The September epidemic of asthma in Israel

Unforeseen changes in seasonality of pediatric respiratory illnesses during the first COVID-19 pandemic year

OBJECTIVES

To investigate whether the three nationwide coronavirus disease 2019 (COVID-19) lockdowns imposed in Israel during the full first pandemic year altered the traditional seasonality of pediatric respiratory healthcare utilization.

METHODS

Month by month pediatric emergency department (ED) visits and hospitalizations for respiratory diagnoses during the first full COVID-19 year were compared to those recorded for the six consecutive years preceding the pandemic. Data were collected from the patients' electronic files by utilizing a data extraction platform (MDClone^© ).

RESULTS

A significant decline of 40% in respiratory ED visits and 54%-73% in respiratory hospitalizations during the first COVID-19 year compared with the pre-COVID-19 years were observed (p < 0.001 and p < 0.001, respectively). The rate of respiratory ED visits out of the total monthly visits, mostly for asthma, peaked during June 2020, compared with proceeding years (109 [5.9%] versus 88 [3.9%] visits; p < 0.001). This peak occurred 2 weeks after the lifting of the first lockdown, resembling the "back-to-school asthma" phenomenon of September.

CONCLUSIONS

This study demonstrates important changes in the seasonality of pediatric respiratory illnesses during the first COVID-19 year, including a new "back-from-lockdown" asthma peak. These dramatic changes along with the recent resurgence of respiratory diseases may indicate the beginnings of altered seasonality in pediatric pulmonary pathologies as collateral damage of the pandemic.

Emergency department visits and hospitalisations for asthma, COPD and respiratory tract infections: what is the role of respiratory viruses, and return to school in September, January and March?

Background

Asthma exacerbations increase in September coinciding with children returning to school. The aim of this study was to investigate whether this occurs 1) for COPD and respiratory tract infections (RTIs); 2) after school resumes in January and March; and 3) identify which viruses may be responsible.

Methods

Emergency department (ED) visits and admissions for asthma, COPD and RTIs and the prevalence of viruses in Ontario, Canada were analysed daily between 2003 and 2013. ED visits and admissions were provided by the Canadian Institute for Health Information. Viral prevalence was obtained from the Centre for Immunisation and Respiratory Infectious Diseases.

Results

ED visits and admissions rates demonstrated a biphasic pattern. Lowest rates occurred in July and August and the highest rates in September for asthma, and after December for COPD and RTI. The increase in rates for 30 days before and after school return in September was greatest for children with asthma <15 years (2.4–2.6×). Event rates fell after school return in January for all three conditions ranging from 10–25%, and no change followed March break for asthma and COPD. Human rhinovirus was prevalent in summer with a modest relationship to asthma rates in September. The prevalence of respiratory syncytial virus, influenza A and coronavirus was associated with sustained event rates for COPD and RTIs.

Conclusions

Asthma, COPD and RTIs increase in September but do not occur after return to school in January and March. Human rhinovirus is associated with ED visits and admissions only in September.

Asthma, COPD and RTIs increase in September but do not occur after return to school in January and March. Human RV is associated with ED visits and admissions only in September.https://bit.ly/3jEy168

Association between Ambient Air Pollution and Hospital Length of Stay among Children with Asthma in South Texas

Although hospital length of stay (LOS) has been identified as a proxy measure of healthcare expenditures in the United States, there are limited studies investigating the potentially important association between outdoor air pollution and LOS for pediatric asthma. This study aims to examine the effect of ambient air pollution on LOS among children with asthma in South Texas. It included retrospective data on 711 children aged 5–18 years old admitted for asthma to a pediatric tertiary care hospital in South Texas between 2010 and 2014. Air pollution data including particulate matter (PM_2.5) and ozone were collected from the U.S. Centers for Disease Control and Prevention. The multivariate binomial logistic regression analyses were performed to determine the association between each air pollutant and LOS, controlling for confounders. The regression models showed the increased ozone level was significantly associated with prolonged LOS in the single- and two-pollutant models (p < 0.05). Furthermore, in the age-stratified models, PM_2.5 was positively associated with LOS among children aged 5–11 years old (p < 0.05). In conclusion, this study revealed a concerning association between ambient air pollution and LOS for pediatric asthma in South Texas.

