Whole-genome sequencing links PX1 mutations to reduced artemether-lumefantrine susceptibility in Ugandan Plasmodium falciparum

Whole-genome sequencing of parasites from Ugandan blood samples revealed a 69-gene genomic region under selection. Additional analyses pinpointed the PX1 variant set as the strongest correlate of reduced in vitro susceptibility to both components of artemether-lumefantrine, the first-line ACT. This marker had not been previously validated for lumefantrine resistance, explaining observed treatment failures beyond known kelch13 variants.

CDC data already show standard AL courses failing in returned travelers, prompting a 2026 recommendation for extended dosing. The rapid spread of these variants mirrors earlier patterns seen with chloroquine and sulfadoxine-pyrimethamine resistance, where large-scale deployment selected for multi-drug tolerance across sub-Saharan Africa.

The study design is observational and cross-sectional, so causal contribution of PX1 to clinical outcomes remains unproven. Next steps require prospective cohort studies tracking PX1 carriage against day-28 cure rates and in vitro IC50 shifts, plus expanded genomic surveillance in neighboring countries to map geographic spread before policy changes.

Evidence quality is moderate: whole-genome association provides hypothesis-generating leads but cannot establish causation or forecast mortality impact without interventional validation.