dieldrin and Malaria

Topics: Africa; Animals; Anopheles; DDT; Diazinon; Dichlorvos; Dieldrin; Europe; Humans; India; Insect Vectors; Insecticide Resistance; Malaria; Malathion; Mosquito Control; North America; Pest Control, Biological; Plasmodium falciparum; South America

Topics: Adipose Tissue; Aldrin; Animals; Central Nervous System Diseases; Chemical and Drug Induced Liver Injury; Chlordan; DDT; Dieldrin; Dogs; Drug Synergism; Endrin; Environmental Pollution; Female; Heptachlor; Hexachlorocyclohexane; Humans; Hydrocarbons, Halogenated; Malaria; Male; Methoxychlor; Mice; Mice, Inbred Strains; Pesticides; Rats; Rats, Inbred Strains; Reproduction; Toxaphene; Typhus, Epidemic Louse-Borne

Topics: Animals; Anopheles; Carbamates; Chlorpyrifos; DDT; Dieldrin; Fenitrothion; Hexachlorocyclohexane; Insecticides; Larva; Malaria; Malathion; Methoxychlor; Mosquito Control; Propoxur

Topics: Animals; Anopheles; Chlorpyrifos; DDT; Dieldrin; Ecology; Environmental Pollution; Fenitrothion; Fenthion; Housing; Humans; Insect Vectors; Insecticide Resistance; Insecticides; Larva; Malaria; Malathion; Mosquito Control; Naled; Pest Control, Biological; Pesticide Residues

Topics: Aedes; Animals; Anopheles; Antimalarials; Asia, Southeastern; Carbamates; Culex; DDT; Dieldrin; Drug Resistance, Microbial; Ecology; Fenitrothion; Fishes; Humans; Malaria; Malathion; Naphthalenes; Organophosphorus Compounds; Pest Control, Biological; Plasmodium; Plasmodium falciparum; Pyrimethamine; Sulfonamides; Triazines; United States; World Health Organization

Broflanilide is a new insecticide being developed for malaria vector control. As new insecticide chemistries become available, strategies to preserve the susceptibility of local malaria vectors and extend their useful life need to be considered before large scale deployment. This requires the development of appropriate testing procedures and identification of suitable discriminating concentrations for monitoring susceptibility in wild vector populations to facilitate decision making by control programmes.. Dose-response WHO bottle bioassays were conducted using the insecticide-susceptible Anopheles gambiae s.s. Kisumu strain to determine a discriminating concentration of broflanilide. Bioassays were performed without the adjuvant Mero® and with two concentrations of Mero® (500 ppm and 800 ppm) to investigate its impact on the discriminating concentration of the insecticide. Probit analysis was used to determine the lethal doses at 50% (LC50) and 99% (LC99) at 24-, 48- and 72-hours post-exposure. Cross-resistance to broflanilide and pyrethroids, DDT, dieldrin and carbamates, was investigated using An. gambiae s.l. Covè and An. coluzzii Akron strains. The susceptibility of wild pyrethroid-resistant mosquitoes from communities in Southern Benin to broflanilide was assessed using the estimated discriminating concentrations.. Broflanilide induced a dose-dependent and delayed mortality effect. Mortality rates in bottles treated without Mero® were <80% using the range of broflanilide doses tested (0-100 μg/bottle) leading to high and unreliable estimates of LC99 values. The discriminating concentrations defined as 2XLC99 at 72h post exposure were estimated to be 2.2 μg/bottle with 800 ppm of Mero® and 6.0 μg/bottle with 500 ppm of Mero®. Very low resistance ratios (0.6-1.2) were determined with the insecticide resistant An. gambiae s.l. Covè and An. coluzzii Akron strains suggesting the absence of cross-resistance via the mechanisms of resistance to pyrethroids, DDT, dieldrin and carbamates they possess. Bottle bioassays performed with broflanilide at both discriminating concentrations of 6 μg/bottle with 500 ppm of Mero® and 2.2 μg/bottle with 800 ppm of Mero®, showed susceptibility of wild highly pyrethroid-resistant An. gambiae s.l. from villages in Southern Benin.. We determined discriminating concentrations for monitoring susceptibility to broflanilide in bottle bioassays, using susceptible An. gambiae vectors. Using the estimated discriminating concentrations, we showed that wild pyrethroid-resistant populations of An. gambiae s.l. from southern Benin were fully susceptible to the insecticide. Broflanilide also shows potential to be highly effective against An. gambiae s.l. vector populations that have developed resistance to other public health insecticides.

