Human Health Improvement in Sub-Saharan

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 enfermedades 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 como 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 salud humana, se necesita un sistema participativo de toma de decisiones, adaptado a las condiciones locales y desarrollado en base a acuerdos institucionales. La aplicabilidad de este esquema es demostrada en la zona rural y urbana de Etiopia. Palabras clave Ecosistemas; Recursos Naturales; Nutrición; Control de Vectores; Salud Pública

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“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

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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 additional 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), cowpeas (Tamò & Baumgärtner, 1993; Tamò et al., 1993), and maize (Bonato et al., 1999) demonstrates mul- tiple stresses on yields of some crops. For example, losses in maize due to stem borers are substantial (Cardwell et al., 1997) and range from 0 to 100%, (Gebre Amlak et al., 1989). Lack of water, nitrogen, and phosphorous are among universe is regarded as an ordered entity with a the main direct and indirect constraints (Bona- hierarchy of multilevel stratified systems, each to et al., 1999). Climatic variability, particularly higher level being composed of lower levels in semi-arid areas, and limited use of fertilizers with additional qualities. The structure and and livestock-mediated nutrient transfers from function of each level cannot be reduced to its pastureland to croplands interfere with forage elementary parts located on the lower level crops. In maize, 10-15% losses due to drought but can be separated into its constituent parts and nitrogen stress have been reported from which may operate as quasi-autonomous units many countries, while 90% yield reduction due (Koestler, 1967; Allan & Starr, 1982; Naveh & to low nitrogen levels have been observed in Liebermann, 1994; Waltner-Toews, this vol- Malawi (Zambesi & Mwambula, 1996). ume). These complex systems may be repre- The definition of the human environment sented by models, which are not depictions of as described here facilitates categorization of reality, but abstractions made for specific pur- health constraints over large spatio-temporal poses. Rather than a single all-purpose model, scales. The characterization of elements such the hierarchical approach entails different the- as the abiotic environment, arthropod-trans- ories for different purposes at different scales mitted diseases, and malnutrition enables iden- (Peters, 1991). Models cannot address every as- tification of relevant environmental factors pect of the system, but must be tuned to spe- suitable for policy-making (Conway, 1984). The cific problems (DeAngelis, 1988): a single sys- design of management schemes adapted to lo- tem is represented by a suite of different mod- cal conditions, however, also needs to take into els. Integration should not be undertaken by account the social environment, the interac- specialists in isolation, but by builder-archi- tion between its actors, and the mutual effects tects with clear views of overall objectives (Pe- between social processes and the environ- ters, 1991). ment. An ecosystem approach is more appro- Tansley (1935) and Begon et al. (1996), priate and more comprehensive in this respect. among others, observe that an ecosystem comprises the biological community together with its physical environment. Irrespective of the An ecosystem approach to human spatial scale in the definition of the ecosystem, health improvement we consider populations as the basic units of communities and rely on demographic princi- People do not live in isolation. They are actors ples for the analysis of their spatio-temporal in highly structured ecological systems. The hi- dynamics. Such principles include resource- erarchical organization of nature has become a based poikilothermic development (e.g. Curry basic philosophical presumption in ecology & Feldman, 1987; Gutierrez, 1996) and the phys- (Naveh & Liebermann, 1994). Accordingly, the iological structure of populations (e.g. Di Cola

