Increased risk of allergy associated with the use of kerosene fuel in the home

Relations of mold, stove, and fragrance products on childhood wheezing and asthma: A prospective cohort study from the Japan Environment and Children's Study

This prospective cohort study aimed to examine the associations between mold growth, type of stoves, and fragrance materials and early childhood wheezing and asthma, using data from the Japan Environment and Children's Study. Mold growth at home, usage of kerosene/gas stove, wood stove/fireplace, and air freshener/deodorizer were surveyed using a questionnaire at 1.5-year-old, and childhood wheezing and doctor-diagnosed asthma during the previous year were obtained using a 3-year-old questionnaire. Multilevel logistic regression analysis was performed to evaluate the association between exposure to childhood wheezing and asthma. A total of 60 529 children were included in the analysis. In multivariate analyses, mold growth and wood stove/fireplace had significantly higher odds ratios (ORs) for wheezing (mold growth: 1.13; 95% CI, 1.06-1.22; wood stove/fireplace: 1.23; 95% CI, 1.03-1.46). All four exposures had no significant ORs for childhood doctor-diagnosed asthma; however, in the supplemental analysis of northern regions, wood stove/fireplace had a significantly higher OR for asthma. Mold growth and wood stove/fireplace had significant associations with childhood wheezing in the northern regions. Mold elimination in the dwellings and use of clean heating (no air pollution emissions) should be taken into consideration to prevent and improve childhood wheezing and asthma.

Secular trends of atopic dermatitis and its comorbidities in United States children between 1997 and 2018

Previous studies found increased prevalence of childhood atopic dermatitis (AD) in the United States over the past few decades. It is unknown whether the prevalence of AD has plateaued or whether AD comorbidities changed over time. The main objective of this study is to assess the prevalence and secular trends of AD and its comorbidities. We analyzed data on 259,818 children, ages 0 to 17 years, from the National Health Interview Survey, 1997-2018, using logistic regression models. The prevalence (95% confidence interval) of childhood AD steadily increased from 2000 [7.3% (6.8-7.9%)] to 2011 [12.8% (12.1-13.5%)] and remained consistent until 2018 [12.6% (11.6-13.5%)]. In logistic regression models, the odds of AD were significantly increased in all years from 2003 to 2018 compared to 1997. However, the increased odds of AD over time were attenuated when adjusting for socio-demographic factors. AD prevalence increased in most socio-demographic groups, but changed variably by age group, race/ethnicity, and region. There were significant trends of AD comorbidities over time, with increasing prevalence of attention deficit (hyperactivity) disorder, and decreasing prevalence of hay fever and depression/sadness. AD prevalence in US children increased between 1997 and 2011, remaining consistent until 2018 with an overall increase of 59%. Prevalence of comorbid hay fever and sadness/depression decreased, while ADD/ADHD increased. Given divergent trends of AD prevalence by socio-demographic characteristics, future studies are better equipped to identify contributing factors of prevalence change.

The global, regional, and national burden of atopic dermatitis in 195 countries and territories: An ecological study from the Global Burden of Disease Study 2017

Introduction

Numerous population-based studies have focused on the global prevalence of atopic dermatitis (AD), but there are few studies on the global trends of the burden associated with AD.

Methods

We analyzed the global AD trends in 2017 in 195 countries worldwide using the Global Burden of Disease (GBD) Study database, including prevalence rates, age and sex patterns, and AD burden, using disability-adjusted life years (DALYs). Age-standardized DALYs were also compared to the sociodemographic index values of all the countries in 2017.

Results

The age-specific DALYs in 2017 showed a right-skewed distribution, with the highest DALYs between 1 and 5 years of age. Females had a higher burden of AD throughout all age groups and geographic regions. The GBD super region with the greatest burden of DALYs caused by AD was high income (178.63 DALYs per 100,000 males, 231.8 for females), and the country with the highest DALYs was Sweden (326.91). The GBD super region with the lowest age-standardized DALY burden caused by AD was south Asia (84.51 DALYs per 100,000 males, 100.54 for females).

Conclusion

There is a large GBD caused by AD. The observed burden is the greatest in resource-rich countries, females, and young children.

Adverse health impacts of cooking with kerosene: A multi-country analysis within the Prospective Urban and Rural Epidemiology Study

BACKGROUND

Kerosene, which was until recently considered a relatively clean household fuel, is still widely used in low- and middle-income countries for cooking and lighting. However, there is little data on its health effects. We examined cardiorespiratory effects and mortality in households using kerosene as their primary cooking fuel within the Prospective Urban Rural Epidemiology (PURE) study.

METHODS

We analyzed baseline and follow-up data on 31,490 individuals from 154 communities in China, India, South Africa, and Tanzania where there was at least 10% kerosene use for cooking at baseline. Baseline comorbidities and health outcomes during follow-up (median 9.4 years) were compared between households with kerosene versus clean (gas or electricity) or solid fuel (biomass and coal) use for cooking. Multi-level marginal regression models adjusted for individual, household, and community level covariates.

RESULTS

Higher rates of prevalent respiratory symptoms (e.g. 34% [95% CI:15-57%] more dyspnea with usual activity, 44% [95% CI: 21-72%] more chronic cough or sputum) and lower lung function (differences in FEV1: -46.3 ml (95% CI: -80.5; -12.1) and FVC: -54.7 ml (95% CI: -93.6; -15.8)) were observed at baseline for kerosene compared to clean fuel users. The odds of hypertension was slightly elevated but no associations were observed for blood pressure. Prospectively, kerosene was associated with elevated risks of all-cause (HR: 1.32 (95% CI: 1.14-1.53)) and cardiovascular (HR: 1.34 (95% CI: 1.00-1.80)) mortality, as well as major fatal and incident non-fatal cardiovascular (HR: 1.34 (95% CI: 1.08-1.66)) and respiratory (HR: 1.55 (95% CI: 0.98-2.43)) diseases, compared to clean fuel use. Further, compared to solid fuel users, those using kerosene had 20-47% higher risks for the above outcomes.

CONCLUSIONS

Kerosene use for cooking was associated with higher rates of baseline respiratory morbidity and increased risk of mortality and cardiorespiratory outcomes during follow-up when compared to either clean or solid fuels. Replacing kerosene with cleaner-burning fuels for cooking is recommended.

