Clinical characteristics and treatments of imported loiasis patients with microfilaraemia diagnosed in France, 2000-2022
Year: 2026
Type: article
Study design: Observational Study
Abstract: INTRODUCTION: Loiasis has been associated with increased morbidity and mortality, particularly in cases of high microfilarial density. Treatment depends on initial microfilaraemia (Mf) and relies on ivermectin (IVM), diethylcarbamazine (DEC) or albendazole (ALB), all associated with serious adverse events. Our objective was to describe the clinical characteristics, management and outcomes of patients diagnosed with loiasis and Mf in France. METHODS: We conducted a multicenter retrospective study including patients with loiasis and Mf diagnosed and treated in France between 2000 and 2022, with at least one follow-up evaluation. We collected clinical and biological data, including Mf kinetics, for each treatment episode. RESULTS: A total of 150 patients (181 treatment episodes) were included across 27 centers. Median age was 35 years, and most patients presented symptoms (75.3%). Median Mf was 500 mf/ml; for 74% of episodes, baseline Mf below 2000 mf/ml, while 8% had baseline Mf above 8000 mf/ml. Twelve different treatment schemes were identified, the most common being a single dose of IVM (39%). Adverse events occurred in 12% of episodes, including one fatal event. On last follow-up visit, 9.3% of patients still experienced symptoms, 24.7% exhibited persistent Mf, and 19.3% had persistent blood eosinophilia, patients treated with stand-alone IVM experienced worse outcomes (18%, 72% and 39%, respectively). CONCLUSION: In France, loiasis treatment is inconsistent and frequently relies on inadequate options, including IVM monotherapy, which lacks therapeutic efficacy, and carries safety concerns. Our findings highlight real-world practices and indicates that better training is needed for practitioners treating patients with loiasis.
Authors: Charles Declerck, Simon Kravetz, Olivier Bouchaud, Justine Dorchies, Damien Dupont, Maeva Lefebvre, Christelle Pomares, Alexandre Duvignaud, Charlotte Boullé, Antoine Specklin, Jordan Leroy, Julie Bonhomme, Laura Courtellemont, Victor Gerber, Jean-Pierre Gangneux, Assia Benelhadj Djelloul, Charles Maurille, Claire Hoffmann, Marie Gladys Robert, Hélène Yera, Benjamin Lefèvre, Coralie L'Ollivier, Estelle Cateau, Gilles Gargala, Yohann Le Govic, Cléa Melenotte, Pierre Danneels, Anne Donnars, Frédéric Grenouillet, Frédérick Gay, Vincent Dubée
Institutions: Centre Hospitalier Universitaire d'Angers, Inserm, Sorbonne Université, Assistance Publique – Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Institut Pierre Louis d‘Épidémiologie et de Santé Publique, Université Sorbonne Paris Nord, Hôpital Bichat-Claude-Bernard, Lyon 1 Université, Centre National de la Recherche Scientifique, Hôpital de la Croix-Rousse, Centre de Recherche en Neurosciences de Lyon, Hospices Civils de Lyon, Centre Hospitalier Universitaire de Nantes, Centre Hospitalier Universitaire de Nice, Université de Bordeaux, Centre Hospitalier Universitaire de Bordeaux, Bordeaux Population Health, Institut de Recherche pour le Développement, Centre Hospitalier Universitaire de Montpellier, Centre Hospitalier Universitaire de Reims, Centre Hospitalier Universitaire de Lille, Centre Hospitalier Universitaire de Caen Normandie, Aliments Bioprocédés Toxicologie Environnements, Université de Caen Normandie, Centre hospitalier universitaire d'Orléans, Hôpitaux Universitaires de Strasbourg, École des Hautes Études en Santé Publique, Institut de Recherche en Santé, Environnement et Travail, Centre Hospitalier Universitaire de Rennes, Université de Rennes, Centre Hospitalier Universitaire de Clermont-Ferrand, Centre Hospitalier du Mans, Centre Hospitalier Régional Universitaire de Brest, Centre Hospitalier Universitaire de Grenoble, Centre Hospitalier Universitaire de Limoges, Centre Hospitalier Régional et Universitaire de Nancy, Interdisciplinarité en Santé Publique Interventions et Instruments de mesure complexes – Région Est, Université de Lorraine, Aix-Marseille Université, Risques Infectieux Tropicaux Microorganismes EmergentS, Centre Hospitalier Universitaire de Poitiers, Centre Hospitalier Universitaire de Rouen, Centre Hospitalier Universitaire Amiens-Picardie, Hôpital Necker-Enfants Malades, Institut Pasteur, Centre Hospitalier Universitaire de Besançon
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,710
OpenAlex ID: W7155177305