 2013-2014, 1.064 [1.009-1.122]), PM2.5 (Season 2013-2014, 1.080 [1.023-1.141]), and PM10 (Season 2018-2019, 1.102 [0.991-1.225]).

CONCLUSION

High levels of PM2.5 , C6 H6 , NO2 , and PM10 may increase the risk of hospitalization in children affected by bronchiolitis. Open-air exposure of infants during rush hours and in the most polluted areas should be avoided.

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

Respiratory syncytial virus (RSV) is an important cause of respiratory illness among children. While studies have focused on the air-quality and climate dependence of RSV infections, few have been undertaken in South-East Asia where the burden of respiratory illness is among the highest across the globe. This study aimed to determine the relationships between climatic factors and air quality with RSV infections among children in Singapore. We obtained all laboratory-confirmed reports of RSV infections in children below 5 years old from the largest public hospital specializing in pediatric healthcare in Singapore. We assessed the independent cumulative effects of air quality and meteorological factors on RSV infection risk using the Distributed Lag Non-Linear Model (DLNM) framework in negative binomial models adjusted for long-term trend, seasonality and changes in the diagnostic systems. We included 15,715 laboratory-confirmed RSV reports from 2009 to 2019. Daily maximum temperature exhibited a complex, non-linear association with RSV infections. Absolute humidity (Relative Risk, 90th percentile [RR_{90th percentile}]: 1.170, 95% CI: [1.102, 1.242]) was positively associated with RSV risk. Higher levels of particulate matter of aerodynamic diameter of less than (i) 2.5 µm (PM_2.5), (ii) 10 µm (PM₁₀), carbon monoxide (CO) and sulfur dioxide (SO₂) were associated with lower RSV infection risk. RSV infections exhibited both annual and within-year seasonality. Our findings suggest that falls in ambient temperature and rises in absolute humidity exacerbated pediatric RSV infection risk while increases in air pollutant concentrations were associated with lowered infection risk. These meteorological factors, together with the predictable seasonality of RSV infections, can inform the timing of mitigation measures aimed at reducing transmission.

Particulate Air Pollution Exposure and Stroke among Adults in Israel

Stroke is the second most common cause of death and disability in the world. Many studies have found fine particulate matter (PM2.5) exposure to be associated with an increased risk of atherosclerotic cardiovascular disease, mostly focusing on ischemic heart disease and acute myocardial infarction. In a national analysis conducted in Israel-an area with unique climate conditions and high air pollution levels, we estimated the association between short-term PM2.5 exposure and ischemic stroke, intracerebral hemorrhage (ICH), or transient ischemic attacks (TIA). Using the Israeli National Stroke Registry, we obtained information on all stroke cases across Israel in 2014-2018. We obtained daily PM2.5 exposures from spatiotemporally resolved exposure models. We restricted the analytical data to days in which PM2.5 levels did not exceed the Israeli 24 h standard (37.5 µg/m3). We repeated the analysis with a stratification by sociodemographic characteristics and comorbidities. For all outcomes, the exposure-response curves were nonlinear. PM2.5 exposure was associated with a higher ischemic stroke risk, with larger effect estimates at higher exposure levels. Although nonsignificant, the exposure-response curve for TIA was similar. The associations with ICH were nonsignificant throughout the PM2.5 exposure distribution. The associations with ischemic stroke/TIA were larger among women, non-Jewish individuals, older adults, and individuals with diabetes, hypertension, and ischemic heart disease. In conclusion, short-term PM2.5 exposure is associated with a higher risk for ischemic stroke and possibly TIA, even when PM2.5 concentrations do not exceed the Israeli air quality guideline threshold. Vulnerability to the air pollution effects differed by age, sex, ethnicity, and comorbidities.