The exposome in atopic dermatitis

Atopic dermatitis (AD) is a complex inflammatory disorder with multiple interactions between genetic, immune and external factors. The sum of external factors that an individual is exposed to throughout their lifetime is termed the exposome. The exposome spans multiple domains from population to molecular levels and, in combination with genetic factors, holds the key to understanding the phenotypic diversity seen in AD patients. Exposomal domains are categorized into nonspecific (human and natural factors affecting populations), specific (eg humidity, ultraviolet radiation, diet, pollution, allergens, water hardness) and internal (cutaneous and gut microbiota and host cell interaction) exposures. The skin, as the organ that most directly interacts with and adapts to the external environment, is a prime target for exploration of exposomal influences on disease. Given the well-recognized physical environmental influences on AD, this condition could be much better understood through insightful exposomal research. In this narrative review, we examine each domain in turn, highlighting current understanding of the mechanisms by which exposomal influences modulate AD pathogenesis at distinct points in time. We highlight current approaches to exposome modification in AD and other allergic disease and propose future directions for exposome characterization and modification using novel research techniques.

Cooking Fuels in Lagos, Nigeria: Factors Associated with Household Choice of Kerosene or Liquefied Petroleum Gas (LPG)

Cooking with dirty-burning fuels is associated with health risk from household air pollution. We assessed the prevalence of and factors associated with the use of cooking fuels, and attitudes and barriers towards use of liquefied petroleum gas (LPG). This was a cross-sectional, population-based survey conducted in 519 households in Lagos, Nigeria. We used a structured questionnaire to obtain information regarding choice of household cooking fuel and the attitudes towards the use of LPG. Kerosene was the most frequently used cooking fuel (n = 475, 91.5%; primary use n = 364, 70.1%) followed by charcoal (n = 159, 30.6%; primary use n = 88, 17%) and LPG (n = 86, 16.6%; primary use n = 63, 12.1%). Higher level of education, higher income and younger age were associated with LPG vs. kerosene use. Fuel expenditure on LPG was significantly lower than for kerosene ( N (Naira) 2169.0 ± 1507.0 vs. N 2581.6 ± 1407.5). Over 90% of non-LPG users were willing to switch to LPG but cited safety issues and high cost as potential barriers to switching. Our findings suggest that misinformation and beliefs regarding benefits, safety and cost of LPG are important barriers to LPG use. An educational intervention program could be a cost-effective approach to improve LPG adoption and should be formally addressed through a well-designed community-based intervention study.

Correlation between socio-economic status and atopic dermatitis in Korean adults: the Korea national health and nutrition examination survey (2007-2014)

INTRODUCTION

Atopic dermatitis (AD) is one of the most common allergic diseases. Its prevalence has been increasing in recent decades. Socio-economic status is well-known risk factor of allergic diseases.

OBJECTIVE

This study was performed to investigate the relationship between socio-economic status and AD in Korean adults.

METHODS

Data were acquired from 47 351 men and women, ≥19 years of age who participated in the Korea National Health and Nutrition Examination Surveys (KNHANES) conducted from 2007 to 2014. The presence of AD was based on self-reported physician diagnosis of AD in the Health Interview Surveys.

RESULTS

The prevalence of AD was 3.1%, which decreased with increasing age. In univariate analysis, adults with AD were prone to be female, younger, never-married, well educated, lower household members, and urban dwelling (all P < 0.01). Monthly family income and smoking status were not associated with the presence of AD. The prevalence of hypertension, diabetes mellitus and asthma was higher in AD subjects (all P < 0.01), while obesity was not associated with adult AD. After adjusting for confounders, logistic regression analysis showed female sex (adjusted odds ratio [aOR]: 1.483, 95% CI: 1.268-1.734), age (P < 0.01), marital status (Single: aOR: 1.307, 95% CI: 1.012-1.690; Never-married: aOR: 1.938, 95% CI: 1.513-2.482), urban residence (aOR: 1.281, 95% CI: 1.045-1.569) and asthma (aOR: 1.788, 95% CI: 1.416-2.258) were associated with higher prevalence of AD (all P < 0.01).

CONCLUSION

Female sex, age, marital status, urban residence, and the presence of asthma are important risk factors of the prevalence of AD in Korean adults.

What have studies of non-industrialized countries told us about the cause of allergic disease?

The increase in allergic diseases that was observed in countries that had experienced rapid economic growth since the mid-20th century initiated a search for environmental exposures that may explain these phenomena that continues to the present day. Societies that are in the earlier stages of the process of industrialization provide an opportunity to compare the initial stages of economic development and the lifestyle changes that may accompany this, with other communities whose way of life may not have changed appreciably for centuries. These studies have consistently demonstrated higher levels of allergic disease in the relatively affluent populations compared with those who maintain a more traditional lifestyle. Environmental changes that have emerged from these studies that may modify the risk of allergic disease include microbial exposures including parasite infection, pollution, diet and obesity. In addition, food and drug allergies represent a neglected area of research in these countries that may be causing a relatively high burden of disease.

Prevalence of Atopic Dermatitis in Korean Children Based on Data From the 2008-2011 Korean National Health and Nutrition Examination Survey

Population-based studies of atopic dermatitis (AD) in Korean children are lacking. Thus, the purpose of this study was to determine the prevalence, geographic distribution, and risk factors of AD in the Korean pediatric population. We examined AD prevalence using data from the 2008-2011 Korea National Health and Nutrition Examination Survey (KNHANES), which was a cross-sectional survey of 8,947 children up to age 18 throughout the country. Overall, 13.50% of children reported a diagnosis of AD. The age-standardized prevalence ranged from 9.13% to 17.67% between cities and provinces, with the highest prevalence-observed in many of the larger cities at low latitudes, as well as Jeju-do. After adjusting for confounders, high economic status was found to be a significant factor for predicting increased prevalence of AD, with an odds ratio of 1.35 (95% confidence interval of 1.02-1.79, P=0.0034). Urban living (odds ratio 1.24, 95% confidence interval of 1.00-1.53, P=0.0526) was also associated with a higher prevalence of AD. In this first large scale, nationwide study in Korean children, we found that the overall prevalence of AD depends on age, household income, and geographic distribution.

