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Open Mike

Michael J. Klag, MD, MPH

Michael J. Klag, MD, MPH

The New Pandemic

Times change, and so do the diseases that kill us.

In the early 20th century, infectious diseases, such as pneumonia and influenza, tuberculosis and diarrheal diseases, were the leading causes of death in the U.S. In fact, our School was in the thick of a public health crisis caused by an infectious disease soon after it was founded: the flu pandemic of 1918 that claimed more than 50 million lives. Our School's first director, William Henry Welch, helped lead the national response to the calamitous epidemic—until he too fell gravely ill.

Thankfully, we have made great strides since then. In the past century, overall mortality in the U.S. has fallen by half. As childhood mortality fell, life expectancy increased and mortality shifted from acute infectious diseases to cardiovascular disease, cancer and other chronic diseases.

Now, the rest of the world has followed in our footsteps. The chronic disease pandemic has arrived. WHO estimates that chronic disease claimed 35 million lives in 2005. Worldwide, cardiovascular disease is the leading cause of death, followed by cancer.

Two of the world's most populous countries illustrate the impact of chronic disease. Both India and China are economic giants who have enjoyed surging prosperity yet suffer from industrialization's unhealthy fallout (high-fat diets and reduced physical activity, among other examples). In a study I co-authored with Jiang He when he was a student at our School (he is now chair of Epidemiology at Tulane), we documented urbanization's startling toll on the health of the Yi people of southwestern China. Soon after the Yi migrated from villages based on subsistence agriculture to more urban centers, they typically adopted a higher-salt, lower-potassium diet and reduced their physical activity. Their blood pressure increased precipitously and quickly reached the levels of Western societies. Recently we documented that death from chronic diseases outweighs infectious disease mortality in China.

Likewise, India is struggling with chronic disease. It's been well documented that South Asians have a genetic predisposition to diabetes and heart disease. Diabetes prevalence is 7 percent in the U.S. but more than 12 percent in India. Already, India has a higher death rate from chronic disease than countries such as the United Kingdom and Canada. Pick any country now enjoying the fruits of globalization, and you will see its citizens are suffering from globalization's costs to human health.

The world is never going to be able to treat its way out of the pandemic of chronic disease. Prevention is key. A recent study estimates that a global reduction of the chronic disease death rate by 2 percent per year between 2005 and 2016 would prevent 36 million deaths.

With more than 5 million premature deaths worldwide each year caused by smoking—far more than from AIDS or malaria—tobacco control is a great place to start. If we sharply reduce tobacco use, then we will have a tremendous impact on cancer, heart disease, respiratory diseases and other tobacco-related diseases. That's why the $500 million antismoking initiative announced in July by New York Mayor Michael R. Bloomberg and Bill Gates is so important. Fifty-seven percent of men in India and China—countries that make up one-third of the world's population—use tobacco. Mayor Bloomberg and Mr. Gates have recognized that, unless something is done, a billion people around the world will die in this century from tobacco-related disease.

The Bloomberg School's role in combating chronic disease is to continue to train future leaders who will devise and implement prevention programs, generate evidence through research that allows the formation of rational polices and preventive strategies, and advocate for fair and equitable health systems. We need to be on the forefront of strategies that encourage people to adopt healthy diets, engage in regular physical activity and avoid tobacco.

We also need to advocate for the development and dissemination of cost-effective treatment of highly prevalent risk factors such as high blood pressure, high cholesterol and cigarette smoking within comprehensive primary health care systems. The evidence strongly supports that such health systems result in better population health. We need to build systems that are flexible, prevention-oriented and able to detect risk factors and disease in the early stages.

Of course, infectious diseases are not going away and we cannot relax our vigilance or stop—or even slow—our vital research into HIV/AIDS, malaria or any infectious disease. We have learned that lesson too many times. The war on chronic diseases will require new resources as Mayor Bloomberg and Mr. Gates have recognized. Those of us in public health need to broaden our thinking and expand our agenda to recognize the major causes of morbidity and mortality.

Public health professionals like BIG problems. I am confident that we will figure out innovative strategies for addressing this new pandemic. Otherwise, we may be saving people from infectious disease only to lose them to chronic disease.

Michael J. Klag's signature
Dean Michael J. Klag
Johns Hopkins Bloomberg School of Public Health

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