Tafenoquine is Transforming the Treatment of Plasmodium vivax Malaria
By: Emma Margarita Iriarte and Edison Soto
Eliminating malaria in Latin America is no longer a distant objective. Although the disease burden remains concentrated primarily in the Amazon region—particularly in Brazil, Colombia, Peru, and Venezuela, which together account for more than 90% of cases on the continent—transmission has steadily declined since 2000, driven by advances in public health and the sustained commitment of governments, communities, and international organizations such as the Inter-American Development Bank (IDB). In contrast, Mesoamerica is among the regions in the world closest to achieving elimination: today its transmission is low, and two of its countries—Belize and El Salvador—have already been certified malaria-free by the World Health Organization (WHO). Achieving this milestone—and preventing reintroduction—now depends on strong local strategies and therapeutic innovations that facilitate treatment.
One of the technical pillars of this progress is the DTI-R strategy, implemented through the Regional Malaria Elimination Initiative (IREM). This framework structures the response around five core components: detection, diagnosis, treatment, investigation, and response; all under a territorial, results-based financing approach.
Microplanning: The Key to Closing the Final Gaps
For the DTI-R strategy to be effective, it must be executed at the local level. This is achieved through microplanning processes in each focus or micro-area where malaria cases are recorded—or have recently been recorded. This territorial approach enables faster responses to epidemiological changes, more efficient resource organization, and the delivery of essential services to the communities most affected.
Beyond optimizing efforts, microplanning strengthens the role of local actors—an essential component in countries where transmission persists sporadically. This type of organization is now indispensable for closing the last gaps on the path toward elimination.
What Strategies Are Integrated into DTI-R?
In contexts where human mobility influences transmission, the World Health Organization (WHO) and the Pan American Health Organization (PAHO) recommend incorporating chemoprevention and radical cure into elimination strategies like DTI-R. Within IREM’s work, this therapeutic option is not an external add-on, but an integral part of the “T” in DTI-R (treatment), articulated with detection, diagnosis, investigation, and response.
Chemoprevention: Acting Before Symptoms Appear
Chemoprevention consists of administering a full first-line treatment not only to infected individuals but also to those at risk. Modalities include:
- Mass Drug Administration (MDA): targeting the entire population of a locality.
- Targeted Drug Administration (TDA): for high-risk groups or areas with high mobility.
- Reactive Drug Administration (RDA): activated after a confirmed case and extended to close contacts.
Radical Cure: Eliminating the Parasite’s Latent Forms
In malaria cases caused by the Plasmodium vivax parasite, radical cure—defined as eliminating parasites in both the active blood stage and the latent liver stage—seeks to remove the forms that can cause relapses weeks or months after the initial infection. Historically, this treatment has combined chloroquine and primaquine for 7 to 14 days, a regimen that can hinder adherence, especially in rural areas.
Tafenoquine: An Innovation Transforming Treatment
In this context, the introduction of tafenoquine represents an important advance. This medication enables radical cure with a single dose, significantly improving adherence. However, both tafenoquine and high-dose primaquine require caution, as they can cause severe adverse effects in people with glucose-6-phosphate dehydrogenase (G6PD) deficiency. For this reason, PAHO recommends semi-quantitative G6PD testing prior to administration.
A PAHO-developed roadmap guides countries on how to incorporate these tools safely and effectively. Brazil is already charting the way: in this South American country, G6PD testing and tafenoquine are part of the public health system, thanks to the leadership of the Ministry of Health and close work with communities. More recently, Peru has also incorporated these tools into its therapeutic guidelines for P. vivax malaria.
In Mesoamerica and the Andean region, several countries are moving in the same direction. Costa Rica, an active member of IREM, has decided to integrate tafenoquine into its strategy to prevent the reestablishment of transmission. Guatemala, Honduras, and Colombia are also in advanced stages of adoption.
A Decisive Moment for the Region
Latin America and the Caribbean face a historic opportunity in the fight against malaria. The combination of an increasingly lower malaria burden with innovative approaches such as chemoprevention and radical cure makes elimination feasible. But achieving this goal requires determination, territorial work, and sustained technical capacity.
The tools are available. The challenge now is to integrate them effectively to protect at-risk populations and consolidate the progress made. Eliminating malaria in our region is within reach: this is the moment to deepen lessons learned, innovate, and strengthen the health systems that will make it possible.