Health of adults
Globally about 51 million people of all ages died in 1993， about three-quarters of them adults. Some 39 million deaths took place in the developing world and about 12 million in the developed. Poor countries had three times more deaths than rich ones.
Communicable diseases such as tuberculosis and respiratory infections as well as maternal， perinatal and neonatal conditions account for about 20 million， or about 40%， of the 51 million global deaths； and 99% of these occur in the developing world.
Noncommunicable diseases such as cancer and heart disease account for about 19 million deaths， or 36% of the global total， divided more or less equally between the developing and the developed world. The great majority of such deaths are among adults.
External causes such as accidents and violence account for about 4 million deaths， or some 8% of the total， again mostly among adults. Developing countries have nearly four times the number of deaths from these causes as the developed world. Other and unknown causes account for the remaining 16% of deaths worldwide.
Maternal complications claim another 508 000 lives a year.
Of the 20 million deaths due to communicable diseases more than 16 million， or about 80%， are due to infectious and parasitic diseases. Tuberculosis kills about 3 million people， malaria around 2 million and hepatitis B possibly 1 million.
Among the major communicable diseases， tuberculosis was responsible for more than 5% of the global total of deaths - over 7 000 a day - and it is estimated that there will be 8.8 million new cases in 1995 - equal to more than 1 000 new cases every hour of every day. Drug treatment， in most cases costing as little as US $13-30 per person for a six-month course， can cure people； but providing the drugs to those who need them， and ensuring that patients take them for the required period， is a major public health challenge.
Meanwhile the lethal relationship of tuberculosis with HIV is making the death toll many times worse. During the next 10 years in Asia alone it is estimated that tuberculosis and AIDS together will kill more people than the entire populations of the cities of Singapore， Beijing， Yokohama and Tokyo combined.
Malaria， directly or in association with acute respiratory infections and anaemia， causes around 2 million deaths a year， the vast majority among young children， and some 400 million cases annually. Globally more than 2 billion people are threatened. The estimated direct and indirect cost of the disease in Africa alone is expected to reach US $1.8 billion by 1995.
Cholera has become endemic in many countries in Africa， Asia and Latin America. In 1993 there were 377 000 new cases reported and only 6 800 deaths. Nevertheless， the number of cases and deaths remain at far higher levels than those reported earlier.
Among the other communicable diseases， dengue and dengue haemorrhagic fever are now the most important and rapidly rising arbovirus infections in the world. There are millions of cases annually， with approximately 500 000 people needing hospital treatment， and thousands of deaths. The ancient scourge of leprosy still causes 600 000 new cases a year. Between 2 and 3 million people are disabled by the disease， including those who have been cured but crippled in some way prior to treatment. Onchocerciasis （river blindness） infects 18 million people in 34 countries， while dracunculiasis （guinea- worm disease） causes terrible suffering and disability among 3 million of the world s most deprived people who have no access to safe water. Chagas disease affects 17 million people in 21 countries in Latin America and causes 45 000 deaths and 400 000 cases of heart and stomach disease annually. African trypanosomiasis （sleeping sickness）， kills an estimated 55 000 people a year. Schistosomiasis （bilharziasis or snailfever） affects 200 million people in 74 countries in the Americas， Africa and Asia and kills perhaps 200 000 people. Leishmaniasis infects about 13million people. Visceral leishmaniasis， also known as kala-azar， is the most severe form. Almost always fatal if untreated， it causes some 500 000 cases and more than 80 000 deaths a year. Lymphatic filariasis （elephantiasis）affects around 100 million people， while Ascaris causes clinical symptoms in as many as 214 million people， Trichuris in 133 million and hookworm in 96 million.
Sexually transmitted diseases impose a huge health burden across the world. Some 236 million people are estimated to have trichomoniasis， with 94 million new cases a year. Chlamydial infections affect some 162 million people， with 97 million new cases annually. An estimated 32 million new cases of genital warts occur each year， and there are some 78 million new cases of gonorrhoea. Genital herpes infects 21 million people a year， and syphilis 19 million. More than 9 million people are infected with chancroid each year.
Many， if not all， STDs could be avoided if condoms were used. Most STDs can be treated effectively and cheaply - the cost of treating genital ulcer disease， for instance being between US $0.5 and US $4 per person. But thereare problems in the supply and accessibility of services， compounded by fear of stigma on the part of patients and the attitude of some service providers.
HIV and AIDS continue to spread relentlessly. WHO estimates that in 1994 HIV prevalence among adults worldwide was over 13 million. Some 6 000 people are becoming infected each day. In parts of Africa and Asia the virus is advancing rapidly. In southern and south-eastern Asia HIV infections were estimated at 2.5 million - a million more than in 1993.
In 1993， 2 065 cases of human plague （with 191 deaths） recorded in 10 countries in Africa， Asia and the Americas were notified to WHO. That numberexceeded the 1992 total and the annual average for the previous 10 years. The outbreak was a stern reminder to the world that a dreaded disease， often regarded as a scourge of the past， still exists.