Topics: Animals; Anopheles; Biological Assay; Carbamates; DDT; Dieldrin; Humans; Insecticide Resistance; Insecticides; Malaria; Mosquito Control; Mosquito Vectors; Pyrethrins; World Health Organization

Although malaria is endemic in some areas of southeastern Iran, following the successful national malaria elimination plan, the local transmission area has been shrunk. The main cases in Iran are due to Plasmodium vivax followed by P. falciparum. This study was aimed to determine the current situation of malaria in Kerman Province of Iran and evaluate the insecticide resistance of main vectors. The field study was conducted in 2019. Data of new malaria cases were obtained from the health centers for the period of 2009-2018. Susceptibility status of Anopheles stephensi and An. dthali was evaluated against dichlorodiphenyltrichloroethane, Dieldrin, Malathion, Bendiocarb, Deltamethrin, and Temephos at the diagnostic dose. A total of 522 malaria cases were recorded and divided into indigenous (33.14%) and imported (66.86%) categories. The highest incidence of the disease was reported from the southern areas of the province, where all indigenous cases occurred. Adults of An. stephensi were resistant to dichlorodiphenyltrichloroethane while its resistance to be confirmed to dieldrin, bendiocarb and deltamethrin. As An. dthali had less than 98% mortality against bendiocarb, the resistance status should be confirmed with more tests. Our findings showed both species had less than 98% mortality against bendiocarb and deltamethrin insecticides which are used in malaria vector control program in Iran. Due to the susceptibility of these vectors to temephos, larviciding can be advised for vector control in this area.

Topics: Animals; Anopheles; DDT; Dieldrin; Insecticide Resistance; Insecticides; Iran; Malaria; Malaria, Falciparum; Mosquito Vectors; Pyrethrins; Temefos; World Health Organization

Novel insecticides are urgently needed to control insecticide-resistant populations of Anopheles malaria vectors. Broflanilide acts as a non-competitive antagonist of the gamma-aminobutyric acid receptor and has shown prolonged effectiveness as an indoor residual spraying product (VECTRON T500) in experimental hut trials against pyrethroid-resistant vector populations. This multi-centre study expanded upon initial discriminating concentration testing of broflanilide, using six Anopheles insectary colonies (An. gambiae Kisumu KCMUCo, An. gambiae Kisumu NIMR, An. arabiensis KGB, An. arabiensis SENN, An. coluzzii N'Gousso and An. stephensi SK), representing major malaria vector species, to facilitate prospective susceptibility monitoring of this new insecticide; and investigated the potential for cross-resistance to broflanilide via the A296S mutation associated with dieldrin resistance (rdl). Across all vector species tested, the discriminating concentration for broflanilide ranged between LC

Topics: Animals; Anopheles; Dieldrin; Insecticide Resistance; Insecticides; Malaria; Mosquito Control; Mosquito Vectors; Prospective Studies; Public Health; Pyrethrins

During five years, from 1953, a village scale indoors residual spraying (IRS) was done in the pilot zone of Bobo-Dioulasso, Burkina Faso, with DDT or dieldrin (DLN) or even HCH with a conceptually both entomological and parasitological evaluation [18].Compared to the control area, DDT induced an approximatively 95% and 67% reduction in the landing rate of

Topics: Animals; Anopheles; Child; DDT; Dieldrin; Humans; Infant; Infant, Newborn; Insecticides; Malaria; Malaria, Falciparum; Mosquito Control; Mosquito Vectors; Plasmodium; Sporozoites

