Introduction
As you learned in Study Session 5, the incidence of malaria varies from place to place and at different times. Such variations are very common in Ethiopia. There are areas where the incidence of malaria is high and other areas where the incidence is low, and some areas are malaria free. In some communities, malaria transmission lasts for several months or happens throughout the year, and in other areas it is very brief.
In this study session you will learn about the factors that affect the transmission and incidence of malaria. Climate affects the natural distribution of malaria in Ethiopia and elsewhere in the world. The three main climatic factors that directly affect malaria transmission are temperature, rainfall and relative humidity (the amount of moisture in the air). Several non-climatic factors, including differences between human hosts, human migration, and development projects, can also affect the pattern of malaria transmission and the severity of the problem.
Climatic means ‘relating to the climate’.
Understanding the climatic and non-climatic factors that affect malaria transmission will help you to understand the risk of malaria in your village better. This kind of understanding will also be useful to you in monitoring, preventing, or controlling local malaria epidemics (Study Session 12).