Noncommunicable diseases such as those of the circulatory system account for10 million deaths globally， with more than 5 million due to heart disease and another 4 million due to cerebrovascular conditions （such as stroke）。 These and other noncommunicable diseases that primarily affect adults are also emerging as a major cause of death in the developing world. Although until recently heart disease and stroke were perceived as problems of the developed countries， about 44% of total deaths from these causes now occur in the developing world. Cancer accounts for 6 million or 12% of deaths globally - with the majority of them， 58%， in the developing world.
Among the other noncommunicable diseases， chronic obstructive pulmonary diseases such as chronic bronchitis and emphysema killed nearly 2.9 million adults in 1993， representing about 6% of total deaths. The number of sufferers in the world from these diseases is put at 600 million. This is the second largest known category of persons with a single disorder recorded by WHO. At the same time there are believed to be 275 million asthma sufferers in the world， although WHO has no data on the number of deaths due to this condition.
Diabetes mellitus is a growing public health problm in both developed and developing countries. A recent WHO expert group estimated that more than 100 million people will suffer from diabetes by the end of this century - 85-90% with the non-insulin dependent form. In Europe the prevalence of diabetes is 2-5% per cent of the adult population. In India a quarter of the populationis affected by the age of 60， and 1 in 5 North Americans will acquire thedisease by the age of 70. One recent estimate put the cost of diabetes in the USA alone， both direct and indirect， at US $92 billion a year.
Mental ill-health is at the bottom of the medical pecking order. Only the most severe cases， such as schizophrenia or manic depression， receive what minimal care there is， even in developed countries. There are disturbing signs that society would sooner have such patients wandering the streets homeless than provide them with the care they need. The stigma of madnessis still a potent barrier in preventing ill people from receiving help. Some500 million people are believed to suffer from neurotic， stress- related and somatoform disorders. A further 200 million are affected by mood disorderssuch as chronic and manic depression. Mental retardation afflicts some 83 million people， epilepsy 30 million， dementia 22 million and schizophrenia16 million.
Smoking is emerging as the world s largest single preventable cause of illness and death. WHO estimates that there are about 1.1 billion smokers in the world today. About 800 million are in the developing world - nearly three times as many as in developed countries. Smoking already kills an average of 3 million adults a year worldwide. If current trends continue， this figure is expected to reach 10 million by the year 2020.
In the area of women s health and childbirth， the differences in maternal mortality between countries are shocking. In Europe maternal mortality is 50 per 100 000 live births. In some of the least developed countries the rate exceeded 700 maternal deaths per 100 000 births in 1991. In developingcountries 1 in 5 deaths of women of reproductive age are due to complications of pregnancy and delivery. Half a million women die every year from conditions which are easily preventable.
Health of the elderly
The increase in the number of old people in the world will be one of the most profound forces affecting health and social services in the next century. Overall， the world s population has been growing at an annual rate of 1.7% during the period 1990-1995 - but the population aged over 65 is increasing by some 2.7% annually. Of a world total of 355 million people over 65 in 1993， more than 200 million are in the developing world， where they make up 4.6% of the population， with more than 150 million in developed countries， where the proportion is 12.6%. Although Europe， Japan and the USA currently have the oldest populations， the most rapid changes are being seen in the developing world， with predicted increases in some countries of up to 400% in people aged over 65 during the next 30 years.
Alongside the increase in the number of people over age 65， there will also be a dramatic rise in the numbers of old old - people over 80. In 1993 they constituted 22% of those over 65 in developed countries and 12% in the developing world. The world elderly support ratio （the number of people over 65 years compared to those aged 20-64） in 1990 was 12 elderly to every 100 people of working age. It is estimated that the figure will be 12.8 in the year 2000 and 13.2 in 2010. In other words， while population increase during1990-2000 is estimated to be 17%， the increase in the number of elderly is likely to be 30%.
One of the most difficult questions for health planners and politicians trying to allocate funds， as well as for the community and individuals themselves， is whether increased life expectancy means more health or simply more years of sickness. This is an area that is greatly underresearched， yet the question is assuming ever greater importance.
Two of the most pressing problems in the future will be the provision of care for people with dementia and those needing joint replacements for arthritic diseases. WHO estimates that there are 165 million people in the world with rheumatoid arthritis. The long-term care of the frail elderly is becoming one of the most debated medical and political issues in many developed countries， and the developing world too will soon have to wrestlewith it. If people are not to be left destitute and uncared for at the end of their lives， more attention must be given to social mechanisms for the support of the elderly and the means to fund them.
General health issues
Although in the past 10 years there has been a global trend towards the democratization of political systems， the much anticipated peace dividend has failed to materialize. Poverty has continued， and will continue， to be a major obstacle to health development. The number of poor people has increased substantially， both in the developing world and among underprivileged groups and communities within developed as well as developing countries. During the second half of the 1980s， the number of people in the world living in extreme poverty increased， and was estimated at over 1.1 billion in 1990 - more than one-fifth of humanity.
