title: Wash resistance and efficacy of Olyset net and Permanet 2.0 against Anopheles stephensi in India.
abstract: Long-lasting insecticidal nets (LLIN) have been developed for wash resistance and long-lasting effects against mosquito vectors. In this study we evaluated 2 LLIN products, Olyset net and Permanet 2.0, washed for 0, 5, 10, 15, and 20 times, against Anopheles stephensi, an urban malaria vector in India. We assessed the wash resistance and efficacy of these nets in relation to bloodfeeding inhibition and percent mortality in cone and tunnel test bioassays. Both Olyset and Permanet showed >80% mortality of An. stephensi in cone bioassays after 20 washes. In tunnel tests there was no significant difference between Olyset and Permanet 2.0 in causing total mosquito mortality (immediate and delayed) up to 10 washes and bloodfeeding inhibition and entry rate up to 15 washes. After the 20th wash, Permanet 2.0 was significantly more effective than the Olyset net in causing total mosquito mortality, whereas Olyset net showed less bloodfeeding and entry of mosquitoes as compared to Permanet 2.0. There was a gradual decline in efficacy of both LLIN products as the number of washings increased. Cone bioassays indicated a strong wash resistance in both the LLIN products after 20 washes. However, the tunnel tests demonstrated a gradual decline in efficacy of both products with the number of washings.
authors.affiliation: Indira Gandhi National Open University, Maidan Garhi, New Delhi-68, India.
authors.forename: Ripu Daman
authors.initials: RD
authors.lastname: Sood
authors.forename: P K
authors.initials: PK
authors.lastname: Mittal
authors.forename: Neera
authors.initials: N
authors.lastname: Kapoor
authors.forename: R K
authors.initials: RK
authors.lastname: Razdan
authors.forename: A P
authors.initials: AP
authors.lastname: Dash
mesh_terms: D000818:Animals; D000852:Anopheles / Q000187:drug effects*; D005247:Feeding Behavior; D007194:India; D057148:Insecticide-Treated Bednets; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology; D007846:Laundering; D009570:Nitriles / Q000737:chemistry / Q000494:pharmacology*; D026023:Permethrin / Q000737:chemistry / Q000494:pharmacology*; D011722:Pyrethrins / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin; D026023:Permethrin