Is K-O Tab 1-2-3((R)) long lasting on non-polyester mosquito nets?
Many societies use locally sourced mosquito nets made from a variety of materials. For protecting against malaria these require regular re-treatment with insecticide. K-O Tab 1-2-3 is a 'dip-it-yourself' long-lasting formulation with time-limited interim recommendation from WHO for treatment of washed white and coloured polyester nets for up to 15 washes. To determine wash-resistance on different fabrics, nets made of polyester, polyethylene, cotton or nylon were treated with K-O Tab 1-2-3 and washed up to 20 times using standard WHO washing procedures. Efficacy was assessed using cone and cylinder bioassays and tunnel tests, and deltamethrin content using high-pressure liquid chromatography. Polyethylene and cotton nets treated with K-O Tab 1-2-3 and washed 20 times achieved the WHO threshold of >80% mortality in tunnel tests. Polyethylene matched the performance of polyester in all bioassays in contrast to cotton and nylon which produced low mortality and knock-down in cone and cylinder bioassays. After 20 washes 16.5% of the loading dose of deltamethrin remained on the polyester nets compared with 28.7% on polyethylene, 38.9% on cotton and 2.2% on nylon. Cotton nets retained a high concentration of insecticide but the relatively poor performance in terms of knock-down and mortality suggest most insecticide is bound within the cotton fibres rather than on the surface. K-O Tab 1-2-3 renders insecticide wash fast on polyethylene nets, less so on cotton and nylon. Nets made from polyethylene can be treated in the home to render the insecticide long lasting.
Oxborough
R M
RM
London School of Hygiene and Tropical Medicine, UK.
Weir
V
V
Irish
S
S
Kaur
H
H
N'Guessan
R
R
Boko
P
P
Odjo
A
A
Metonnou
C
C
Yates
A
A
Akogbeto
M
M
Rowland
M W
MW
D000818:Animals; D009033:Culicidae / Q000187:drug effects*; D004355:Drug Stability; D005260:Female; D006796:Household Work; D007306:Insecticides / Q000494:pharmacology*; D009032:Mosquito Control / Q000379:methods*; D009570:Nitriles / Q000494:pharmacology*; D011482:Protective Devices; D011722:Pyrethrins / Q000494:pharmacology*
D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin