Development of a single resistance to damage metric for mosquito nets related to physical integrity in the field

• Published in: Malaria Journal
• Main Authors: Amy Wheldrake, Estelle Guillemois, Vera Chetty, Albert Kilian, Stephen J. Russell
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2021
• Subjects: Long-lasting insecticidal mosquito nets; Resistance to damage; Physical integrity; Durability; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic; Snag
• Online Access: https://doi.org/10.1186/s12936-020-03566-1; https://doaj.org/article/d30d2d5d84884c22ab5829f4c1baedca

Abstract Background In common with the majority of personal protective equipment and healthcare products, the ability for long-lasting insecticidal nets (LLINs) to remain in good physical condition during use is a key factor governing fitness for purpose and serviceability. The inherent ability of a product to resist physical deterioration should be known in advance of it being used to ensure it has maximum value to both the end-user and procurer. The objective of this study was to develop a single performance metric of resistance to damage (RD) that can be applied to any LLIN product prior to distribution. Methods Algorithms to calculate RD values were developed based on consideration of both human factors and laboratory testing data. Quantitative reference forces applied to LLINs by users during normal use were determined so that aspirational performance levels could be established. The ability of LLINs to resist mechanical damage was assessed based on a new suite of textile tests, reflecting actual mechanisms of physical deterioration during normal household use. These tests quantified the snag strength, bursting strength, abrasion resistance and resistance to hole enlargement. Sixteen different unused LLINs were included in the analysis. The calculated RD values for all LLINs and the corresponding physical integrity data for the same nets retrieved from the field (up to 3 years of use) were then compared. Results On a RD scale of 0 (lowest resistance) – 100 (highest resistance), only six of the sixteen LLINs achieved an RD value above 50. No current LLIN achieved the aspirational level of resistance to damage (RD = 100), suggesting that product innovation is urgently required to increase the RD of LLINs. LLINs with higher RD values were associated with lower hole damage (PHI) in the field when adjusted for normal use conditions. Conclusions The RD value of any LLIN product can be determined prior to distribution based on the developed algorithms and laboratory textile testing data. Generally, LLINs need to ...