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et al., 1999). Here, the biological communities, Integrated management of the human including human populations, interact with health improvement system factors of the physical environment and are ap- propriate subsystems for investigation and Introduction management. Dealing with people involves eth- ical considerations. Prudence is called for when Traditionally, a curative or therapeutic rather applying demographic principles to human than a preventive approach has been used for population dynamics (Capra, 1997). The defin- improving human health. Moreover, different ition of subsystems and constituent popula- disciplines and institutions have favored a sec- tion is done purposely (Peters, 1991), but fur- torial approach, wherein individual ecological ther modifications should be considered (Pe- processes and system components received ters, 1991; Gould, 1998). The interactions be- more attention than interactions influencing tween the subsystems and their environment the functioning and structure of subsystems as determine the structure and function of the well as ecosystems. system under management. The importance of preventive approaches Kochtcheeva & Singh (this volume) provide is increasingly being recognized: it has even a useful list for the identification of subsys- been acclaimed that the 21st century must be tems. Factors of the physical environment, the one of prevention. Less appreciated is the arthropod-transmitted diseases, and resources limited applicability of exclusively curative ap- are regarded as particularly important for hu- proaches. They are useful for practitioners, man health. Resources refer to everything that while a combination of curative and preventive permanently reduces in quantity through con- approaches can be applied by a wide range of sumption by an organism (Tilman, 1982; Be- end users including practitioners, extension- gon et al., 1996). For people, the initially select- ists, and policy-makers (Conway, 1984). The ed resources are food provided by crops and curative approach often focuses on individual livestock. Additional resources such as time ecological processes, such as pest mortality, available for human activities are included as but provides little insight into the dynamics well. The physical environment, arthropod- of pest populations, and hence is a hindrance transmitted diseases, other pests, and limited for combining control factors into integrated resources – feed and water for livestock, radia- management schemes (Roux & Baumgärtner, tion, water and nutrients for plants – affect the 1998). Despite the interest in Integrated Pest health of crops and livestock. To address local Management (IPM) (Kogan, 1998), pest control conditions and needs, management proce- research and practice is still dominated by the dures need to be developed in close collabora- quest for a silver bullet (Lewis et al., 1997), i.e., tion with the people concerned and imple- the search for a single factor able to solve a pest mented within specially designed decision- problem. support subsystems. The sectorial approach focusing on individ- The human health improvement system ual populations rather than on subsystems and comprises 3 sets of subsystems: the disease ecosystems is also a hindrance for the design subsystems (A), the resource subsystems (B), of integrated control programs. For example, and the decision-support subsystems (C) (Fig- Saini et al. (1999a) argued that a comprehen- ure 2). In the decision-support subsystems, sive vector and bovine trypanosomiasis man- people interact through exchange of informa- agement scheme would be more efficient than tion with people living outside the disease and uncoordinated reliance on methods for both resource subsystems (A and B). The mode of pathogen and vector control. Furthermore, the interactions between the community and the villagers involved in the BioVillage project (see managed ecosystem facilitates identification of below) were not satisfied with a successful the system’s boundary. Once the system and tsetse control program but asked for help to subsystems are defined we can proceed to an control diseases of both humans and livestock outline of important management concepts. and sought assistance in improving food pro- Thereby, we use the term “scheme” for an orga- duction. nized control system, which comprises the ac- An exclusively curative and sectorial ap- tivities required for managing the systems and proach precludes consideration of system qual- subsystems as defined above. ities such as sustainability issues, which are critical to socioeconomic development (Good- land, 1995). The Brundtland Commission defined sustainable development as development that meets the needs of the present with-

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Figure 2

The biotic elements of the human health improvement system (disease subsystems, nutrition-related resource subsystems, and decision-support subsystems).

Pathogens Beneficials

v v v

Crops v Arthropod pests v

v Pathogens v

v Humans v

Vectors v v

Livestock v v v

Vectors v Pathogens

v Disease subsystems Resource subsystems

Decision-support subsystems

out compromising the ability of future genera- Management issues tions to meet their own needs (Eppel, 1999). In conclusion, an exclusively curative and The objective of improving human health is sectorial approach is too narrow. Integrated met by adequately managing both the human comprehensive management schemes, relying disease and the resource subsystems (Figure primarily on preventive methods, are more 2). While the first activity aims at controlling promising approaches for further improve- human diseases, the second activity seeks to ments to human health. Moreover, community reduce losses in livestock and crops as well as participation in decision-making processes is to manage natural resources to attain environ- fundamental to the development and imple- mental sustainability. Goodland (1995) defines mentation of management schemes for im- environmental, economic, and social sustain- proving human health. ability and recognizes the strong link between the first two. He also recognizes the impor-

