Novel malaria control by strategic net-hoisting with S/O channel/grip devices

Hoisting of netting screens with battens on windows/vents suffers from unsightly gathering of dust and allergens, which may provoke respiratory diseases and therefore lack popularity as a mosquito/malaria control tool. Furthermore, installing them in high-rise buildings can be cumbersome and risky. An S/O channel/grip device was, therefore, conceived to eliminate impediments to screening windows/openings in houses.

Thin sheet metal strips were transformed into s-shaped channels. The lower ends provided for attachment to buildings while the upper ends allowed net attachments with O-rubber pipes. Effectiveness was ascertained by applying these to screen a room against adult Anopheles and Aedes mosquitoes. Net hoisting/de-hoisting periods were measured for windows at various locations, and opinions of bystanders were obtained.

The device maintained a firmgrip of metal, fabric or natural nets placed on them. Over a 7-day period, 1036 mosquitoes could not enter rooms protected by either the novel or the traditional methods. Placement/removal of nets with the new device on experimental windows had a mean of 4.5/1 min, respectively, with all the nets intact, hence being reusable; whereas the traditional method had a mean of 4.25/8.75 min with all the nets torn/not-reusable. In high-rise buildings, employing ladders/scaffolds to mount nets were unnecessary: period of hoisting/removal on windows was 11/2 min irrespective of the location of windows whereas the traditional method hoisting period increased substantially as the height of the window increased.

S/O channel/grip devices can improve mosquito control through screening because it engenders net hoisting on windows that is simple, effective, affordable, accessible and convenient, especially on high-rise buildings. The intact removal and recovery of used nets creates opportunities for cleaning them, retreatment with insecticide, regular maintenance, etc. which underline its potential roles in control of asthma and insect-borne diseases.