The gamma-aminobutyric acid (GABA) receptor, RDL, plays important roles in neuronal signaling and is the target of highly effective insecticides. A mutation in RDL, commonly A296S, underlies resistance to several insecticides such as cyclodienes. Even though the use of cyclodienes has been banned, the occurrence of mutations substituting A296 is notably high in mosquitoes from several countries. Here, we report a survey investigating the prevalence of the Rdl mutant allele in mosquitoes from Laos, a country where mosquito-borne diseases such as malaria and dengue fever are health concerns. Anopheles and Aedes mosquitoes were collected from 12 provinces in Laos. Adult bioassays on Aedes aegypti (Linnaeus) (Diptera: Culicidae) and Aedes albopictus (Skuse) (Diptera: Culicidae) showed that all the populations tested were susceptible to dieldrin (4%) following WHO protocols. Exon 7 from a total of 791 mosquitoes was sequenced to identify the amino acid encoded for at 296 of RDL. Only one of these mosquitoes, Anopheles maculatus rampae Harbach and Somboon (Diptera: Culicidae) from Attapeu, carried the mutant allele being heterozygous for A296S. We therefore found a general lack of the Rdl mutant allele indicating that mosquitoes from Laos are not exposed to insecticides that act on the GABA receptor compared to mosquitoes in several other countries. Identifying the prevalence of the Rdl mutation may help inform the potential use of alternative insecticides that act on the GABA receptor should there be a need to replace pyrethroids in order to prevent/manage resistance.

Topics: Aedes; Alleles; Animals; Anopheles; Dengue; Dieldrin; Insect Proteins; Insecticide Resistance; Insecticides; Laos; Malaria; Mosquito Vectors; Mutation

Understanding the mechanisms used by Anopheles mosquitoes to survive insecticide exposure is key to manage existing insecticide resistance and develop more suitable insecticide-based malaria vector control interventions as well as other alternative integrated tools. To this regard, the molecular basis of permethrin, DDT and dieldrin resistance in Anopheles funestus (sensu stricto) at Akaka-Remo was investigated.. Bioassays were conducted on 3-5-day-old adult An. funestus (s.s.) mosquitoes for permethrin, DDT and dieldrin susceptibility test. The molecular mechanisms of mosquito resistance to these insecticides were investigated using microarray and reverse transcriptase PCR techniques. The voltage-gated sodium channel region of mosquitoes was also screened for the presence of knockdown resistance mutations (kdr west and east) by sequencing method.. Anopheles funestus (s.s.) population was resistant to permethrin (mortality rate of 68%), DDT (mortality rate of 10%) and dieldrin (mortality rate of 8%) insecticides. Microarray and RT-PCR analyses revealed the overexpression of glutathione S-transferase genes, cytochrome P450s, esterase, trypsin and cuticle proteins in resistant mosquitoes compared to control. The GSTe2 was the most upregulated detoxification gene in permethrin-resistant (FC = 44.89), DDT-resistant (FC = 57.39) and dieldrin-resistant (FC = 41.10) mosquitoes compared to control population (FC = 22.34). The cytochrome P450 gene, CYP6P9b was also upregulated in both permethrin- and DDT-resistant mosquitoes. The digestive enzyme, trypsin (hydrolytic processes) and the cuticle proteins (inducing cuticle thickening leading to reduced insecticides penetration) also showed high involvement in insecticide resistance, through their overexpression in resistant mosquitoes compared to control. The kdr east and west were absent in all mosquitoes analysed, suggesting their non-involvement in the observed mosquito resistance.. The upregulation of metabolic genes, especially the GSTe2 and trypsin, as well as the cuticle proteins is driving insecticide resistance of An. funestus (s.s.) population. However, additional molecular analyses, including functional metabolic assays of these genes as well as screening for a possible higher cuticular hydrocarbon and lipid contents, and increased procuticle thickness in resistant mosquitoes are needed to further describe their distinct roles in mosquito resistance.