Increased risk of respiratory illness associated with kerosene fuel use among women and children in urban Bangalore, India

BACKGROUND

Kerosene is a widely used cooking and lighting fuel in developing countries. The potential respiratory health effects of cooking with kerosene relative to cooking with cleaner fuels such as liquefied petroleum gas (LPG) have not been well characterised.

METHODS

We sampled 600 households from six urban neighbourhoods in Bangalore, India. Each household's primary cook, usually the woman of the house, was interviewed to collect information on current domestic fuel use and whether there was any presence of respiratory symptoms or illness in her or in the children in the household. Our analysis was limited to 547 adult females (ages 18-85) and 845 children (ages 0-17) in households exclusively cooking with either kerosene or LPG. We investigated the associations between kerosene use and the likelihood of having respiratory symptoms or illness using multivariate logistic regression models.

RESULTS

Among adult women, cooking with kerosene was associated with cough (OR=1.88; 95% CI 1.19 to 2.99), bronchitis (OR=1.54; 95% CI 1.00 to 2.37), phlegm (OR=1.51; 95% CI 0.98 to 2.33) and chest illness (OR=1.61; 95% CI 1.02 to 2.53), relative to cooking with LPG in the multivariate models. Among children, living in a household cooking with kerosene was associated with bronchitis (OR=1.91; 95% CI 1.17 to 3.13), phlegm (OR=2.020; 95% CI 1.29 to 3.74) and chest illness (OR=1.70; 95% CI 0.99 to 2.90) after adjusting for other covariates. We also found associations between kerosene use and wheezing, difficulty breathing and asthma in adults and cough and wheezing in children, though these associations were not statistically significant.

CONCLUSIONS

Women and children in households cooking with kerosene were more likely to have respiratory symptoms and illnesses compared with those in households cooking with LPG. Transitioning from kerosene to LPG for cooking may improve respiratory health among adult women and children in this population.

Association between wheeze and selected air pollution sources in an air pollution priority area in South Africa: a cross-sectional study

BACKGROUND

An association between wheeze (a symptom of asthma) and environmental tobacco smoke (ETS), types of fuel used for residential heating or cooking and the frequency of trucks passing near homes, has been reported mainly in developed countries. Little is known about the strength of such associations in developing countries. This study was conducted in residential areas situated in Ekurhuleni Metropolitan Municipality, namely Tembisa and Kempton Park, which form part of the Highveld region, a priority area in terms of air pollution in South Africa.

METHODS

From 3764 eligible school children, aged between 13 and 14 years, from 16 selected high schools in the study area, 3468 completed a modified questionnaire based on the International Study of Asthma and Allergies in Childhood (ISAAC). Data were analysed using multiple logistic regression models.

RESULTS

The results are based on data from 3424 children. In the adjusted models, exposure to ETS at school was associated with wheeze ever (OR 1.22 95% CI: 1.03 - 1.45) and current wheeze (OR 1.33 95% CI: 1.08 - 1.64). When gas was most frequently used for residential heating the likelihood of wheeze ever increased by 47% (OR 1.47 95% CI: 1.15 - 1.88). Trucks passing near homes for almost the whole day during weekdays, increased the likelihood of wheeze ever (OR 1.32 95% CI: 1.01 - 1.73), current wheeze (OR 1.61 95% CI: 1.15 - 2.24) and current severe wheeze (OR 2.22 95% CI: 1.28 - 3.77). When data were stratified according to residential area, for children living in Tembisa, ETS exposure at home was associated with current wheeze (OR 1.36 95% CI: 1.06 - 1.77); gas most frequently used for residential heating was associated with wheeze ever (OR 1.68 95% CI: 1.23 - 2.28) and current wheeze (OR 1.61 95% CI: 1.08 - 2.39); paraffin most frequently used for residential heating was associated with current severe wheeze (OR 1.85 95% CI: 1.04 - 3.28).

CONCLUSION

It was concluded that children living in one of the air pollution priority areas of South Africa, have an increased risk of wheezing due to exposure to both indoor and outdoor air pollution sources.

Association of mechanical ventilation and flue use in heaters with asthma symptoms in Japanese schoolchildren: a cross-sectional study in Sapporo, Japan

Background

Use of fuel heaters is associated with childhood asthma. However, no studies have evaluated the associations of flue use and mechanical ventilation (ventilation) with asthma symptoms in schoolchildren.

Methods

This cross-sectional study investigated schoolchildren in grades 1 through 6 (age 6–12 years) in Sapporo, Japan. From November 2008 through January 2009, parents completed questionnaires regarding their home environment and their children’s asthma symptoms.

Results

In total, 4445 (69.5%) parents of 6393 children returned the questionnaire. After excluding incomplete responses, data on 3874 children (60.6%) were analyzed. The prevalence of current asthma symptoms and ever asthma symptoms were 12.8% and 30.9%, respectively. As compared with electric heaters, current asthma symptoms was associated with use of flued heaters without ventilation (OR = 1.62; 95% CI, 1.03–2.64) and unflued heaters with ventilation (OR = 1.77; 95% CI, 1.09–2.95) or without ventilation (OR = 2.23; 95% CI, 1.31–3.85). Regardless of dampness, unflued heaters were significantly associated with current asthma symptoms in the presence and absence of ventilation.

Conclusions

Use of unflued heaters was associated with current asthma symptoms, regardless of dampness. In particular, the prevalence of current asthma symptoms was higher in the absence of ventilation than in the presence of ventilation. Ever asthma symptoms was only associated with use of unflued heaters without ventilation. Consequently, use of fuel heaters, especially those that have no flue or ventilation, deserves attention, as their use might be associated with childhood asthma symptoms.

Atopic dermatitis and indoor use of energy sources in cooking and heating appliances

BACKGROUND

Atopic dermatitis (AD) prevalence has considerably increased worldwide in recent years. Studying indoor environments is particularly relevant, especially in industrialised countries where many people spend 80% of their time at home, particularly children. This study is aimed to identify the potential association between AD and the energy source (biomass, gas and electricity) used for cooking and domestic heating in a Spanish schoolchildren population.

