World health report

Executive summary

Crossing the threshold

Together, these and related achievements should help humankind to step confidently across the threshold into the new century. However, the future will pose many new as well as continuing challenges.

The war against ill-health in the 21st century will have to be fought simultaneously on two main fronts: infectious diseases and chronic, noncommunicable diseases. Many developing countries will come under greater attack from both, as heart disease, cancer and diabetes and other "lifestyle" conditions become more prevalent, while infectious illnesses remain undefeated. Of this latter group, HIV/AIDS will continue to be the deadliest menace.

This double threat imposes the need for difficult decisions about the allocation of scarce resources. Experience shows that reduced spending on controlling infectious diseases can cause them to return with a vengeance, while globalization - particularly expanding international travel and trade, including the transportation of foodstuffs - increases the risks of their global spread. At the same time, the stealthy onset of chronic conditions also saps a nation's strength. This trend will increasingly be the main focus of attention in industrialized countries which, however, must not lower their guard against infectious diseases.

The past few decades have seen the growing impact on health of poverty and malnutrition; widening health inequalities between rich and poor; the emergence of "new" diseases such as HIV/AIDS; the growing problem of antibiotic-resistant infections; and the epidemic of tobacco-related diseases.

These are only some of the problems representing the unfinished agenda of public health actions at the end of one century and requiring urgent action at the beginning of the next.

This report looks at the health implications for all age groups - infants and small children under 5; older children of school age and adolescents (5-19 years); adults (20-64 years); and older people (65 and over). Some of the main findings of the report, as they apply to each age group, are summarized below.