Incidence of respiratory viral infections and associated factors among children attending a public kindergarten in Taipei City

BACKGROUND

Kindergarteners frequently encounter various infectious diseases, so surveillance of viral infectious diseases would provide information for their health promotion.

METHODS

We enrolled kindergarten attendees, age 2-5 years, during the academic years of 2006 and 2007 in a Taipei City kindergarten. Daily monitoring of illness and regular biweekly physical examinations were undertaken. Multiple infections were defined as one child having two or more laboratory-confirmed viral infections with different viruses or different serotypes during one academic year.

RESULTS

The overall laboratory-confirmed incidence rate of respiratory viral infection was 239 per 100 person-years in the 2006 academic year and 136 per 100 person-years in the 2007 academic year. The attack rate for seasonal influenza was 17% in the 2006 academic year and 27% in the 2007 academic year. Boys and children with allergies had significantly higher risks to get multiple viral infections [odds ratio (OR) 1.81, 95% confidence interval (CI) 1.20-2.75; OR 1.56, 95% CI 1.00-2.39, respectively]. Boys also tended to get enterovirus infections (OR 1.56, 95% CI 1.02-2.38) while children with allergies tended to acquire adenovirus infections (OR 1.71, 95% CI 1.12-2.66).

CONCLUSION

Boys and children with allergies were more susceptible to multiple viral infections, so they should be more cautious about viral infections.

Fatal asthma; is it still an epidemic?

BACKGROUND

Asthma mortality has declined since the 1980s. Nevertheless the World Health Organization (WHO) identified asthma as responsible for 225.000 deaths worldwide in 2005, and 430.000 fatal cases are expected by 2030. Some unexpected and concentrated fatal asthma events all occurred between 2013 and 2015 in Veneto, a North Eastern region of Italy, which prompted a more in-depth investigation of characteristics and risk factors.

METHODS

A web search including key words related to fatal asthma in Italy between 2013 and 2015 has been performed. Concerning the cases that occurred in Veneto, subjects' clinical records have been evaluated and details about concomitant weather conditions, pollutants and pollen count have been collected.

RESULTS

Twenty-three cases of asthma deaths were found in Italy; 16 of them (69%) occurred in the Veneto Region. A prevalence of male and young age was observed. Most of patients were atopic, died in the night-time hours and during the weekends. The possible risk factors identified were the sensitization to alternaria, previous near fatal asthma attacks and the incorrect treatment of the disease. Weather condition did not appear to be related to the fatal exacerbations, whereas among the pollutants only ozone was detected over the accepted limits. Smoking habits, possible drug abuse and concomitant complementary therapies might be regarded as further risk factors.

DISCUSSION

Although not free from potential biases, our web search and further investigations highlight an increasing asthma mortality trend, similarly to what other observatories report. The analysis of available clinical data suggests that the lack of treatment more than a severe asthma phenotype characterizes the fatal events.

CONCLUSIONS

Asthma mortality still represents a critical issue in the management of the disease, particularly in youngsters. Once more the inadequate treatment and the lack of adherence seem to be not only related to the uncontrolled asthma but also to asthma mortality.

The Annual September Peak in Asthma Exacerbation Rates. Still a Reality?

RATIONALE

Recent research suggests that the asthma epidemic observed in the 1980s and 1990s has stabilized. Changing trends in asthma may have an impact on the well-reported global phenomenon of the "asthma September peak." The 38th week of the year has been identified as the peak time for asthma exacerbations among children.

OBJECTIVES

The purposes of this study were to examine the longitudinal trend of the September peak and to see if it changed over time, differed by age groups, or varied across different geographical regions.

METHODS

Monthly rates of asthma emergency department (ED) and physician outpatient visits were calculated using data provided by the Ontario Asthma Surveillance Information System from 2003 to 2013 for patients of all ages. The Ontario Asthma Surveillance Information System is a population-based surveillance system with over 2 million individuals with asthma. Age-specific rates were calculated using the prevalent asthma population-asthma individuals with at least one health service claim for asthma in the respective year-as the denominator. Rates were stratified by age group and region of residence. Spatial relationships within the province were tested to examine if the September peak was more prominent in certain regions of Ontario.

