OBJECTIVE:

To discuss the effect of the construction of the Belo Monte Hydroelectric Power Plant (UHEBM) on human malaria transmission in the directly affected municipalities.

MATERIALS AND METHODS:

Data were collected on the number of malaria cases, the annual parasite index (API), and the number of Anopheles mosquitoes in municipalities within the UHEBM area of influence. The study period was divided into pre-construction (2007-2010), construction (2011-2015), and post-construction (2016-2024). The Z-test was applied to assess differences in API and mosquito density among periods, and a simple linear regression was performed to analyze the relationship between these variables.

RESULTS:

There was a significant reduction in API between the pre- and post-construction periods (p = 0.0171) and between construction and post-construction (p = 0.044). A significant decrease was also observed in the number of mosquitoes between the pre- and post-construction periods (p = 0.0280). When Anopheles darlingi was analyzed separately, significant differences were found between the pre- and post-construction (p = 0.0313) and between the construction and post-construction (p = 0.0455) periods. A positive correlation was identified between the number of mosquitoes and API in the region (p = 0.016; R2 = 0.32), with similar correlations in Anapu (p = 0.002; R2 = 0.497) and Senador José Porfírio (p = 0.001; R2 = 0.528), as well as in tests restricted to An. darlingi (p = 0.0093; R2 = 0.37).

CONCLUSION:

The construction of the Belo Monte Hydroelectric Power Plant illustrates that malaria transmission can be controlled in settings of environmental change, provided that legal requirements are followed and joint actions are undertaken across government levels.