Asthma, the Epidemic That Came and Stayed

In 1983, the Lancet published an article describing an asthma epidemic in Barcelona. Over a period of a few hours, dozens of patients were treated for severe asthma attacks in the emergency departments of several hospitals. These transient epidemics occurred repeatedly over several years, affecting several thousand people and causing more than 10 deaths. It took intense research to demonstrate that the epidemics were caused by inhalation of soybean dust produced by the unloading of soybeans from ships in the Port of Barcelona. The epidemics ceased in 1987 after filters were installed on the silos that had caused the problem and a proper system was established to monitor levels of soy allergen in the air.

During the same period, another asthma epidemic was developing, in this case a silent and more generalised one. As a result of this widespread epidemic, asthma has become the most common disease in childhood and one of the chronic diseases with the greatest impact on health in many countries. The prevalence of chronic diseases tends to rise and fall for reasons that are often difficult to establish. While the reason, or to be more precise the reasons, for the epidemic increase of asthma remain a mystery, the most popular theory—known as the hygiene hypothesis—postulates that a decrease in childhood infections has given rise to an imbalance in the immune response, which in turn has led to an increase in allergy and asthma. The worst thing about this epidemic is that it came and never left. The best news is that, in the areas of the world where the increase in asthma has been the highest, its prevalence appears to have stopped rising.

Today, an estimated 300 million people worldwide suffer from asthma, a disease that affects all ages and socioeconomic groups and is found throughout the world. In the latest report on the Global Burden of Disease published in the Lancet in 2012, asthma was twenty-eighth in the ranking of causes of health loss measured in disability-adjusted life years (DALYs); it ranked twenty-third in Europe, fifteenth in the U.S.A, and eighth in Oceania. Although the mortality associated with asthma is relatively low, the condition causes an estimated 250,000 deaths every year. Unfortunately, we have no effective strategies to prevent or cure asthma. However, the condition can be effectively managed and controlled, and treatment very significantly reduces its impact on the patient’s daily activities, work, and social life as well as minimising emergency ward and hospital admissions. And this is one of the global challenges we now face: to provide universal access to effective treatment for asthma.

A national strategy in Finland has demonstrated the feasibility of reducing the health burden and economic cost of asthma. However, for most of the world’s population, access to basic health care is far from a reality, and access to inhaled corticosteroids, the cornerstone of asthma treatment, even further. The proposal that inhaled corticosteroids should be considered an essential drug seeks to address this problem and facilitate access to this medication in the world’s poorest countries. The other major challenge we face—developing effective strategies to prevent asthma—continues to be the focus of numerous research projects, including some that are investigating ways to restore the immune balance that has apparently been lost in these patients. The possibility of discovering effective strategies for preventing and controlling asthma worldwide in the near future depends on this research.

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Global Initiative for Asthma

Dr. Josep M. Antó is the Director of CREAL, an ISGlobal research centre, and Professor of medicine at the Universitat Pompeu Fabra (UPF) in Barcelona.