METHODS

As part of the ISAAC (International Study of Asthma and Allergies in Childhood) phase III study, a cross-sectional population-based survey was conducted with 21,355 6-to-7-year-old children from 8 Spanish ISAAC centres. AD prevalence, environmental risk factors and the use of domestic heating/cooking devices were assessed using the validated ISAAC questionnaire. Crude and adjusted odds ratios (cOR, aOR) and 95% confidence intervals (CIs) were obtained. A logistic regression analysis was performed (Chi-square test, p-value < 0.05).

RESULTS

It was found that the use of biomass systems gave the highest cORs, but only electric cookers showed a significant cOR of 1.14 (95% CI: 1.01-1.27). When the geographical area and the mother's educational level were included in the logistic model, the obtained aOR values differed moderately from the initial cORs. Electric heating was the only type which obtained a significant aOR (1.13; 95% CI: 1.00-1.27). Finally, the model with all selected confounding variables (sex, BMI, number of siblings, mother's educational level, smoking habits of parents, truck traffic and geographical area), showed aOR values which were very similar to those obtained in the previous adjusted logistic analysis. None of the results was statistically significant, but the use of electric heating showed an aOR close to significance (1.14; 95% CI: 0.99-1.31).

CONCLUSION

In our study population, no statistically significant associations were found between the type of indoor energy sources used and the presence of AD.

Kerosene: a review of household uses and their hazards in low- and middle-income countries

Kerosene has been an important household fuel since the mid-19th century. In developed countries its use has greatly declined because of electrification. However, in developing countries, kerosene use for cooking and lighting remains widespread. This review focuses on household kerosene uses, mainly in developing countries, their associated emissions, and their hazards. Kerosene is often advocated as a cleaner alternative to solid fuels, biomass and coal, for cooking, and kerosene lamps are frequently used when electricity is unavailable. Globally, an estimated 500 million households still use fuels, particularly kerosene, for lighting. However, there are few studies, study designs and quality are varied, and results are inconsistent. Well-documented kerosene hazards are poisonings, fires, and explosions. Less investigated are exposures to and risks from kerosene's combustion products. Some kerosene-using devices emit substantial amounts of fine particulates, carbon monoxide (CO), nitric oxides (NO(x)), and sulfur dioxide (SO(2)). Studies of kerosene used for cooking or lighting provide some evidence that emissions may impair lung function and increase infectious illness (including tuberculosis), asthma, and cancer risks. However, there are few study designs, quality is varied, and results are inconsistent. Considering the widespread use in the developing world of kerosene, the scarcity of adequate epidemiologic investigations, the potential for harm, and the implications for national energy policies, researchers are strongly encouraged to consider collecting data on household kerosene uses in studies of health in developing countries. Given the potential risks of kerosene, policymakers may consider alternatives to kerosene subsidies, such as shifting support to cleaner technologies for lighting and cooking.

Treatment with anthelminthics during pregnancy: what gains and what risks for the mother and child?

In 1994 and 2002, respectively, the World Health Organisation proposed that treatment for hookworm and schistosomiasis could be provided during pregnancy. It was hoped that this might have benefits for maternal anaemia, fetal growth and perinatal mortality; a beneficial effect on the infant response to immunisation was also hypothesised. Three trials have now been conducted. Two have examined the effects of benzimidazoles; one (the Entebbe Mother and Baby Study) the effects of albendazole and praziquantel. All three were conducted in settings of high prevalence but low intensity helminth infection. Results suggest that, in such settings and given adequate provision of haematinics, the benefit of routine anthelminthics during pregnancy for maternal anaemia may be small; none of the other expected benefits has yet been demonstrated. The Entebbe Mother and Baby Study found a significant adverse effect of albendazole on the incidence of infantile eczema in the whole study population, and of praziquantel on the incidence of eczema among infants of mothers with Schistosoma mansoni. Further studies are required in settings that differ in helminth species and infection intensities. Further research is required to determine whether increased rates of infantile eczema translate to long-term susceptibility to allergy, and to explore the underlying mechanisms of these effects. The risks and benefits of routine anthelminthic treatment in antenatal clinics may need to be reconsidered.

Traffic air pollution and other risk factors for respiratory illness in schoolchildren in the niger-delta region of Nigeria

BACKGROUND

Association of childhood respiratory illness with traffic air pollution has been investigated largely in developed but not in developing countries, where pollution levels are often very high.

OBJECTIVES

In this study we investigated associations between respiratory health and outdoor and indoor air pollution in schoolchildren 7-14 years of age in low socioeconomic status areas in the Niger Delta.

METHODS

A cross-sectional survey was carried out among 1,397 schoolchildren. Exposure to home outdoor and indoor air pollution was assessed by self-report questionnaire. School air pollution exposures were assessed using traffic counts, distance of schools to major streets, and particulate matter and carbon monoxide measurements, combined using principal components analysis. Hierarchical logistic regression was used to examine associations with reported respiratory health, adjusting for potential confounders.

RESULTS

Traffic disturbance at home (i.e., traffic noise and/or fumes evident inside the home vs. none) was associated with wheeze [odds ratio (OR) = 2.16; 95% confidence interval (CI), 1.28-3.64], night cough (OR = 1.37; 95% CI, 1.03-1.82), phlegm (OR = 1.49; 95% CI, 1.09-2.04), and nose symptoms (OR = 1.40; 95% CI, 1.03-1.90), whereas school exposure to a component variable indicating exposure to fine particles was associated with increased phlegm (OR = 1.38; 95% CI, 1.09-1.75). Nonsignificant positive associations were found between cooking with wood/coal (OR = 2.99; 95% CI, 0.88-10.18) or kerosene (OR = 2.83; 95% CI, 0.85-9.44) and phlegm compared with cooking with gas.

CONCLUSION

Traffic pollution is associated with respiratory symptoms in schoolchildren in a deprived area of western Africa. Associations may have been underestimated because of nondifferential misclassification resulting from limitations in exposure measurement.

