“Slash and Clear”, a Community-Based Vector Control Method to Reduce Onchocerciasis Transmission by <i>Simulium sirbanum</i> in Maridi, South Sudan: A Prospective Study
Background: High ongoing <i>Onchocerca volvulus</i> transmission was recently documented in Maridi County, South Sudan. To complement community-directed treatment with ivermectin (CDTI) as the main onchocerciasis control strategy, we initiated a community-based vector control method “sla...
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MDPI AG
2021-10-01
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| Series: | Pathogens |
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| Online Access: | https://www.mdpi.com/2076-0817/10/10/1329 |
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| author | Stephen Raimon Tom L. Lakwo Wilson John Sebit Joseph Nelson Siewe Fodjo Peter Alinda Jane Y. Carter Rory J. Post Robert Colebunders |
| author_facet | Stephen Raimon Tom L. Lakwo Wilson John Sebit Joseph Nelson Siewe Fodjo Peter Alinda Jane Y. Carter Rory J. Post Robert Colebunders |
| author_sort | Stephen Raimon |
| collection | DOAJ |
| description | Background: High ongoing <i>Onchocerca volvulus</i> transmission was recently documented in Maridi County, South Sudan. To complement community-directed treatment with ivermectin (CDTI) as the main onchocerciasis control strategy, we initiated a community-based vector control method “slash and clear” at the Maridi dam, a <i>Simulium damnosum</i> s.l. breeding site, to reduce <i>O. volvulus</i> transmission. Methods: <i>Simulium damnosum</i> s.l. biting rates were collected before and during the twenty months following the “slash and clear” intervention using the human landing catches. Black flies were dissected to measure parity rates before and twelve months after the intervention. Larvae and pupae of <i>S. damnosum</i> s.l. were collected from the dam for morphological and chromosomal characterization to identify the cytospecies involved. Results: Biting rates of <i>S. damnosum</i> s.l. close to the Maridi dam spillway decreased by >90% post-“slash and clear” for more than six months. Twelve months after the “slash and clear” intervention, the reduction in biting rates was still at <50% (<i>p</i> = 0.0007). Parity rates reduced from 13% pre-“slash and clear” (November 2019) to 5.6% post-“slash and clear” (November 2020). Larvae collected from the dam were identified as <i>Simulium sirbanum</i>. Conclusion: The “slash and clear” method was found to be an effective and cheap community-based method to reduce black fly biting rates caused by <i>S. sirbanum</i>. When repeated at least annually together with a high CDTI coverage, this intervention has the potential to considerably accelerate onchocerciasis elimination. |
| first_indexed | 2024-03-10T06:17:09Z |
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| institution | Directory Open Access Journal |
| issn | 2076-0817 |
| language | English |
| last_indexed | 2024-03-10T06:17:09Z |
| publishDate | 2021-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Pathogens |
| spelling | doaj.art-57f3da134cee431b9b9302d92a40430d2023-11-22T19:34:25ZengMDPI AGPathogens2076-08172021-10-011010132910.3390/pathogens10101329“Slash and Clear”, a Community-Based Vector Control Method to Reduce Onchocerciasis Transmission by <i>Simulium sirbanum</i> in Maridi, South Sudan: A Prospective StudyStephen Raimon0Tom L. Lakwo1Wilson John Sebit2Joseph Nelson Siewe Fodjo3Peter Alinda4Jane Y. Carter5Rory J. Post6Robert Colebunders7Amref Health Africa, Juba P.O. Box 410, South SudanVector Control Division, Ministry of Health, Kampala P.O. Box 1661, UgandaPublic Health Laboratory, Ministry of Health, May Rd, Juba P.O. Box 30125, South SudanGlobal Health Institute, University of Antwerp, 2610 Antwerp, BelgiumVector Control Division, Ministry of Health, Kampala P.O. Box 1661, UgandaAmref Health Africa Headquarters, Nairobi P.O. Box 27691-00506, KenyaDisease Control Department, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UKGlobal Health Institute, University of Antwerp, 2610 Antwerp, BelgiumBackground: High ongoing <i>Onchocerca volvulus</i> transmission was recently documented in Maridi County, South Sudan. To complement community-directed treatment with ivermectin (CDTI) as the main onchocerciasis control strategy, we initiated a community-based vector control method “slash and clear” at the Maridi dam, a <i>Simulium damnosum</i> s.l. breeding site, to reduce <i>O. volvulus</i> transmission. Methods: <i>Simulium damnosum</i> s.l. biting rates were collected before and during the twenty months following the “slash and clear” intervention using the human landing catches. Black flies were dissected to measure parity rates before and twelve months after the intervention. Larvae and pupae of <i>S. damnosum</i> s.l. were collected from the dam for morphological and chromosomal characterization to identify the cytospecies involved. Results: Biting rates of <i>S. damnosum</i> s.l. close to the Maridi dam spillway decreased by >90% post-“slash and clear” for more than six months. Twelve months after the “slash and clear” intervention, the reduction in biting rates was still at <50% (<i>p</i> = 0.0007). Parity rates reduced from 13% pre-“slash and clear” (November 2019) to 5.6% post-“slash and clear” (November 2020). Larvae collected from the dam were identified as <i>Simulium sirbanum</i>. Conclusion: The “slash and clear” method was found to be an effective and cheap community-based method to reduce black fly biting rates caused by <i>S. sirbanum</i>. When repeated at least annually together with a high CDTI coverage, this intervention has the potential to considerably accelerate onchocerciasis elimination.https://www.mdpi.com/2076-0817/10/10/1329onchocerciasis<i>Simulium damnosum</i><i>Simulium sirbanum</i>vector controlslash and clearelimination |
| spellingShingle | Stephen Raimon Tom L. Lakwo Wilson John Sebit Joseph Nelson Siewe Fodjo Peter Alinda Jane Y. Carter Rory J. Post Robert Colebunders “Slash and Clear”, a Community-Based Vector Control Method to Reduce Onchocerciasis Transmission by <i>Simulium sirbanum</i> in Maridi, South Sudan: A Prospective Study Pathogens onchocerciasis <i>Simulium damnosum</i> <i>Simulium sirbanum</i> vector control slash and clear elimination |
| title | “Slash and Clear”, a Community-Based Vector Control Method to Reduce Onchocerciasis Transmission by <i>Simulium sirbanum</i> in Maridi, South Sudan: A Prospective Study |
| title_full | “Slash and Clear”, a Community-Based Vector Control Method to Reduce Onchocerciasis Transmission by <i>Simulium sirbanum</i> in Maridi, South Sudan: A Prospective Study |
| title_fullStr | “Slash and Clear”, a Community-Based Vector Control Method to Reduce Onchocerciasis Transmission by <i>Simulium sirbanum</i> in Maridi, South Sudan: A Prospective Study |
| title_full_unstemmed | “Slash and Clear”, a Community-Based Vector Control Method to Reduce Onchocerciasis Transmission by <i>Simulium sirbanum</i> in Maridi, South Sudan: A Prospective Study |
| title_short | “Slash and Clear”, a Community-Based Vector Control Method to Reduce Onchocerciasis Transmission by <i>Simulium sirbanum</i> in Maridi, South Sudan: A Prospective Study |
| title_sort | slash and clear a community based vector control method to reduce onchocerciasis transmission by i simulium sirbanum i in maridi south sudan a prospective study |
| topic | onchocerciasis <i>Simulium damnosum</i> <i>Simulium sirbanum</i> vector control slash and clear elimination |
| url | https://www.mdpi.com/2076-0817/10/10/1329 |
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