Topics: Animals; Anopheles; Biological Assay; Cytochrome P-450 Enzyme System; DDT; Dieldrin; Disease Vectors; Esterases; Gene Expression Regulation; Genes, Insect; Glutathione Transferase; Insect Proteins; Insecticide Resistance; Insecticides; Malaria; Mosquito Vectors; Nigeria; Oligonucleotide Array Sequence Analysis; Permethrin; Trypsin; Voltage-Gated Sodium Channels

To determine the susceptibility and irritability level of malaria vector Anopheles sacharovi (An. sachrovi) to different insecticides in a malaria-prone area.. Susceptibility and irritability levels of field collected strain of An. sacharovi to WHO standard papers of DDT 4%, dieldrin 0.4%, malathion 5%, fenitrothion 1%, permethrin 0.75%, and deltamethrin 0.05% were determined in East Azerbaijan of Iran during reemerging of malaria as described by WHO.. Results showed that at the diagnostic dose of insecticides this species exhibited resistance to DDT, tolerant to dieldrin and but somehow susceptible to fenitrothion, malathion, permethrin and deltamethrin. The results of irritability of this species to DDT, lambdacyhalothrin, permethrin cyfluthrin and deltamethrin revealed that DDT had had the most and deltamethrin the least irritancy effect. The average number of take offs/fly/minutes for DDT was 0.8±0.2. The order of irritability for permethrin, lambdacyhalothrin, cyfluthrin and deltamethrin were 0.7±0.2, 0.5±0.2, 0.5±0.3, and 0.2±0.1, respectively.. Results of this study reveals the responsiveness of the main malaria vector to different insecticides. This phenomenon is depending on several factors such as type and background of insecticide used previously, insecticide properties, and physiology of the species. Careful monitoring of insecticide resistance and irritability level of species could provide a clue for appropriate selection of insecticide for malaria control.

Topics: Animals; Anopheles; DDT; Dieldrin; Female; Fenitrothion; Insecticide Resistance; Insecticides; Iran; Malaria; Malathion; Mosquito Control; Permethrin; Species Specificity

The use of DDT to control malaria has been a contentious practice for decades. This controversy centers on concerns over the ecological harm caused by DDT relative to the gains in public health from its use to prevent malaria. Given the World Health Organization's recent policy decisions concerning the use of DDT to control malaria, it is worth reviewing the historical context of DDT use. Ecological concerns focused on evidence that DDT ingestion by predatory birds resulted in eggs with shells so thin they were crushed by adult birds. In addition, DDT spraying to control malaria allegedly resulted in cats being poisoned in some areas, which led to increased rodent populations and, in turn, the parachuting of cats into the highlands of the island of Borneo to kill the rodents, a story that influenced the decision to ban DDT spraying. I focus on this story with the intention of grounding the current debate on lessons from the past.

Topics: Animals; Anopheles; Birds; Borneo; Cats; DDT; Dieldrin; Ecosystem; Food Chain; Hexachlorocyclohexane; History, 20th Century; Housing; Humans; Insect Vectors; Insecticide Resistance; Insecticides; Malaria; Mosquito Control; Public Health Administration; Rats; Species Specificity; World Health Organization

