Which population level environmental factors are associated with asthma, rhinoconjunctivitis and eczema? Review of the ecological analyses of ISAAC Phase One.

The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One showed large worldwide variations in the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema, up to 10 to 20 fold between countries. Ecological analyses were undertaken with ISAAC Phase One data to explore factors that may have contributed to these variations, and are summarised and reviewed here.In ISAAC Phase One the prevalence of symptoms in the past 12 months of asthma, rhinoconjunctivitis and eczema were estimated from studies in 463,801 children aged 13 - 14 years in 155 centres in 56 countries, and in 257,800 children aged 6-7 years in 91 centres in 38 countries. Ecological analyses were undertaken between symptom prevalence and the following: Gross National Product per capita (GNP), food intake, immunisation rates, tuberculosis notifications, climatic factors, tobacco consumption, pollen, antibiotic sales, paracetamol sales, and outdoor air pollution.Symptom prevalence of all three conditions was positively associated with GNP, trans fatty acids, paracetamol, and women smoking, and inversely associated with food of plant origin, pollen, immunisations, tuberculosis notifications, air pollution, and men smoking. The magnitude of these associations was small, but consistent in direction between conditions. There were mixed associations of climate and antibiotic sales with symptom prevalence.The potential causality of these associations warrant further investigation. Factors which prevent the development of these conditions, or where there is an absence of a positive correlation at a population level may be as important from the policy viewpoint as a focus on the positive risk factors. Interventions based on small associations may have the potential for a large public health benefit

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

Global variations in prevalence of eczema symptoms in children from ISAAC Phase Three

BACKGROUND: In 1999, The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One reported the prevalence of eczema symptoms in 715,033 children from 154 centers in 56 countries by using standardized epidemiologic tools. OBJECTIVE: To update the world map of eczema prevalence after 5 to 10 years (ISAAC Phase Three) and include additional data from over 100 new centers. METHODS: Cross-sectional surveys using the ISAAC questionnaire on eczema symptoms were completed by adolescents 13 to 14 years old and by parents of children 6 to 7 years old. Current eczema was defined as an itchy flexural rash in the past 12 months and was considered severe eczema if associated with 1 or more nights per week of sleep disturbance. RESULTS: For the age group 6 to 7 years, data on 385,853 participants from 143 centers in 60 countries showed that the prevalence of current eczema ranged from 0.9% in India to 22.5% in Ecuador, with new data showing high values in Asia and Latin America. For the age group 13 to 14 years, data on 663,256 participants from 230 centers in 96 countries showed prevalence values ranging from 0.2% in China to 24.6% in Columbia with the highest values in Africa and Latin America. Current eczema was lower for boys than girls (odds ratio, 0.94 and 0.72 at ages 6 to 7 years and 13 to 14 years, respectively). CONCLUSION: ISAAC Phase Three provides comprehensive global data on the prevalence of eczema symptoms that is essential for public health planning. New data reveal that eczema is a disease of developing as well as developed countries

Gray Wolf Restoration in the Northwestern United States

Gray wolf (Canis lupus) populations were eliminated from Montana, Idaho, and Wyoming, as well as adjacent southwestern Canada by the 1930s. After human-caused mortality of wolves in southwestern Canada began to be regulated in the 1960s, populations began expanding southward. Dispersing individuals occasionally reached the northern Rocky Mountains of the United States, but lacked legal protection there until 1974, after passage of the Endangered Species Act of 1973. In 1986, wolves from Canada successfully raised a litter of pups in Glacier National Park, Montana, and a small population was soon established. In 1995 and 1996, wolves from western Canada were reintroduced to remote public lands in central Idaho and Yellowstone National Park. These wolves were designated as nonessential experimental populations to increase management flexibility and address local and state concerns. Wolf restoration is rapidly occurring in Montana, Idaho, and Wyoming, and there were at least 28 breeding pairs in December 2000. There are now about 63 adult wolves in northwestern Montana, 192 in central Idaho, and 177 in the Greater Yellowstone area. Dispersal of wolves between Canada, Montana, Idaho, and Wyoming has been documented. Occasional lone wolves may disperse into adjacent states, but population establishment outside of Montana, Idaho, and Wyoming is probably not imminent. The gray wolf population in the northwestern U.S. should be recovered and, depending on the completion of state and tribal wolf conservation plans, could be proposed to be removed from Act protection within three years. Wolf restoration has proceeded more quickly and with more benefits, such as public viewing than predicted. Problems, including confirmed livestock depredations, have been lower than estimated. The Service led interagency recovery program focuses its efforts on achieving wolf recovery while addressing the concerns of people who live near wolves. Wolves have restored an important ecological process to several large wild areas in the northern Rocky Mountains of the U.S. The program has been widely publicized and is generally viewed as highly successful