The lethal effect of soap on Schistosoma mansoni cercariae in water.

Autor: Zhang J; Department of Civil and Environmental Engineering, South Kensington Campus, Imperial College London, London, United Kingdom., Pitol AK; Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom., Kinung'hi S; National Institute for Medical Research (NIMR), Mwanza Centre, Mwanza, Tanzania., Angelo T; School of Life Science and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania., Emery AM; Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, United Kingdom., Cieplinski A; Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, United Kingdom., Templeton MR; Department of Civil and Environmental Engineering, South Kensington Campus, Imperial College London, London, United Kingdom., Braun L; Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom.
Jazyk: angličtina
Zdroj: PLoS neglected tropical diseases [PLoS Negl Trop Dis] 2024 Jul 29; Vol. 18 (7), pp. e0012372. Date of Electronic Publication: 2024 Jul 29 (Print Publication: 2024).
DOI: 10.1371/journal.pntd.0012372
Abstrakt: Background: Schistosomiasis is a parasitic disease which is spread through skin contact with water containing Schistosoma cercariae. Drug treatment has been the main control method, but it does not prevent reinfection. The use of soap can be a complementary measure to reduce transmission. Therefore, this study investigates the quantitative effect of different soaps on the mortality of Schistosoma mansoni cercariae.
Methodology: Four soaps including two powder soaps (Kleesoft and Omo) and two bar soaps (B29 and Rungu) which are used in a schistosomiasis-endemic Tanzanian village were studied. S. mansoni cercariae were exposed to powder soaps of 0 (control), 10, 50, 75, 100 and 1000 mg/L and to bar soaps of 0 (control), 100, 500 and 1000 mg/L. The highest concentration of 1000 mg/L was selected based on the laboratory-estimated average soap concentration during handwashing. Cercariae were observed under a microscope after 0, 5, 15, 30, 45 and 60 minutes of exposure to determine their survival.
Conclusions: All four soaps can kill S. mansoni cercariae and this lethal effect was related to soap concentration and exposure time. At the highest concentration of 1000 mg/L, all cercariae were dead at 5 minutes post-exposure with two powder soaps and Rungu, while 100% cercarial death was achieved between 5 minutes to 15 minutes for B29. Almost all cercariae survived after being exposed to 10 mg/L powder soaps and 100 mg/L bar soaps for 60 minutes. Powder soaps were more lethal than bar soaps. Considering the widely varying concentrations of soap during real-world hygiene activities and the necessity for a very high soap concentration to eliminate all cercariae in a short 5-minute exposure, providing the efficacy of soap in preventing schistosomiasis becomes challenging. Future studies should investigate whether soap can influence alternative mechanisms such as making cercariae unable to penetrate the skin, thereby providing protection.
Competing Interests: The authors have declared that no competing interests exist.
(Copyright: © 2024 Zhang 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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