Airway exposure to hypochlorite prior to ovalbumin induces airway hyperreactivity without evidence for allergic sensitization

BACKGROUND

Some epidemiologic studies have indicated that attendance to chlorinated swimming pools is associated with airway hyperreactivity (AHR), allergies and asthma.

AIM

To investigate the effects of sodium hypochlorite (NaClO), the main pool disinfectant, on allergic sensitization and airway inflammation in mice.

METHODS

In a first series of experiments, mice were sensitized to ovalbumin (OVA), followed by OVA aerosols with or without prior nasal instillation of NaClO (3ppm active chlorine). In a second series, naïve mice received 1-7 nasal instillations of OVA, 10min after instillations of NaClO or water. After 1, 3, 5 and 7 exposures airway reactivity to methacholine, cellular inflammation in bronchoalveolar lavage (BAL), serum OVA-specific IgEs and lung Th2 cytokines were measured.

RESULTS

In the first mouse model, airway allergy parameters were not significantly altered upon NaClO administration. However in the second model, NaClO exposure prior to OVA did induce AHR, already after 1 combined application. Combined NaClO+OVA exposure did not lead to an influx of inflammatory cells in BAL fluid or production of anti-OVA IgEs. No AHR developed when OVA was heat-denatured, pre-chlorinated, or replaced by bovine serum albumin or lipopolysaccharide.

CONCLUSION

Nasal instillation of NaClO prior to OVA induces AHR without allergic sensitization. This response is OVA-specific.

Geographical and sociodemographic risk factors for allergic diseases in korean children

PURPOSE

(a) To examine geographical distribution of childhood allergic diseases in Korea and (b) to identify geographical and sociodemographic risk factors for allergic diseases.

METHODS

Data on doctor-diagnosed asthma during lifetime and allergic rhinitis and atopic dermatitis during the past 12 months of 8,631 children (≤ 18 years) were obtained from the Third Korea National Health and Nutrition Examination Survey, along with information on housing type and presence of an indoor smoker. The SaTScan program identified geographical case clusters of allergic diseases, and multiple logistic regression determined risk factors, including geographical case clusters, for each allergic disease.

RESULTS

Prevalence of asthma, allergic rhinitis, and atopic dermatitis was 3.2%, 13.2%, and 15.5%, respectively. Older children (10-18 years) were more likely to have allergic rhinitis whereas younger children were more likely to have atopic dermatitis. It is noteworthy that children living in areas of geographical risk for asthma and atopic dermatitis were more likely to develop the respective allergic disease than children living in other areas (odds ratio [OR] = 3.47 for asthma, and OR = 9.74 for atopic dermatitis).

CONCLUSIONS

This study indicates that the areas in which children live may influence the development of certain allergic diseases. Implications include the need to assess geographical location of children with allergic diseases and to develop community-based preventive programs for children with allergic diseases.

Atopy and current intestinal parasite infection: a systematic review and meta-analysis

BACKGROUND

The rate of increase in prevalence of allergic disease in some countries implies environmental exposures may be important etiological factors. Our aim was to undertake a systematic review and meta-analysis of epidemiological studies to quantify the association between current intestinal parasite infection and the presence of atopy and to determine whether this relation is species specific.

METHODS

We searched MEDLINE, EMBASE, LILIACS and CAB Abstracts (to March 2009); reviews; and reference lists from publications. No language restrictions were applied. We included studies that measured current parasite infection using direct fecal microscopy and defined atopy as allergen skin sensitization or presence of specific IgE. We estimated pooled odds ratios (OR) and 95% confidence intervals (95% CI) using data extracted from published papers using random-effects model.

RESULTS

Twenty-one studies met our inclusion criteria. Current parasite infection was associated with a reduced risk of allergen skin sensitization OR 0.69 (95% CI 0.60-0.79; P < 0.01). When we restricted our analyses to current geohelminth infection, the size of effect remained similar OR 0.68 (95% CI 0.60-0.76; P < 0.01). In species-specific analysis, a consistent protective effect was found for infection with Ascaris lumbricoides, Tricuris trichuria, hookworm and Schistosomiasis. There were insufficient data to pool results for atopy defined by the presence of specific IgE.

CONCLUSION

Intestinal parasite infection appears to protect against allergic sensitization. Work should continue to identify the mechanisms of this effect and means of harnessing these to reduce the global burden of allergic disease.

Eczema prevalence in the United States: data from the 2003 National Survey of Children's Health

Using the 2003 National Survey of Children's Health sponsored by the federal Maternal and Child Health Bureau, we calculated prevalence estimates of eczema nationally and for each state among a nationally representative sample of 102,353 children 17 years of age and under. Our objective was to determine the national prevalence of eczema/atopic dermatitis in the US pediatric population and to further examine geographic and demographic associations previously reported in other countries. Overall, 10.7% of children were reported to have a diagnosis of eczema in the past 12 months. Prevalence ranged from 8.7 to 18.1% between states and districts, with the highest prevalence reported in many of the East Coast states, as well as in Nevada, Utah, and Idaho. After adjusting for confounders, metropolitan living was found to be a significant factor in predicting a higher disease prevalence with an odds ratio of 1.67 (95% confidence interval of 1.19-2.35, P=0.008). Black race (odds ratio 1.70, P=0.005) and education level in the household greater than high school (odds ratio 1.61, P=0.004) were also significantly associated with a higher prevalence of eczema. The wide range of prevalence suggests that social or environmental factors may influence disease expression.

Importance of allergic rhinitis management in achieving asthma control: ARIA update

Asthma continues to be a major burden for the health and healthcare of people worldwide. The recent updates of the Global Initiative for Asthma and the National Heart, Lung and Blood Institute asthma guidelines stress the need for achieving and monitoring asthma 'control', emphasizing the importance of identifying, assessing and treating comorbid conditions. Allergic rhinitis (AR) is a major comorbid condition in people with asthma and is related to inflammation of the upper portions of the airway. Recognizing and treating AR has been shown to improve asthma control, specifically by decreasing rates of asthma attacks or asthma exacerbations. In 2008, updated Allergic Rhinitis in Asthma (ARIA) guidelines were published. The updated version of the guidelines has a familiar look, with classification systems and care algorithms that are similar to those presented in other asthma guidelines. The new ARIA guidelines make one major change that should affect the care of adults and children with asthma: everyone with asthma should be assessed for AR. In addition, AR should be considered a risk factor for asthma, and all children and adults with AR, especially persistent AR, should be assessed for asthma, including testing lung function for reversible obstruction whenever feasible. Treatment for AR follows a similar format to that for asthma, including symptom management, treatment of chronic inflammation, identification and management of triggers, including allergens, and ongoing education for self-management. Pharmacotherapies that address both asthma and AR include corticosteroids (intranasal and inhaled), leukotriene receptor antagonists, immunomodulation or immunotherapy. Too often, pharmacotherapy is not supplemented by the necessary education and evaluation related to allergen, trigger identification and management.