The burden and surveillance of RSV disease in young children in Belgium-expert opinion

Infections with respiratory syncytial virus (RSV) can cause severe disease. In young children, RSV is the most common cause of lower respiratory tract illness and life-threatening infections most commonly occur in the first years of life. In adults, elderly and immunocompromised people are most vulnerable. Recently there has been an acceleration in the development of candidate RSV vaccines, monoclonal antibodies and therapeutics which are expected to become available in Europe within the next 2-10 years. Understanding the true burden of childhood RSV disease will become very important to support public health authorities and policy makers in the assessment of new therapeutic opportunities against RSV disease. A systematic literature search was performed to map local data on the burden of RSV disease and to evaluate available RSV surveillance systems. A group of 9 paediatric infectious diseases specialists participated in an expert panel. The purpose of this meeting was to evaluate and map the burden associated with RSV infection in children, including patient pathways and the epidemiological patterns of virus circulation in Belgium. Sources of information on the burden of RSV disease in Belgium are very limited. For the outpatient setting, it is estimated that 5-10% of young patients seen in primary care are referred to the hospital. Around 3500 children between 0 and 12 months of age are hospitalized for RSV-bronchiolitis every year and represent the majority of all hospitalizations. The current Belgian RSV surveillance system was evaluated and found to be insufficient. Knowledge gaps are highlighted and future perspectives and priorities offered.

CONCLUSION

The Belgian population-based RSV surveillance should be improved, and a hospital-led reporting system should be put in place to enable the evaluation of the true burden of RSV disease in Belgium and to improve disease management in the future.

WHAT IS KNOWN

• RSV bronchiolitis is a very important cause of infant hospitalization. • The burden of disease in the community is poorly studied and underestimated.

WHAT IS NEW

• This expert opinion summarizes knowledge gaps and offers insights that allow improvement of local surveillance systems in order to establish a future-proof RSV surveillance system.

Structural racism and the health of Palestinian citizens of Israel

Palestinian citizens of Israel (PCI) constitute almost 20% of the Israeli population. Despite having access to one of the most efficient healthcare systems in the world, PCI have shorter life expectancy and significantly worse health outcomes compared to the Jewish Israeli population. While several studies have analysed the social and policy determinants driving these health inequities, direct discussion of structural racism as their overarching etiology has been limited. This article situates the social determinants of health of PCI and their health outcomes as stemming from settler colonialism and resultant structural racism by exploring how Palestinians came to be a racialized minority in their homeland. In utilising critical race theory and a settler colonial analysis, we provide a structural and historically responsible reading of the health of PCI and suggest that dismantling legally codified racial discrimination is the first step to achieving health equity.

[Association of Haemophilus influenzae infection with environmental and climatic factors in Suzhou, China]

OBJECTIVES

To investigate the epidemiological characteristics of respiratory Haemophilus influenzae (HI) infection in children in Suzhou, China and its association with climatic factors and air pollutants.

METHODS

The data on air pollutants and climatic factors in Suzhou from January 2016 to December 2019 were collected. Respiratory secretions were collected from 7 940 children with acute respiratory infection who were hospitalized during this period, and bacterial culture results were analyzed for the detection of HI. A stepwise regression analysis was used to investigate the association of HI detection rate with air pollutants (PM2.5, PM10, NO2, SO2, CO, and O3) and climatic factors (monthly mean temperature, monthly mean humidity, monthly total rainfall, monthly total sunshine duration, and monthly mean wind speed).

RESULTS

In 2016-2019, the 4-year overall detection rate of HI was 9.26% (735/7 940) among the children in Suzhou. The children aged <1 year and 1-<3 years had a significantly higher HI detection rate than those aged ≥3 years (P<0.01). The detection rate of HI in spring was significantly higher than that in the other three seasons, and the detection rate of HI in autumn was significantly lower than that in the other three seasons (P<0.001). The multiple linear regression analysis showed that PM10 and monthly mean wind speed were independent risk factors for the detection rate of HI: the detection rate of HI was increased by 0.86% for every 10 µg/m3 increase in the concentration of PM10 and was increased by 5.64% for every 1 m/s increase in monthly mean wind speed. Air pollutants and climatic factors had a lag effect on the detection rate of HI.

CONCLUSIONS

HI is an important pathogen for acute respiratory infection in children in Suzhou and is prevalent in spring. PM10 and monthly mean wind speed are independent risk factors for the detection rate of HI.

