The development of insecticide-treated durable wall lining for malaria control: insights from rural and urban populations in Angola and Nigeria

Abstract

Background: Durable lining (DL) is a deltamethrin-impregnated polyethylene material, which is designed to cover domestic walls that would normally be sprayed with residual insecticide. The operational success of DL as a long-lasting insecticidal substrate will be dependent on a high level of user acceptability as households must maintain correctly installed linings on their walls for several years. Preliminary trials were undertaken to identify a material to develop into a marketable wall lining and to assess its level of acceptability among rural and urban populations.

Methods: In Angola (n=60), prototype DL and insecticide-treated plastic sheeting (ITPS) were installed on urban house walls and ceilings, respectively, and acceptability was compared to indoor residual spraying (IRS) (n=20) using a knowledge, attitude and practice (KAP) questionnaire. In Nigeria (n=178), three materials (prototype DL, ITPS and insecticide-treated wall netting) were distributed among rural and urban households. User opinions were gathered from focus group discussions, in-depth interviews and KAP questionnaires.

Results: In Angola, after two weeks, the majority of participants (98%) expressed satisfaction with the products and identified the killing of insects as the materials' principal benefits (73%). After one year, despite a loss of almost 50% of households to refugee repatriation, all 32 remaining households still asserted that they had liked the DL/ITPS in their homes and given the choice of intervention preferred DL/ITPS to IRS (94%) or insecticide-treated nets (78%). In Nigeria, a dichotomy between rural and urban respondents emerged. Rural participants favoured wall adornments and accepted wall linings because of their perceived decorative value and entomological efficacy. By contrast, urban households preferred minimal wall decoration and rejected the materials based upon objections to their aesthetics and installation feasibility.

Conclusions: The high level of acceptability among rural inhabitants in Nigeria identifies these communities as the ideal target consumer group for durable wall linings. The poorer compliance among urban participants suggests that wall linings would not be readily adopted or sustained in these regions. If DL is as well received by other rural populations it could overcome some of the logistical constraints associated with spray campaigns and has the potential to become a long-lasting alternative to IRS in malaria endemic areas.

Figure 1

Cacilhas, Huambo Province, Angola. Sixty households (left) in an urban area of Huambo Province, Angola, received a polyethylene shade cloth durable lining (DL) and a heavy-weight insecticide-treated plastic sheeting (ITPS) to cover the walls and ceilings of their houses, respectively (right).

Figure 2

Examples of prototype DL (left), wall netting (middle) and ITPS (right) materials installed in houses in Enugu, Nigeria.

Figure 3

Summary of focus group discussions conducted in rural and urban areas of Nigeria.

Figure 4

Differences between urban (left) and rural (right) house exteriors (top) and interiors (bottom) in Kano, Nigeria. Urban and rural populations in Nigeria disagreed about how a wall should be decorated to be considered attractive. In urban areas (left) wall decorations were minimal. By contrast, in rural houses (right) occupants took pleasure from decorating their walls.