Air pollution and allergic disease

Over the past several decades, there has been increased awareness of the health effects of air pollution and much debate regarding the role of global warming. The prevalence of asthma and allergic disease has risen in industrialized countries, and most epidemiologic studies focus on possible causalities between air pollution and these conditions. This review examines salient articles and summarizes findings important to the interaction between allergies and air pollution, specifically volatile organic compounds, global warming, particulate pollutants, atopic risk, indoor air pollution, and prenatal exposure. Further work is necessary to determine whether patients predisposed to developing allergic disease may be more susceptible to the health effects of air pollutants due to the direct interaction between IgE-mediated disease and air pollutants. Until we have more definitive answers, patient education about the importance of good indoor air quality in the home and workplace is essential. Health care providers and the general community should also support public policy designed to improve outdoor air quality by developing programs that provide incentives for industry to comply with controlling pollution emissions.

Common characteristics of upper and lower airways in rhinitis and asthma: ARIA update, in collaboration with GA(2)LEN

This update aimed to review the new evidence available to support or refute prior Allergic Rhinitis and its Impact on Asthma (ARIA) statements. A Medline search of publications between 2000 and 2005 was conducted, with articles selected by experts. New evidence supports previous ARIA statements, such as: (i) allergic rhinitis (AR) is a risk factor for asthma; (ii) patients with persistent rhinitis should be evaluated for asthma; (iii) most patients with asthma have rhinitis; (iv) a combined strategy should be used to treat the airways and (v) in low- to middle-income countries, a different strategy may be needed. The increased risk of asthma has also been found among sufferers from non-AR. Recent reports show AR is a global problem. Many studies demonstrated parallel increasing prevalence of asthma and rhinitis, but in regions of highest prevalence, it may be reaching a plateau. Factors associated with a reduced risk of asthma and AR have been identified, confirming previous findings of protection related to exposure to infections. Treatment of rhinitis with intranasal glucocorticosteroids, antihistamines, leukotriene antagonists or immunotherapy may reduce morbidity because of asthma. To take advantage of the paradigm of unified airways, there is a need to rationalize diagnosis and treatment to optimize management.

Today's allergic rhinitis patients are different: new factors that may play a role

Most of today's patients suffering from allergic rhinitis (AR) are sensitized to more than one trigger and suffer from persistent and moderate/severe symptoms, which severely impair their quality of life (QOL). The objective of this article was to review the data on the effect of increased air pollution, changes in indoor environment/lifestyle/affluence, exposure to new allergens and psychologically stressful lifestyles, as also to explore their potential in the development of this more 'aggressive' form of disease. Increased fossil fuel-generated air pollution may increase the risk of allergic sensitization, airway responsiveness to allergens, and allergenicity and the bioavailability of airborne allergens. Changes in indoor environment/lifestyle/affluence appear to have led to more time being spent indoors and resulted in perennial exposure to indoor allergens, changes in sensitization patterns, and polysensitization to a variety of novel cross-reacting exotic food and pet allergens. Although evidence suggests an association between psychological stress and increased risk for atopy and allergic disease, further studies are required to demonstrate this unequivocally. The more persistent and moderate/severe nature of the disease suggests a need for modification of current treatment strategies and advocacy of the use from the outset of agents, which are both efficacious and safe in managing severe and persistent AR symptoms and in improving the QOL of affected individuals.

Allergic disorders in African countries: linking immunology to accurate phenotype

Identification and characterization of risk and protective factors for allergy is important for developing strategies for prevention or treatment. The prevalence of allergy is clearly higher in affluent countries than in developing countries like, e.g. Africa. Especially in urban areas of developing countries, allergy is however on the increase. In Africa, we have the unique opportunity to investigate risk and protective factors and the influence of urbanization and westernization, i.e. almost to take a look at Europe, Australia or the USA as they were before their allergy epidemics. Moreover, migrants from developing to affluent countries experiencing an increased burden of allergy provide new insights into risk and protective factors. Allergen exposure, diet and infections are the major exogenous influences playing a role as risk and protective factors. Depending on the nature, timing, chronicity and level of exposure, each of them can promote or inhibit allergy. Perhaps with the exception of infections, availability of data from Africa on their role in the development of allergy is limited. Detailed epidemiological studies in rural and urban Africa combined with basic immunological research are needed to unravel mechanisms of increase in allergy and of protection. The maturation of the immune system at young age under influence of exogenous factors results in differences in T-cell-skewing (Th1/Th2/Treg) and humoral responses. It is essential to perform studies from a 'non-Eurocentric' angle (e.g. local allergens, locally validated questionnaires and diagnostic procedures). Such studies will provide the affluent countries with new leads to combat the allergy epidemic and more importantly help prevent it in Africa.

Exercise-induced bronchospasm and atopy in Ghana: two surveys ten years apart

BACKGROUND

Asthma and allergic diseases have increased in the developed countries. It is important to determine whether the same trends are occurring in the developing countries in Africa. We aimed to determine the time trend in the prevalence of exercise-induced bronchospasm (EIB) and atopic sensitisation over a ten-year period in Ghanaian schoolchildren.

