Noncommunicable diseases: tomorrow's pandemics.

Abstract

For centuries infectious diseases were the main causes of death worldwide. Life expectancy was short and epidemics raged. In the 19th century, public health measures, basic hygiene and antiseptics marked the beginning of a way to counter the scourge, but infection continued to be the main cause of death until the Second World War. The second revolution in disease control came with the introduction of penicillin and other antibiotics after 1945. Effective treatment for tuberculosis soon followed. But then came the inexorable rise of non-infectious diseases. Ischaemic heart disease and cancers became the scourges of the West together with chronic pulmonary diseases and cerebrovascular disease. As life expectancy increased so did the prevalence of these disorders. Chronic mental diseases and the diseases of ageing such as dementias and "structural" diseases also became more evident. During the past three decades, great efforts have been made to deal with these chronic diseases. Many of the risk factors for heart disease, cancers, stroke and chest disease have been identified. Smoking, known to be a major health problem for the past four decades, is finally being attacked in the developed world, and lifestyle factors (particularly nutrition and physical activity) are slowly being tackled although much remains to be done. Scientific developments, including the new genetics, are being used to pinpoint causes of chronic diseases and to develop more sophisticated organ replacement treatment. Life expectancy in the developed world is slowly but surely increasing, but at a cost. Economically, the cost per head of health care is mushrooming at the rate of hundreds of dollars per head, in some countries thousands. Socially, the cost is an increasing divide in health care and health between the richest and poorest nations. In the developing world infectious diseases remain a major cause of death. Malaria and gastroenteritis continue to take their toll. Over the past two decades any advances against infection have been reversed by the rise of HIV-related disorders. Life expectancy in many countries, particularly in sub-Saharan Africa, has fallen dramatically -- to make a near 30 year gap between the North and South in some cases. Tuberculosis has surged with resistant forms appearing. In our work in the United Republic of Tanzania with the Adult Mortality and Morbidity Project we have shown consistently over the past decade that HIV, with or without tuberculosis and "acute febrile illness" (presumably malaria), is the main causes of death in adults, with gastroenteritis killing both children and adults. Against this gloomy background noncommunicable diseases are emerging as major problems as well. This is particularly the case where economic conditions have improved with rapid industrialization, such as Singapore (see Cutter et al., pp. 908-915). Diabetes and cardiovascular disease are the main chronic diseases to have reached alarming proportions. As the work of Murray and Lopez on the burden of diseases shows, the whole NCD cluster is a major problem in the middle income countries, with ischaemic heart disease taking the lead. As a percentage of deaths, NCDs accounted for 87% in the established market economies, 84% in the former Soviet economies, 73% in China, 40% in India and 23% in sub-Saharan Africa. …