dieldrin and Plague

Insecticide susceptibility tests with 4% DDT, 0.5% and 5.0% malathion, 1% fenitrothion, and 0.2% dieldrin impregnated papers were carried out with fleas spp. from the Boyolali plague zone. The field flea (Stivalius cognatus) which was highly susceptible to malathion before, has now been found to be resistant to the insecticide, but was found susceptible to the other three insecticides. The oriental rat flea (X. cheopis) which found previously highly resistant to DDT, was now found to be less resistant, and susceptible to other insecticides tested. From preliminary tests with DDT to another field flea (Neopsylla sondiacus), it was found to be susceptible to the insecticide.

Topics: Animals; DDT; Dieldrin; Disease Reservoirs; Drug Resistance; Fenitrothion; Humans; Indonesia; Malathion; Plague; Rodentia; Siphonaptera; Species Specificity

Rat fleas and mosquitoes are insect vectors of public health importance in Burma. Plague is endemic in Central Burma and DDT has been the principal insecticide used for its control to date. Dengue haemorrhagic fever, recently introduced and transmitted by Aedes aegypti, has been spreading to major towns since 1971. The rodents, Rattus rattus, R. exulans, Bandicota bengalensis, Mus musculus, as well as shrews were commonly caught during routine trapping in the country. Rattus norvegicus, prevalent in Rangoon City, is not found in Central Burma. The rat fleas, Xenopsylla cheopis and X. astia, were found to be infesting these rodents, the former being the principal vector of plague. Insecticide susceptibility tests have been carried out periodically in plague endemic areas and Rangoon since 1966 and it is now observed that rat fleas in most of these endemic towns and Rangoon Port are no longer susceptible to DDT. Subsequent rechecks in towns where fleas became resistance to DDT show that fleas are persistently resistant to the insecticide. Aedes aegypti is found to be highly prevalent both in rural and urban areas of almost every major town and townships below 900 meters. Insecticide susceptible tests on this mosquito in limited areas show that the mosquito is generally resistant to DDT but susceptible to other insecticides. With the development of DDT resistance in fleas, it is now necessary to change to an effective insecticide in the control of plague in Burma.

Topics: Aedes; Animals; DDT; Dieldrin; Insect Vectors; Insecticide Resistance; Insecticides; Mosquito Control; Myanmar; Plague; Rats; Siphonaptera

Topics: Agriculture; Animals; Chagas Disease; Communicable Disease Control; Culicidae; DDT; Dengue; Developing Countries; Dieldrin; Economics; Encephalitis; Encephalitis Virus, Japanese; Encephalitis Virus, Western Equine; Filariasis; History, 20th Century; Humans; Insect Control; Insect Vectors; Insecticide Resistance; Onchocerciasis; Plague; Typhus, Epidemic Louse-Borne; Yellow Fever

Topics: Animals; Dieldrin; Disease Vectors; Insecticides; Methods; Plague; Sciuridae; Siphonaptera; Time Factors