Researchers at Brown University sequencing malaria parasite genomes in Uganda have identified a rapidly spreading genetic variant set, including three mutations and two deletions in a PX1-associated region, linked to decreased susceptibility to front-line artemether-lumefantrine combination therapy and mefloquine.
A cluster of genetic mutations in the malaria parasite Plasmodium falciparum is spreading rapidly in Uganda, threatening the effectiveness of front-line treatments used across Africa and the United States, according to a study published in Nature Medicine.
Researchers leading the investigation sequenced whole genomes extracted from blood samples collected from hundreds of infected individuals in Uganda. Their findings connect a specific set of genetic variants to reduced susceptibility to artemisinin and lumefantrine—the two components making up artemether-lumefantrine (AL)—as well as the drug mefloquine.
Decades of Drug Pressure and Genomic Surveillance
AL serves as the primary treatment for uncomplicated malaria in Uganda, a role it has held for approximately two decades, and stands as the most widely used artemisinin-based combination therapy across sub-Saharan Africa. Drug resistance typically emerges when therapies are deployed at a very large scale, prompting public health systems to build surveillance infrastructure that tracks pathogen mutations and drug performance over time.
Laboratories such as the research group led by Brown University have worked to build genomics systems supporting surveillance programs through DNA sequencing and mutation tracking, funded by federal and foundation grants across Africa. Yet, existing monitoring programs have largely focused on individual biological markers rather than cross-drug effects.
“Malaria still is a major killer, particularly in sub-Saharan Africa. As drug resistance continues to emerge, we worry it will undermine control of its spread and result in even more deaths for a large number of people there and beyond.”
Dr. Jeffrey Bailey, Associate Professor of Translational Research and of Pathology and Laboratory Medicine at Brown University
Shifting From Targeted Markers to Whole-Genome Sequencing
To uncover the genetic drivers behind decreasing drug susceptibility, investigators altered their methodology from targeted marker tracking to whole-genome sequencing.
“We decided to sequence the entire genome to get a better sense of what was going on.”
Karamoko Niaré, Adjunct Assistant Professor of Pathology and Laboratory Medicine at Brown University
The sequencing approach mapped an area of the parasite genome encompassing 69 genes. Subsequent analyses narrowed this down to a linked variant set featuring three specific mutations and two deletions. These alterations were located in a gene encoding a phosphoinositide-binding protein known as PX1, situated near another gene already recognized for conferring moderate resistance to artemisinin.
International Treatment Strain and Surveillance Implications
International concerns regarding AL durability have grown as reports of treatment failures accumulated among travelers returning from malaria-endemic regions. In response to slower parasite clearance and late treatment failures, the Centers for Disease Control and Prevention adjusted its recommended AL regimen for uncomplicated infections in the United States, extending the course from three days to five days, amounting to ten total doses.
The discovery marks the first time researchers have linked a single gene mutation to reduced susceptibility across multiple drugs deployed within the same combination therapy.
“That’s a very important tool for public health.”
Karamoko Niaré, Adjunct Assistant Professor of Pathology and Laboratory Medicine at Brown University