METHODS AND FINDINGS

Two surveys conducted using the same methodology ten years apart (1993 and 2003) among schoolchildren aged 9-16 years attending urban rich (UR), urban poor (UP), and rural (R) schools. Exercise provocation consisted of free running for six minutes. Children were skin tested to mite, cat, and dog allergen. 1,095 children were exercised in 1993 and 1,848 in 2003; 916 were skin tested in 1993 and 1,861 in 2003. The prevalence of EIB increased from 3.1% (95% CI 2.2%-4.3%) to 5.2% (4.3%-6.3%); absolute percentage increase 2.1% (95% CI 0.6%-3.5%, p < 0.01); among UR, UP, and R children EIB had approximately doubled from 4.2%, 1.4%, and 2.2% to 8.3%, 3.0% and 3.9% respectively. The prevalence of sensitisation had also doubled from 10.6%, 4.7%, and 4.4% to 20.2%, 10.3%, and 9.9% (UR, UP, and R respectively). Mite sensitisation remained unchanged (5.6% versus 6.4%), but sensitisation to cat and dog increased considerably from 0.7% and 0.3% to 4.6% and 3.1%, respectively. In the multiple logistic regression analysis, sensitisation (odds ratio [OR] 1.77, 95% CI 1.12-2.81), age (OR 0.88, 95% CI 0.79-0.98), school (the risk being was significantly lower in UP and R schools: OR 0.40, 95% CI 0.23-0.68 and OR 0.54, 95% CI 0.34-0.86, respectively) and year of the study (OR 1.73, 95% CI 1.13-2.66) remained significant and independent associates of EIB.

CONCLUSIONS

The prevalence of both EIB and sensitisation has approximately doubled over the ten-year period amongst 9- to 16-year-old Ghanaian children irrespective of location, with both EIB and atopy being more common among the UR than the UP and R children.

The impact of helminths on the response to immunization and on the incidence of infection and disease in childhood in Uganda: design of a randomized, double-blind, placebo-controlled, factorial trial of deworming interventions delivered in pregnancy and early childhood [ISRCTN32849447]

BACKGROUND

Helminths have profound effects on the immune response, allowing long-term survival of parasites with minimal damage to the host. Some of these effects "spill-over", altering responses to non-helminth antigens or allergens. It is suggested that this may lead to impaired responses to immunizations and infections, while conferring benefits against inflammatory responses in allergic and autoimmune disease. These effects might develop in utero, through exposure to maternal helminth infections, or through direct exposure in later life.

PURPOSE

To determine the effects of helminths and their treatment in pregnancy and in young children on immunological and disease outcomes in childhood.

METHODS

The trial has three randomized, double-blind, placebo-controlled interventions at two times, in two people: a pregnant woman and her child. Pregnant women are randomized to albendazole or placebo and praziquantel or placebo. At age 15 months their children are randomized to three-monthly albendazole or placebo, to continue to age five years. The proposed designation for this sequence of interventions is a 2 x 2(x2) factorial design. Children are immunized with BCG and against polio, Diphtheria, tetanus, Pertussis, Haemophilus, hepatitis B and measles. Primary immunological outcomes are responses to BCG antigens and tetanus toxoid in whole blood cytokine assays and antibody assays at one, three and five years of age. Primary disease outcomes are incidence of malaria, pneumonia, diarrhoea, tuberculosis, measles, vertical HIV transmission, and atopic disease episodes, measured at clinic visits and twice-monthly home visits. Effects on anaemia, growth and intellectual development are also assessed.

CONCLUSION

This trial, with a novel design comprising related interventions in pregnant women and their offspring, is the first to examine effects of helminths and their treatment in pregnancy and early childhood on immunological, infectious disease and allergic disease outcomes. The results will enhance understanding of both detrimental and beneficial effects of helminth infection and inform policy.

Proximity of the home to roads and the risk of wheeze in an Ethiopian population

BACKGROUND

There is widespread public concern that exposure to road vehicle traffic pollution causes asthma, but epidemiological studies in developed countries have not generally confirmed a strong effect and may have underestimated the risk as a result of relatively high and widespread exposure to traffic in everyday life.

AIMS

To investigate the effect of living close to a traffic bearing road on the risk of wheezing in Jimma, Ethiopia where road traffic is generally low and restricted to a limited network of roads.

METHODS

Data have been previously collected on respiratory symptoms, allergic sensitisation, and numerous demographic and lifestyle factors in a systematic sample of inhabitants of Jimma town. In 2003 the homes of these people were retraced; the shortest distance to the nearest surfaced road, and traffic flows on these roads were measured.

RESULTS

Distance measurements were collected for 7609 (80%) individuals. The overall prevalence of wheeze was similar in those living within 150 m of a road compared to those living further away (3.9% v 3.7%), but among the 3592 individuals living within 150 m, the risk of wheeze increased significantly in linear relation to proximity to the road (adjusted odds ratio = 1.17 per 30 m proximity, 95% CI 1.01 to 1.36). This relation was stronger, though not significantly so, for roads with above median traffic flows.

CONCLUSION

These findings indicate that living in close proximity to road vehicle traffic is associated with an increased risk of wheeze, but that other environmental factors are also likely to be important.

Indoor Heating Sources and Respiratory Symptoms in Nonsmoking Women

BACKGROUND

Secondary heating appliances are important indoor sources of air pollution, including particulate matter, nitrogen dioxide (NO2), and sulfur dioxide (SO2). We hypothesized that the use of secondary heating sources increases respiratory symptoms in women living in nonsmoking households and specifically that concentrations of SO2 and NO2 emitted from heating sources are associated with respiratory symptoms.

METHODS

Mothers who delivered babies at 12 hospitals in Connecticut and Virginia (1993-1996) were enrolled. There were 888 women who contributed symptom and exposure information during the winter heating season (15 October to 15 April), for a total of 9783 reporting periods (median = 12 reporting periods per woman, interquartile range 11-12). Adjusted rate ratios (RRs) of effects of source use and measured concentrations on rate of days with symptoms were obtained using generalized estimating equations for a log-linear Poisson model, controlling age, education, race, history of allergies, number of children, dwelling type, and residence state.

RESULTS

In adjusted models, each hour-per-day increase in kerosene heater use is associated with an increase in wheezing (RR = 1.06; 95% confidence interval (CI) = 1.01-1.11). Each hour of fireplace use is associated with increased cough (1.05; 1.01-1.09), sore throat (1.04; 1.00-1.08), and marginally with chest tightness (1.05; 0.99-1.12). Each 10 ppb increase in SO2 (a proxy for sulfate aerosol) is associated with increased wheezing (1.57; 1.10-2.26) and chest tightness (1.32; 1.01-1.71).

