When Diagnosis Meets Reality: Operational Performance of Routine Malaria Diagnostics Against Molecular Evidence in Southwestern Saudi Arabia.
9 affiliations
- 1Main Laboratory and Blood Bank Medical and Molecular Microbiology Laboratory Jazan Health Cluster Jazan Saudi Arabia.
- 2Main Laboratory and Blood Bank Medical and Molecular Microbiology Laboratory King Faisal Medical City for Southern Region Abha Saudi Arabia.
- 3Department of Medical Laboratory Sciences Faculty of Applied Medical Sciences King Abdulaziz University Jeddah 21589 Saudi Arabia kau.edu.sa.
- 4Special Infectious Agents Unit King Fahd Medical Research Center King Abdulaziz University Jeddah 21589 Saudi Arabia kau.edu.sa.
- 5Vaccines and Immunotherapy Unit King Fahd Medical Research Center King Abdulaziz Aziz University Jeddah Saudi Arabia kau.edu.sa.
- 6Molecular Biology Department Jazan Health Cluster Jazan Saudi Arabia.
- 7Biotechnology Department Jazan Health Cluster Jazan Saudi Arabia.
- 8Main Laboratory and Blood Bank Medical Microbiology Laboratory Jazan 86735 Saudi Arabia.
- 9Main Laboratory and Blood Bank Medical Microbiology Laboratory Jazan Health Cluster Jazan Saudi Arabia.
Abstract
Background
Saudi Arabia has reported no indigenous malaria since 2021 and is in the prevention-of-reintroduction phase, with residual and imported infections concentrated in Jazan and Aseer. At this stage, each reported case triggers programmatic action, yet the operational accuracy of routine facility diagnostics has not been measured in this setting.Objective
To evaluate the operational accuracy of facility-performed routine light microscopy (RLM) and two Pf/PAN rapid diagnostic tests (RDTs) against species-specific nested PCR.Methods
Retrospective diagnostic accuracy study on consecutively archived specimens. Of 118 archived EDTA samples from febrile patients tested for suspected malaria at hospitals in nine governorates of southwestern Saudi Arabia during January-December 2023, 106 were eligible (12 were excluded). Index tests were performed by facility staff during routine care; nested PCR was later performed blinded. Accuracy was assessed against nested PCR and, in a sensitivity analysis, a composite reference (RLM or PCR positive).Results
Nested PCR detected Plasmodium in 81/106 samples (76.4%; 95% CI 67.2-84.0), all single-species (P. falciparum 56/81; P. vivax 25/81). RLM was positive in 98/106 (92.5%), CareStart in 106/106 (100%), QuickProfile in 100/106 (94.3%). RLM called 29/98 positives mixed (29.6%) versus 0/81 by PCR (Fisher's exact, p < 0.001). Against PCR, RLM sensitivity was 97.5% (91.3-99.6) and specificity 24.0% (10.2-45.5); CareStart specificity 0% (0-13.9), QuickProfile 20.0% (8.1-39.8). PCR confirmation increased with reported parasitemia, from 12/23 (52.2%) at 10-90 parasites/μL to 22/24 (91.7%) at 1000-10,000 parasites/μL (Cochran-Armitage, p < 0.001).Conclusion
In the selected clinically suspected cases, routine diagnostics returned more positives, and far more mixed infections, than nested PCR; both routine false positives and reduced PCR sensitivity in archived material plausibly contribute. Findings should not be extrapolated beyond this population. Strengthened microscopy training, RDT quality assurance, and evaluation of molecular confirmation may support case classification during the prevention-of-reintroduction phase.
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BibTeX
@article{ayashi2026when,
title = {{When Diagnosis Meets Reality: Operational Performance of Routine Malaria Diagnostics Against Molecular Evidence in Southwestern Saudi Arabia.}},
author = {Musa A Ayashi and Ahmed A Muyidi and Majed H Wakid and Fadi M Baakdah and Maimonah S Alghanmi and Hattan S Gattan and Amro A Zalah and Emad E A Wasili and Abdulaziz Y Bajawi and Thamer M Brek},
journal = {Journal of tropical medicine},
year = {2026},
month = oct,
doi = {10.1155/jotm/8453252},
url = {https://europepmc.org/article/MED/42910361},
note = {CC BY},
}
RIS
TY - JOUR
TI - When Diagnosis Meets Reality: Operational Performance of Routine Malaria Diagnostics Against Molecular Evidence in Southwestern Saudi Arabia.
AU - Musa A Ayashi
AU - Ahmed A Muyidi
AU - Majed H Wakid
AU - Fadi M Baakdah
AU - Maimonah S Alghanmi
AU - Hattan S Gattan
AU - Amro A Zalah
AU - Emad E A Wasili
AU - Abdulaziz Y Bajawi
AU - Thamer M Brek
PY - 2026
DA - 2026/10/21
JO - Journal of tropical medicine
DO - 10.1155/jotm/8453252
UR - https://europepmc.org/article/MED/42910361
AB - Background Saudi Arabia has reported no indigenous malaria since 2021 and is in the prevention-of-reintroduction phase, with residual and imported infections concentrated in Jazan and Aseer. At this stage, each reported case triggers programmatic action, yet the operational accuracy of routine facility diagnostics has not been measured in this setting.Objective To evaluate the operational accuracy of facility-performed routine light microscopy (RLM) and two Pf/PAN rapid diagnostic tests (RDTs) against species-specific nested PCR.Methods Retrospective diagnostic accuracy study on consecutively archived specimens. Of 118 archived EDTA samples from febrile patients tested for suspected malaria at hospitals in nine governorates of southwestern Saudi Arabia during January-December 2023, 106 were eligible (12 were excluded). Index tests were performed by facility staff during routine care; nested PCR was later performed blinded. Accuracy was assessed against nested PCR and, in a sensitivity analysis, a composite reference (RLM or PCR positive).Results Nested PCR detected Plasmodium in 81/106 samples (76.4%; 95% CI 67.2-84.0), all single-species (P. falciparum 56/81; P. vivax 25/81). RLM was positive in 98/106 (92.5%), CareStart in 106/106 (100%), QuickProfile in 100/106 (94.3%). RLM called 29/98 positives mixed (29.6%) versus 0/81 by PCR (Fisher's exact, p < 0.001). Against PCR, RLM sensitivity was 97.5% (91.3-99.6) and specificity 24.0% (10.2-45.5); CareStart specificity 0% (0-13.9), QuickProfile 20.0% (8.1-39.8). PCR confirmation increased with reported parasitemia, from 12/23 (52.2%) at 10-90 parasites/μL to 22/24 (91.7%) at 1000-10,000 parasites/μL (Cochran-Armitage, p < 0.001).Conclusion In the selected clinically suspected cases, routine diagnostics returned more positives, and far more mixed infections, than nested PCR; both routine false positives and reduced PCR sensitivity in archived material plausibly contribute. Findings should not be extrapolated beyond this population. Strengthened microscopy training, RDT quality assurance, and evaluation of molecular confirmation may support case classification during the prevention-of-reintroduction phase.
SN - 1687-9686
SN - 1687-9694
ER -