Prevalence of Chronic airflow limitation in Kashmir, North India: Results from the BOLD study.

BACKGROUND: Data on spirometrically defined chronic airflow limitation (CAL) are scarce in developing countries. OBJECTIVE: To estimate the prevalence of spirometrically defined CAL in Kashmir, North India. METHODS: Using Burden of Obstructive Lung Disease survey methods, we administered questionnaires to randomly selected adults aged 40 years. Post-bronchodilator spirometry was performed to estimate the prevalence of CAL and its relation to potential risk factors. RESULTS: Of 1100 participants initially recruited, 953 (86.9%) responded and 757 completed acceptable spirometry and questionnaires. The prevalence of a forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) ratio less than the lower limit of normal was 17.3% (4.5) in males and 14.8% (2.1) in females. Risk factors for CAL included higher age, cooking with wood and lower educational status. The prevalence of current smoking was 61% in males and 22% in females; most smoked hookahs. CAL was found equally in non-smoking males and females, and was independently associated with the use of the hookah, family history of respiratory disease and poor education. A self-reported doctor's diagnosis of chronic obstructive pulmonary disease was reported in 8.4/1000 (0.9% of females and 0.8% of males). CONCLUSION: Spirometrically confirmed CAL is highly prevalent in Indian Kashmir, and seems to be related to the high prevalence of smoking, predominantly in the form of hookah smoking

Prevalence of food sensitization and probable food allergy among adults in India: the EuroPrevall INCO study

Data are lacking regarding the prevalence of food sensitization and probable food allergy among general population in India. We report the prevalence of sensitization and probable food allergy to 24 common foods among adults from general population in Karnataka, South India. The study was conducted in two stages: a screening study and a case-control study. A total of 11 791 adults in age group 20-54 were randomly sampled from general population in South India and answered a screening questionnaire. A total of 588 subjects (236 cases and 352 controls) participated in the case-control study involving a detailed questionnaire and specific IgE estimation for 24 common foods. A high level of sensitization (26.5%) was observed for most of the foods in the general population, higher than that observed among adults in Europe, except for those foods that cross-react with birch pollen. Most of the sensitization was observed in subjects who had total IgE above the median IgE level. A high level of cross-reactivity was observed among different pollens and foods and among foods. The prevalence of probable food allergy (self-reports of adverse symptoms after the consumption of food and specific IgE to the same food) was 1.2%, which was mainly accounted for cow's milk (0.5%) and apple (0.5%). Very high levels of sensitization were observed for most foods, including those not commonly consumed in the general population. For the levels of sensitization, the prevalence of probable food allergy was low. This disassociation needs to be further explored in future studie

Reference values for methacholine reactivity (SAPALDIA study)

BACKGROUND: The distribution of airway responsiveness in a general population of non-smokers without respiratory symptoms has not been established, limiting its use in clinical and epidemiological practice. We derived reference equations depending on individual characteristics (i.e., sex, age, baseline lung function) for relevant percentiles of the methacholine two-point dose-response slope. METHODS: In a reference sample of 1567 adults of the SAPALDIA cross-sectional survey (1991), defined by excluding subjects with respiratory conditions, responsiveness during methacholine challenge was quantified by calculating the two-point dose-response slope (O'Connor). Weighted L1-regression was used to estimate reference equations for the 95(th ), 90(th ), 75(th )and 50(th )percentiles of the two-point slope. RESULTS: Reference equations for the 95(th ), 90(th ), 75(th )and 50(th )percentiles of the two-point slope were estimated using a model of the form a + b* Age + c* FEV(1 )+ d* (FEV(1))(2 ), where FEV(1 )corresponds to the pre-test (or baseline) level of FEV(1). For the central half of the FEV(1 )distribution, we used a quadratic model to describe the dependence of methacholine slope on baseline FEV(1). For the first and last quartiles of FEV(1), a linear relation with FEV(1 )was assumed (i.e., d was set to 0). Sex was not a predictor term in this model. A negative linear association with slope was found for age. We provide an Excel file allowing calculation of the percentile of methacholine slope of a subject after introducing age – pre-test FEV(1 )– and results of methacholine challenge of the subject. CONCLUSION: The present study provides equations for four relevant percentiles of methacholine two-point slope depending on age and baseline FEV(1 )as basic predictors in an adult reference population of non-obstructive and non-atopic persons. These equations may help clinicians and epidemiologists to better characterize individual or population airway responsiveness

