**Abstract**

House-screening (HS) using fixed-aluminium frames to reduce the risk of indoor infestation with *Aedes aegypti* mosquitoes as well as the risk of *Aedes*-transmitted diseases in communities living in endemic areas. However, the success of this approach has been hindered by the elevated cost of the aluminium-based materials as well as their professional installation, which cannot be afforded by people living under vulnerable conditions. Cost-saving strategies such as the use of low-cost materials including wood, PVC, and Velcro are within the list of HS options available and offered by HS businesses and/or Do-it-yourself (DIY) packages *verbi gratia* ready-made and ready-to-install mosquito-screens. Here, we evaluated the efficacy of low-cost frames constructed with different materials to protect against *Ae. aegypti* indoor infestation using experimental huts. The efficacy of protection in preventing female mosquito passing inside the huts of any of the options of frames was high (>93%) compared to the control with no-screen. People's perceptions on the different materials showed the most "popular" alternative was the frame made of wood (62%). All the prototype-frames of HS made of different materials were effective at blocking *Ae. aegypti* entering-mosquitoes particularly, low-cost options like magnets and Velcro.

**Keywords:** house-screening, *Ae. aegypti*, low-cost materials, Zika, dengue, chikungunya

#### **1. Introduction**

"Building the vector out" and "keeping the vector out" are principles encouraged by the world health organisation (WHO) [1–3] to promote effective and sustainable housing interventions for the prevention of vector-borne diseases. Covering doors and windows with insect mesh, known as house-screening (HS), is one such intervention to "build-out" vector-borne diseases [4–7]. The WHO has historically recommended HS as a method of environmental management [8] to prevent the entry of diseasetransmitting vectors into human habitations and to reduce human-vector-pathogen contact. Unfortunately, HS has been underutilised [4] and overlooked by policies & programs for the prevention and control of *Aedes*-transmitted diseases (ATDs), namely dengue, chikungunya, and Zika [9–12]. In 2017, HS was finally cited as a promising vector management approach for preventing and controlling dengue and ATDs in a research-to-policy forum convened by tropical disease research (TDR)/WHO [13–19].

HS on doors and windows, the most common entry points of mosquitoes into a house, works as a physical barrier that reduces the access and subsequent contact of humans with "hungry" female mosquitoes searching for blood within houses. We recently evaluated the efficacy of HS permanently fixed with aluminium frames to reduce *Ae. aegypti* mosquitoes and the risk of ATDs in a cluster randomised controlled trial in the Mexican city of Merida, Mexico [20–23]. Compared to unprotected households located in the control arm, houses with HS showed a lower risk (OR≈0.50) of finding indoor *Ae. aegypti* female mosquitoes. On the note, compared to those unprotected households, the presence of *Ae. aegypti* infected with dengue and Zika viruses was reduced in clusters with HS by 71%.

Although HS can be considered an effective and, more importantly, an "available" method to reduce mosquito contact with humans in the households of Merida, the cost of the house-installing of HS is high. Thus, no HS was installed prior to the intervention [22]. The current cost for the professional installation of HS by "aluminium & mosquito-screens" (A&MS) establishments in Merida with aluminium frames in an average house is ~\$ 140 USD (two doors and 7 windows). Although the price per m2 of a regular fibber-glass net used for HS is ~\$ 0.85 USD, most of the cost for protecting a house with HS is due to the cost of frames and hardware (72.5% of the total cost) and hand labor (18% of the total cost) if installed by an A&MS professional.

Potential solutions to increase community access and make HS more affordable identified in a previous phase of implementation [22, 23] included introducing low-cost strategies such as the use of less-expensive materials rather than using the aluminium frames offered by A&MS companies and/or the commercialised Do-ityourself (DIY) packages v.gr. ready-made and ready-to-instal mosquito screens with low-cost materials. Here we described some evidence of the use of inexpensive materials for the installation of HS as additional options used by households and/or small businesses in increasing HS affordability, HS efficacy and acceptance, and ultimately, HS access to the community.
