Figure 3

Evolution of the annual malaria incidence, and rainfall, in Piura department: 1990–2010. Information on annual malaria cases, registered by Regional Health Direction of Piura, was obtained from the National Institute of Statistics and Informatics [27]. Numbers in the timeline point out important events that influenced malaria incidence: 1) moderate ENSO phenomenon (1991–1992), 2) first reports of chloroquine (CQ) failure for Plasmodium falciparum (since 1994), 3) very strong ENSO phenomenon (1997–1998), 4) confirmed CQ resistance for Plasmodium falciparum (1999), 5) ACT implementation (2001–2003), 6) intense droughts (2004–2007).