Serum IgE Reactivity Profiling in an Asthma Affected Cohort

BACKGROUND: Epidemiological evidence indicates that atopic asthma correlates with high serum IgE levels though the contribution of allergen specific IgE to the pathogenesis and the severity of the disease is still unclear. METHODS: We developed a microarray immunoassay containing 103 allergens to study the IgE reactivity profiles of 485 asthmatic and 342 non-asthmatic individuals belonging to families whose members have a documented history of asthma and atopy. We employed k-means clustering, to investigate whether a particular IgE reactivity profile correlated with asthma and other atopic conditions such as rhinitis, conjunctivitis and eczema. RESULTS: Both case-control and parent-to-siblings analyses demonstrated that while the presence of specific IgE against individual allergens correlated poorly with pathological conditions, particular reactivity profiles were significantly associated with asthma (p<10E-09). An artificial neural network (ANN)-based algorithm, calibrated with the profile reactivity data, correctly classified as asthmatic or non-asthmatic 78% of the individual examined. Multivariate statistical analysis demonstrated that the familiar relationships of the study population did not affect the observed correlations. CONCLUSIONS: These findings indicate that asthma is a higher-order phenomenon related to patterns of IgE reactivity rather than to single antibody reactions. This notion sheds new light on the pathogenesis of the disease and can be readily employed to distinguish asthmatic and non-asthmatic individuals on the basis of their serum reactivity profile

Prevalence of asthma symptoms based on the European Community Respiratory Health Survey questionnaire and FENO in university students: gender differences in symptoms and FENO

<p>Abstract</p> <p>Background</p> <p>The fractional concentration of nitric oxide in exhaled air (F<smcaps>E</smcaps>NO) is used as a biomarker of eosinophilic airway inflammation. F<smcaps>E</smcaps>NO is increased in patients with asthma. The relationship between subjective asthma symptoms and airway inflammation is an important issue. We expected that the subjective asthma symptoms in women might be different from those in men. Therefore, we investigated the gender differences of asthma symptoms and F<smcaps>E</smcaps>NO in a survey of asthma prevalence in university students.</p> <p>Methods</p> <p>The information about asthma symptoms was obtained from answers to the European Community Respiratory Health Survey (ECRHS) questionnaire, and F<smcaps>E</smcaps>NO was measured by an offline method in 640 students who were informed of this study and consented to participate.</p> <p>Results</p> <p>The prevalence of asthma symptoms on the basis of data obtained from 584 students (266 men and 318 women), ranging in age from 18 to 24 years, was analyzed. Wheeze, chest tightness, an attack of shortness of breath, or an attack of cough within the last year was observed in 13.2% of 584 students. When 38.0 ppb was used as the cut-off value of F<smcaps>E</smcaps>NO to make the diagnosis of asthma, the sensitivity was 86.8% and the specificity was 74.0%. F<smcaps>E</smcaps>NO was ≥ 38.0 ppb in 32.7% of students. F<smcaps>E</smcaps>NO was higher in men than in women. The prevalence of asthma symptoms estimated by considering F<smcaps>E</smcaps>NO was 7.2%; the prevalence was greater in men (9.4%) than women (5.3%). A F<smcaps>E</smcaps>NO ≥ 38.0 ppb was common in students who reported wheeze, but not in students, especially women, who reported cough attacks.</p> <p>Conclusions</p> <p>The prevalence of asthma symptoms in university students age 18 to 24 years in Japan was estimated to be 7.2% on the basis of F<smcaps>E</smcaps>NO levels as well as subjective symptoms. Gender differences were observed in both F<smcaps>E</smcaps>NO levels and asthma symptoms reflecting the presence of eosinophilic airway inflammation.</p> <p>Trial registration number</p> <p>UMIN000003244</p

Multiple Crimean-Congo Hemorrhagic Fever Virus Strains Are Associated with Disease Outbreaks in Sudan, 2008–2009

The tick-borne virus which causes the disease Crimean-Congo hemorrhagic fever (CCHF) is known to be widely distributed throughout much of Africa, Southern Europe, the Middle East, Central Asia, and Southern Russia. Humans contract the virus from contact with infected people, infected animals (which do not show symptoms), and from the bite of infected ticks. CCHF was recently recognized in the Sudan when several hospital staff and patients died from the disease in a rural hospital. The genetic analysis of viruses associated with the 2008 and 2009 outbreaks shows that several CCHF viral strains currently circulate and cause human outbreaks in the Sudan, highlighting CCHF virus as an emerging pathogen. The Sudanese strains are similar to others circulating in Africa, indicating movement of virus over large distances with introduction and disease outbreaks in rural areas possible. Understanding the epidemiology of zoonotic diseases such as CCHF is especially important in the Sudan given the large numbers of livestock in the country, and their importance to the economy and rural communities. It is imperative that hospital staff consider CCHF as a possible disease agent, since they are at a high risk of contracting the disease, especially in hospitals with limited medical supplies

