This study, with the participation of the principal investigator of CISeAL, Dr. Fabián Sáenz, analyzes the presence of asymptomatic malaria infections in communities of the Putumayo canton in the Ecuadorian Amazon, a border area characterized by high human mobility and persistent transmission despite national advances in disease control. The research reveals a critical gap in epidemiological surveillance: while rapid diagnostic tests detected no cases and microscopy identified only high-density infections, the use of qPCR uncovered a hidden reservoir of asymptomatic malaria that remains invisible to routine methods. The results confirm a low but epidemiologically relevant prevalence, dominated by submicroscopic infections, consistent with the regional pattern of Plasmodium vivax predominance and with cross-border transmission dynamics sustained by river corridors and extractive activities.

The finding that most infections occur in men and during the middle and late phases of the rainy season reinforces the need for focused and temporally targeted active surveillance strategies, especially in mobile populations with limited access to health services. The study emphasizes that malaria elimination in Ecuador cannot be sustained solely through passive surveillance, and that the incorporation of sensitive molecular tools, the strengthening of access to radical cure treatments for P. vivax, and binational coordination are key elements to prevent resurgences in strategic areas such as Putumayo, where the cost of failing to intervene in a timely manner could far exceed the investment required for proactive and effective surveillance.

To further explore the quantitative results, understand the methodological approach employed, and grasp the challenges facing malaria elimination in pre-elimination contexts and border areas such as Putumayo, the full article can be consulted at the following link:

https://link.springer.com/article/10.1186/s12936-025-05740-9