Air pollution and pediatric respiratory hospital admissions in Bursa, Turkey: A time series study

We aimed to investigate the relation between air pollution and the number of daily hospitalizations due to pneumonia, asthma, bronchitis in children aged 0-18 in Bursa city of Turkey, between the years 2013-2018. The daily values of air pollutants (PM10, SO2, NO2, NOx, CO, and O3) from 2013 until 2018, were obtained. Adjusted Quasi-Poisson regression models including distributed lags, controlled for climate variables were used for data analysis. Increases in SO2, ozone, PMs, and nitrogen oxides were associated with pneumonia hospitalizations, increases in SO2 NOx and PMs were associated with asthma hospitalizations, and increases in SO2 and ozone were associated with bronchitis hospitalizations. Male hospitalization was related with SO2, ozone, and NOx; while female hospitalization was only related with SO2. This study showed that short-term exposure to air pollution is associated with an increased risk of pneumonia, asthma, and bronchitis hospitalization among children in Bursa.

PM2 .5, PM10 and bronchiolitis severity: A cohort study

BACKGROUND

A few studies suggest that particulate matter (PM) exposure might play a role in bronchiolitis. However, available data are mostly focused on the risk of hospitalization and come from retrospective studies that provided conflicting results. This prospective study investigated the association between PM (PM_2.5 and PM₁₀ ) exposure and the severity of bronchiolitis.

METHODS

This prospective cohort study was conducted between November 2019 and February 2020 at the pediatric emergency department of the Fondazione IRCCS Ca' Ospedale Maggiore Policlinico, Milan, Italy. Infants <1 year of age with bronchiolitis were eligible. The bronchiolitis severity score was assessed in each infant and a nasal swab was collected to detect respiratory viruses. The daily PM₁₀ and PM_2.5 exposure in the 29 preceding days were considered. Adjusted regression models were employed to evaluate the association between the severity score and PM₁₀ and PM_2.5 exposure.

RESULTS

A positive association between the PM_2.5 levels and the severity score was found at day-2 (β 0.0214, 95% CI 0.0011-0.0417, p = .0386), day-5 (β 0.0313, 95% CI 0.0054-0.0572, p = .0179), day-14 (β 0.0284, 95% CI 0.0078-0.0490, p = .0069), day-15 (β 0.0496, 95% CI 0.0242-0.0750, p = .0001) and day-16 (β 0.0327, 95% CI 0.0080-0.0574, p = .0093).Similar figures were observed considering the PM₁₀ exposure and limiting the analyses to infants with respiratory syncytial virus.

CONCLUSION

This study shows for the first time a direct association between PM_2.5 and PM₁₀ levels and the severity of bronchiolitis.

Air Pollutants' Concentrations Are Associated with Increased Number of RSV Hospitalizations in Polish Children

Respiratory syncytial virus (RSV) contributes significantly to pediatric hospitalizations. An association between air pollution and an increased number of RSV cases has been suggested. We sought to evaluate the short-term impact of air pollutants on RSV hospitalizations in Polish children in the period 2010–2019. Daily concentrations of PM₁₀ and PM_2.5 (particulate matter with an aerodynamic diameter less than or equal to 10 μm and 2.5 μm, respectively) and nitrogen dioxide (NO₂) were analyzed in general regression models (GRM) to establish their influence and full interaction scheme. Significant seasonal and annual periodicity among 53,221 hospitalizations was observed; finally, data from the 2012–2019 RSV high-risk seasons created models for seven agglomerations. The addition of PM_2.5, PM₁₀, and NO₂ to the basic model for RSV seasonality explained 23% (4.9–31%, univariate model) to 31.4% (8.4–31%, multivariate model) of the variance in RSV hospitalizations. A 10 μg/m³ increase in PM_2.5, PM₁₀, and NO₂ concentrations was associated with 0.134 (0.087–0.16), 0.097 (0.031–0.087), and 0.212 (0.04–0.29) average increases in hospitalizations, respectively. In the multivariate models, PM_2.5, PM₁₀, and NO₂ alone, as well as PM_2.5–NO₂, PM_2.5–PM₁₀, and PM₁₀–NO₂ interactions, were associated with hospitalizations in some of the locations, while the metaregression showed statistically significant interactions between each of the pollutants, and between the pollutants and the year of the study. The inclusion of PM_2.5, PM₁₀, and NO₂ in GRM explains a significant number of RSV hospitalizations. The pollutants act alone and interact together in a varied manner. Reducing air contamination might decrease the costs of hospital healthcare.

