Coating formulation change leads to inferior performance of long-lasting insecticidal nets in Papua New Guinea
Abstract Background Long-lasting insecticidal nets (LLINs) play a key role in reducing malaria transmission in endemic countries. In a previous study, the authors demonstrated a substantial decrease in the bioefficacy of LLINs for malaria prevention delivered to Papua New Guinea (PNG) between 2013 a...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2022-11-01
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| Series: | Malaria Journal |
| Online Access: | https://doi.org/10.1186/s12936-022-04392-3 |
| _version_ | 1811304493875200000 |
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| author | Nakei Bubun Evodia Anetul Melanie Koinari Timothy W. Freeman Stephan Karl |
| author_facet | Nakei Bubun Evodia Anetul Melanie Koinari Timothy W. Freeman Stephan Karl |
| author_sort | Nakei Bubun |
| collection | DOAJ |
| description | Abstract Background Long-lasting insecticidal nets (LLINs) play a key role in reducing malaria transmission in endemic countries. In a previous study, the authors demonstrated a substantial decrease in the bioefficacy of LLINs for malaria prevention delivered to Papua New Guinea (PNG) between 2013 and 2019. This coincided with a rise in malaria cases in the country. The present study was aimed at determining the underlying cause of the reduced bioefficacy observed in these LLINs. The main hypothesis was that a change in the coating formulation of the respective LLIN product was responsible, and had led to significantly altered product properties and performance. Methods A set of PermaNet® 2.0 LLIN samples (n = 12) manufactured between 2007 and 2019 was subjected to combustion ion chromatography in order to understand the chemistry of the LLIN polymer coating formulation. In addition, World Health Organization (WHO) LLIN standard wash tests and cone bioassays were conducted to further characterize the change in product performance that occurred between 2012 and 2013. Results High polymer fluorine content (average 3.2 g/kg) was measured in PermaNet® 2.0 manufactured up to 2012, whereas nets which were manufactured after 2012 contained very little polymer fluorine (average 0.04 g/kg) indicating a coating formulation change from a fluorocarbon (FC)-based to a non-FC-based formulation. The coating formulation change as part of the manufacturing process thus resulted in a significant reduction in bioefficacy. In addition, the manufacturing change affected wash resistance leading to a faster reduction in 24 h mosquito mortality in the non-FC-coated product with consecutive washes. Conclusion A change in coating formulation of PermaNet® 2.0 resulted in reduced product performance in PNG. Post-2012 PermaNet® 2.0 LLINs should not be considered to be the same product as PermaNet® 2.0 LLINs produced prior to and in 2012. Coating formulation changes should be validated to not impact LLIN product performance. |
| first_indexed | 2024-04-13T08:08:06Z |
| format | Article |
| id | doaj.art-7aab69783dc34b88864479fd3c7d306d |
| institution | Directory Open Access Journal |
| issn | 1475-2875 |
| language | English |
| last_indexed | 2024-04-13T08:08:06Z |
| publishDate | 2022-11-01 |
| publisher | BMC |
| record_format | Article |
| series | Malaria Journal |
| spelling | doaj.art-7aab69783dc34b88864479fd3c7d306d2022-12-22T02:55:06ZengBMCMalaria Journal1475-28752022-11-012111710.1186/s12936-022-04392-3Coating formulation change leads to inferior performance of long-lasting insecticidal nets in Papua New GuineaNakei Bubun0Evodia Anetul1Melanie Koinari2Timothy W. Freeman3Stephan Karl4Vector-Borne Diseases Unit, Papua New Guinea Institute of Medical ResearchVector-Borne Diseases Unit, Papua New Guinea Institute of Medical ResearchAustralian Institute of Tropical Health and Medicine, James Cook UniversityRotarians Against Malaria Papua New GuineaVector-Borne Diseases Unit, Papua New Guinea Institute of Medical ResearchAbstract Background Long-lasting insecticidal nets (LLINs) play a key role in reducing malaria transmission in endemic countries. In a previous study, the authors demonstrated a substantial decrease in the bioefficacy of LLINs for malaria prevention delivered to Papua New Guinea (PNG) between 2013 and 2019. This coincided with a rise in malaria cases in the country. The present study was aimed at determining the underlying cause of the reduced bioefficacy observed in these LLINs. The main hypothesis was that a change in the coating formulation of the respective LLIN product was responsible, and had led to significantly altered product properties and performance. Methods A set of PermaNet® 2.0 LLIN samples (n = 12) manufactured between 2007 and 2019 was subjected to combustion ion chromatography in order to understand the chemistry of the LLIN polymer coating formulation. In addition, World Health Organization (WHO) LLIN standard wash tests and cone bioassays were conducted to further characterize the change in product performance that occurred between 2012 and 2013. Results High polymer fluorine content (average 3.2 g/kg) was measured in PermaNet® 2.0 manufactured up to 2012, whereas nets which were manufactured after 2012 contained very little polymer fluorine (average 0.04 g/kg) indicating a coating formulation change from a fluorocarbon (FC)-based to a non-FC-based formulation. The coating formulation change as part of the manufacturing process thus resulted in a significant reduction in bioefficacy. In addition, the manufacturing change affected wash resistance leading to a faster reduction in 24 h mosquito mortality in the non-FC-coated product with consecutive washes. Conclusion A change in coating formulation of PermaNet® 2.0 resulted in reduced product performance in PNG. Post-2012 PermaNet® 2.0 LLINs should not be considered to be the same product as PermaNet® 2.0 LLINs produced prior to and in 2012. Coating formulation changes should be validated to not impact LLIN product performance.https://doi.org/10.1186/s12936-022-04392-3 |
| spellingShingle | Nakei Bubun Evodia Anetul Melanie Koinari Timothy W. Freeman Stephan Karl Coating formulation change leads to inferior performance of long-lasting insecticidal nets in Papua New Guinea Malaria Journal |
| title | Coating formulation change leads to inferior performance of long-lasting insecticidal nets in Papua New Guinea |
| title_full | Coating formulation change leads to inferior performance of long-lasting insecticidal nets in Papua New Guinea |
| title_fullStr | Coating formulation change leads to inferior performance of long-lasting insecticidal nets in Papua New Guinea |
| title_full_unstemmed | Coating formulation change leads to inferior performance of long-lasting insecticidal nets in Papua New Guinea |
| title_short | Coating formulation change leads to inferior performance of long-lasting insecticidal nets in Papua New Guinea |
| title_sort | coating formulation change leads to inferior performance of long lasting insecticidal nets in papua new guinea |
| url | https://doi.org/10.1186/s12936-022-04392-3 |
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