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tance of social sustainability, but stresses that 2 Natural resource management environmental sustainability or maintenance of life support systems is a prerequisite to so- Management of the resources subsystem fo- cial sustainability. Hence, our approach initial- cuses on increases in food security – through ly focuses on environmental sustainability. improved animal and crop agriculture – and Goodland (1995) further reminds us that envi- sustainable use of natural resources (Figure 3). ronmental sustainability requires that the two The subjects of management are the sub- fundamental environmental services – the systems including either livestock or crops (Fig- source and the sink functions – must be main- ure 2). Integrated pest management schemes tained unimpaired during the period in which relying on natural control are used for pest sustainability is sought. control purposes. Environmental sustainabili- A decision-support subsystem is indispens- ty seeks to improve human welfare by protect- able for interactive development and imple- ing the sources of raw materials used for hu- mentation of management schemes (Figure 2). man needs, and by ensuring that the sinks for Components of the systems to be managed human wastes are not exceeded, to prevent and management schemes are designed and harm to humans (Goodland, 1995). Moreover, implemented together with the community it means that natural capital must be main- through inter-institutional arrangements. The tained both as a provider of inputs and as a sink necessary measures may be better implement- for wastes. This means holding the scale of the ed when relying on particular segments of the human economic system within the biophysi- society. There is a special need to focus on cal limits of the overall ecosystem on which it women and children. Children, being the par- depends. On the sink side this translates into ents of the future, need to be involved to facili- holding waste emission within the assimilation tate the sustainability of the system. In African capacity of the environment without impairing society, women are mainly responsible for it. On the source side, harvest traits of renew- health and family care, water and fuel collec- ables must be kept within regeneration rate tion, and food provision. Their valuable knowl- (Goodland, 1995). edge of the environment and its resources is of- To achieve environmental sustainability the ten underestimated (Wallace, 1991). A detailed flow of water and matter is adequately man- analysis of gender roles in a particular cultural aged, with the aim of minimizing the necessity context facilitates the design and implementa- for external inputs of resources such as energy tion of an integrated health system for sustain- and fertilizers and of meeting sanitation re- able development. quirements. This can be attained through ex- The design and implementation of man- traction of energy from organic waste and agement schemes requires initial capital in- transforming feces or slurry into organic fertil- vestments, which can be recovered by pricing izers by minimizing loss of nutrients such as resources such as water and energy as imple- nitrogen. The soil flora and fauna are indis- mentation proceeds. Additional investments pensable for making nutrients available to into the infrastructure can also be made on a crops. High-quality fertilizers are important el- cost-recovery basis. ements in maintaining sustainable soils (Buol, A comprehensive health and integrated re- 1995). They can be produced by separating source management scheme is considered as a urine from other organic wastes and process- prerequisite for undertaking income-generating them further (Bieri et al., 1998). Energy in ing activities which should be developed on the form of biogas can be extracted from or- the basis of the available resources (Hufschmidt ganic waste for cooking purposes. Further- et al., 1983). For example, we recommend bee- more, availability of an alternative resource of keeping and silk production as new sources of energy reduces the workload of women with income. respect to the collection of, often scarce and heavy, firewood. It may allow women more 1 Human disease management time for empowering educational and income- generating activities. This in turn will benefit The subjects of management are subsystems human health improvement since it has been including humans, pathogens, and vectors shown that education and a better economic (Figure 2). Disease management aims at reduc- position of women contributes to better nutri- ing morbidity and mortality through the pre- tion and health of the entire family (Øster- vention and control of diseases. gaard, 1992). The use of biogas rather than firewood is expected to reduce indoor pollution, which causes airborne diseases (WRI, 1998;

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Figure 3

The organization of matter and water flows in a human health improvement system (bold lines: matter including micronutrients, dashed line: water, dotted line: energy).

Pathogens v vv

v Humans v vv Vectors

Pathogens v

v Livestock v v v v Vectors v Biogas digester

v Nitrogen binder

v Compost producer Storage

Beneficials v v v

Arthropod pests v Crops v vv v Pathogens v Soils

Gopalan & Saksena, 1999). Note that in this stitutions is a serious hindrance for the imple- case, environmental sustainability is directly mentation of agricultural management schemes linked to a healthy abiotic human environment. in Sub-Saharan Africa. Empowered institu- The management decisions should be tions need to be involved with the develop- based on a quantitative understanding of flows ment of the decision-support subsystem and as obtained by the development and use of play a crucial role in assigning responsibili- simulation models. ties in management schemes. The interactions between experts and lay people, mediated 3 Decision-support through social workers (Figure 2), will benefit the development of improved management Institutional diversity is essential for sustain- procedures whose effects can be monitored able systems (Becker & Ostrom, 1995). Eicher (Gopalan, 1999). (1999), for instance, recognizes that lack of in-