Jiroft district has subtropical climate and prone to seasonal malaria transmission with annual parasite index (API) 4.2 per 1000 in 2006. Anopheles stephensi Liston is a dominant malaria vector. The monitoring of insecticide susceptibility and irritability was conducted using discriminative dose as described by WHO.. The IV instar larvae were collected from different larval breeding places and transported to the temporary insectary, fed with Bemax and then 2-3 days-old emerged and sugar-fed adults were used for susceptibility and irritability tests employing WHO methods and kits to organochlorine (OC) and pyrethroid (PY) insecticides.. Mortality rates of field strain of An. stephensi were 91.3 +/- 0.14 and 90 +/- 0.47% to DDT and dieldrin, respectively at one hour exposure time but was susceptible to all pyrethroids tested. The average number of take-offs per min per adult was 2.09 +/- 0.13 for DDT, 0.581 +/- 0.05 for dieldrin, 1.85 +/- 0.08 for permethrin, 1.87 +/- 0.21 for lambda-cyhalothrin, 1.53 +/- 0.13 for cyfluthrin, and 1.23 +/- 0.1 for deltamethrin.. Currently, deltamethrin is being used for indoor residual spraying against malaria vectors in the endemic areas of Iran. The findings revealed that the main malaria species is susceptible to all pyrethroids including deltamethrin, permethrin, cyfluthrin and lambda-cyhalothrin but was tolerant to DDT and dieldrin. This report and the finding are coincided with results of previous studies carried out during 1957-61 in the same area. Irritability tests to OC and PY insecticides revealed the moderate level of irritability to DDT compared to pyrethroids and dieldrin. Monitoring for possible cross-resistance between OC and PY insecticides should come into consideration for malaria control programme.

Topics: Animals; Anopheles; DDT; Dieldrin; Drug Tolerance; Insect Vectors; Insecticide Resistance; Insecticides; Iran; Malaria; Mosquito Control; Nitriles; Permethrin; Pyrethrins

Knowledge of how mosquitoes respond to insecticides is of paramount importance in understanding how an insecticide functions to prevent disease transmission. A suite of laboratory assays was used to quantitatively characterize mosquito responses to toxic, contact irritant, and non-contact spatial repellent actions of standard insecticides. Highly replicated tests of these compounds over a range of concentrations proved that all were toxic, some were contact irritants, and even fewer were non-contact repellents. Of many chemicals tested, three were selected for testing in experimental huts to confirm that chemical actions documented in laboratory tests are also expressed in the field. The laboratory tests showed the primary action of DDT is repellent, alphacypermethrin is irritant, and dieldrin is only toxic. These tests were followed with hut studies in Thailand against marked-released populations. DDT exhibited a highly protective level of repellency that kept mosquitoes outside of huts. Alphacypermethrin did not keep mosquitoes out, but its strong irritant action caused them to prematurely exit the treated house. Dieldrin was highly toxic but showed no irritant or repellent action. Based on the combination of laboratory and confirmatory field data, we propose a new paradigm for classifying chemicals used for vector control according to how the chemicals actually function to prevent disease transmission inside houses. The new classification scheme will characterize chemicals on the basis of spatial repellent, contact irritant and toxic actions.

Topics: Animals; Culicidae; DDT; Dieldrin; Female; High-Throughput Screening Assays; Insecticides; Malaria; Mosquito Control; Pyrethrins

The susceptibility of the malaria vector Anopheles culicifacies to DDT, dieldrin, malathion, and lambda-cyhalothrin was determined in Karnal, Yamunanagar, and Ambala districts of Haryana State, India. The vector population showed a high degree of resistance to DDT and dieldrin. The test mortality to DDT and dieldrin ranged from 25% to 28% and 18% to 20%, respectively, in Nadasahib of Ambala districts. The mortality of An. culicifacies to malathion ranged between 65% and 68%. All the tests with lambda-cyhalothrin resulted in 100% mortality of An. culicifacies. DDT and dieldrin resistance did not confer cross-resistance to lambda-cyhalothrin in An. culicifacies.

Topics: Animals; Anopheles; DDT; Dieldrin; India; Insect Vectors; Insecticide Resistance; Insecticides; Malaria; Malathion; Mosquito Control; Nitriles; Pyrethrins

Topics: Animals; Anopheles; DDT; Dieldrin; Evaluation Studies as Topic; India; Insect Vectors; Insecticide Resistance; Insecticides; Malaria; Malathion

Topics: Animals; Anopheles; DDT; Dieldrin; Drug Resistance; Evaluation Studies as Topic; Humans; India; Insect Vectors; Malaria; Malathion; Mosquito Control

