Changes in susceptibility of Plasmodium falciparum to antimalarial drugs in Uganda over time: 2019–2024

Abstract The treatment and control of malaria in Africa is challenged by drug resistance. We characterized ex vivo susceptibilities to nine drugs of isolates collected from individuals presenting with uncomplicated falciparum malaria in eastern (2019-2024) and northern (2021-2024) Uganda and perform...

Full description

Saved in:
Bibliographic Details
Main Authors: Martin Okitwi, Stephen Orena, Patrick K. Tumwebaze, Thomas Katairo, Yoweri Taremwa, Oswald Byaruhanga, Stephen Tukwasibwe, Samuel L. Nsobya, Jennifer Legac, Jeffrey A. Bailey, Roland A. Cooper, Melissa D. Conrad, Philip J. Rosenthal
Format: Article
Language:English
Published: Nature Portfolio 2025-08-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-025-62810-x
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849343663473164288
author Martin Okitwi
Stephen Orena
Patrick K. Tumwebaze
Thomas Katairo
Yoweri Taremwa
Oswald Byaruhanga
Stephen Tukwasibwe
Samuel L. Nsobya
Jennifer Legac
Jeffrey A. Bailey
Roland A. Cooper
Melissa D. Conrad
Philip J. Rosenthal
author_facet Martin Okitwi
Stephen Orena
Patrick K. Tumwebaze
Thomas Katairo
Yoweri Taremwa
Oswald Byaruhanga
Stephen Tukwasibwe
Samuel L. Nsobya
Jennifer Legac
Jeffrey A. Bailey
Roland A. Cooper
Melissa D. Conrad
Philip J. Rosenthal
author_sort Martin Okitwi
collection DOAJ
description Abstract The treatment and control of malaria in Africa is challenged by drug resistance. We characterized ex vivo susceptibilities to nine drugs of isolates collected from individuals presenting with uncomplicated falciparum malaria in eastern (2019-2024) and northern (2021-2024) Uganda and performed deep sequencing, with analysis of 80 Plasmodium falciparum genes, to evaluate associations between susceptibilities and potential resistance markers for samples studied since 2016. For 1114 evaluated isolates, median half-maximal inhibitory concentrations (IC50s) were low-nanomolar for chloroquine, monodesethylamodiaquine, piperaquine, pyronaridine, lumefantrine, mefloquine, and DHA, but higher for quinine and pyrimethamine. Over time, susceptibilities improved for chloroquine, decreased for lumefantrine, mefloquine, and DHA, and were unchanged for other drugs. Changes in prevalences of known markers of altered drug susceptibility followed the same patterns. Genotypes associated with drug susceptibility were those previously identified for aminoquinolines and pyrimethamine. For lumefantrine, susceptibility was decreased with wild-type PfCRT K76T or PfMDR1 N86Y, mutant PfK13 C469Y or A675V, mutant PfCARL D611N, and other polymorphisms. For DHA, susceptibility was decreased with the PfK13 C469Y or A675V and PfMDR1 Y500N mutations. Decreasing activities of lumefantrine and DHA suggest potential loss of efficacies of leading regimens, although the clinical consequences of these changes are, to date, uncertain.
format Article
id doaj-art-b0a126b38cce4f89a62ad73ef848d6cf
institution Kabale University
issn 2041-1723
language English
publishDate 2025-08-01
publisher Nature Portfolio
record_format Article
series Nature Communications
spelling doaj-art-b0a126b38cce4f89a62ad73ef848d6cf2025-08-20T03:42:55ZengNature PortfolioNature Communications2041-17232025-08-011611910.1038/s41467-025-62810-xChanges in susceptibility of Plasmodium falciparum to antimalarial drugs in Uganda over time: 2019–2024Martin Okitwi0Stephen Orena1Patrick K. Tumwebaze2Thomas Katairo3Yoweri Taremwa4Oswald Byaruhanga5Stephen Tukwasibwe6Samuel L. Nsobya7Jennifer Legac8Jeffrey A. Bailey9Roland A. Cooper10Melissa D. Conrad11Philip J. Rosenthal12Infectious Diseases Research CollaborationInfectious Diseases Research CollaborationInfectious Diseases Research CollaborationInfectious Diseases Research CollaborationInfectious Diseases Research CollaborationInfectious Diseases Research CollaborationInfectious Diseases Research CollaborationInfectious