MEASUREMENTS AND MAIN RESULTS

The highest September peak in ED visits was observed in 2005 for children aged 0-4 years and 5-9 years (18.35 and 8.11 per 1,000 asthma prevalence, respectively). The rate of asthma ED visits of all children was consistently highest in September; however, the spike became marginally less pronounced over time. Since 2005, there has been a 51.7% decrease in the September asthma ED visit rate for all age groups. Monthly physician visits for all age groups usually peaked in October, roughly 4 weeks following the peak in ED visits. Analysis by residence showed that rates throughout Ontario were higher in September than in other months, suggesting that the spike was widespread rather than localized.

CONCLUSIONS

While the magnitude of the September peak has decreased over time, the asthma ED visit rate remains significantly higher in September than in other months. Physician visits are also highest in the fall. These findings stress the importance of empowering children and families to maintain good asthma control throughout the year, including hand washing, to minimize respiratory viral infections in September.

Respiratory virus transmission dynamics determine timing of asthma exacerbation peaks: Evidence from a population-level model

Asthma exacerbations exhibit a consistent annual pattern, closely mirroring the school calendar. Although respiratory viruses--the "common cold" viruses--are implicated as a principal cause, there is little evidence to link viral prevalence to seasonal differences in risk. We jointly fit a common cold transmission model and a model of biological and environmental exacerbation triggers to estimate effects on hospitalization risk. Asthma hospitalization rate, influenza prevalence, and air quality measures are available, but common cold circulation is not; therefore, we generate estimates of viral prevalence using a transmission model. Our deterministic multivirus transmission model includes transmission rates that vary when school is closed. We jointly fit the two models to 7 y of daily asthma hospitalizations in adults and children (66,000 events) in eight metropolitan areas. For children, we find that daily viral prevalence is the strongest predictor of asthma hospitalizations, with transmission reduced by 45% (95% credible interval =41-49%) during school closures. We detect a transient period of nonspecific immunity between infections lasting 19 (17-21) d. For adults, hospitalizations are more variable, with influenza driving wintertime peaks. Neither particulate matter nor ozone was an important predictor, perhaps because of the large geographic area of the populations. The school calendar clearly and predictably drives seasonal variation in common cold prevalence, which results in the "back-to-school" asthma exacerbation pattern seen in children and indirectly contributes to exacerbation risk in adults. This study provides a framework for anticipating the seasonal dynamics of common colds and the associated risks for asthmatics.

Absence of back to school peaks in human rhinovirus detections and respiratory symptoms in a cohort of children with asthma

Much of what is known about the seasonality of human rhinovirus (hRV) infections has been learned from the study of acute asthma exacerbations presenting to emergency care, including those among children at the start of the school term. Much less is known about the patterns of hRVs in the community. In this study, viruses and day-to-day symptoms of asthma and colds were monitored twice weekly in 67 children with asthma aged 5-12 years, over a 15 month period in Sydney, Australia. Overall hRV was detected in 314/1232 (25.5%) of nasal wash samples and 142/1231 (11.5%) of exhaled breath samples; of these, 231 and 24 respectively were genotyped. HRVs were detected with similar prevalence rate throughout the year, including no peak in hRV prevalence following return to school. No peaks were seen in asthma and cold symptoms using twice-weekly diary records. However, over the same period in the community, there were peaks in asthma emergency visits both at a large local hospital and in state-wide hospitalizations, following both return to school (February) and in late autumn (May) in children of the same age. This study suggests that hRV infections are common throughout the year among children, and differences in virus prevalence alone may not account for peaks in asthma symptoms.

Back-to-school upper respiratory infection in preschool and primary school-age children in Israel

BACKGROUND

Increased upper respiratory infection (URI) among children at the beginning of school year is well known to parents and pediatricians. However, this phenomenon is not well documented or characterized.

METHODS

Computerized datasets from a large health maintenance organization in Israel were used to calculate the weekly rates of URI among children 3-14 years old for the years 2007-2012. In addition, nasopharyngeal swabs were collected in 2010-2012 from children with URI symptoms and controls during school opening time. Swabs were tested by real-time polymerase chain reaction for the presence of respiratory viruses.