The use of infectious pathogens has allowed the detection of the development of synergism between pathogens and ubiquitous environmental chemical contaminants. This synergism has been demonstrated to result in a state of immunosuppression which either did not occur in the independent and singular presence of the chemical or pathogen and/or was greater than additive when both were combined. The immunosuppression was distinct with regard to the organochloride used and, therefore, is not a ubiquitous characteristic of all organohalides. The production of a macrophage soluble factor which appeared to induce T-suppressor cells was demonstrated in hepatic Kupffer cells from mice administered 5 ppm of dieldrin for 10 weeks and then infected with Leishmania tropical promastigotes. The factor was not generated in mice administered dieldrin and infected with malaria nor in mice administered only dieldrin nor in mice only infected with Leishmania. Additional studies revealed a profound impairment in macrophage antigen processing with macrophages obtained from mice administered dieldrin. The use of pathogen models may allow the immunosuppressive potential of environmental chemical contaminants to be expressed in a more sensitive manner.

Topics: Animals; Dieldrin; Hexachlorobenzene; Immunity; Leishmaniasis; Macrophages; Malaria; Male; Mice; Mice, Inbred Strains; Pesticides; Phytohemagglutinins; Protozoan Infections; T-Lymphocytes; T-Lymphocytes, Regulatory

The gene for dieldrin resistance has been artificially male-linked so that females can be selectively killed with dieldrin. By intercrossing different sibling species of the Anopheles gambiae complex, batches consisting of sterile males only can be reared. This seems to have potential for use in genetic control operations.

Topics: Animals; Anopheles; Dieldrin; Drug Resistance, Microbial; Humans; Hybridization, Genetic; Malaria; Mosquito Control; Pest Control, Biological

Topics: Adolescent; Adult; Antimalarials; Blood Group Antigens; Blood Proteins; Child; Child, Preschool; Chloroquine; DDT; Dieldrin; Electrophoresis, Starch Gel; Female; Haptoglobins; Hemoglobins; Humans; Infant; Infant, Newborn; Insecticides; Iron; Malaria; Male; New Guinea; Plasmodium malariae; Pyrimethamine; Splenomegaly; Transferrin

Topics: Anopheles; Costs and Cost Analysis; DDT; Dieldrin; Financing, Government; Humans; Insect Control; Insect Vectors; Insecticide Resistance; Iraq; Jordan; Lebanon; Malaria; Mosquito Control; Organization and Administration; Population Surveillance; Syria

Topics: Anopheles; Child; Chloroquine; DDT; Dieldrin; Housing; Humans; Insect Vectors; Insecticide Resistance; Malaria; Malaysia; Mosquito Control; Pyrimethamine; Seasons; Thailand

Topics: Anopheles; DDT; Dieldrin; Malaria; Turkey

Topics: DDT; Dieldrin; Humans; Malaria; Mosquito Control; Peru

Topics: Anopheles; Climate; DDT; Dieldrin; Humans; Insecticides; Malaria; Mosquito Control; Romania

Topics: Adolescent; Adult; Anopheles; Child; Child, Preschool; Dieldrin; Follow-Up Studies; Humans; Insect Vectors; Malaria; Mosquito Control; Tanzania

The spread of insecticide-resistance in the two main vectors of malaria in Java, Anopheles aconitus Dönitz and A. sundaicus Rodenwaldt, has been of concern to workers in the Indonesian malaria eradication programme since DDT-resistance was first detected, in A. sundaicus, in 1954. The history of development of resistance in these two vectors has been summarized in this paper by assembling the available records in chronological order, thus facilitating reference.The picture which emerges is that of somewhat erratic occurrence of DDT-resistance in A. sundaicus and more stable, expanding areas of DDT-resistant A. aconitus. Dieldrin-resistance is more widespread than DDT-resistance in both species and preceded the onset of DDT-resistance in A. aconitus but not in A. sundaicus. These features should not be regarded as species characteristics, however, since selection pressures on the two species have been far from uniform.Malathion appears to be a promising alternative to DDT and dieldrin for the control of the two vectors in the circumstances described.

