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Titolo:
Anopheles funestus resistant to pyrethroid insecticides in South Africa
Autore:
Hargreaves, K; Koekemoer, LL; Brooke, BD; Hunt, RH; Mthembu, J; Coetzee, M;
Indirizzi:
S African Inst Med Res, Sch Pathol, Dept Clin Microbiol & Infect Dis, ZA-2000 Johannesburg, South Africa S African Inst Med Res Johannesburg South Africa ZA-2000 g, South Africa Dept Hlth, Malaria Control Programme, Kwazulu, Natal Province, South Africa Dept Hlth Kwazulu Natal Province South Africa tal Province, South Africa Univ Witwatersrand, Dept Anim Plants & Environm Sci, Johannesburg, South Africa Univ Witwatersrand Johannesburg South Africa Johannesburg, South Africa
Titolo Testata:
MEDICAL AND VETERINARY ENTOMOLOGY
fascicolo: 2, volume: 14, anno: 2000,
pagine: 181 - 189
SICI:
0269-283X(200006)14:2<181:AFRTPI>2.0.ZU;2-0
Fonte:
ISI
Lingua:
ENG
Soggetto:
PERMETHRIN-IMPREGNATED NETS; POLYMERASE-CHAIN-REACTION; SODIUM-CHANNEL GENE; PLASMODIUM-FALCIPARUM; HUMAN MALARIA; COTE-DIVOIRE; GAMBIAE; VECTOR; KDR; IDENTIFICATION;
Keywords:
Anopheles funestus; deltamethrin; malaria vector; molecular identification; permethrin; pyrethroid resistance; susceptibility tests; South Africa;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
49
Recensione:
Indirizzi per estratti:
Indirizzo: Coetzee, M S African Inst Med Res, Dept Med Entomol, POB 1038, ZA-2000 Johannesburg, South Africa S African Inst Med Res POB 1038 Johannesburg SouthAfrica ZA-2000
Citazione:
K. Hargreaves et al., "Anopheles funestus resistant to pyrethroid insecticides in South Africa", MED VET ENT, 14(2), 2000, pp. 181-189

Abstract

Northern Kwazulu/Natal (KZN) Province of South Africa borders on southern Mozambique, between Swaziland and the Indian Ocean. To control malaria vectors in KZN, houses were sprayed annually with residual DDT 2 g/m(2) until 1996 when the treatment changed to deltamethrin 20-25 mg/m(2). At Ndumu (27 degrees 02' S, 32 degrees 19' E) the recorded malaria incidence increased more than six-fold between 1995 and 1999. Entomological surveys during late 1999 found mosquitoes of the Anopheles funestus group (Diptera: Culicidae) resting in sprayed houses in some sectors of Ndumu area. This very endophilic vector of malaria had been eliminated from South Africa by DDT spraying in the 1950s, leaving the less endophilic An. arabiensis Patton as the onlyvector of known importance in KZN. Deltamethrin-sprayed houses at Ndumu were checked for insecticide efficacy by bioassay using susceptible An. arabiensis (laboratory-reared) that demonstrated 100% mortality. Members of the An. funestus group from Ndumu houses (29 males, 116 females) were identified by the rDNA PCR method and four species were found: 74 An. funestus Gilessensu stricto, 34 An. parensis Gillies, seven An. rivulorum Leeson and oneAn. leesoni Evans. Among An. funestus s.s. females, 5.4% (4/74) were positive for Plasmodium falciparum by ELISA and PCR tests. To test for pyrethroid resistance, mosquito adults were exposed to permethrin discriminating dosage and mortality scored 24 h post-exposure: survival rates of wild-caught healthy males were 5/10 An. funestus, 1/9 An. rivulorum and 0/2 An. parensis; survival rates of laboratory-reared adult progeny from 19 An. funestus females averaged 14% (after 1 h exposure to 1% permethrin 25 : 75 cis : trans on papers in WHO test kits) and 27% (after 30 min in a bottle with 25 mu g permethrin 40 : 60 cis : trans). Anopheles funestus families showing > 20% survival in these two resistance test procedures numbered 5/19 and 12/19,respectively. Progeny from 15 of the families were tested on 4% DDT impregnated papers and gave 100% mortality. Finding these proportions of pyrethroid-resistant An. funestus, associated with a malaria upsurge at Ndumu, has serious implications for malaria vector control operations in southern Africa.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 09/04/20 alle ore 10:48:56