Figure 1.

Number of malaria cases registered yearly from 1960 to 2009 in the Brazilian Amazon according to the Plasmodium species responsible. The great increase of malaria cases during late 70's and 80's was due to massive and uncontrolled migration to the Amazon region of people attracted by colonization programmes, sponsored by the government. The highest figures were recorded in 1999 (637 470 cases) when the government decided to implement the Plan for Intensification of Actions for Malaria Control (PIACM) in high-risk areas focusing on the early diagnosis and treatment of the cases. The circle with the intersection lines shows that the present number of malaria cases corresponds to the figures recorded in 1983. Notice also the progressively decreasing proportion of cases due to P. falciparum after 1988. In 1990 44.3% of cases were due to P. falciparum and the situation of the most prominent predominance of P. vivax transmission was reached in 1999 (only 18.6% of cases being due to P. falciparum).