Air quality, Environment and Respiratory Outcomes in Bronchopulmonary Dysplasia, the AERO-BPD cohort study: design and adaptation during the SARS-CoV-2 pandemic

INTRODUCTION

Almost half of all school-age children with bronchopulmonary dysplasia (BPD) have asthma-like symptoms and more suffer from lung function deficits. While air pollution and indoor respiratory irritants are known to affect high-risk populations of children, few studies have objectively evaluated environmental contributions to long-term respiratory morbidity in this population. This study aimed to examine the role of indoor environmental exposures on respiratory morbidity in children with BPD.

METHODS AND ANALYSIS

The Air quality, Environment and Respiratory Ouctomes in BPD (AERO-BPD) study is a prospective, single-centre observational study that will enrol a unique cohort of 240 children with BPD and carefully characterise participants and their indoor home environmental exposures. Measures of indoor air quality constituents will assess the relationship of nitrogen dioxide (NO2), particulate matter (PM2.5), nitric oxide (NO), temperature and humidity, as well as dust concentrations of allergens, with concurrently measured respiratory symptoms and lung function.Adaptations to the research protocol due to the SARS-CoV-2 pandemic included remote home environment and participant assessments.

ETHICS AND DISSEMINATION

Study protocol was approved by the Boston Children's Hospital Committee on Clinical Investigation. Dissemination will be in the form of peer-reviewed publications and participant information products.

TRIAL REGISTRATION NUMBER

NCT04107701.

Exposure to metals and morbidity at eight years follow-up in women of childbearing age

This exploratory study was aimed to investigate the link between toxic metal content in women's urine and their morbidity 2 years before and 6 years after the test. Concentrations of 25 metals in urine were analyzed for 111 pregnant women collected prior to delivery. All women were of Arab-Bedouin origin. Information on primary care and hospital visits during the study period was obtained. In a Poisson regression model, a health outcome was regressed over metal exposure and other factors. A Weighted Quantile Sum Regression (WQS) approach was used to indicate metals dominating in their possible impact on women's morbidity. Obesity was the most frequently diagnosed condition in this population (27.9%). Diagnoses in a neurological category accounted for 36.0%, asthma or respiratory-25.2%, psychiatric-12.6%, cardiovascular-14.4% and cancer or benign growth-for 13.5%. Based on WQS analysis, cancer and benign growth were mostly attributed to the increased levels of cadmium, cardiovascular outcomes were linked with lead, and obesity was found associated with elevated levels of nickel. Hematological, neurological and respiratory outcomes were attributed to multiple non-essential metals. The health and exposure profile of women in the study warrants a periodic biomonitoring in attempt to identify and reduce exposure to potentially dangerous elements.

The effect of exposure to particulate matter during pregnancy on lower respiratory tract infection hospitalizations during first year of life

BACKGROUND

Lower respiratory tract infections (LRTI) in early life, including pneumonia, bronchitis and bronchiolitis, can lead to decreased lung function, persistent lung damage and increased susceptibility to various respiratory diseases such as asthma. In-utero exposure to particulate matter (PM) during pregnancy may disrupt biological mechanisms that regulate fetal growth, maturation and development. We aimed to estimate the association between intrauterine exposure to PM of size < 2.5 μm in diameter (PM_2.5) and incidence of LRTIs during the first year of life.

METHODS

A retrospective population-based cohort study in a population of mothers and infants born in Soroka University Medical Center (SUMC) in the years 2004-2012. All infants < 1 year old that were hospitalized due to LRTIs were included. The main exposure assessment was based on a hybrid model incorporating daily satellite-based predictions at 1 km² spatial resolution. Data from monitoring stations was used for imputation of main exposure and other pollutants. Levels of environmental exposures were assigned to subjects based on their residential addresses and averaged for each trimester. Analysis was conducted by a multivariable generalized estimating equation (GEE) Poisson regression. Data was analyzed separately for the two main ethnic groups in the region, Jewish and Arab-Bedouin.

