Title: Environmental factors
Course: Communicable Diseases Part 1 - Ethiopia (Full)

Environmental factors

Temperature, humidity and rainfall are major environmental factors affecting the development of both mosquitoes and parasites, as you learned in Study Session 6.

Higher environmental temperatures, between 22°C and 30°C, increase the potential lifespan of mosquitoes, and also increase the frequency of blood meals taken by female mosquitoes. Higher temperatures also speed up development of the mosquito larvae, shortening the amount of time it takes the mosquito to develop from egg to adult. All these increase the risk of malaria transmission.

Can you mention the stages of the lifecycle of the Anopheles mosquito?

Show answer

Egg → larva → pupa → adult.

Increased rainfall generally leads to the creation of new water pools, allowing mosquitoes to breed in larger numbers. Increased rainfall also leads to increased humidity. On the other hand, sometimes during the dry season, rivers and streams can shrink to create water pools, making them ideal for mosquito breeding.

So observing significant changes in rainfall, temperature and humidity in your village can help you assess the risk of malaria epidemics.