Chlorination of Schistosoma mansoni cercariae.
<h4>Background</h4>Schistosomiasis is a water-based disease acquired through contact with cercaria-infested water. Communities living in endemic regions often rely on parasite-contaminated freshwater bodies for their daily water contact activities, resulting in recurring schistosomiasis...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2020-08-01
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| Series: | PLoS Neglected Tropical Diseases |
| Online Access: | https://doi.org/10.1371/journal.pntd.0008665 |
| _version_ | 1818726288356016128 |
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| author | Laura Braun Yasinta Daniel Sylivester Meseret Dessalegne Zerefa Muluwork Maru Fiona Allan Feleke Zewge Aidan M Emery Safari Kinung'hi Michael R Templeton |
| author_facet | Laura Braun Yasinta Daniel Sylivester Meseret Dessalegne Zerefa Muluwork Maru Fiona Allan Feleke Zewge Aidan M Emery Safari Kinung'hi Michael R Templeton |
| author_sort | Laura Braun |
| collection | DOAJ |
| description | <h4>Background</h4>Schistosomiasis is a water-based disease acquired through contact with cercaria-infested water. Communities living in endemic regions often rely on parasite-contaminated freshwater bodies for their daily water contact activities, resulting in recurring schistosomiasis infection. In such instances, water treatment can provide safe water on a household or community scale. However, to-date there are no water treatment guidelines that provide information on how to treat water containing schistosome cercariae. Here, we rigorously test the effectiveness of chlorine against Schistosoma mansoni cercariae.<h4>Method</h4>S. mansoni cercariae were chlorinated using sodium hypochlorite under lab and field condition. The water pH was controlled at 6.5, 7.0 or 7.5, the water temperature at 20°C or 27°C, and the chlorine dose at 1, 2 or 3 mg/l. Experiments were conducted up to contact times of 45 minutes. 100 cercariae were used per experiment, thereby achieving up to 2-log10 inactivations of cercariae. Experiments were replicated under field conditions at Lake Victoria, Tanzania.<h4>Conclusion</h4>A CT (residual chlorine concentration x chlorine contact time) value of 26±4 mg·min/l is required to achieve a 2-log10 inactivation of S. mansoni cercariae under the most conservative condition tested (pH 7.5, 20°C). Field and lab-cultivated cercariae show similar chlorine sensitivities. A CT value of 30 mg·min/l is therefore recommended to disinfect cercaria-infested water, though safety factors may be required, depending on water quality and operating conditions. This CT value can be achieved with a chlorine residual of 1 mg/l after a contact time of 30 minutes, for example. This recommendation can be used to provide safe water for household and recreational water activities in communities that lack safe alternative water sources. |
| first_indexed | 2024-12-17T21:55:49Z |
| format | Article |
| id | doaj.art-2bbc21bf1c4d4208a9c160e6b7f13ae2 |
| institution | Directory Open Access Journal |
| issn | 1935-2727 1935-2735 |
| language | English |
| last_indexed | 2024-12-17T21:55:49Z |
| publishDate | 2020-08-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Neglected Tropical Diseases |
| spelling | doaj.art-2bbc21bf1c4d4208a9c160e6b7f13ae22022-12-21T21:31:07ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352020-08-01148e000866510.1371/journal.pntd.0008665Chlorination of Schistosoma mansoni cercariae.Laura BraunYasinta Daniel SylivesterMeseret Dessalegne ZerefaMuluwork MaruFiona AllanFeleke ZewgeAidan M EmerySafari Kinung'hiMichael R Templeton<h4>Background</h4>Schistosomiasis is a water-based disease acquired through contact with cercaria-infested water. Communities living in endemic regions often rely on parasite-contaminated freshwater bodies for their daily water contact activities, resulting in recurring schistosomiasis infection. In such instances, water treatment can provide safe water on a household or community scale. However, to-date there are no water treatment guidelines that provide information on how to treat water containing schistosome cercariae. Here, we rigorously test the effectiveness of chlorine against Schistosoma mansoni cercariae.<h4>Method</h4>S. mansoni cercariae were chlorinated using sodium hypochlorite under lab and field condition. The water pH was controlled at 6.5, 7.0 or 7.5, the water temperature at 20°C or 27°C, and the chlorine dose at 1, 2 or 3 mg/l. Experiments were conducted up to contact times of 45 minutes. 100 cercariae were used per experiment, thereby achieving up to 2-log10 inactivations of cercariae. Experiments were replicated under field conditions at Lake Victoria, Tanzania.<h4>Conclusion</h4>A CT (residual chlorine concentration x chlorine contact time) value of 26±4 mg·min/l is required to achieve a 2-log10 inactivation of S. mansoni cercariae under the most conservative condition tested (pH 7.5, 20°C). Field and lab-cultivated cercariae show similar chlorine sensitivities. A CT value of 30 mg·min/l is therefore recommended to disinfect cercaria-infested water, though safety factors may be required, depending on water quality and operating conditions. This CT value can be achieved with a chlorine residual of 1 mg/l after a contact time of 30 minutes, for example. This recommendation can be used to provide safe water for household and recreational water activities in communities that lack safe alternative water sources.https://doi.org/10.1371/journal.pntd.0008665 |
| spellingShingle | Laura Braun Yasinta Daniel Sylivester Meseret Dessalegne Zerefa Muluwork Maru Fiona Allan Feleke Zewge Aidan M Emery Safari Kinung'hi Michael R Templeton Chlorination of Schistosoma mansoni cercariae. PLoS Neglected Tropical Diseases |
| title | Chlorination of Schistosoma mansoni cercariae. |
| title_full | Chlorination of Schistosoma mansoni cercariae. |
| title_fullStr | Chlorination of Schistosoma mansoni cercariae. |
| title_full_unstemmed | Chlorination of Schistosoma mansoni cercariae. |
| title_short | Chlorination of Schistosoma mansoni cercariae. |
| title_sort | chlorination of schistosoma mansoni cercariae |
| url | https://doi.org/10.1371/journal.pntd.0008665 |
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