RESULTS

Time-series analysis demonstrated a peak of URI in September each year. The peaks reached their height 2 weeks after school opening and returned to baseline within 4-7 weeks. The main 3 viruses detected both in URI patients and in healthy controls during the first weeks of school opening were rhinovirus, adenovirus and enterovirus. The detection rate of any respiratory virus, and of rhinovirus in particular, was significantly higher among cases than among controls (54% vs. 16%, P < 0.001 for any virus, and 35% vs. 6.0%, P < 0.01 for rhinovirus). When adjusting for age and sex cases had 5.8 times more viral detection when compared with controls. Upper respiratory symptoms were significantly more prevalent among the virus-positive cases when compared with negative ones.

CONCLUSIONS

Back-to-school illness consisting of URI has a distinct epidemiological pattern demonstrating a rapid rise peaking within 2 weeks of school opening and is associated predominantly with rhinovirus.

Seasonal changes in prescribing of long-acting beta-2-agonists-containing drugs

BACKGROUND

For patients with asthma, COPD, or asthma-COPD overlap syndrome (ACOS), inter-country comparisons of seasonal changes in drug prescriptions are scarce or missing. Hence, we aimed to compare seasonal changes in prescription rates of long-acting beta-2-agonist (LABA) in four European countries.

METHODS

A common study protocol was applied to six health care databases (Germany, Spain, the Netherlands (2), and the UK (2)) to calculate age- and sex-standardized point prevalence rates (PPRs) of LABA-containing prescriptions by the 1st of March, June, September, and December of each year during the study period 2002-2009. Seasonal variation of PPRs was quantified using seasonal indexes (SIs; based on the ratio-to-moving-average-method) and SIs averaged over the study period (aSI) stratified by sex, age, and indication (asthma, COPD, or ACOS).

RESULTS

There was a moderate seasonal change in LABA-containing prescriptions which was more pronounced in asthma or COPD patients compared to ACOS patients. For asthma and ACOS patients, highest seasonal variation was found for patients living in Spain (aSI: 87.3-110.7, aSI: 93.2-103.1) whereas for COPD highest seasonal variation was revealed for the NPCRD database (the Netherlands) (aSI: 92.2-105.6). Regarding age and sex, highest seasonal variation was found in Spanish boys under 10 years of age having a diagnosis of asthma.

CONCLUSIONS

By applying a common analysis in six databases, we could observe moderate overall seasonal changes in LABA-containing prescription rates in patients with asthma, COPD, or ACOS.

Seasonality of asthma: a retrospective population study

OBJECTIVES

Seasonal variations in asthma are widely recognized, with the highest incidence during September. This retrospective population study aimed to investigate whether this holds true in a large group of asthmatic children in primary care and to assess the impact of age, gender, urban/rural living, and population sector.

METHODS

The key study outcomes were the diagnosis of asthma exacerbations and asthma medication prescriptions, recorded by family physicians during 2005 to 2009. These were analyzed by "week of diagnosis" in Clalit Health Services' electronic medical record database. Regression models were built to assess relative strength of secular trends, seasonality, and age-group in explaining the incidence of asthma exacerbations.

RESULTS

A total of 919,873 children aged 2 to 15 years were identified. Of these, 82,234 (8.9%) were asthmatic, 61.6% boys and 38.4% girls; 49.1% aged 2 to 5 years, 24.1% 6 to 9 years, and 26.8% 10 to 15 years. We observed a 2.01-fold increase in pediatric asthma exacerbations and 2.28-fold increase in prescriptions of asthma bronchodilator medications during September (weeks 37-39 vs weeks 34-36) compared with August. The association between the opening of school and the incidence of asthma-related visits to the primary care physician was greatest in children aged 2 to 5 years (odds ratio, 2.15) and 6 to 11 years (1.90-fold). Adolescents (age 12-15 years) had a lesser peak (1.81-fold). In late fall there was a second rise, lasting with fluctuations throughout winter, with a trough in summer.

CONCLUSIONS

Returning to school after summer is strongly associated with an increased risk for asthma exacerbations and unscheduled visits to the primary care physician.

