The hidden malaria: misidentification of Plasmodium malariae and Plasmodium ovale in low-transmission setting targeted for elimination in Ethiopia.
11 affiliations
- 1School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia. [email protected].
- 2Department of Medical Laboratory Sciences, Arba Minch College of Health Sciences, Arba Minch, Ethiopia. [email protected].
- 3Tropical and Infectious Diseases Research Center (TIDRC), Jimma University, Jimma, Ethiopia. [email protected].
- 4Department of Population Health and Disease Prevention, University of California at Irvine, Irvine, CA, 92697, USA.
- 5Menelik II Medical & Health Science College, Addis Ababa, Ethiopia.
- 6Department of Medical Laboratory Sciences, College of Medicine and Health Sciences, Ambo University, Ambo, Ethiopia.
- 7School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia.
- 8Tropical and Infectious Diseases Research Center (TIDRC), Jimma University, Jimma, Ethiopia.
- 9West Valley Mosquito and Vector Control Agency, Ontario, CA, USA.
- 10Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA.
- 11Veterans Affairs Medical Center, Cleveland, OH, USA.
Abstract
Background
Quartan malaria caused by Plasmodium malariae (Pm) and tertian Plasmodium ovale (Po) malaria has been largely overlooked in Ethiopia due to their milder clinical symptoms, lower prevalence, and frequently misdiagnosis during routine microscopic. This study estimated the prevalence of Pm and Po infections misdiagnosed as P. vivax (Pv) in selected health facilities in southwestern Ethiopia.Methods
A cross-sectional study was conducted among study participants who were positive for Pv by microscopy or rapid diagnostic test (RDT) and who were attending health facilities within Arjo-Didessa sugarcane plantations and surrounding areas in Oromia, southwestern Ethiopia, between September 2019 and July 2022. Of the 3590 febrile patients attending health facilities, 323 were Pv positive by microscopy or RDT. Among these, 245 Pv-positive samples were re-evaluated using quantitative polymerase chain reaction (qPCR). Species-specific primers targeting Pv, P. falciparum (Pf), Pm, and Po were used for species confirmation.Results
From 245 vivax malaria cases, RDT were performed to 162 sub-samples, among them 8.6% (14/162) were negative by RDT. None of the samples tested by RDT and microscopy detected Pm or Po. Of these 245 tested and reported as Pv positive by microscopy, qPCR confirmed that 215 (87.7%, 95% CI 82.98-91.58) were positive for Pv, 9 (3.7%, 95% CI 1.69-6.86) for Pf, 8 (3.3%, 95% CI 1.42-6.33) for Pm, 6 (2.4%, 95% CI 0.90-5.25) were positive for Po, and 7 (2.8%, 95% CI 1.16-5.80) had mixed infections (Pf and Pv).Conclusions
The findings of this study highlights the need for a strategic shift to integrate Pm and Po into Ethiopia's malaria control and elimination program. Moreover, strengthening the diagnostic capacity should include training of microscopists for accurate Plasmodium species identification and adopting highly sensitive diagnostic tool for all four Plasmodium species in resource-limited settings. This is essential for enhancing malaria control and accelerating progress toward elimination.
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BibTeX
@article{getachew2026hidden,
title = {{The hidden malaria: misidentification of Plasmodium malariae and Plasmodium ovale in low-transmission setting targeted for elimination in Ethiopia.}},
author = {Hallelujah Getachew and Chloe Wang and Kassahun Habtamu and Assalif Demissew and Teshome Degefa and Solomon K Birhanie and James W Kazura and Christopher L King and Guiyun Yan and Delenasaw Yewhalaw},
journal = {Parasites \& vectors},
year = {2026},
month = aug,
doi = {10.1186/s13071-026-07511-0},
url = {https://europepmc.org/article/MED/42958344},
note = {CC BY},
}
RIS
TY - JOUR
TI - The hidden malaria: misidentification of Plasmodium malariae and Plasmodium ovale in low-transmission setting targeted for elimination in Ethiopia.
AU - Hallelujah Getachew
AU - Chloe Wang
AU - Kassahun Habtamu
AU - Assalif Demissew
AU - Teshome Degefa
AU - Solomon K Birhanie
AU - James W Kazura
AU - Christopher L King
AU - Guiyun Yan
AU - Delenasaw Yewhalaw
PY - 2026
DA - 2026/08/03
JO - Parasites & vectors
DO - 10.1186/s13071-026-07511-0
UR - https://europepmc.org/article/MED/42958344
AB - Background Quartan malaria caused by Plasmodium malariae (Pm) and tertian Plasmodium ovale (Po) malaria has been largely overlooked in Ethiopia due to their milder clinical symptoms, lower prevalence, and frequently misdiagnosis during routine microscopic. This study estimated the prevalence of Pm and Po infections misdiagnosed as P. vivax (Pv) in selected health facilities in southwestern Ethiopia.Methods A cross-sectional study was conducted among study participants who were positive for Pv by microscopy or rapid diagnostic test (RDT) and who were attending health facilities within Arjo-Didessa sugarcane plantations and surrounding areas in Oromia, southwestern Ethiopia, between September 2019 and July 2022. Of the 3590 febrile patients attending health facilities, 323 were Pv positive by microscopy or RDT. Among these, 245 Pv-positive samples were re-evaluated using quantitative polymerase chain reaction (qPCR). Species-specific primers targeting Pv, P. falciparum (Pf), Pm, and Po were used for species confirmation.Results From 245 vivax malaria cases, RDT were performed to 162 sub-samples, among them 8.6% (14/162) were negative by RDT. None of the samples tested by RDT and microscopy detected Pm or Po. Of these 245 tested and reported as Pv positive by microscopy, qPCR confirmed that 215 (87.7%, 95% CI 82.98-91.58) were positive for Pv, 9 (3.7%, 95% CI 1.69-6.86) for Pf, 8 (3.3%, 95% CI 1.42-6.33) for Pm, 6 (2.4%, 95% CI 0.90-5.25) were positive for Po, and 7 (2.8%, 95% CI 1.16-5.80) had mixed infections (Pf and Pv).Conclusions The findings of this study highlights the need for a strategic shift to integrate Pm and Po into Ethiopia's malaria control and elimination program. Moreover, strengthening the diagnostic capacity should include training of microscopists for accurate Plasmodium species identification and adopting highly sensitive diagnostic tool for all four Plasmodium species in resource-limited settings. This is essential for enhancing malaria control and accelerating progress toward elimination.
SN - 1756-3305
ER -