The changing demographic picture across the world， together with the rapid shift towards urbanization， will have profound implications for the delivery of health services. The unplanned and often chaotic growth of megacities in the developing world will pose particular challenges， as poor sanitation and housing encourage the spread of infectious diseases.
Against any optimism about the global economy throughout the remainder of this century and beyond should be set a number of major uncertainties. There has been a disproportionate flow of resources from the developing to the developed world - poor countries paying money to rich ones - because of debt servicing and repayment and as a consequence of prices for raw materials that favour the latter at the expense of the former. Structural adjustment policies aimed at improving the economic performance of poor countries have in many cases made the situation worse. The words of Robert McNamara， spoken in 1980 when he was President of the World Bank， still hold true： The pursuit of growth and financial adjustment without a reasonable concern for equity is ultimately socially destabilizing.
A further worrying global trend is growing unemployment， especially in developing countries without social security arrangements to cushion those out of work. Long-term unemployment is creating a new class of untouchables - by excluding a large group of people from the mainstream of development and society. The unemployed are a potent reminder of the dangers of assuming that the general prosperity of a country will trickle down to all its members.
There is also considerable concern about the adverse health effects of continuing environmental degradation， pollution and the uncontrolled dumping of chemical wastes， diminishing natural resources， depletion of the ozone layer and predicted global climate changes.
Social mores are also undergoing profound changes， with a move towards shorter marriages and more divorces in many countries， leading to family breakdowns which have repercussions for individuals and for social services that may be called on to provide help for children and single parents.
Beyond any considerations for improving the health of the world must be the recognition that the growing world population will strain to the limit the ability of social， political， environmental and health infrastructures to cope. Health infrastructure - buildings and equipment， the staff， the drugs， the vehicles - is central to good health care. Services must be integrated， cost-effective and provided as close as possible to the people who need them.
With health resources unlikely to be greatly increased but with ever growing demands for services， because of expanding populations and the advances of science which make more conditions treatable， the debate about the rationing of health care， with the attendant ethical problems， is likely to become intense. Hard choices will have to be made - and greatly enhanced mechanisms found for listening to the voice of the health consume
WHOs contributions to world health
Within the framework of the organization s constitution and the guidance given in the periodic general programmes of work， all WHO activities are geared to respond to the priority problems of the age groups referred to in this summary. The full extent of WHOs work at national， regional and global levels cannot be reflected here， but examples are given of different types of action.
Child and adolescent health
WHO encourages self-reliance of countries in conducting immunization through basic health services. It cooperates with UNICEF in its initiative of supplying vaccines to over 100 countries. Major priorities are to at least sustain the accomplishments of previous years and to continue to strive for achievement of the 1992 World Summit for Children goal of immunization against the six vaccine-preventable diseases （diphtheria， pertussis， tetanus， measles， poliomyelitis， tuberculosis）。
In an effort to make the best use of limited resources to eliminate neonatal tetanus， WHO has given priority to countries that account for 80% of total cases and have an estimated mortality of 5 or more per 1 000 live births. WHO initiated a series of measures to arrest the spread of diphtheria in eastern Europe， including the formulation of a plan of action and the establishment of a European task force. In 1993 progress towards the poliomyelitis eradication goal was heartening. Efforts are being made to develop a more heat-stable poliovirus vaccine that can be delivered with a less rigorously maintained cold chain. Large donations for poliomyelitis eradication were coordinated with different organizations. In 1994 the region of the Americas committed itself to eliminating measles by the year 2000， and incidence is now at the lowest level ever. If the momentum is sustained the Americas may well lead the way towards global elimination of this major killer of children.
By the end of 1994 virtually all developing countries had implemented plans of action against diarrhoeal diseases in children. Nearly 42% of health staff in the countries had been trained in supervisory skills using materials developed by WHO， and almost 30% of doctors and other health workers had been trained in diarrhoea case management， many of them in the more than 420 diarrhoea training units established in over 90 countries. It is estimated that nearly 85% of the population of the countries had access to oral rehydration salts at the end of 1994.
Particular emphasis is given to training in the management of acute respiratory infections WHO supports courses for workers in first-level health facilities and referral hospitals on standard case management， and distributes training and technical materials. More than 190 000 health managers， doctors， nurses and community health workers in over 60 countries have been trained so far. WHO is involved in numerous studies on acute respiratory infections in Africa， Asia and Latin America.
Activities for better nutrition are promoted in 62 countries， mostly in collaboration with FAO and UNICEF. A global database on child growth was established and more than 90 countries are receiving technical and financial support to give effect to the International Code of Marketing of Breast milk Substitutes. The new WHO/UNICEF baby-friendly hospital initiative has proved hugely successful in encouraging proper infant feeding practices， starting at birth. It has already been implemented in two-thirds of African countries. A number of countries have introduced national nutrition policies with WHO support.
A wide range of WHO programmes focus on the needs of adolescents in such fields as nutrition， mental health， sexuality， disease and injury prevention， and substance abuse. A joint UNICEF/WHO/UNFPA policy statement on the reproductive health of adolescents was disseminated. WHO supported the formulation of policies on adolescent health in 20 countries.