Behavioral factors associated with artemisinin resistance: linking community treatment practices with pfkelch13...

Uganda is listed among the few African countries where artemisinin partial resistance has already emerged. It has been increasing there since 2017, providing a unique opportunity to track the dynamics of its spread. Although selection of artemisinin resistant parasites by sub-optimal dosing has been suggested in vitro, epidemiological evidence that community knowledge, attitudes, and practices (KAP) toward treatment seeking or adherence affect the spread of artemisinin resistance is lacking.

In 2023, we conducted active case detection of Plasmodium falciparum (Pf) malaria in 15 villages of Gulu city, Northern Uganda. With informed consent, blood samples were collected and used for 18S ribosomal DNA PCR for Pf detection and subsequent genotyping of pfkelch13 gene by direct sequencing. Structured interviews were administered to household heads to assess their KAP regarding malaria prevention and treatment-seeking behaviors. Factors associated with Pf infection and the presence of WHO-validated artemisinin partial resistance mutations were analyzed using multiple linear regression models.

A total of 1249 participants from 298 households were enrolled, and the overall Pf prevalence by PCR was 20.7%. Prevalence was highest in school-aged children (6-17 years; 31.5%), followed by adults (≥ 18 years; 18.2%). The risk of Pf infection among the general population was 10% higher in households lacking sustained bed net use for children (95% CI 1.1-18.9), 6.9% higher in households with lower educational levels (95% CI 0.8-12.9), and 9.7% higher in rural households (95% CI 4.5-14.9). The overall prevalence of C469Y and A675V validated pfkelch13 mutations was 23.9% and was highest in school-aged children (30.5%). Importantly, the prevalence of C469Y or A675V mutation was 13.1% higher in households where individuals did not consistently take the correct antimalarial dosage (95% CI 0.5-25.6).

Improper bed net use and non-adherence to the antimalarial regimen were associated with a higher risk of Pf infection and artemisinin resistance mutations, underscoring the need for community-based education to reduce the further spread of these mutations. As school-aged children represent the largest reservoir of Pf and artemisinin resistance mutations presence, targeted preventive measures and interventions for this age group are essential.