Reported reasons for non-use of insecticide-treated nets in large national household surveys, 2009-2021

Abstract

Background: Insecticide-treated nets (ITN) are the cornerstone of modern malaria vector control, with nearly 3 billion ITNs delivered to households in endemic areas since 2000. ITN access, i.e. availability within the household, based on the number of ITNs and number of household members, is a pre-requisite for ITN use. Factors determining ITN use are frequently examined in published literature, but to date, large household survey data on reasons given for non-use of nets have not been explored.

Methods: A total of 156 DHS, MIS, and MICS surveys conducted between 2003 and 2021 were reviewed for questions on reasons why nets were not used the previous night, identifying twenty-seven surveys. The percent of nets that were reported used the previous night was calculated for the 156 surveys, and frequencies and proportions of reasons for non-use were calculated within the twenty-seven surveys. Results were stratified by household supply of ITNs in three categories (not enough", "enough", and "more than enough") and by residence (urban/rural).

Results: The proportion of nets used the previous night averaged over 70% between 2003 and 2021, with no discernible change over this period. Reported reasons for why a net goes unused fell largely into three categories-nets that are extra/being saved for future use; the perception that there is little risk of malaria (particularly in dry season); and "other" responses. Net attributes such as colour, size, shape, and texture, and concerns related to chemicals were the least frequent reasons given. Reasons for non-use of nets varied by household net supply, and in some surveys by residence. In Senegal's continuous DHS, the proportion of nets used peaked during high transmission season, and the proportion of nets that went unused due to "no/few mosquitoes" peaked during the dry season.

Conclusions: Unused nets were primarily those being saved for later use, or were not used due to perceived low risk of malaria. Classifying reasons for non-use into broader categories facilitates the design of appropriate social and behaviour change interventions to address the major underlying reasons for non-use, where this is feasible.

Fig. 1

A Number of DHS, MICS, MIS surveys per country included in study objective 1; B Number of surveys per country containing questions about the reasons nets were not used the previous night

Fig. 2

Percentage of nets used the night before the survey with linear trend: DHS, MICS, MIS surveys 2003–2020

Fig. 3

Violin plots with means for ITNs used the previous night and population use of ITNs, by household net supply level

Fig. 4

Distribution of reasons nets were not used, across surveys. Surveys allowing multiple responses total more than 100% of all nets in the survey

Fig. 5

Summary of reasons nets were not used the previous night across surveys, by household supply of ITNs

Fig. 6

Proportion of households reporting year-round net use and households’ reported reasons for not using nets, Senegal 2008–2019

Fig. 7

Percent of nets used the previous night (green) and reasons for non-use, Senegal 2011–2019