What was the impact of government intervention on malaria cases in the Yanomami indigenous lands?

Background Roraima has recently experienced an increase in malaria cases, particularly among the Yanomami indigenous group, due to the presence of illegal miners. In January 2023, a Public Health Emergency was declared in the Yanomami Indigenous Land (YIL) because of a severe humanitarian crisis. This aims to assess the impact of the 2023 government effort to remove miners from the YIL on the local malaria burden. Methods A descriptive retrospective study was performed using secondary data from Brazil’s Health Information System (SIS), including confirmed cases (SIVEP-Malaria), hospitalizations (SIH), and deaths (SIM) due to malaria in Roraima from 2021 to 2024. Results Between January 2021 and December 2024, Roraima (RR) reported 117,214 autochthonous cases of malaria. Unexpectedly, following the 2023 intervention, there was a significant increase in cases (from 52,210 to 65,004; p = 0.0005). Hospitalizations decreased (from 789 to 638; p = 0.0304), but no significant change in the number of deaths (111 overall; p = 09089) was observed. P. vivax was the predominant species (p < 0001), while P. falciparum and mixed P. falciparum  +  P. vivax infections were associated with the highest lethality (p < 0.0001). Children aged 0–9 years had the highest mortality rate (p = 0.0005), and young adults aged 20–39 years accounted for nearly all hospitalizations (p < 0.0001). Men experienced more cases (p = 0.0031), yet women had a higher mortality rate (p = 0.0031), with indigenous people being the most affected (p = 0.0155). Malaria cases in the DSEI-Yanomami from 2021 to 2024 decreased in the municipalities of Mucajaí, Iracema, and Caracaraí, whereas Alto Alegre saw an increase in 2024. Interestingly, imported cases exported from RR decreased in Maranhão (− 95.5%), Pará (− 86.8%), and Amazonas (− 71.5%). Conclusions Although indigenous malaria cases have increased, the intervention was linked to fewer hospitalizations. Strategies should target indigenous populations, especially children, and mining areas, focusing on early diagnosis, integrated surveillance, and care for vulnerable groups.