Topics: Animals; Anopheles; DDT; Dieldrin; Indonesia; Insecticide Resistance; Insecticides; Malaria; Malathion

The human blood index, or estimated proportion of the blood meals of a mosquito population obtained from man, is provisionally assessed for certain anophelines from blood-meal samples collected during the period 1959-62 and subjected to precipitin testing at the Lister Institute. In malaria eradication programmes this index is relevant to epidemiological assessment and to the modification of measures to interrupt transmission, since a mosquito's vectorial capacity and the malaria reproduction rate both vary as the square of the human blood index.There are serious difficulties in achieving representative sampling for this index and in interpreting the index obtained. These are discussed in some detail. In practice, the human blood index is often best estimated by applying the unweighted mean of a part-sample collected from human dwellings and one from other types of resting-place.Applying this calculation to the samples under review, it appears that DDT exerts a moderate, and dieldrin a more pronounced, impact on the human blood index of Anopheles gambiae and A. funestus; such an effect, indeed, may be general in house-visiting anophelines. Some 18 anopheline species are tentatively graded as having low, medium or high natural human blood indices. Regular and careful sampling, combined with recording of all relevant information, is recommended in view of the epidemiological and operational importance of the human blood index in assessment of eradication programmes.

Topics: Animals; Anopheles; DDT; Dieldrin; Epidemiology; Humans; Insect Vectors; Malaria; Pharmacology

Observations made in Kigezi District, Uganda, had shown a great reduction in the number of Anopheles gambiae entering an experimental hut treated with DDT. The work reported in this paper confirms the phenomenon of reduced entry by A. gambiae and A. funestus in two experiments carried out in Masaka, another district of Uganda, using mud-walled huts, roofed with thatch or corrugated-iron sheets and sprayed with DDT and dieldrin. The fact that no similar reduction was observed with Mansonia (mansonioides) uniformis, a common species in the area, indicates the need to determine and take into account any reduction in the number of entering mosquitos when assessing the effect of residual insecticides. Of interest in these experiments was the finding that DDT and dieldrin produced satisfactory kills with all the local anopheline species in spite of their rapid sorption by the mud walls, an indication of the importance of thatch or metal roofs as a source of active insecticide.

Topics: Animals; Anopheles; Culicidae; DDT; Dieldrin; Health Services Needs and Demand; Homicide; Insecticides; Iron; Malaria; Mosquito Control; Uganda

Topics: Animals; Anopheles; DDT; Dieldrin; Ecology; Humans; Insecticides; Malaria; Malaysia

Topics: Animals; Dieldrin; Epidemics; Humans; Kenya; Malaria; Mosquito Control; Pyrimethamine

Topics: Adolescent; Animals; Anopheles; Child; Chloroquine; Communicable Disease Control; Dieldrin; Drug Therapy; Epidemics; Epidemiology; Humans; Infant; Insect Vectors; Kenya; Malaria; Pyrimethamine

Topics: Animals; Anopheles; Classification; Dieldrin; Epidemiology; Humans; Malaria; Malaysia

Topics: Adolescent; Animals; Anopheles; Child; DDT; Dieldrin; Fever; Health Surveys; Humans; Infant; Infant, Newborn; Malaria; Precipitin Tests; Spleen; Uganda

Topics: Animals; Anopheles; Culicidae; DDT; Dieldrin; Insect Vectors; Insecticides; Malaria; Research; Tanzania; Uganda

Following residual spraying of houses in Pemba Island with dieldrin as part of a malaria eradication programme, Anopheles gambiae were found breeding in salt-water pools in many parts of the island. Studies were made on the bionomics of this salt-water form of the mosquito, dealing in particular with its behaviour, feeding preferences, role as a malaria vector, larval reaction to brackish water and adult susceptibility to dieldrin.The first-stage larvae of the freshwater and salt-water forms were found to exhibit a distinct difference in their reaction to 75% sea water, the former dying within 1(1/2) hours and the latter surviving 6 hours or more. It is suggested that this reaction may provide the best way of distinguishing with certainty between the two forms in East Africa.The results of precipitin tests and indoor and outdoor catches showed that, after spraying, the salt-water form was mainly exophilic with a preference for feeding on cattle. Exposure of adult to 0.4% dieldrin by the WHO test method indicated that they were still susceptible to that insecticide after two spraying cycles.

