Coloured scanning electron mcirograph (SEM) of an Anopheles sp. mosquito's midgut. There are approximately 400 species of the Anopheles mosquito, 30 to 40 transmit four different species of the Plasmodium parasite that causes malaria. Malaria is a vector-borne infectious disease that is widespread in tropical and subtropical regions. It causes disease in approximately 400 million people every year and is the cause of between one and three million deaths annually, mostly among young children in Sub-Saharan Africa. The parasites, which develop in the mosquito's midgut, are transmitted by the female mosquito when she sucks blood. Magnification: x300 when shortest axis printed at 25 millimetres.