ISSN 2756-3391
African Journal of Parasitology Research ISSN 2756-3391 Vol. 14 (1), pp. 001-009, January, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals
Full Length Research Paper
Molecular surveillance of antimalarial resistance in Chad
Issa Mahamat Souleymane1,3, Adam Batrane, Kerah Hinzoumbé Clément2, Mahamat Saleh Issakha Diar1, Kodbesse Boulotigam1, Mahamat Idriss Djaskano1, N’garadoum Olivier1, Riguide Mbaïssanadjé1, Mahamat Moussa Hassane Taisso3, Honoré Djimrasengar4, Fissou Henri8, Djidi Ali Sougoudi3,5, Mahamat Adano6, Issa Ali Hagar6, Hassoumi Manah7, Kaltam Abderaman Yakhoub5, Ngam-Asra3, Ongram Kouleta II8, Djimadoum Djionadji8, Meram Atteib8, Kaltam Abderaman Yakhoub5, Oumaima Mahamat Djarma3,5, Mahamat Ali BOLTI3,5, and Brahim Boy Otchom3
1,3Chad National Malaria Control Program, N’Djamena, Chad (NMCP). 2Projet d'appui à la lutte antipaludique au Tchad (PALAT/PNUD. 3Faculty of Science and Human Health, University of N’Djamena, Chad. 4World Health Organization, N’Djamena, Chad. 5Renaissance National University Hospital / Infectious Diseases Department, N'Djamena, Chad
6Ecole Nationale des agents sanitaires et Sociaux (ENASS). 7Hôpital de l’amitié Tchad-Chine. 8Ministry of public health.
Received 10 December, 205; Revised 15 December, 2025; Accepted 03 January, 2026 and Published 24 January, 2026
Abstract
Background: The emergence of Plasmodium falciparum resistance to antimalarial drugs remains a major public health concern in Africa. In Chad, molecular data on resistance markers are scarce. This study aimed to assess the prevalence of mutations associated with resistance to sulfadoxine-pyrimethamine (SP), chloroquine (CQ), amodiaquine (AQ), and artemisinin. Methods: Blood samples infected with P. falciparum were collected from 21 health districts across Chad. The samples were collected from patients with uncomplicated malaria, and parasite DNA was extracted from dried blood spots. Molecular markers of antimalarial resistance were investigated by nested PCR amplification of pfdhfr, pfdhps, pfcrt, pfmdr1, and the pfk13 propeller domain, followed by sequencing and polymorphism analysis. Results: A total of 2053 P. falciparum isolates were successfully sequenced and analyzed. Mutations in pfdhps were detected at codons A437G (36.6%) and K540E (10.3%), while the triple pfdhfr mutant I51R59N108 was highly prevalent (97.1%). Combined pfdhfr/pfdhps haplotypes showed 35.2% quadruple and 3.9% quintuple mutants. Moderate frequencies of pfcrt K76T (37.9%) and pfmdr1 N86Y (20.6%) suggest partial persistence of CQ/AQ resistance. Only one non-synonymous k13 mutation (Asp-605) was observed at 0.5% frequency. Conclusion: In Chad, molecular markers indicate widespread resistance to sulfadoxine–pyrimethamine but preserved susceptibility to artemisinin, supporting the continued use of ACTs while underscoring the need for sustained resistance surveillance. These findings provide critical baseline data on antimalarial drug resistance in Chad, supporting current ACT-based treatment policies while emphasizing the need for continued molecular surveillance to inform national malaria control strategies.
Keywords: Plasmodium falciparum, molecular markers, antimalarial resistance, Chad, SP, CQ, AQ, ACTs.