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. Last Updated: 07/27/2016

Killers of the Future: Cars, Cigarettes, Suicide

WASHINGTON -- The coming plague is not Ebola virus, flesh-eating bacteria and cryptosporidium, it's not even malaria, tuberculosis and AIDS. It's heart attacks, emphysema and car accidents.

Over the next 25 years, most of the world's population will retrace the path of illness and death laid down over the last half-century by the globe's affluent minority of Americans, Canadians and Western Europeans.

There will be some new wrinkles, of course. Men in the former Soviet bloc may suffer even more from the effects of tobacco than American men once did. Africans will pay an enormous toll in death from trauma, much of it suffered on the highways. Suicide -- already epidemic among Chinese women -- will rise around the world as a cause of death.

Overall, however, deaths from infection and malnutrition will continue to decline, as they have for most of the 20th century. Rising to take their place will be "noncommunicable" diseases and injuries that are the hallmarks of an escape from extreme poverty and ignorance.

Those are among the conclusions of a massive new assessment of the world's state of health, and of the changes it is likely to undergo between now and 2020. Five years in the making, the report was sponsored by the World Health Organization, or WHO, and the World Bank, and produced by researchers at the Harvard School of Public Health and WHO, with 100 collaborators around the world.

Two volumes, "The Global Burden of Disease," which explains the project's methods and conclusions, and "Global Health Statistics," which contains most of the underlying epidemiological data, were published Monday. Eight more volumes, which contain data on 107 diseases and 483 health effects examined by the researchers, as well as country-by-country analyses, will appear later.

Taken together, the volumes are likely to be an essential source of information for health policy planners for the next few decades.

In its most utterly pared-down form, the probable vision for the future is this: Things will get better.

Over the next 25 years, life expectancy will be greater for men and women in all regions of the world than it is now. The one exception is men in the former Soviet bloc, and even they are expected to make up the loss of longevity they have suffered since 1990.

Furthermore, the years gained are likely to be relatively healthy ones. People in the developing world, whose lives now contain a larger fraction of disabled or unhealthy time than do the lives of more affluent people, will gain the most. Their added longevity -- which in the case of sub-Saharan African women will be an astonishing 13 years -- is predicted to be relatively disability-free.

In children and adolescents younger than 15, the risk of death will decline everywhere. In India and sub-Saharan Africa, it will fall by two-thirds. Worldwide, the fraction of deaths caused by infection, childbirth and malnutrition -- the major health problems of poverty -- will drop by more than half, from 34 percent now to about 15 percent in 2020.

This is true even in the face of the AIDS epidemic, which is peaking in Africa but has not yet peaked in India and Southeast Asia. (The researchers assumed the epidemic will be steady 25 years from now, with regional death rates about 50 percent of what they were at their peaks.)

"Basically, it's a pretty upbeat message," said Christopher Murray, a physician at the Harvard School of Public Health, who was one of the two lead researchers of the "Global Burden of Disease" project.

The driving force behind these trends is not primarily improvements in medical care. Instead, it's demographic, economic and technological change.

Most important among these is the simple aging of the world's population. That is occurring because of trends toward longer life, combined with a steady decline in fertility, or the number of children produced by the average woman. As just one example of this dramatic shift, the proportion of the population age 45 and older is expected to rise 200 percent between 1990 and 2020.

Simultaneously, income is predicted to rise in most regions, and education will become more widely available. In addition, technological advances are expected to occur at least at the rate they have over the last 30 years, and existing tools such as vaccines and water chlorination are expected to be more fully used. All three of those variables have profound positive effects on a population's health.

Both the increased longevity and rising wealth of the world's population are major reasons that "noncommunicable" diseases and injuries are expected to account for nearly three-quarters of deaths in 2020, compared with just over half now. But there are other reasons, too.

Perhaps the most important single variable affecting the world's health 25 years from now is the use of tobacco. Smoking caused 2.6 percent of the disease "burden" -- death and disability -- in 1990. This is expected to increase to just under 10 percent by 2020, the result of huge epidemics of smoking-related disease now forming in Eastern Europe, China and in many developing countries. "This is a global health emergency that many governments have yet to confront," Murray and his co-author, Alan Lopez of the World Health Organization, wrote in the report.

Perhaps the most overlooked cause of death and disability, however, is injury. (Use of the word "accident" is frowned upon by epidemiologists, as it suggests the injurious events are unavoidable.) Injuries now cause about 5 million of the 50 million deaths that occur each year on the globe. For men between the ages of 15 and 44, road traffic injuries are the leading cause of death. As more people enter this age group (as will occur dramatically in sub-Saharan Africa), this cause of death and disability will rise steeply.

"In most countries, there is almost no attention paid by governments to injury prevention," Murray said.