Asthma prevalence

Genetic factors cannot explain the recent rapid rise in asthma prevalence. Asthma appears to require both genetic predisposition and environmental exposure. Many patients with occupational asthma develop the disease late in life upon exposure to specific allergens in the workplace. Environmental influences in utero or in infancy may contribute to the development of asthma. Maternal smoking during pregnancy or exposure to secondhand smoke after birth increases the risk of childhood asthma.3 Adult-onset asthma is not uncommon and may be related to atopy, nasal polyps, aspirin sensitivity, occupational exposure, or a recurrence of childhood asthma. 

Asthma is a common disease worldwide, affecting more than 300 million individuals in the developed world [1]. The incidence of asthma varies in children worldwide from 2.1% in developing countries such as Albania to 32.2% in the United Kingdom (Fig. 1) [2]. In the United States, a trend of increasing asthma prevalence has occurred since 1980, with a possible plateau after 1997, regardless of gender, age, or ethnic group (Fig. 2) [3]. Approximately 7.1% of the United States population—more than 21 million Americans—currently experience asthma. 

Fig. 1. Worldwide asthma prevalence in children. The prevalence is higher in Western countries than Eastern countries. (From Lugogo NL, Kraft M. Epidemiology of asthma. Clin Chest Med 2006 27(l) l-15, v with pennission.)...

Centers for Disease Control and Prevention. Asthma prevalence and control characteristics by race/ethnicity-United States, 2002. MMWR Morb Mortal Wkly Rep 2004 53 145-8. 

The differences between the conditions are illustrated by their different geographical distribution. In Britain, the pattern of hay fever at the county level did not closely resemble that of atopic eczema , whereas the geographical distribution of asthma prevalence by county exhibited some similarities with the distribution of atopic eczema [15(111)]. The worldwide picture from ISAAC shows that there are differences in the geographical distribution of high, medium and low prevalences for the three conditions [6(III)]. 

Burr ML, Butland BK, King S, Vaughan-Williams E Changes in asthma prevalence Two surveys 15 years apart. Arch Dis Child 1989 64 1452-1456. 

Janson C, Anto J, Burney P, Chinn S, de Marco R, Heinrich J, Jarvis D, Kuenzli N, Leynaert B, Luczynska C, Neukirch F, Svanes C, Sunyer J, Wjst M European Community Respiratory Health Survey II The European Community Respiratory Health Survey What are the main results so far European Community Respiratory Health Survey II. Eur Respir J 2001 18 598-611. Robertson CF, Bishop J, Sennhauser FH, Mallol J International comparison of asthma prevalence in children Australia, Switzerland, Chile. Pediatr Pulmonol 1993 16 219-226. 

Partridge MR, Gibson GJ, Pride NB Asthma in Asian immigrants. Clin Allergy 1979 9 489-494. Waite DA, Eyles EF, Tonkin SL, O Donnell TV Asthma prevalence in Tokelauan children in two environments. Clin Allergy 1980 10 71-75. 

Cassano PA, Navon L, Rubin R The relation of serum antioxidants to the risk of asthma prevalence in children in NHANES III. Am J Respir Crit Care Med 2001 163 A39. 

Woolcock AJ, Peat JK, Trevillion LM Is the increase in asthma prevalence linked to increase in allergen load Allergy 1995 50 935-940. 

Akinbami LJ, Schoendorf KC Trends in childhood asthma Prevalence, health care utilization, and mortality. Pediatrics 2002 110 315-322. 

CDC National Center for Health Statistics. Asthma Prevalence, Health Care Use and Mortality, 2000-2001. Bethesda, MD, US Department of Health and Human Services, January 2003 http //www.cdc.gov/nchs/ products/pubs/pubd/hestats/asthma/asthma.htm accessed September 2003. 

Adult Asthma Prevalence and Morbidity in Rural vs. Urban Areas. 36... 

Because asthma and asthma-related symptoms constitutes a growing heallh problem around the world (Yu et al. 2011a, b), we undertook to investigate the disparities that exist between those living in urban vs. rural areas, in regard to the prevalence of asthma and asthma symptoms that they incur, hi particular, we evaluated the importance of geographic variations and their effects on asthma prevalence and morbidity among adults. In addition, we evaluated the possible causes of asthma morbidity between urban vs. mral residents. 

This article extends our earlier work (Yu et al. 2011a, b), in which we tried to determine the factors that affect the prevalence of asthma, allergy, and respiratory symptoms among adults, and whether rural/urban living has an effect on asthma prevalence. Investigating the differences that environmental risk factors pose to adults on prevalence of asthma and asthma-related symptoms in urban and rural locations may provide clues to the mechanisms by which asthma and asthma morbidity occur, and may also uncover needs that are currently unmet. 

Variability in urban-rural prevalence of asthma and asthma-related symptoms has been observed in many parts of the world (Nguyen et al. 2010). Several authors of international smdies have reported that exposure of sensitized asthmatics to allergens affected asthma prevalence and morbidity in urban vs. rural areas. 

In India, Gaur et al. (2006) found that the prevalence of asthma among the rural, urban city and urban-slum adult population of Delhi were 13.34%, 7.9% and 11.92%, respectively. The current prevalence of asthma was more pronounced if there was a history of family atopy, or where more vegetable debris, poor ventilation, air pollution and increased human density were present. There was also an association with increased smoking habits. However, no significant difference was noted in asthma prevalence between those living in urban and rural areas (Gaur et al. 2006). 

Exposure to smoking Ghosh et al. (2009), Canada Cross-sectional study Residents aged 18-64 years (n=1,362/4,240) Asthma Rural female smokers 1.4 times (95% Cl, 1.02 1.94) more likely to be diaguosed with asthma Living in a rural area and smoking increased asthma prevalence. 

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