Resurgence of malaria in Uganda despite sustained indoor residual spraying and repeated long lasting insecticidal net distributions.
Five years of sustained indoor residual spraying (IRS) of insecticide from 2014 to 2019, first using a carbamate followed by an organophosphate, was associated with a marked reduction in the incidence of malaria in five districts of Uganda. We assessed changes in malaria incidence over an additional...
| Main Authors: | , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2022-01-01
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| Series: | PLOS Global Public Health |
| Online Access: | https://doi.org/10.1371/journal.pgph.0000676 |
| _version_ | 1827830034295947264 |
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| author | Adrienne Epstein Catherine Maiteki-Sebuguzi Jane F Namuganga Joaniter I Nankabirwa Samuel Gonahasa Jimmy Opigo Sarah G Staedke Damian Rutazaana Emmanuel Arinaitwe Moses R Kamya Samir Bhatt Isabel Rodríguez-Barraquer Bryan Greenhouse Martin J Donnelly Grant Dorsey |
| author_facet | Adrienne Epstein Catherine Maiteki-Sebuguzi Jane F Namuganga Joaniter I Nankabirwa Samuel Gonahasa Jimmy Opigo Sarah G Staedke Damian Rutazaana Emmanuel Arinaitwe Moses R Kamya Samir Bhatt Isabel Rodríguez-Barraquer Bryan Greenhouse Martin J Donnelly Grant Dorsey |
| author_sort | Adrienne Epstein |
| collection | DOAJ |
| description | Five years of sustained indoor residual spraying (IRS) of insecticide from 2014 to 2019, first using a carbamate followed by an organophosphate, was associated with a marked reduction in the incidence of malaria in five districts of Uganda. We assessed changes in malaria incidence over an additional 21 months, corresponding to a change in IRS formulations using clothianidin with and without deltamethrin. Using enhanced health facility surveillance data, our objectives were to 1) estimate the impact of IRS on monthly malaria case counts at five surveillance sites over a 6.75 year period, and 2) compare monthly case counts at five facilities receiving IRS to ten facilities in neighboring districts not receiving IRS. For both objectives, we specified mixed effects negative binomial regression models with random intercepts for surveillance site adjusting for rainfall, season, care-seeking, and malaria diagnostic. Following the implementation of IRS, cases were 84% lower in years 4-5 (adjusted incidence rate ratio [aIRR] = 0.16, 95% CI 0.12-0.22), 43% lower in year 6 (aIRR = 0.57, 95% CI 0.44-0.74), and 39% higher in the first 9 months of year 7 (aIRR = 1.39, 95% CI 0.97-1.97) compared to pre-IRS levels. Cases were 67% lower in IRS sites than non-IRS sites in year 6 (aIRR = 0.33, 95% CI 0.17-0.63) but 38% higher in the first 9 months of year 7 (aIRR = 1.38, 95% CI 0.90-2.11). We observed a resurgence in malaria to pre-IRS levels despite sustained IRS. The timing of this resurgence corresponded to a change of active ingredient. Further research is needed to determine causality. |
| first_indexed | 2024-03-12T04:16:09Z |
| format | Article |
| id | doaj.art-80a2b4b0b02542bc8bc138903286a299 |
| institution | Directory Open Access Journal |
| issn | 2767-3375 |
| language | English |
| last_indexed | 2024-03-12T04:16:09Z |
| publishDate | 2022-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLOS Global Public Health |
| spelling | doaj.art-80a2b4b0b02542bc8bc138903286a2992023-09-03T10:39:13ZengPublic Library of Science (PLoS)PLOS Global Public Health2767-33752022-01-0129e000067610.1371/journal.pgph.0000676Resurgence of malaria in Uganda despite sustained indoor residual spraying and repeated long lasting insecticidal net distributions.Adrienne EpsteinCatherine Maiteki-SebuguziJane F NamugangaJoaniter I NankabirwaSamuel GonahasaJimmy OpigoSarah G StaedkeDamian RutazaanaEmmanuel ArinaitweMoses R KamyaSamir BhattIsabel Rodríguez-BarraquerBryan GreenhouseMartin J DonnellyGrant DorseyFive years of sustained indoor residual spraying (IRS) of insecticide from 2014 to 2019, first using a carbamate followed by an organophosphate, was associated with a marked reduction in the incidence of malaria in five districts of Uganda. We assessed changes in malaria incidence over an additional 21 months, corresponding to a change in IRS formulations using clothianidin with and without deltamethrin. Using enhanced health facility surveillance data, our objectives were to 1) estimate the impact of IRS on monthly malaria case counts at five surveillance sites over a 6.75 year period, and 2) compare monthly case counts at five facilities receiving IRS to ten facilities in neighboring districts not receiving IRS. For both objectives, we specified mixed effects negative binomial regression models with random intercepts for surveillance site adjusting for rainfall, season, care-seeking, and malaria diagnostic. Following the implementation of IRS, cases were 84% lower in years 4-5 (adjusted incidence rate ratio [aIRR] = 0.16, 95% CI 0.12-0.22), 43% lower in year 6 (aIRR = 0.57, 95% CI 0.44-0.74), and 39% higher in the first 9 months of year 7 (aIRR = 1.39, 95% CI 0.97-1.97) compared to pre-IRS levels. Cases were 67% lower in IRS sites than non-IRS sites in year 6 (aIRR = 0.33, 95% CI 0.17-0.63) but 38% higher in the first 9 months of year 7 (aIRR = 1.38, 95% CI 0.90-2.11). We observed a resurgence in malaria to pre-IRS levels despite sustained IRS. The timing of this resurgence corresponded to a change of active ingredient. Further research is needed to determine causality.https://doi.org/10.1371/journal.pgph.0000676 |
| spellingShingle | Adrienne Epstein Catherine Maiteki-Sebuguzi Jane F Namuganga Joaniter I Nankabirwa Samuel Gonahasa Jimmy Opigo Sarah G Staedke Damian Rutazaana Emmanuel Arinaitwe Moses R Kamya Samir Bhatt Isabel Rodríguez-Barraquer Bryan Greenhouse Martin J Donnelly Grant Dorsey Resurgence of malaria in Uganda despite sustained indoor residual spraying and repeated long lasting insecticidal net distributions. PLOS Global Public Health |
| title | Resurgence of malaria in Uganda despite sustained indoor residual spraying and repeated long lasting insecticidal net distributions. |
| title_full | Resurgence of malaria in Uganda despite sustained indoor residual spraying and repeated long lasting insecticidal net distributions. |
| title_fullStr | Resurgence of malaria in Uganda despite sustained indoor residual spraying and repeated long lasting insecticidal net distributions. |
| title_full_unstemmed | Resurgence of malaria in Uganda despite sustained indoor residual spraying and repeated long lasting insecticidal net distributions. |
| title_short | Resurgence of malaria in Uganda despite sustained indoor residual spraying and repeated long lasting insecticidal net distributions. |
| title_sort | resurgence of malaria in uganda despite sustained indoor residual spraying and repeated long lasting insecticidal net distributions |
| url | https://doi.org/10.1371/journal.pgph.0000676 |
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