1. Safety and infectivity of female cercariae in Schistosoma-naïve, healthy participants: a controlled human Schistosoma mansoni infection study.
- Author
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Koopman JPR, Houlder EL, Janse JJ, Casacuberta-Partal M, Lamers OAC, Sijtsma JC, de Dood C, Hilt ST, Ozir-Fazalalikhan A, Kuiper VP, Roozen GVT, de Bes-Roeleveld LM, Kruize YCM, Wammes LJ, Smits HH, van Lieshout L, van Dam GJ, van Amerongen-Westra IM, Meij P, Corstjens PLAM, Jochems SP, van Diepen A, Yazdanbakhsh M, Hokke CH, and Roestenberg M
- Subjects
- Adult, Animals, Humans, Male, Female, Healthy Volunteers, Schistosoma mansoni, Praziquantel pharmacology, Praziquantel therapeutic use, Cytokines, Schistosomiasis mansoni drug therapy, Anthelmintics pharmacology, Anthelmintics therapeutic use
- Abstract
Background: A controlled human infection model for schistosomiasis (CHI-S) can speed up vaccine development and provides insight into early immune responses following schistosome exposure. Recently, we established CHI-S model using single-sex male-only Schistosoma mansoni (Sm) cercariae in Schistosoma-naïve individuals. Given important differences in antigenic profile and human immune responses to schistosomes of different sex, we pioneered a single-sex female-only CHI-S model for future use in vaccine development., Methods: We exposed 13 healthy, Schistosoma-naïve adult participants to 10 (n = 3) or 20 (n = 10) female cercariae and followed for 20 weeks, receiving treatment with praziquantel (PZQ) 60 mg/kg at week 8 and 12 after exposure., Findings: The majority (11/13) participants reported rash and/or itch at the site of exposure, 5/13 had transient symptoms of acute schistosomiasis. Exposure to 20 cercariae led to detectable infection, defined as serum circulating anodic antigen levels >1.0 pg/mL, in 6/10 participants. Despite two rounds of PZQ treatment, 4/13 participants showed signs of persistent infection. Additional one- or three-day PZQ treatment (1 × 60 mg/kg and 3 × 60 mg/kg) or artemether did not result in cure, but over time three participants self-cured. Antibody, cellular, and cytokine responses peaked at week 4 post infection, with a mixed Th1, Th2, and regulatory profile. Cellular responses were (most) discriminative for symptoms., Interpretation: Female-only infections exhibit similar clinical and immunological profiles as male-only infections but are more resistant to PZQ treatment. This limits future use of this model and may have important implications for disease control programs., Funding: European Union's Horizon 2020 (grant no. 81564)., Competing Interests: Declaration of interests Authors declare that they have no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2023
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