ARTIGO ARTICLE 37 Human health improvement in Sub-Saharan Africa through integrated management of arthropod transmitted diseases and natural resources Johann Baumgärtner 1 Markus Bieri 2 Giuseppe Buffoni 3 Mejoramiento de la salud humana en África Gianni Gilioli 4 al sur del Sahara mediante el manejo integrado Hiremagalur Gopalan 5 de enfermedades transmitidas por artrópodos Jürgen Greiling 1 y el manejo de recursos naturales Getachew Tikubet 1 Ingeborg Van Schayk 1 1 International Centre Abstract A concept of an ecosystem approach to human health improvement in Sub-Saharan of Insect Physiology and Africa is presented here. Three factors mainly affect the physical condition of the human body: Ecology (ICIPE), P.O. Box 30772, Nairobi, Kenya. the abiotic environment, vector-transmitted diseases, and natural resources. Our concept relies 2 Swiss Federal Institute on ecological principles embedded in a social context and identifies three sets of subsystems for of Technology (ETH), 8092 study and management: human disease subsystems, natural resource subsystems, and decision- Zurich, Switzerland. 3 Italian National Agency support subsystems. To control human diseases and to secure food from resource subsystems in- for New Technology, cluding livestock or crops, integrated preventive approaches are preferred over exclusively cura- Energy, and the Environment tive and sectorial approaches. Environmental sustainability – the basis for managing matter (ENEA), C.P.31619100, La Spezia, Italy. and water flows – contributes to a healthy human environment and constitutes the basis for so- 4 Dipartimento di cial sustainability. For planning and implementation of the human health improvement Agrochimica e Agrobiologia, scheme, participatory decision-support subsystems adapted to the local conditions need to be Università degli Studi di Reggio Calabria. designed through institutional arrangements. The applicability of this scheme is demonstrated Piazza S. Francesco in urban and rural Ethiopia. di Sales 4, 89061 Gallina di Reggio Calabria. Key words Ecosystem; Natural Resources; Nutrition; Vector Control; Public Health 5 United Nations Environment Program Resumen Se presenta un concepto, basado en el ecosistema, para el mejoramiento de la salud (UNEP), P.O. Box 30552, Nairobi, Kenya. humana en la región del África al sur del Sahara. Las condiciones físicas del cuerpo humano es- tan afectadas por tres factores: factores ambientales abióticos, enfermedades transmitidas por vectores, y por los recursos naturales. Este concepto se basa en princípios ecológicos dentro de un contexto social, e identifica tres series de subsistemas para estudio y manejo: subsistemas de en- fermedades humanas, subsistemas de recursos naturales y subsistemas participativos de toma de decisiones. En el manejo de enfermedades humanas, así como en el manejo de recursos tales co- mo ganadería o agricultura, se da prioridad a programas preventivos de manejo integrado. El concepto de sostenibilidad ambiental – base para el manejo de materia y de aguas – contribuye a un medio ambiente favorable para las condiciones de vida del ser humano, y es la base de la sostenibilidad social. Para la planificación y la ejecución del esquema de mejoramiento de la sa- lud humana, se necesita un sistema participativo de toma de decisiones, adaptado a las condi- ciones locales y desarrollado en base a acuerdos institucionales. La aplicabilidad de este esque- ma es demostrada en la zona rural y urbana de Etiopia. Palabras clave Ecosistemas; Recursos Naturales; Nutrición; Control de Vectores; Salud Pública Cad. Saúde Pública, Rio de Janeiro, 17(Suplemento):37-46, 2001 38 BAUMGÄRTNER, J. et al. “Human beings are at the center of concerns for improving human health in Sub-Saharan Africa. sustainable development. They are entitled to a The applicability of the concepts is being tested healthy and productive life in harmony with in urban and rural environments in Ethiopia. nature” (Rio Declaration: Principle 1, UNCED, Rio de Janeiro, Brazil, 1992) Human health and the environment Introduction The components of the human environment, regarded as everything that is external to the in- The World Health Organization (WHO, 1995) dividual human host (Last & Abramson, 1995), defines human health as a state of complete can be divided into: atmospheric, aquatic, and physical, mental, and social well-being and not terrestrial components, encompassing both merely as the absence of disease or infirmity. abiotic and biotic elements (Figure 1). To address this comprehensive concept is a Among the biotic elements, the malarial major challenge but undoubtedly goes beyond parasite is the main cause of morbidity and the scope of this paper. Here we focus on those mortality in the African region. Ninety-three