RESULTS

The study cohort included 57,331 deliveries that met the inclusion criteria. Overall, 1871 hospitalizations of infants < 1 year old due to pneumonia or bronchiolitis were documented. In a multivariable analysis, intrauterine exposure to high levels of PM_2.5 (> 24 μg/m³) in the first and second trimesters was found to be adversely associated with LRTIs in the Arab-Bedouin population (1st trimester, RR = 1.31, CI 95% 1.08-1.60; 2nd trimester: RR = 1.34, CI 95% 1.09-1.66).

CONCLUSION

Intrauterine exposure to high levels of PM_2.5 is associated with a higher risk of hospitalizations due to lower respiratory tract infections in Arab-Bedouin infants.

Effects of short-term fine particulate matter exposure on acute respiratory infection in children

BACKGROUND

Previous studies on the association between fine particulate matter (PM_2.5) exposure and acute respiratory infection in children are scarce and present inconsistent results. We estimated the association between short-term PM_2.5 exposure and acute respiratory infection among children aged 0-4 years using a difference-in-differences approach.

METHODS

We used data on the daily PM_2.5 concentrations, hospital admissions for acute respiratory infection, and meteorological factors of the 15 regions in the Republic of Korea (2013-2015). To estimate the cumulative effects, we used a difference-in-differences approach generalized to multiple spatial units (regions) and time periods (day) with distributed lag non-linear models.

RESULTS

With PM_2.5 levels of 20.0 μg/m³ as a reference, PM_2.5 levels of 30.0 μg/m³ were positively associated with the risk of acute upper respiratory infection (relative risk (RR) = 1.048, 95% confidence interval (CI): 1.028, 1.069) and bronchitis or bronchiolitis (RR = 1.060, 95% CI: 1.038, 1.082) but not with the risk of acute lower respiratory infection and pneumonia. PM_2.5 levels of 40.0 μg/m³ were also positively associated with the risk of acute upper respiratory infection (RR = 1.083, 95% CI: 1.046, 1.122) and bronchitis or bronchiolitis (RR = 1.094, 95% CI: 1.054, 1.136).

CONCLUSIONS

We found the associations of short-term PM_2.5 exposure with acute upper respiratory infection and bronchitis or bronchiolitis among children aged 0-4 years. As causal inference methods can provide more convincing evidence of the effects of PM_2.5 levels on respiratory infections, public health policies and guidelines regarding PM_2.5 need to be strengthened accordingly.

[Urban air pollution and hospital admissions for asthma and acute respiratory disease in Murcia city (Spain)]

INTRODUCTION

Urban air pollution is a major threat to child and adolescent health. Children are more vulnerable to its effects, being associated with higher morbidity and mortality due to acute and chronic diseases, especially respiratory ones. A study is performed on the relationship between urban air pollution and the rate of hospital admissions due to acute respiratory diseases.

PATIENTS AND METHODS

An ecological study was conducted on young people under 17 years-old in the city of Murcia, who had visited hospital emergency departments due to respiratory diseases (ICD-9) during 2015. A logistic regression was performed on the risk of hospital admission that included consultations in relation to the average daily levels of environmental pollutants (NO₂, O₃, PM10, SO₂) obtained from the Air Quality Surveillance and Control network of the Region of Murcia. Other control variables, such as gender, age, average daily ambient temperature, and season of the year.

RESULTS

A total of 12,354 (56% boys and 44% girls) children consulted in the emergency department for respiratory disease. Of those, 3.5% were admitted, with a mean age of 2.54 (95% CI; 2.16-2.91) years. The odds ratio (OR) of hospital admission for respiratory diseases: NO₂ 1.02 (95% CI; 1.01-1.04; P<.01), O₃ 1.01 (95% CI; 1.00-1.03; P<.01) male 1.4 (95% CI 1.11-1.79; P<.01) and winter 2.10 (95% CI 1.40-3.21; P<.01). Admissions for asthma: PM10 1.02 (95% CI; 1.01-1.04; P<.05), O₃ 1.04 (95% CI; 1.01-1.06; P<.01). Admissions for bronchiolitis: Age 0.69 (95% CI; 0.48-0.99; P<.05); NO₂ 1.03 (95% CI; 1.01-1.05; P<.01).