Diseases Research CollaborationDepartment of Medicine, University of CaliforniaBrown UniversityDepartment of Natural Sciences and Mathematics, Dominican University of CaliforniaDepartment of Medicine, University of CaliforniaDepartment of Medicine, University of CaliforniaAbstract The treatment and control of malaria in Africa is challenged by drug resistance. We characterized ex vivo susceptibilities to nine drugs of isolates collected from individuals presenting with uncomplicated falciparum malaria in eastern (2019-2024) and northern (2021-2024) Uganda and performed deep sequencing, with analysis of 80 Plasmodium falciparum genes, to evaluate associations between susceptibilities and potential resistance markers for samples studied since 2016. For 1114 evaluated isolates, median half-maximal inhibitory concentrations (IC50s) were low-nanomolar for chloroquine, monodesethylamodiaquine, piperaquine, pyronaridine, lumefantrine, mefloquine, and DHA, but higher for quinine and pyrimethamine. Over time, susceptibilities improved for chloroquine, decreased for lumefantrine, mefloquine, and DHA, and were unchanged for other drugs. Changes in prevalences of known markers of altered drug susceptibility followed the same patterns. Genotypes associated with drug susceptibility were those previously identified for aminoquinolines and pyrimethamine. For lumefantrine, susceptibility was decreased with wild-type PfCRT K76T or PfMDR1 N86Y, mutant PfK13 C469Y or A675V, mutant PfCARL D611N, and other polymorphisms. For DHA, susceptibility was decreased with the PfK13 C469Y or A675V and PfMDR1 Y500N mutations. Decreasing activities of lumefantrine and DHA suggest potential loss of efficacies of leading regimens, although the clinical consequences of these changes are, to date, uncertain.https://doi.org/10.1038/s41467-025-62810-x
spellingShingle Martin Okitwi
Stephen Orena
Patrick K. Tumwebaze
Thomas Katairo
Yoweri Taremwa
Oswald Byaruhanga
Stephen Tukwasibwe
Samuel L. Nsobya
Jennifer Legac
Jeffrey A. Bailey
Roland A. Cooper
Melissa D. Conrad
Philip J. Rosenthal
Changes in susceptibility of Plasmodium falciparum to antimalarial drugs in Uganda over time: 2019–2024
Nature Communications
title Changes in susceptibility of Plasmodium falciparum to antimalarial drugs in Uganda over time: 2019–2024
title_full Changes in susceptibility of Plasmodium falciparum to antimalarial drugs in Uganda over time: 2019–2024
title_fullStr Changes in susceptibility of Plasmodium falciparum to antimalarial drugs in Uganda over time: 2019–2024
title_full_unstemmed Changes in susceptibility of Plasmodium falciparum to antimalarial drugs in Uganda over time: 2019–2024
title_short Changes in susceptibility of Plasmodium falciparum to antimalarial drugs in Uganda over time: 2019–2024
title_sort changes in susceptibility of plasmodium falciparum to antimalarial drugs in uganda over time 2019 2024
url https://doi.org/10.1038/s41467-025-62810-x
work_keys_str_mv AT martinokitwi changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT stephenorena changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT patrickktumwebaze changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT thomaskatairo changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT yoweritaremwa changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT oswaldbyaruhanga changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT stephentukwasibwe changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT samuellnsobya changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT jenniferlegac changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT jeffreyabailey changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT rolandacooper changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT melissadconrad changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024
AT philipjrosenthal changesinsusceptibilityofplasmodiumfalciparumtoantimalarialdrugsinugandaovertime20192024