1. Performance of two serodiagnostic tests for loiasis in a Non-Endemic area
- Author
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Marco A. Biamonte, Federico Gobbi, Francesca Tamarozzi, Ronaldo Silva, Cédric B Chesnais, Sébastien D. S. Pion, Lucia Moro, Dora Buonfrate, Zeno Bisoffi, Michel Boussinesq, Paola Rodari, IRCCS Sacro Cuore Don Calabria Hospital [Vérone, Italie], Recherches Translationnelles sur le VIH et les maladies infectieuses endémiques et émergentes (TransVIHMI), Institut de Recherche pour le Développement (IRD)-Université de Yaoundé I-Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), Istituto Superiore di Sanità (ISS), Drugs & Diagnostics for Tropical Diseases [San Diego, CA, États-Unis] (DDTD), Università degli studi di Verona = University of Verona (UNIVR), This work was supported by the Italian Ministry of Health 'Fondi Ricerca Corrente - Linea 3, progetto 8' to IRCCS Sacro Cuore Don Calabria Hospital., Recherches Translationnelles sur le VIH et les maladies infectieuses endémiques er émergentes (TransVIHMI), Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD)-Institut de Recherche pour le Développement (IRD)-Université de Yaoundé I-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Université Montpellier 1 (UM1), Istituto Superiore di Sanita [Rome], University of Verona (UNIVR), and Bodescot, Myriam
- Subjects
0301 basic medicine ,Male ,Nematoda ,Physiology ,RC955-962 ,Loa Loa ,Mansonellum ,0302 clinical medicine ,[SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases ,Arctic medicine. Tropical medicine ,Medicine and Health Sciences ,Medicine ,Eosinophilia ,Non endemic ,Enzyme-Linked Immunoassays ,Nematode Infections ,[SDV.BBM.BC] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM] ,biology ,Eukaryota ,3. Good health ,Body Fluids ,Infectious Diseases ,Strongyloidiasis ,Blood ,Helminth Infections ,[SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases ,Female ,Ascaris lumbricoides ,medicine.symptom ,Public aspects of medicine ,RA1-1270 ,Anatomy ,Loa loa ,[SDV.MP.PAR] Life Sciences [q-bio]/Microbiology and Parasitology/Parasitology ,Research Article ,Neglected Tropical Diseases ,Adult ,medicine.medical_specialty ,030231 tropical medicine ,Antibodies, Helminth ,Schistosomiasis ,Research and Analysis Methods ,Microfilaria ,Sensitivity and Specificity ,Loiasi ,03 medical and health sciences ,Young Adult ,Loiasis ,Diagnostic Medicine ,Internal medicine ,parasitic diseases ,Parasitic Diseases ,Animals ,Humans ,Serologic Tests ,[SDV.MP.PAR]Life Sciences [q-bio]/Microbiology and Parasitology/Parasitology ,[SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM] ,Immunoassays ,Hookworm infection ,business.industry ,Public Health, Environmental and Occupational Health ,Organisms ,Biology and Life Sciences ,Mansonellum, Loiasi, Microfilaria ,medicine.disease ,biology.organism_classification ,Tropical Diseases ,Invertebrates ,030104 developmental biology ,[SDV.SPEE] Life Sciences [q-bio]/Santé publique et épidémiologie ,Immunologic Techniques ,[SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie ,business - Abstract
Loiasis, caused by the filarial nematode Loa loa, is endemic in Central and West Africa where about 10 million people are infected. There is a scarcity of convenient, commercial diagnostics for L. loa. Microscopy requires trained personnel and has low sensitivity, while the serodiagnosis is currently not standardized. Individual case management is also important in non-endemic countries to treat migrants, expatriates and tourists. We retrospectively compared the performance of a Loa Antibody Rapid Test (RDT) and a commercial ELISA pan-filarial test on 170 patients, 65 with loiasis [8 with eyeworm, 29 with positive microfilaremia, 28 with neither microfilaremia nor history of eyeworm but eosinophilia and history of Calabar swelling (probable loiasis)], 95 with other common parasitic infections and no previous exposure to L. loa (37 with M. perstans, 1 with Brugia sp., 18 with strongyloidiasis, 20 with schistosomiasis, 5 with hookworm, 4 with Ascaris lumbricoides infection, 10 with hyper-reactive malarial splenomegaly), and 10 uninfected controls. The sensitivity of the RDT and of the ELISA were 93.8% (61/65) and 90.8% (59/65), respectively. For the RDT, most of the cross-reactions were observed in patients with M. perstans: 7/37 (18.9%), followed by 1/10 (10%) with hyper-reactive malarial splenomegaly and 1/20 (5%) with schistosomiasis. None of the 27 subjects infected with intestinal nematodes was found positive at this test. The ELISA is meant to be a pan-filarial assay, and reacted extensively with cases of M. perstans (95%), as expected, and also in 11/18 (61.1%) patients with strongyloidiasis and in 3/5 (60%) with hookworm infection. The RDT and the ELISA are both highly sensitive for the diagnosis of loiasis. The main difference lies in the extent of cross-reactivity with other parasites. Considering that the RDT is specifically meant for Loa loa infection, and its high sensitivity, this test could be a useful tool for the diagnosis of occult loiasis., Author summary Loa loa is a filarial worm which infects millions of people living in the forested areas of central Africa. The infection is rarely diagnosed outside Africa, but individual case management is also important in non-endemic countries to treat migrants, tourists and expatriates. Aim of this study was to describe the performance of a Rapid Test and an ELISA pan filarial test for the diagnosis of Loa loa infection. Both tests demonstrated good performance for the detection of cases of loiasis. In case of infection with other parasites, the RDT gave less false positive results.
- Published
- 2020