Diseases of affluence and poverty

The Economist challenges the common distinction between the diseases of the rich and the diseases of the poor in its current issue (9 August). Poor countries are increasingly suffering as a result of chronic diseases while infectious ones become relatively less important. The main reason for this shift seems to be rising life expectancy in the poorer countries – so in many ways the shift can be seen as a sign of success. But people in the poor countries tend to get chronic diseases earlier than in the rich ones and they have a more deadly effect.

“Heart disease—supposedly an illness of affluence—is by far and away the biggest cause of global mortality. It was responsible for 17.5m deaths worldwide in 2005. Next comes cancer, another non-infectious sickness, which caused more deaths than HIV/AIDS, tuberculosis and malaria put together (see chart 1). Chronic conditions such as heart disease took the lives of 35m people in 2005, according to the World Health Organisation (WHO)—twice as many as all infectious diseases.”

“If you look at lower-middle income countries, such as China, or upper-middle income ones, like Argentina, you find that what kills people there is the same as in the West (see chart 2). Four-fifths of all deaths in China are from chronic sicknesses. That is also true of countries as varied as Egypt, Jamaica and Sri Lanka.

“The main difference between these countries and rich ones is that chronic illnesses are more deadly there. Five times as many people die of heart disease in Brazil as in Britain, though Brazil is not five times as populous. Rich countries have become better at dealing with chronic conditions: death rates from heart disease among men over 30 have fallen by more than half in the past generation, from 600-800 per 100,000 in 1970 to 200-300 per 100,000 now.

“This has not happened in middle-income countries. In 1980 the death rate for Brazilian men was below the rich-country average (300 compared with 500-600). Its death rate has not changed—and is now higher than all but a few rich countries. Russia is worse off. In 1980 its death rate was 750 per 100,000. Now it is 900, about four times as high as most rich countries.”

Only in Africa are infectious diseases killing more people than chronic conditions. But even among low income countries the balance is likely to shift over the next few years.