Evaluation of the Leptocheck-WB IgM Rapid Test for Acute Leptospirosis Among Acute Undifferentiated Fever Patients in Hoima, Western Uganda: Very Low Sensitivity in a Setting Where Non-Icterohaemorrhagiae Leptospira Serogroups Predominate.
- 1Section of Epidemiology, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland.
- 2Central Diagnostic Laboratory, College of Veterinary Medicine, Animal Resources & Biosecurity, Makerere University, Kampala P.O. Box 7062, Uganda.
- 3Infectious Diseases Institute, Makerere University, Kampala P.O. Box 22418, Uganda.
Abstract
Leptospirosis contributes substantially to acute undifferentiated fever (AUF) in sub-Saharan Africa but is underdiagnosed. Rapid diagnostic tests could enable early detection, yet the Leptocheck-WB has not been evaluated in Africa. We evaluated the Leptocheck-WB IgM rapid test in AUF patients at two health facilities in Hoima District, western Uganda (November 2023 to December 2024). Acute leptospirosis was defined by a composite reference standard combining lipL32 real-time PCR on blood and urine and the microscopic agglutination test (MAT) on paired sera. Two production batches were tested on acute-presentation whole blood and serum. Accuracy estimates carry exact binomial confidence intervals. Of 330 participants, 89 (27.0%, 95% CI 22.5-32.0) had leptospirosis. The first batch detected one of 89 cases (sensitivity of 1.1%, 0.03-6.1), and the second one detected two (2.2%, 0.3-7.9). Neither batch produced a false positive among 241 non-cases (specificity of 100%, 98.5-100). The test was negative in all 40 participants who were MAT-seropositive at presentation, including two with titres of 1:1600, while high-titre control sera reacted as expected. Across the 89 cases, MAT reactivity was dominated by the serogroup Bataviae (60 cases), followed by Australis (15) and Tarassovi (11), while Icterohaemorrhagiae was recorded in one case only, at a titre of 1:200. Sensitivity this low makes the test unsuitable for the screening or surveillance of acute leptospirosis in this setting. Limited cross-reactivity between the kit antigen and locally circulating strains is a plausible explanation that this study was not designed to test.
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BibTeX
@article{kirabo2026evaluation,
title = {{Evaluation of the Leptocheck-WB IgM Rapid Test for Acute Leptospirosis Among Acute Undifferentiated Fever Patients in Hoima, Western Uganda: Very Low Sensitivity in a Setting Where Non-Icterohaemorrhagiae Leptospira Serogroups Predominate.}},
author = {Andrew Vivian Kirabo and Lordrick Alinaitwe and Edgar Charles Ndawula and Kenneth Kobba and Joel Ogwang and Moses Kirungi and Angella Ndagire and Mohammed Lamorde and Jonathan Mayito and Anou Dreyfus},
journal = {Pathogens (Basel, Switzerland)},
year = {2026},
month = oct,
doi = {10.3390/pathogens15101046},
url = {https://europepmc.org/article/MED/42931197},
note = {CC BY},
}
RIS
TY - JOUR
TI - Evaluation of the Leptocheck-WB IgM Rapid Test for Acute Leptospirosis Among Acute Undifferentiated Fever Patients in Hoima, Western Uganda: Very Low Sensitivity in a Setting Where Non-Icterohaemorrhagiae Leptospira Serogroups Predominate.
AU - Andrew Vivian Kirabo
AU - Lordrick Alinaitwe
AU - Edgar Charles Ndawula
AU - Kenneth Kobba
AU - Joel Ogwang
AU - Moses Kirungi
AU - Angella Ndagire
AU - Mohammed Lamorde
AU - Jonathan Mayito
AU - Anou Dreyfus
PY - 2026
DA - 2026/10/02
JO - Pathogens (Basel, Switzerland)
DO - 10.3390/pathogens15101046
UR - https://europepmc.org/article/MED/42931197
AB - Leptospirosis contributes substantially to acute undifferentiated fever (AUF) in sub-Saharan Africa but is underdiagnosed. Rapid diagnostic tests could enable early detection, yet the Leptocheck-WB has not been evaluated in Africa. We evaluated the Leptocheck-WB IgM rapid test in AUF patients at two health facilities in Hoima District, western Uganda (November 2023 to December 2024). Acute leptospirosis was defined by a composite reference standard combining lipL32 real-time PCR on blood and urine and the microscopic agglutination test (MAT) on paired sera. Two production batches were tested on acute-presentation whole blood and serum. Accuracy estimates carry exact binomial confidence intervals. Of 330 participants, 89 (27.0%, 95% CI 22.5-32.0) had leptospirosis. The first batch detected one of 89 cases (sensitivity of 1.1%, 0.03-6.1), and the second one detected two (2.2%, 0.3-7.9). Neither batch produced a false positive among 241 non-cases (specificity of 100%, 98.5-100). The test was negative in all 40 participants who were MAT-seropositive at presentation, including two with titres of 1:1600, while high-titre control sera reacted as expected. Across the 89 cases, MAT reactivity was dominated by the serogroup Bataviae (60 cases), followed by Australis (15) and Tarassovi (11), while Icterohaemorrhagiae was recorded in one case only, at a titre of 1:200. Sensitivity this low makes the test unsuitable for the screening or surveillance of acute leptospirosis in this setting. Limited cross-reactivity between the kit antigen and locally circulating strains is a plausible explanation that this study was not designed to test.
SN - 2076-0817
ER -