CONCLUSIONS

Emissions from fireplaces, gas space heaters, and kerosene heaters may contribute to respiratory symptoms in a population of nonsmoking women.

Prevalence and associated factors of atopic dermatitis symptoms in rural and urban Ethiopia

BACKGROUND

Allergic diseases, including atopic dermatitis (AD), are increasingly becoming a clinical problem in developing countries.

OBJECTIVE

We investigated the prevalence of AD symptoms and the effects of potential environmental aetiologies in rural and urban areas of Jimma in southwestern Ethiopia.

METHODS

Information on allergic disease symptoms and lifestyle factors was gathered in an interviewer-led cross-sectional questionnaire-based population survey of 9844 urban and 3032 rural participants of all ages. A one-in-four subsample underwent skin prick testing for hypersensitivity to Dermatophagoides pteronyssinus, mixed threshings, and aspergillus.

RESULTS

Around 95% of those eligible took part in the survey. Lifetime cumulative prevalence of AD symptoms was generally low with an overall prevalence of 1.2%, but was higher in the urban (1.5%) than in the rural area (0.3%; odds ratio (OR)=4.45 [95% CI 2.34-8.47]). AD symptoms were strongly associated with wheeze (adjusted OR=22.03 [15.45-31.42]) and rhinitis symptoms (61.94 [42.66-89.95]). Of several environmental exposures assessed, residence in a house made of brick (rather than mud) walls with wooden (rather than clay) floor, exposure to cigarette smoke as a child, having lived outside of Jimma in the past, and being of the Tigrean ethnic group were associated with an increased risk of AD symptoms.

CONCLUSION

Although the overall prevalence of AD symptoms was low in this Ethiopian population, a marked urban-rural gradient was evident. Lifestyle factors linked to urbanization were associated with an increased risk of AD symptoms.

Domestic risk factors for wheeze in urban and rural Ethiopian children

BACKGROUND

To identify which environmental exposures underpin the emergence of asthma epidemics, we need to study epidemics as they appear, as is now happening in the Jimma region of Ethiopia. We have previously studied risk factors for asthma in adults in Jimma and have now completed a survey of young children.

AIM

To establish the prevalence of asthma in urban and rural children in Jimma, and to identify locally important risk factors.

DESIGN

Cross-sectional survey.

METHODS

All children aged 1-5 years living in Jimma town and three surrounding rural regions were identified. Data were collected using an interviewer-led questionnaire, and consenting children had skin prick tests to house dust mite and cockroach.

RESULTS

We surveyed 7155 children, of whom 3623 (51%) were female and 4285 (60%) lived in the urban area. The prevalence of wheeze in the last year was 3.4%, and was lower in the rural area (OR 0.47; 95%CI 0.34-0.66). In the urban area, the main risk factors for wheeze were a longer duration of breastfeeding, use of kerosene, and environmental tobacco smoke, while living with animals was protective. In rural children, the main risk factors were a positive skin prick test and living with animals.

DISCUSSION

The prevalence of wheeze in children in the Jimma region is low, particularly in rural children. In addition to having an impact on disease prevalence, place of residence also appears to modify the impact of environmental risk factors for wheeze.

Infant respiratory symptoms associated with indoor heating sources

This study examined the effects of indoor heating sources on infant respiratory symptoms during the heating season of the first year of life. Mothers delivering babies between 1993 and 1996 at 12 hospitals in Connecticut and Virginia were enrolled. Daily symptom and heating source use information about their infant was obtained every 2 weeks during the first year of life. Heating sources included fireplace, wood stove, kerosene heater, and gas space heater use. Four health outcomes were analyzed by reporting period: days of wheeze, episodes of wheeze, days of cough, and episodes of cough. A large percentage of infants had at least one episode of cough (88%) and wheeze (33%) during the heating season of the first year of life. Wood stove, fireplace, kerosene heater, and gas space heater use was intermittent across the study period. In adjusted Poisson regression models controlling for important confounders, gas space heater use was associated with episodes and days of wheeze. Wood stove use was associated with total days of cough, and kerosene heater use was associated with episodes of cough. Fireplace use was not associated with any of the respiratory symptoms. Use of some heating sources appears related to respiratory symptoms in infants.

Independent effects of intestinal parasite infection and domestic allergen exposure on risk of wheeze in Ethiopia: a nested case-control study

BACKGROUND

Why asthma is rare in rural subsistence societies is not clear. We tested the hypotheses that the risk of asthma is reduced by intestinal parasites or hepatitis A infection, and increased by exposure to dust-mite allergen or organophosphorus insecticides in urban and rural areas of Jimma, Ethiopia.

METHODS

From 12876 individuals who took part in a study of asthma and atopy in urban and rural Jimma in 1996, we identified all who reported wheeze in the previous 12 months, and a random subsample of controls. In 1999, we assessed parasites in faecal samples, Der p 1 levels in bedding, hepatitis A antibodies, serum cholinesterase (a marker of organophosphorus exposure), total and specific serum IgE, and skin sensitisation to Dermatophagoides pteronyssinus in 205 cases and 399 controls aged over 16 years. The effects of parasitosis, Der p 1 level, hepatitis A seropositivity, and cholinesterase concentration on risk of wheeze, and the role of IgE and skin sensitisation in these associations, were analysed by multiple logistic regression.

FINDINGS

The risk of wheeze was independently reduced by hookworm infection by an odds ratio of 0.48 (95% CI 0.24-0.93, p=0.03), increased in relation to Der p 1 level (odds ratio per quartile 1.26 [1.00-1.59], p=0.05), and was unrelated to hepatitis A seropositivity or cholinesterase concentration. In the urban population, D pteronyssinus skin sensitisation was more strongly related to wheeze (9.45 [5.03-17.75]) than in the rural areas (1.95 [0.58-6.61], p for interaction=0.017), where D pteronyssinus sensitisation was common, but unrelated to wheeze in the presence of high-intensity parasite infection.

INTERPRETATION

High degrees of parasite infection might prevent asthma symptoms in atopic individuals.