Emmanuel Obi1, Festus Okoh2, Sean Blaufuss3, Bolanle Olapeju3, Joel Akilah2, Okefu Oyale Okoko2, Abidemi Okechukwu4, Mark Maire5, Kehinda Popoola6, Muhammad Abdullahi Yahaya7, Chigozie Jesse Uneke8, Samson Awolola9, Olivier Pigeon10, Stella Babalola3, Hannah Koenker3, Albert Kilian11. 1. PMI VectorWorks Project, Tropical Health LLP, Abuja, Nigeria. 2. National Malaria Elimination Programme, Abuja, Nigeria. 3. PMI VectorWorks Project, JHU Center for Communication Programs, Baltimore, MD, USA. 4. U.S. President's Malaria Initiative, U.S. Agency for International Development, Abuja, Nigeria. 5. U.S. President's Malaria Initiative, Centers for Disease Control and Prevention, Abuja, Nigeria. 6. Dept. of Zoology, University of Ibadan, Ibadan, Nigeria. 7. Dept. of Biological Sciences, Usmanu Danfodiyo University, Sokoto, Nigeria. 8. Dept. of Medical Microbiology/Parasitology, Ebonyi State University, Abakaliki, Nigeria. 9. Nigerian Institute for Medical Research, Lagos, Nigeria. 10. Walloon Agricultural Research Centre, Gembloux, Belgium. 11. PMI VectorWorks Project, Tropical Health LLP, Montagut, Spain. albert@trophealth.com.
Abstract
BACKGROUND: Following guidance from the US President's Malaria Initiative, durability monitoring of DawaPlus® 2.0 brand of long-lasting insecticidal net (LLIN) distributed during the 2015/16 mass campaign was set up in three ecologically different states: Zamfara, Ebonyi and Oyo. METHODS: This was a prospective cohort study of representative samples of households from each location, recruited at baseline, 1 to 6 months after the mass campaign. All campaign nets in the households were labelled and followed up over a period of 36 months in Zamfara and Ebonyi and 24 months in Oyo. Primary outcome was the "proportion of nets surviving in serviceable condition" based on attrition and integrity measures and the median survival in years. The outcome for insecticidal durability was determined by bio-assay from sub-samples of campaign nets. RESULTS: A total of 439 households (98% of target) and 1096 campaign nets (106%) were included in the study. Definite outcomes could be determined for 92% of the cohort nets in Zamfara, 88% in Ebonyi and 75% in Oyo. All-cause attrition was highest in Oyo with 47% no longer present after 24 months, 53% in Ebonyi and 28% in Zamfara after 36 months. Overall only 1% of all campaign nets were used for other purposes. Estimated survival in serviceable condition of the campaign nets was 80% in Zamfara, 55% in Ebonyi (36 months follow-up) and 75% in Oyo (24 months follow-up) corresponding to median survival of 5.3, 3.3, 3.2 years, respectively. Factors associated with better survival were exposure to social messaging combined with a positive net-care attitude and only adult users. Failing to fold the net when hanging and having children under 5 years of age in the household negatively impacted net survival. Insecticidal effectiveness testing at final survey showed knock-down rates of 50-69%, but 24-h mortality above 95% resulting in 100% optimal performance in Ebonyi and Oyo and 97% in Zamfara. CONCLUSIONS: Results confirm the strong influence of net-use environment and behavioural factors in the physical survival of the same LLIN brand, which can increase the time until 50% of nets are no longer serviceable by up to 2 years.
