• Background
• Hypothesis
• Wetland density in West Africa (map)
• Research results
• Population perception and behavior
• Exposure and disease impact of wetland rice farming
• Preliminary conclusions
• For agricultural development planners
• For health planners
• Consortium members

Wetland water management and irrigation schemes are thought to make vector-borne disease endemicity worse in West Africa. The development and promotion of wetland / irrigated rice cultivation has been restrained because of such health concerns. However, with the rapidly growing consumer demand for rice in the region (5.6% annual growth rate) and the limited options for intensification of upland areas, wetland rice developments becomes a major focus for agricultural policymakers and farmers. Inland valley bottoms in West Africa represent approximately 50% of the agriculturally available wetland area (375,000 to 842,910 km²). 

The WARDA / WHO-PEEM¹/ IDRC / DANIDA / Government of Norway Health Research Consortium, brings together six multidisciplinary West African research institutions to evaluate health and social impact of various degrees of wetland water management / irrigation in the humid rain forest, savanna and Sahel within a planning and policy relevant framework. Results will be used to develop environmental management strategies minimizing health risks related to land use.

¹PEEM = WHO/FAO/UNEP/UNCHS Panel of Experts on Environmental Management for Vector Control

Qualitative socio-cultural studies in the savanna indicate that rice double-cropping: 

• Attracts mainly young families
• Improves women's income
• Transfers financial responsibility for health care and education from men to women
• Affects treatment-seeking behavior by shortening the delay between disease onset and initiation of treatment.

Data adapted from: Henry, M.C., J. Dossou Yovo, I. Nzeyimana, S. Diarassouba, E. Akodo, T. Teuscher & P. Carnevale, 1998. Impact of rice cultivation systems on malaria incidence in the savanna of northern Côte d'Ivoire. Poster 67, Abstracts, 2nd European Congress on Tropical Medicine, Liverpool, 14-18 September 1998.

• In the Sahel, irrigation does not increase malaria transmission and possibly maintains endemicity at a reduced level.

• Reduced vector population density results in prolonged life of each mosquito and, therefore, increases both the chances of transmission and the disease rates. Therefore, alternative intensified rice cultivation strategies (dry seeding and improved pest management), through a shortening of flooding, may decrease overall vector population density in the Sahel and thus increase malaria transmission and disease rates.

• In the savanna, wetland water management for rice double-cropping does not increase malaria transmission and does not impact on malaria-related burden of disease.

• A strategy to improve access to rapid, appropriate fever treatment needs to be included in wetland development plans in order to develop the full socioeconomic potential of intensified rice production systems at household level. 

• In the Sahel, measures to reduce dry season human-vector contact could further reduce the incidence of malaria.

• Insecticide treatment of already highly utilized bednets during the rainy season has the potential to substantially reduce the malaria-related burden of disease. 

• In savanna areas, increases in women's disposable income accelerate treatment-seeking behavior irrespective of nature of treatment provider (household, market, formal health sector).

• In savanna areas with seasonal, intermediate malaria endemicity, IEC messages need to consider the low nuisance perception leading to very low bednet utilization rates.

• Contrary to the case of malaria fevers, the frequency of non-malarial fever episodes (arbovirus, etc.) is associated with specific agroecologies.

• Rice cultivation improves household food security and improves access to/ utilization of "Bamako Initiative" based health interventions by population.

Mali: Faculté de médecine, de pharmacie et d'odonto-stomatologie, Centre de recherche et de formation sur le paludisme, DEAP, Bamako; Institut d'économie rurale, Niono/Bamako; Institut national de recherche en santé publique, Bamako 

Côte d'Ivoire: Centre universitaire de formation en entomologie médicale et vétérinaire (CEMV), Bouaké; Institut Pierre Richet (IPR) / O.C.C.G.E., Bouaké; West Africa Rice Development Association (WARDA), Bouaké; International Development Research Centre (IDRC, Ottawa, Canada).

WARDA, WHO-PEEM and IDRC provide technical input to the Consortium, while IDRC, the Royal  Government of Denmark (DANIDA) and the Royal Government of Norway (Ministry of Foreign Affairs) provide funding. 
 
 
 
 

Coordinated by: Health Consortium, West Africa Rice Development Association (WARDA), 01 B.P. 2551, Bouaké 01, Côte d'Ivoire; Tel: +225 31 63 45 14, Fax: +225 31 63 47 14;
E-mail host institution: warda@cgiar.org.