CONCLUSIONS

Urban air pollution increases hospital admissions in children due to acute respiratory diseases, especially asthma and bronchiolitis. Implementing preventive measures, expanding time series and collaborative studies with open data, would help improve public health and air quality in the cities.

The association between climate, geography and respiratory syncitial virus hospitalizations among children in Ontario, Canada: a population-based study

Background

Respiratory syncytial virus (RSV) infection is a major cause of hospitalization in young children in Canada, despite routine immunoprophylaxis in those with medical risk factors. We aimed to determine if cold temperatures are associated with RSV hospitalization.

Methods

We conducted a population-based nested case–control study of children in Ontario, Canada, using health administrative data. We compared children hospitalized for RSV between September 1, 2011 and August 31, 2012 to age and sex matched controls. We used multivariable logistic regression to identify associations between minimum daily temperature and RSV hospitalizations with adjustment for sociodemographic and environmental factors.

Results

We identified 1670 children with RSV hospitalizations during the study period and 6680 matched controls. Warmer temperatures (OR = 0.94, 95%CI: 0.93, 0.95) were associated with lower odds of RSV hospitalization. Southern ecozone (OR = 1.6, 95%CI: 1.2, 2.1), increased ozone concentration (OR = 1.03, 95%CI: 1.01, 1.06) and living in a lower income neighbourhood (OR = 1.3, 95%CI: 1.1, 1.5) significantly increased the odds of RSV hospitalization, as did living in a household with a larger number of siblings in a sub-cohort of children (OR = 1.34, 95%CI: 1.26, 1.41).

Conclusions

In Ontario, the likelihood of having an RSV hospitalization is associated with colder temperature exposures and socioeconomic factors.

Ambient Air Pollution and Daily Hospital Admissions for Respiratory Disease in Children in Guiyang, China

Objectives: To investigate the association between ambient air pollutant exposure and daily hospital admissions for respiratory diseases in children in Guiyang. Methods: Clinical data of pediatric inpatients with respiratory disease from 2009 to 2016 in Guizhou Provincial People's Hospital and PM2.5, NO₂, PM10, and SO₂ concentration data were retrieved. A canonical correlation analysis (CCA) was applied to analyse the association between air pollutants and daily hospital admissions for respiratory diseases. A reproducibility analysis was applied to analyse the association between air pollution and the duration and direct cost of hospitalization. The support vector regression (SVR) method was applied to determine whether air pollution data could predict the daily hospital admissions for the upcoming day. Results: A total of 10,876 inpatients with respiratory diseases were included between January 1, 2009 and December 31, 2016. The CCA showed significant correlations between air pollution and daily hospital admissions (r = 0.3564, p < 0.001), the duration of hospitalization (r = 0.2911, p < 0.001) and the economic cost of hospitalization (r = 0.2933, p < 0.001) for respiratory disease. PM10 contributed most to daily hospital admissions for respiratory disease; the concentration the day before hospitalization contributed most to the daily hospital admissions for respiratory disease. There was a slightly stronger correlation between air pollution and respiratory disease in children aged 2-18 years (R = 0.36 vs. R = 0.31 in those under 2 years old). No significant difference was found between male and female patients. The prediction analysis showed that air pollution could successfully predict daily pediatric inpatient hospital admissions (R = 0.378, permutation p < 0.001). Conclusions: Air pollution was significantly associated with hospital admissions, hospitalization duration and the economic cost of hospitalization in children with respiratory diseases. The maximum effect occurred on the day before hospitalization. The effect of PM10 on daily pediatric inpatient hospital admissions for respiratory disease was the greatest among the pollutants evaluated.

Spatiotemporal patterns of PM10 concentrations over China during 2005-2016: A satellite-based estimation using the random forests approach

BACKGROUND

Few studies have estimated historical exposures to PM₁₀ at a national scale in China using satellite-based aerosol optical depth (AOD). Also, long-term trends have not been investigated.

OBJECTIVES

In this study, daily concentrations of PM₁₀ over China during the past 12 years were estimated with the most recent ground monitoring data, AOD, land use information, weather data and a machine learning approach.

