A mother and her baby sleep under a mosquito net: malaria prevention in Nigeria. Colour lithograph by FGN, ca. 2010.

The ITN mosquito net was introduced in 2010. Previously, nets had to be retreated every 6-12 months, more frequently if the nets were washed. Nets were retreated by simply dipping them in a mixture of water and insecticide and allowing them to dry in a shady place. The need for frequent retreatment was a major barrier to widespread use of ITNs in endemic countries. The additional cost of the insecticide and the lack of understanding of its importance resulted in very low retreatment rates in most African countries. (Source: CDC, Center for Disease Control)