Evaluation and investigation of the effect of oil spraying on the interruption of malaria disease
Mossadegh, A.; Motabar, M.; Javadian, E.
Bulletin de la Societe de Pathologie Exotique et de Ses Filiales 66(1): 92-100
1973
ISSN/ISBN: 0037-9085 PMID: 4801796 Document Number: 66612
When residual sprays fail to prevent malaria transmission because of insecticide resistance in the Anopheline vectors or lack of adequate contact between vectors and treated surfaces on account of the exophilous or exophagous tendencies of the mosquitos or the use of temporary seasonal dwellings by the people, larvicides may be used as an alternative or supplement, particularly oil where this is cheap and plentiful. Breeding places were sprayed with oil from 1967 on Minoo in southern Iran where the main vector, Anopheles stephensi List., is resistant to DDT. DDT has been used twice yearly (in March and September) over the area as a residual spray since 1963 when there was a considerable outbreak of malaria. On Minoo I. and in two nearby districts, malathion was substituted for the autumn spraying in 1967 and 1968 and for both sprayings in 1969 and 1970. The oil used on Minoo I. was 80% gas oil and 20% crude oil with 0.05% detergent to assist spreading, and it was applied every 7-10 days in the warm seasons and less frequently in colder weather. The annual parasite incidence was reduced by about 99.3% on the island in 1967, as compared with the rate for 1963. The corresponding reduction in districts treated with malathion but not oil was 30%. Such cases of malaria as occurred on Minoo I. in 1967 were found to be imported, and it is claimed that the district was fully cleared of malaria in that year. Malathion spraying cleared the whole area in two years.