BACKGROUND: Following guidance from the US President's Malaria Initiative, durability monitoring of DawaPlus® 2.0 brand of long-lasting insecticidal net (LLIN) distributed during the 2015/16 mass campaign was set up in three ecologically different states: Zamfara, Ebonyi and Oyo. METHODS: This was a prospective cohort study of representative samples of households from each location, recruited at baseline, 1 to 6 months after the mass campaign. All campaign nets in the households were labelled and followed up over a period of 36 months in Zamfara and Ebonyi and 24 months in Oyo. Primary outcome was the "proportion of nets surviving in serviceable condition" based on attrition and integrity measures and the median survival in years. The outcome for insecticidal durability was determined by bio-assay from sub-samples of campaign nets. RESULTS: A total of 439 households (98% of target) and 1096 campaign nets (106%) were included in the study. Definite outcomes could be determined for 92% of the cohort nets in Zamfara, 88% in Ebonyi and 75% in Oyo. All-cause attrition was highest in Oyo with 47% no longer present after 24 months, 53% in Ebonyi and 28% in Zamfara after 36 months. Overall only 1% of all campaign nets were used for other purposes. Estimated survival in serviceable condition of the campaign nets was 80% in Zamfara, 55% in Ebonyi (36 months follow-up) and 75% in Oyo (24 months follow-up) corresponding to median survival of 5.3, 3.3, 3.2 years, respectively. Factors associated with better survival were exposure to social messaging combined with a positive net-care attitude and only adult users. Failing to fold the net when hanging and having children under 5 years of age in the household negatively impacted net survival. Insecticidal effectiveness testing at final survey showed knock-down rates of 50-69%, but 24-h mortality above 95% resulting in 100% optimal performance in Ebonyi and Oyo and 97% in Zamfara. CONCLUSIONS: Results confirm the strong influence of net-use environment and behavioural factors in the physical survival of the same LLIN brand, which can increase the time until 50% of nets are no longer serviceable by up to 2 years.
Authors: Jean Baptiste Yaro; Alphonse Ouedraogo; Z Amidou Ouedraogo; Amidou Diarra; Malik Lankouande; Efundem Agboraw; Eve Worrall; Kobié Hyacinthe Toe; Antoine Sanou; W Moussa Guelbeogo; N'Fale Sagnon; Hilary Ranson; Alfred B Tiono; Steven W Lindsay; Anne L Wilson Journal: Malar J Date: 2020-10-16 Impact factor: 2.979
Authors: Ummi Abdul Kibondo; Olukayode G Odufuwa; Saphina H Ngonyani; Ahmadi B Mpelepele; Issaya Matanilla; Hassan Ngonyani; Noel O Makungwa; Antony P Mseka; Kyeba Swai; Watson Ntabaliba; Susanne Stutz; James W Austin; Sarah Jane Moore Journal: Parasit Vectors Date: 2022-04-11 Impact factor: 3.876
Authors: Peter W Gething; Samir Bhatt; Amelia Bertozzi-Villa; Caitlin A Bever; Hannah Koenker; Daniel J Weiss; Camilo Vargas-Ruiz; Anita K Nandi; Harry S Gibson; Joseph Harris; Katherine E Battle; Susan F Rumisha; Suzanne Keddie; Punam Amratia; Rohan Arambepola; Ewan Cameron; Elisabeth G Chestnutt; Emma L Collins; Justin Millar; Swapnil Mishra; Jennifer Rozier; Tasmin Symons; Katherine A Twohig; T Deirdre Hollingsworth Journal: Nat Commun Date: 2021-06-11 Impact factor: 14.919
Authors: Olivier Briet; Hannah Koenker; Laura Norris; Ryan Wiegand; Jodi Vanden Eng; Alex Thackeray; John Williamson; John E Gimnig; Filomeno Fortes; Martin Akogbeto; Anges W Yadouleton; Maurice Ombok; M Nabie Bayoh; Themba Mzilahowa; Ana Paula Abílio; Samuel Mabunda; Nelson Cuamba; Elhadji Diouf; Lassana Konaté; Busiku Hamainza; Cecilia Katebe-Sakala; Gabriel Ponce de León; Kwame Asamoa; Adam Wolkon; Stephen C Smith; Isabel Swamidoss; Mike Green; Salam Gueye; Jules Mihigo; Juliette Morgan; Ellen Dotson; Allen S Craig; Kathrine R Tan; Robert A Wirtz; Tom Smith Journal: Malar J Date: 2020-08-28 Impact factor: 2.979