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Management scheme implementation management concept into an integrated resource management scheme for sustainable The concepts proposed above are being imple- rural development. A social worker operating mented with urban (BioFarm Initiative) and at the interface between community and pro- rural (BioVillage Initiative) communities in ject management facilitates the exchange of in- Ethiopia. Preliminary observations show the formation and manages monitoring work for applicability of the human health systems con- system evaluation and improvement. cepts. This is further supported by the interest of various stakeholders in setting up human health improvement systems in other parts of Concluding remarks Ethiopia and in neighboring countries. In this work, we briefly refer to important system com- In Sub-Saharan Africa, the physical condition ponents and address some management issues of the human body is primarily affected by abi- with relevance to the planning of future pro- otic factors, vector-transmitted diseases and jects. natural resources. The ecosystem approach to human health improvement is adequate to BioFarm Initiative identify subsystems for investigation and management in its social context. A preventive in- Recently, one of us (Dr. Getachew Tikubet) de- tegrated management approach for the im- signed and implemented a management provement of human health is suitable for sus- scheme for improving the health of inhabitants tainable development. of Addis Ababa. Currently, the scheme focuses The human health management scheme on human nutrition. The inhabitants provide aims to control vector-transmitted diseases the required labor in exchange for food. Live- and secures food supply from resource subsys- stock is kept under zero grazing conditions to tems including either livestock or crops. Inte- protect them from disease vectors and to con- grated Pest Management relying on natural trol feed supply. Wastes of livestock and the control factors is the key strategy for reducing community are processed for energy extraction losses to biotic constraints, while the concept and organic fertilizer production thereby re- of environmental sustainability allows ade- ducing mosquito and filth fly menace. quate management of flows of matter and water. Environmental sustainability is linked to a BioVillage Initiative healthy human environment and is considered as the basis for social and economic sustain- Historically, the BioVillage Initiative evolved ability. from a successful community-based tsetse A decision-support subsystem is indispens- control project, which resulted in a significant able for planning and implementing manage- reduction in livestock disease incidence. Fol- ment procedures. To achieve sustainability, lowing detailed discussions at the community this subsystem has to be developed together level, it became apparent that an approach with communities concerned through inter-in- tackling exclusively the trypanosomiasis vec- stitutional arrangements. Cost-recovery and tor, while desirable, would not fully address the resource pricing are important elements for a health problems of rural communities. For ex- sustainable management scheme. ample, farmers stressed that both oxen and Experience from two initiatives in Ethiopia men have to be healthy to plow the fields. It demonstrates the applicability of the concepts was agreed that only a combined livestock and to human health improvement in both urban human health management program could and rural environments. provide a solution to the most urgent problems limiting rural development, and that a comprehensive health management scheme empha- sizing preventive rather than curative methods should be initiated. Thereby, it became apparent that health and well-being have to rely on a secured supply of high-quality food and water as well as on a healthy environment. To achieve the latter, efficient waste management with concomitant reduction of disease vector breeding sites became important. These aspects broadened the comprehensive health

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Acknowledgments

The Austrian Development Corporation (ADC) provided the financial support to plan and carry out the BioVillage initiative. We are also grateful to the donors of ICIPE’s core funds and to other international part- ners for financial support. We greatly appreciate the logistic and financial support given by national and regional Ethiopian institutions. The communities of Mamede and Luke in Ethiopia showed us the limita- tions of the sectorial approach, encouraged us to develop a system approach, and participated in all program activities. Dr. Hans Herren, Director General of ICIPE, provided continuous support and encouragement. Dr. W. Overholt, Dr. R. Saini, Dr. J. Githure, and Prof. A. Has- sanali assisted in project planning and execution. We thank Dr. V. Mares and Dr. H. Li-Pun (ILRI, Addis Aba- ba) for useful comments and Mrs. Veronica Baum- gärtner for assistance with editing of the paper.

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