The effect of seasonality on sleep-disordered breathing severity in children

OBJECTIVE

Sleep-disordered breathing (SDB) is a common disorder associated with substantial morbidity that occurs in otherwise healthy children. Atopy, asthma, and viral upper respiratory tract infections are known risk factors for pediatric SDB that exhibit seasonal variability. The aim of our study was to investigate the effect of seasonality on SDB severity in children and adolescents referred for polysomnographic evaluation for suspected SDB and to examine the effect of atopy/asthma on this variability.

METHODS

The medical records of all children and adolescents referred for a polysomnography (PSG) for suspected SDB between 2008 and 2010 were retrospectively assessed for seasonal patterns. The effect of atopy/asthma, age, and obesity on seasonal variability was investigated.

RESULTS

A total of 2178 children and adolescents (65% boys) were included. The mean age of the cohort was 4.9±3.5 years (range, 3 months-18 years). Eighteen percent of patients had a history of asthma/atopy. The mean obstructive apnea-hypopnea index (OAHI) in the winter was significantly higher compared to the summer (9.1±9.6 vs. 7.5±7.0; P=.01; Cohen d=0.19), particularly in children younger than the age of 5 years (10.2±10.5 vs. 7.9±7.3; P=.008; Cohen d=0.25). Asthma/atopy had no significant effect on seasonal variability.

CONCLUSIONS

SDB severity alters in a season-dependent manner in children and adolescents referred for polysomnographic evaluation for suspected SDB. These alterations are more prominent in children younger than the age of 5 years. The presence of asthma/atopy does not contribute to this seasonal variability. These findings suggest that viral respiratory infections are most likely the major contributor for the seasonal variability observed in pediatric SDB; additionally, the time of the year when a child is evaluated for suspected SDB may affect the clinical management and outcome in borderline cases.

Correlations between clinical illness, respiratory virus infections and climate factors in a tropical paediatric population

Weekly (August 2003-December 2008) numbers of five common paediatric diseases and the incidence of respiratory viruses were obtained from a children's hospital in Singapore and correlated with climate data using multivariate time-series techniques. Upper respiratory tract infections were positively correlated with the incidences of influenza A, B, respiratory syncytial virus (RSV) and parainfluenza viruses (types 1-3 combined). Lower respiratory tract infections were positively correlated with only the incidence of RSV. Both upper and lower respiratory tract infections were negatively correlated with relative humidity. Asthma admissions were negatively correlated with maximum temperature and positively correlated with the incidence of influenza B and increasing hours of sunshine. Although sporadic cases of adenovirus infection were identified, not enough cases were available for a more detailed analysis. Gastroenteritis and urinary tract infections, included as control diseases, were not correlated significantly with any climate parameters. These correlations are compatible with current understanding of respiratory virus survival under certain climate conditions and may assist the prediction of disease burdens and hospital resource planning in such tropical environments.

A modern miasma hypothesis and back-to-school asthma exacerbations

A sudden increase in the rate of asthma exacerbations has been observed among young children in many countries 2-3 weeks after their return-to-school following the summer holidays. These exacerbations are frequently associated with human rhinovirus (hRV) infections, with possible interactions with allergen sensitisation, allergen exposure and medication use. It was originally proposed that the sudden increase resulted from new strains of respiratory viruses acquired during the holidays spreading rapidly on return to school. While there is compelling evidence implicating hRV in these exacerbations, recent observations on virus transmission, infection patterns and immune responses to both viruses and allergens have led us to propose an additional hypothesis for this increase in exacerbations. We propose that classrooms typically provide persistent exposure to a mixture of airborne viruses, viral proteins, endotoxin, community allergens and other human-derived aerosols - a modern miasma. During the preceding school term, this exposure establishes and maintains a level of immune tolerance and herd immunity, which then declines during the two-month holidays due to lack of such exposure, creating a transitory window of susceptibility to viral infections and asthma. The return to school re-establishes exposure to these aerosols resulting in an acceleration of exacerbations, until the tolerance and herd immunity are re-established. Thus, the peak in return-to-school asthma is more a function of a transitory increase in susceptibility due to a temporary lack of this complex exposure, than it is to novel, locally endemic strains of hRV.