aspects of human health that concern the phys- percent of the 550 million people living on this ical condition of the human body, considering continent are at risk. Over 90% of the annual that physical well-being contributes to mental global 1.4-2.6 million deaths are reported from and social well-being. In due course, when nor- Africa (WHO, 1995). A second vector, the tsetse mative sciences are applied to issues of human fly (Glossinidae), transmits human trypanoso- health and inherent values are added to the miasis, or sleeping sickness. With an estimated systems to be managed (Fitzsimmons, 1999), 300,000 cases per year, the disease has returned we look forward to broadening our concept in to its epidemic levels of the 1930s (Saini et al., accordance with the above-described compre- 1999b). Diseases transmitted by hard ticks hensive definition of human health. (Ixodidae) and tick paralysis (Kettle, 1995) also Global trends in human health improve- hamper the continent. ments are positive. In Sub-Saharan Africa, how- Disease incidence is directly related to nu- ever, progress has been slow and life expectan- trition: approximately 32% of the disease bur- cy still lags some 25 years behind that of the den in Africa can be attributed to protein- wealthiest nations (WRI, 1998). Taken into ac- energy malnutrition. This refers to the conse- count both premature death and disability, quences of the combination of an inadequate nearly 90% of the global disease burden occurs intake of protein and energy as well as mi- in developing countries (WRI, 1998). In Sub- cronutrients, such as vitamin A, iron, and io- Saharan Africa, morbidity rates show a disease dine. Fifty-five percent of all child deaths in de- burden that doubles the global average. Protec- veloping countries are associated with malnu- tion against and treatment of diseases is often trition. This includes deaths from diarrhea beyond reach of the poor, and the increasing (19%), acute respiratory infections (19%), peri- effects of manmade and natural disasters will natal causes (18%), measles (7%), malaria (5%), further exacerbate poverty and disease. and other causes (32%). In Africa, 10% of the Management of the environment is a disease burden is caused by inadequate drink- promising strategy to improve human health ing water, sanitation, and hygiene. Degraded (WRI, 1998). Systematic and coordinated pro- households increase the incidence of airborne cedures, developed together with the commu- diseases and diarrhea (WRI, 1998). Poor envi- nities involved, will facilitate the design and ronmental conditions increase diseases such implementation of management schemes in as tuberculosis, acute respiratory track infec- Africa. A holistic approach that is based on eco- tions, and diarrhea. logical principles as well as on the participa- Livestock and crops are the main sources of tion of the community and its relevant institu- food. Factors affecting these sources have an tions in the design, implementation, and eval- immediate impact on human health. In live- uation of management schemes is promising stock, tsetse fly transmitted trypanosome para- with respect to improving human health and, sites cause debilitating and often fatal livestock moreover, alleviating poverty in developing diseases (Saini et al., 1999b). In cattle, losses countries. amount to an estimated 3 million deaths annu- This paper presents a conceptual frame- ally, mainly of young stock. Sick animals pro- work for the design and implementation of a duce lower milk and meat yields, and repro- community-driven, comprehensive health and duce less. With nearly 50 million head of cattle integrated resource management scheme for – 94% of the continent’s total – distributed at Cad. Saúde Pública, Rio de Janeiro, 17(Suplemento):37-46, 2001 HUMAN HEALTH IN SUB-SAHARAN AFRICA 39 the fringes of the tsetse belt, the direct annual Figure 1 monetary loss is estimated at US$ 0.6 to 1.2 bil- lion. Hard ticks (Ixodidae) transmit protozoan The human health improvement system composed of humans and their (theileriosis and babesiosis) as well as rickettsial environment, separated into atmospheric, terrestrial, and aquatic components. diseases and predispose animals to secondary infections. In eastern and central Africa alone, the damage caused by theileriosis is estimated at US$ 168 million annually, including an esti- Atmosphere mated mortality of 1.1 million cattle (Mukhebi, 1992). Inadequate feed supply has an addition- al impact on animal health. In agriculture, crop production is con- strained by abiotic factors and pests (Yudelman et al., 1998). Research on cotton (Baumgärtner Humans et al., 1986), cassava (Gutierrez et al., 1988), Aquatic Terrestrial component component rice (Baumgärtner et al., 1989),