In which countries can it be found?
Malaria is found in many parts of Africa, Latin America, Asia, and Oceania. The exact distribution depends on climatic variables (namely heat and sufficient rainfall, for the development of the mosquitoes which transmit malaria) and also how successful a particular country or region has been at controlling malaria.
For example, malaria was once found in parts of the U.S. and Europe, but successful campaigns to control mosquitoes and treat cases led to elimination of transmission. The same is true in other parts of the world; for example, in Malaysia, transmission is successfully controlled in Kuala Lumpur, but malaria can still be found in many parts of the surrounding countryside.
Please visit the CDC website for an interactive map of malaria distribution around the world.