METHODS

Daily measurements of PM₁₀ during 2014-2016 were collected from 1479 sites in China. Two types of Moderate Resolution Imaging Spectroradiometer (MODIS) AOD data, land use information, and weather data were downloaded and merged. A random forests model (non-parametric machine learning algorithms) and two traditional regression models were developed and their predictive abilities were compared. The best model was applied to estimate daily concentrations of PM₁₀ across China during 2005-2016 at 0.1⁰ (≈10 km).

RESULTS

Cross-validation showed our random forests model explained 78% of daily variability of PM₁₀ [root mean squared prediction error (RMSE) = 31.5 μg/m³]. When aggregated into monthly and annual averages, the models captured 82% (RMSE = 19.3 μg/m³) and 81% (RMSE = 14.4 μg/m³) of the variability. The random forests model showed much higher predictive ability and lower bias than the other two regression models. Based on the predictions of random forests model, around one-third of China experienced with PM₁₀ pollution exceeding Grade Ⅱ National Ambient Air Quality Standard (>70 μg/m³) in China during the past 12 years. The highest levels of estimated PM₁₀ were present in the Taklamakan Desert of Xinjiang and Beijing-Tianjin metropolitan region, while the lowest were observed in Tibet, Yunnan and Hainan. Overall, the PM₁₀ level in China peaked in 2006 and 2007, and declined since 2008.

CONCLUSIONS

This is the first study to estimate historical PM₁₀ pollution using satellite-based AOD data in China with random forests model. The results can be applied to investigate the long-term health effects of PM₁₀ in China.

PM10 exposure is associated with increased hospitalizations for respiratory syncytial virus bronchiolitis among infants in Lombardy, Italy

Respiratory syncytial virus (RSV) is the primary cause of acute lower respiratory infections in children, bronchiolitis in particular. Airborne particulate matter (PM) may influence the children's immune system and foster the spread of RSV infection. We aimed to verify whether PM10 exposure is associated with hospitalization due to RSV bronchiolitis. We selected hospital discharge records (HRD) with ICD-9-CM code 466.11 of infants < 1 year of age, occurring in the epidemic seasons of two years (2012-2013) in Lombardy, Italy. Cases were assigned daily PM10 and apparent temperature levels of the capital city of their residential province. Different exposure windows were considered: single days preceding hospitalization (lag 0 to 30), their average estimates (lag 0-1 to 0-30), and the four weeks preceding hospitalization (week 1 to 4). Negative binomial regression models adjusted for apparent temperature and season were applied to the daily counts of hospitalizations in each province. Results were expressed as incidence rate ratios (IRR) and 95% confidence intervals (95%CI) per 10 µg/m³ increase in PM10 concentration. Random effects meta-analyses of province-specific IRR were performed to obtain regional estimates. 2814 HRD met our inclusion criteria; males represented about 55% of the cases. A 6% increased risk of hospitalization (95%CI: 1.03-1.10) was found at lag 0 and an almost overlapping 7% increase at lag 1. IRR ranged from 1.03 to 1.05 between lags 2 and 11. No increased risk was observed from lag 12. When considering averaged daily lags, risk estimates gradually increased in the two weeks preceding hospitalization from 1.08 (1.04-1.12) at lag 0-1 to 1.15 (1.08-1.23) between lags 0-11 and 0-13. Analyses on weekly lags showed a risk increase of 6% (1.01-1.12) during week 1 and of 7% (1.02-1.13) during week 2. Our study found a clear association between short- and medium-term PM10 exposures and increased risk of hospitalization due to RSV bronchiolitis among infants.

Respiratory virus prophylaxis in congenital heart disease

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections and causes up to 200,000 infant deaths a year worldwide. The average rate of hospitalization for severe RSV infection is 5 per 1000 children, and the rate is three-times higher in those with congenital heart disease (CHD). Palivizumab, a monoclonal antibody, reduces hospitalization rates and intensive care admissions. It is used prophylactically and is administered as monthly doses during the RSV season. Hemodynamically unstable CHD is the most susceptible CHD to a severe episode of RSV infection. This review explores current evidence surrounding therapies, patterns of infection and identifies groups which may still be vulnerable to severe RSV infection.