Diet and asthma: looking back, moving forward

Asthma is an increasing global health burden, especially in the western world. Public health interventions are sought to lessen its prevalence or severity, and diet and nutrition have been identified as potential factors. With rapid changes in diet being one of the hallmarks of westernization, nutrition may play a key role in affecting the complex genetics and developmental pathophysiology of asthma. The present review investigates hypotheses about hygiene, antioxidants, lipids and other nutrients, food types and dietary patterns, breastfeeding, probiotics and intestinal microbiota, vitamin D, maternal diet, and genetics. Early hypotheses analyzed population level trends and focused on major dietary factors such as antioxidants and lipids. More recently, larger dietary patterns beyond individual nutrients have been investigated such as obesity, fast foods, and the Mediterranean diet. Despite some promising hypotheses and findings, there has been no conclusive evidence about the role of specific nutrients, food types, or dietary patterns past early childhood on asthma prevalence. However, diet has been linked to the development of the fetus and child. Breastfeeding provides immunological protection when the infant's immune system is immature and a modest protective effect against wheeze in early childhood. Moreover, maternal diet may be a significant factor in the development of the fetal airway and immune system. As asthma is a complex disease of gene-environment interactions, maternal diet may play an epigenetic role in sensitizing fetal airways to respond abnormally to environmental insults. Recent hypotheses show promise in a biological approach in which the effects of dietary factors on individual physiology and immunology are analyzed before expansion into larger population studies. Thus, collaboration is required by various groups in studying this enigma from epidemiologists to geneticists to immunologists. It is now apparent that this multidisciplinary approach is required to move forward and understand the complexity of the interaction of dietary factors and asthma

Spatial analysis of air pollution and childhood asthma in Hamilton, Canada: comparing exposure methods in sensitive subgroups

<p>Abstract</p> <p>Background</p> <p>Variations in air pollution exposure within a community may be associated with asthma prevalence. However, studies conducted to date have produced inconsistent results, possibly due to errors in measurement of the exposures.</p> <p>Methods</p> <p>A standardized asthma survey was administered to children in grades one and eight in Hamilton, Canada, in 1994–95 (N ~1467). Exposure to air pollution was estimated in four ways: (1) distance from roadways; (2) interpolated surfaces for ozone, sulfur dioxide, particulate matter and nitrous oxides from seven to nine governmental monitoring stations; (3) a kriged nitrogen dioxide (NO₂) surface based on a network of 100 passive NO₂monitors; and (4) a land use regression (LUR) model derived from the same monitoring network. Logistic regressions were used to test associations between asthma and air pollution, controlling for variables including neighbourhood income, dwelling value, state of housing, a deprivation index and smoking.</p> <p>Results</p> <p>There were no significant associations between any of the exposure estimates and asthma in the whole population, but large effects were detected the subgroup of children without hayfever (predominately in girls). The most robust effects were observed for the association of asthma without hayfever and NO₂LUR OR = 1.86 (95%CI, 1.59–2.16) in all girls and OR = 2.98 (95%CI, 0.98–9.06) for older girls, over an interquartile range increase and controlling for confounders.</p> <p>Conclusion</p> <p>Our findings indicate that traffic-related pollutants, such as NO₂, are associated with asthma without overt evidence of other atopic disorders among female children living in a medium-sized Canadian city. The effects were sensitive to the method of exposure estimation. More refined exposure models produced the most robust associations.</p

Variability of the chronic obstructive pulmonary disease key epidemiological data in Europe: systematic review

<p>Abstract</p> <p>Background</p> <p>Chronic obstructive pulmonary disease (COPD) is predicted to become a major cause of death worldwide. Studies on the variability in the estimates of key epidemiological parameters of COPD may contribute to better assessment of the burden of this disease and to helpful guidance for future research and public policies. In the present study, we examined differences in the main epidemiological characteristics of COPD derived from studies across countries of the European Union, focusing on prevalence, severity, frequency of exacerbations and mortality, as well as on differences between the studies' methods.</p> <p>Methods</p> <p>This systematic review was based on a search for the relevant literature in the Science Citation Index database via the Web of Science and on COPD mortality rates issued from national statistics. Analysis was finally based on 65 articles and Eurostat COPD mortality data for 21 European countries.</p> <p>Results</p> <p>Epidemiological characteristics of COPD varied widely from country to country. For example, prevalence estimates ranged between 2.1% and 26.1%, depending on the country, the age group and the methods used. Likewise, COPD mortality rates ranged from 7.2 to 36.1 per 10⁵inhabitants. The methods used to estimate these epidemiological parameters were highly variable in terms of the definition of COPD, severity scales, methods of investigation and target populations. Nevertheless, to a large extent, several recent international guidelines or research initiatives, such as GOLD, BOLD or PLATINO, have boosted a substantial standardization of methodology in data collection and have resulted in the availability of more comparable epidemiological estimates across countries. On the basis of such standardization, severity estimates as well as prevalence estimates present much less variation across countries. The contribution of these recent guidelines and initiatives is outlined, as are the problems remaining in arriving at more accurate COPD epidemiological estimates across European countries.</p> <p>Conclusions</p> <p>The accuracy of COPD epidemiological parameters is important for guiding decision making with regard to preventive measures, interventions and patient management in various health care systems. Therefore, the recent initiatives for standardizing data collection should be enhanced to result in COPD epidemiological estimates of improved quality. Moreover, establishing international guidelines for reporting research on COPD may also constitute a major contribution.</p