Protective efficacy of skin-applied arthropod repellents against Chrysops bites in a Loa loa hyperendemic region in Gabon: A placebo-controlled randomized clinical trial of DEET, icaridin, citriodiol, and IR3535.
Gespeichert in:
| Titel: | Protective efficacy of skin-applied arthropod repellents against Chrysops bites in a Loa loa hyperendemic region in Gabon: A placebo-controlled randomized clinical trial of DEET, icaridin, citriodiol, and IR3535. |
|---|---|
| Autoren: | Doumba Ndalembouly AG; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon; École Doctorale Régionale d'Afrique Centrale en Infectiologie Tropicale, Franceville, Gabon., Boussougou-Sambe ST; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon; Institute for Tropical Medicine, Eberhard-Karl-Universität, Tübingen, Germany., Ngossanga B; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon., Djida Y; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon., Werner J; Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany., Zoleko Manego R; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon; Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany., Zinga Koumba RC; Institut de Recherche en Écologie Tropicale, Libreville, Gabon; Institut de Recherche Agronomique et Forestière, Libreville, Gabon., Mintsa R; Institut de Recherche Agronomique et Forestière, Libreville, Gabon., Adegnika AA; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon; Institute for Tropical Medicine, Eberhard-Karl-Universität, Tübingen, Germany; German Center for Infection Research, Tübingen, Germany; Fondation pour la Recherche Scientifique (FORS), Cotonou, Benin., Eisenbarth A; Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany; Bundeswehr Hospital Hamburg, Hamburg, Germany. Electronic address: albert.eisenbarth@bnitm.de., Ramharter M; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon; Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany; Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; German Center for Infection Research, Partner Site Hamburg-Lübeck-Borstel-Riems, Germany. Electronic address: ramharter@bnitm.de. |
| Quelle: | Travel medicine and infectious disease [Travel Med Infect Dis] 2025 Sep-Oct; Vol. 67, pp. 102899. Date of Electronic Publication: 2025 Aug 28. |
| Publikationsart: | Journal Article; Randomized Controlled Trial |
| Sprache: | English |
| Info zur Zeitschrift: | Publisher: Elsevier Science Country of Publication: Netherlands NLM ID: 101230758 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1873-0442 (Electronic) Linking ISSN: 14778939 NLM ISO Abbreviation: Travel Med Infect Dis Subsets: MEDLINE |
| Imprint Name(s): | Original Publication: Amsterdam : Elsevier Science, 2003- |
| MeSH-Schlagworte: | Insect Repellents*/administration & dosage , Insect Repellents*/therapeutic use , Insect Bites and Stings*/prevention & control , Diptera* , Loiasis*/prevention & control , Loiasis*/epidemiology , Loiasis*/transmission, Humans ; Animals ; Male ; Female ; Adult ; Gabon/epidemiology ; Loa ; Young Adult ; DEET/administration & dosage ; Middle Aged ; Adolescent ; Endemic Diseases/prevention & control |
| Abstract: | Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Background: Loa loa - a filarial pathogen causing loiasis -is transmitted by deer fly species Chrysops dimidiata and C. silacea. There are no established control tools available to reduce loiasis transmission in endemic regions. Although the use of repellents has been explored against other arthropods, their protective efficacy against Chrysops bites in humans has not yet been systematically evaluated. The aim of this randomized controlled clinical trial was to assess the efficacy of four commercial skin-applied arthropod repellents against Chrysops bites in a hyperendemic region in Gabon. Methods: Volunteers were randomly assigned to apply the skin repellents DEET, icaridin, citriodiol, IR3535 or an inactive control. The primary endpoint was the number of blood meal attempts by Chrysops flies. Secondary outcomes were the frequency and duration of Chrysops landings on clothing and skin. This study is registered with the Pan African Clinical Trials Registry (PACTR202406779622099). Results: Blood meal attempts were significantly reduced by citriodiol (-50 %, p = 0.04) and DEET (-50 %, p < 0.001), but not by icaridin (0 %, p = 0.48) and IR3535 (0 %, p = 0.69). Concordantly, the time spent by the fly on the skin was significantly shortened by citriodiol (-66 %, p = 0.02) and DEET (-46 %, p < 0.001), but not with icaridin (+2 %, p = 0.35) and IR3535 (0 %, p = 0.93). Conversely, the number of Chrysops landings on untreated clothing was not reduced by DEET and icaridin, while citriodiol and IR3535 treated individuals experienced a higher number of landings (p = 0.005 and p = 0.01, respectively). Conclusions: Citriodiol and DEET showed substantial but not complete protective efficacy against the bite of loiasis vectors. Icaridin and IR3535 were ineffective. (Copyright © 2025 The Authors. Published by Elsevier Ltd.. All rights reserved.) |
| Contributed Indexing: | Keywords: Arthropod repellent; Chrysops; Citriodiol; DEET; Deer fly; Gabon; IR3535; Icaridin; Loa loa; Loiasis |
| Substance Nomenclature: | 0 (Insect Repellents) 134-62-3 (DEET) |
| Entry Date(s): | Date Created: 20250830 Date Completed: 20251011 Latest Revision: 20251120 |
| Update Code: | 20251121 |
| DOI: | 10.1016/j.tmaid.2025.102899 |
| PMID: | 40885295 |
| Datenbank: | MEDLINE |
Full Text Finder 
Nájsť tento článok vo Web of Science | Abstract: | Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.<br />Background: Loa loa - a filarial pathogen causing loiasis -is transmitted by deer fly species Chrysops dimidiata and C. silacea. There are no established control tools available to reduce loiasis transmission in endemic regions. Although the use of repellents has been explored against other arthropods, their protective efficacy against Chrysops bites in humans has not yet been systematically evaluated. The aim of this randomized controlled clinical trial was to assess the efficacy of four commercial skin-applied arthropod repellents against Chrysops bites in a hyperendemic region in Gabon.<br />Methods: Volunteers were randomly assigned to apply the skin repellents DEET, icaridin, citriodiol, IR3535 or an inactive control. The primary endpoint was the number of blood meal attempts by Chrysops flies. Secondary outcomes were the frequency and duration of Chrysops landings on clothing and skin. This study is registered with the Pan African Clinical Trials Registry (PACTR202406779622099).<br />Results: Blood meal attempts were significantly reduced by citriodiol (-50 %, p = 0.04) and DEET (-50 %, p < 0.001), but not by icaridin (0 %, p = 0.48) and IR3535 (0 %, p = 0.69). Concordantly, the time spent by the fly on the skin was significantly shortened by citriodiol (-66 %, p = 0.02) and DEET (-46 %, p < 0.001), but not with icaridin (+2 %, p = 0.35) and IR3535 (0 %, p = 0.93). Conversely, the number of Chrysops landings on untreated clothing was not reduced by DEET and icaridin, while citriodiol and IR3535 treated individuals experienced a higher number of landings (p = 0.005 and p = 0.01, respectively).<br />Conclusions: Citriodiol and DEET showed substantial but not complete protective efficacy against the bite of loiasis vectors. Icaridin and IR3535 were ineffective.<br /> (Copyright © 2025 The Authors. Published by Elsevier Ltd.. All rights reserved.) |
|---|---|
| ISSN: | 1873-0442 |
| DOI: | 10.1016/j.tmaid.2025.102899 |