Charting the future
The situation described in the report - the emergence or re-emergence of certain infectious diseases and increasing resistance to antibiotic drugs - constitutes a serious crisis requiring immediate action. Some of the diseases can be controlled, eliminated or eradicated, for instance, by means of immunization, personal hygiene and/or public health and sanitation practices. The proper use of antimicrobial drugs and vector control methods have a part to play in the fight against certain diseases. All these measures can lead to a rapid reduction in infectious diseases and thus enhance overall development, provided that there is political and professional commitment to finance and sustain well-planned, cost-effective interventions.
The diseases concerned can be conveniently classified in three categories, each requiring a different type of intervention. First, there are what may be termed "old diseases - old problems": those that can be eradicated (poliomyelitis, dracunculiasis), eliminated as public health problems (leprosy, neonatal tetanus, measles, Chagas disease, onchocerciasis) or controlled (cholera and other diarrhoeal diseases, intestinal worms, hepatitis, typhoid). What is needed is the commitment and resources to undertake the following cost-effective interventions (the per capita cost in low-income countries is indicated in most cases):
- immunization of children against six vaccine-preventable diseases - diphtheria, pertussis, tetanus, poliomyelitis, measles and tuberculosis (US$ 0.50);
- the integrated approach to the management of the sick child (US$ 1.60);
- provision of adequate clean drinking-water and of basic sanitation facilities and collection of household garbage, as well as the simple hygienic measures of washing hands after defecation and before preparing food;
- school health programmes treating worm infections and micronutrient deficiencies and providing health education (US$ 0.50);
- case management of conventional sexually transmitted diseases using simple algorithms to decide on the appropriate diagnosis and treatment in peripheral health facilities (US$ 11).
The second category of diseases - "old diseases - new problems" - are tuberculosis, malaria, dengue and other vector-borne diseases. Cost-effective interventions exist, but drug or pesticide resistance poses a problem, requiring the use of additional or more expensive or toxic drugs. The strategy for controlling these diseases includes such interventions as early diagnosis and prompt treatment, vector control measures and the prevention of epidemics, for malaria; as well as directly observed treatment, short-course (DOTS) therapy for tuberculosis; undertaking research on treatment regimens and improved diagnostics, drugs and vaccines; and above all, epidemiological and drug-resistance surveillance mechanisms and procedures with laboratory support for early detection, confirmation and communication.
The natural history and the reasons for the emergence of the third category - "new diseases - new pathogens" - such as Ebola and other viral haemorrhagic fevers, is not well understood. Research is therefore needed on the disease agents, their evolution, the vectors of disease spread and methods of controlling them, and vaccines and drug development. Much of this already applies to HIV/AIDS, one of the most serious diseases to emerge in recent decades. The strategy required includes improving surveillance systems and public health infrastructure, strengthening laboratory services, and responding rapidly to urgent threats to public health. WHO is developing a global surveillance programme to recognize and respond to emerging diseases, making maximum use of existing WHO collaborating centres. A further component is WHONET, the computer programme that is designed to facilitate management of the results of antibiotic susceptibility tests, for use by microbiology laboratories.
Epidemics of various infectious diseases have been occurring repeatedly in several countries. As a result, there is now an international consensus that priorities have to be set and activities initiated speedily. This favourable environment for action needs to be exploited, and in WHO's view there are three priorities for international action during the next five years.
The first priority is to complete unfinished business, namely to complete the eradication and elimination of diseases such as poliomyelitis, dracunculiasis, leprosy, measles, Chagas disease and onchocerciasis. This does not require a huge expenditure, and if the resources are not found, these diseases will return with a vengeance, and previous efforts will be wasted.
The second priority is to tackle old diseases such as tuberculosis and malaria which present new problems of drug and insecticide resistance. Here there is a need to remove infectious sources in the community and cure a high proportion of infectious cases, establish appropriate national and international epidemiological surveillance, and undertake research on treatment regimens and improved diagnostics, drugs and vaccines. Work is needed on developing new and improved vaccines against measles, neonatal tetanus, bacterial meningitis, tuberculosis and other diseases.
The third priority is to take short-term and long-term action to combat newly emerging diseases. A speedy response is needed to outbreaks of important new infections, wherever they occur. At the same time, there is a need for intensive research on the natural history of new diseases and on possibilities for preventing, treating and controlling them. A global surveillance programme is also essential.
The world health report 1995 indicated how poverty could be alleviated by enabling the poor to earn their way out of poverty and by enhancing their health potential through measures for preventing diseases, promoting positive health and protecting people against health hazards, thereby improving their social and economic productivity. The world health report 1996 outlines opportunities that now exist for improving the health of the present generation while laying the foundation for better health for future generations.