While the malaria paradigms may be oversimplifications, the simplicity may allow the approach to work where others have failed. Previous epidemiologic approaches to malaria control, including stratification, have been faulted for being overly complex. Even if one accepts the underlying principles, it is difficult to know how to begin to plan malaria control interventions based on these approaches. In terms of substance, the paradigms are simply a new way of examining and understanding the sound epidemiologic principles already extensively explored. They are not dicta, but a way of thinking about and systematically organizing malaria control activities.
The paradigm approach is in an early stage of development. Even so, it may help program managers and others better define the malaria problem and prioritize control interventions. The approach will require refinement and field validation before we can adequately assess its usefulness in rationalizing malaria control.
The paradigm approach begins with the observation that most malaria problems in the world can be categorized as one or more major types: malaria of the African savannah; forest malaria; malaria associated with irrigated agriculture; highland fringe malaria; desert fringe and oasis malaria; urban malaria; plains malaria associated with traditional agriculture; and seashore malaria. Although certain situations may not fit easily into any of these categories, such cases are of limited importance on a global scale. There may also be unique hybrids of two or more of the paradigm types which will require special consideration.
Use of these easily conceptualized types, rather than more abstract epidemiologic principles, enables even nonspecialists to gain an understanding of the malaria problem. Application of the paradigm approach requires a logical progression through a series of steps in which attributes of a particular malaria problem, from the most general through the more specific, are considered (see Appendix A). The goal is to classify the situation only as narrowly as necessary, not as narrowly as possible, before choosing control tools and planning interventions.
The following is a brief description of the paradigm approach. A more complete discussion of the method and its use should soon be available from the Malaria Unit of the Control of Tropical Diseases at the World Health Organization.
Malaria of the African Savannah Eighty percent of the world's malaria and 90 percent of mortality due to the disease occur in Africa south of the Sahara, mostly in the savannah regions. The principal vectors, Anopheles gambiae, An. funestus, and An. arabiensis are efficient transmitters of the malaria parasite and are found in abundance. Malaria transmission is sea-