Analysis of diagnostic test outcomes in a large loiasis cohort from an endemic region: Serological tests are often false negative in hyper-microfilaremic infections.

Autor: Veletzky L; Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria.; Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Dep. of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.; German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel-Riems, Germany., Eberhardt KA; Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Dep. of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany., Hergeth J; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon., Stelzl DR; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.; Department of Urology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany., Zoleko Manego R; Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Dep. of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon., Kreuzmair R; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon., Burger G; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany & German Center for Infection Research, partner site Tübingen, Tübingen, Germany.; Department of Internal Medicine, Infectious Diseases, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany., Mischlinger J; Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Dep. of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon., McCall MBB; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.; Radboud University Medical Center, Department of Medical Microbiology, HB Nijmegen, The Netherlands., Mombo-Ngoma G; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.; Department of Implementation Research, Bernhard Nocht Institute for Tropical Medicine & I. Dep. of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany., Adegnika AA; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany & German Center for Infection Research, partner site Tübingen, Tübingen, Germany., Agnandji ST; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany & German Center for Infection Research, partner site Tübingen, Tübingen, Germany., Matsiegui PB; Centre de Recherches Médicales de la Ngounié, Fougamou, Gabon., Lell B; Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria.; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon., Kremsner P; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany & German Center for Infection Research, partner site Tübingen, Tübingen, Germany., Mordmüller B; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany & German Center for Infection Research, partner site Tübingen, Tübingen, Germany.; Radboud University Medical Center, Department of Medical Microbiology, HB Nijmegen, The Netherlands., Tappe D; National Reference Centre for Tropical Pathogens, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany., Ramharter M; Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Dep. of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.; German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel-Riems, Germany.
Jazyk: angličtina
Zdroj: PLoS neglected tropical diseases [PLoS Negl Trop Dis] 2024 Mar 14; Vol. 18 (3), pp. e0012054. Date of Electronic Publication: 2024 Mar 14 (Print Publication: 2024).
DOI: 10.1371/journal.pntd.0012054
Abstrakt: Background: The parasitic disease loiasis is associated with significant morbidity and mortality. Individuals with hyper-microfilaremia (greater than 20,000 microfilariae per mL of blood) may suffer from serious treatment-related or spontaneous adverse events. Diagnosing loiasis remains complex and primarily relies on direct parasite detection. In this study, we analyzed the performance of various diagnostic tests and the influence of parasitological and clinical factors on test outcomes in samples from individuals living in an endemic region.
Methods: Data and samples were collected from rural Gabon. Loiasis was defined as either detectable microfilaremia, or a positive history of eyeworm as assessed by the RAPLOA questionnaire. Diagnostic testing included a quantitative PCR (qPCR) for detection of Loa loa DNA in blood samples, an in-house crude L. loa antigen IgG ELISA, and a rapid test for antibodies against the Ll-SXP-1 antigen (RDT). Sensitivity and specificity were determined for each test and factors potentially influencing outcomes were evaluated in an exploratory analysis.
Results: ELISA, RDT and qPCR results were available for 99.8%, 78.5%, and 100% of the 1,232 participants, respectively. The ELISA and RDT had only modest diagnostic accuracy. qPCR was specific for L. loa microfilaremia and Cycle threshold values correlated with microfilarial density. Anti-L. loa IgG levels were highest in occult loiasis, and antibody levels correlated inversely with L. loa microfilarial density as did RDT line intensities. Only 84.6% and 16.7% of hyper-microfilaremic individuals tested positive by ELISA (11/13) and RDT (2/12), respectively.
Conclusion: None of the tests demonstrated high sensitivity and specificity for loiasis. Indirect diagnostic assays were characterized by low specificity. Additionally, hyper-microfilaremic individuals often tested negative by RDT and ELISA, indicating that these tests are not suitable for individual case management in endemic populations.
Competing Interests: The authors have declared that no competing interests exist.
(Copyright: © 2024 Veletzky et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
Databáze: MEDLINE
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