Efficacy of mosquito nets treated with permethrin in Suriname
Article first published online: 7 MAR 2008
Medical and Veterinary Entomology
Volume 3, Issue 4, pages 353–365, October 1989
How to Cite
ROZENDAAL, J. A., VOORHAM, J., VANHOOF, J. P. M. and OOSTBURG, B. F. J. (1989), Efficacy of mosquito nets treated with permethrin in Suriname. Medical and Veterinary Entomology, 3: 353–365. doi: 10.1111/j.1365-2915.1989.tb00242.x
- Issue published online: 7 MAR 2008
- Article first published online: 7 MAR 2008
- Accepted 15 December 1988
- Anopheles darlingi;
- Culex quinquefasciatus;
- malaria control;
- malaria vectors;
ABSTRACT. In the rain-forest of Suriname, where malaria is endemic, 95% of the Maroons (who call themselves bush-negroes) and all Amerindians use mosquito nets made of cotton cloth or, less frequently, nylon or cotton gauze over their hammocks or beds. Bush-negroes usually wash their nets weekly; Amerindians wash nets at 1–4-month intervals.
Females of the principal local malaria vector, Anopheles darlingi Root, were seen blood-feeding through cotton cloth netting (at 22.30-23.30 hours) on a person sleeping in a hammock; others fed successfully after the net was opened in the morning.
Cotton cloth impregnated with permethrin at a rate of 0.5 g/m2 killed all An. darlingi females exposed for 2 min, but after the material had been washed twice in soapy water the bioassay mortality fell to only 21.4%.
Exit traps on a hut with a single sleeper protected by a permethrin-impregnated net yielded 185 An. darlingi females (12% blood-fed) in 74 nights, compared with 276 females (19% blood-fed) from another hut with a sleeper using an untreated net on the same nights (P< 0.001). No An. dar-lingi females remained resting alive indoors in these huts during the daytime, and very few were found dead on the floor in the mornings (one treated, seven untreated). The 24 h mortality rate for those collected in exit traps was 58.4% for the test hut and 27.1% for the control hut (P< 0.001).
Bioassays of permethrin-treated cotton cloth using laboratory-reared sugar-fed Culex quinquefasciatus Say females showed that sprayed nets were less effective than nets impregnated by soaking (at equivalent dosages of 0.16-1.34 g/m2 measured by chemical assay) and confirmed that washing causes severe decline in insecticidal activity.
The feasibility of local mass treatment of mosquito nets is discussed.