Topics: Africa, Eastern; Animals; Anopheles; Cattle; Dieldrin; Environment; Insect Vectors; Insecticides; Malaria; Mosquito Control

Topics: Animals; Dieldrin; Humans; Malaria; Turkey

The appearance of resistance to both dieldrin and DDT in several malaria vectors has intensified investigations on the potential of organophosphorus compounds for residual application. This report describes the final year's activities of a three-year study on malathion. Water-wettable formulations of malathion and of Bayer 29493 were evaluated against DDT/dieldrin-resistant Anopheles albimanus in El Salvador.The results indicate that neither compound at a dosage of 0.5 g/m(2) offers any promise as a residual agent. At dosages of 1.0 g/m(2) or 2.0 g/m(2) the two toxicants gave effective kills (70%-100%) for periods of 21/2-3 months, based on 1-hour exposure to the treated surfaces. Up to 3 months, both compounds gave similar levels of effectiveness on wood, thatch, and mud. On whitewash and plaster surfaces, Bayer 29493 was superior to malathion.The findings indicate that each insecticide has considerable potential value for residual treatment in areas where the malaria vector cannot be killed effectively by either DDT or dieldrin. In such areas, further investigation into their utility as replacements for the chlorinated hydrocarbon insecticides is warranted.

Topics: Animals; Anopheles; Dieldrin; El Salvador; Homicide; Insecticides; Malaria; Malathion

Topics: Dieldrin; Humans; Insect Control; Malaria

Topics: Animals; Dieldrin; Humans; Malaria; Mosquito Control; Tanzania

Topics: Dieldrin; Humans; Kenya; Malaria; Tanzania

Increased use of dieldrin for malaria control has been caused by several factors, including sporadic resistance of some vectors to DDT. Poisoning of spray-men by dieldrin has been recognized in five widely separated countries and reported informally from several others. In some cases illness has recurred months after the last exposure. Observations of antimalaria programmes in Kenya, Tanganyika, Indonesia, India (Bombay State), and Iran and a review of the relevant literature have shown that the hazard associated with dieldrin is proportional to the degree of workers' exposure as determined by concentration of spray, area of bare skin, duration of contact, and lack of hygiene. Measurements of workers' exposure and a review of toxicity by different routes incriminates skin contamination as the greatest hazard under practical conditions. It is considered that dieldrin should not be used without justification; if it is required, then certain individual and group protective measures listed in this paper may minimize, but not necessarily eliminate, the risk. The author enumerates certain features of the toxicology of dieldrin which require intensive research.

Topics: Dieldrin; Humans; India; Indonesia; Kenya; Malaria; Male; Tanzania

Various dieldrin water-dispersible powder formulations have been subjected to elevated temperature storage and the effect on their suspensibilities compared. The Shell Chemical Company's 50% dieldrin formulation AC 1630 was recommended for use in the malaria control programmes of the International Cooperation Administration rather than its 50% formulation AC 1631, on the basis of superior performance after storage at 50 degrees C and 65 degrees C. In a similar series of tests on 75% dieldrin water-dispersible powders, Shell formulation AC 1621, which contains Hi-Sil as diluent, was judged better than AC 6621, which contains Micro-Cel as diluent. A series of samples of AC 1621 was subjected to temperatures of 90-120 degrees C for periods of 1-20 hours and the effect on suspensibility determined. Most samples withstood the treatment reasonably well at temperatures up to 110 degrees C for 20 hours.

Topics: Dieldrin; Malaria; Powders; Water

In 1953, the fifth year of a malaria control programme with DDT in Eastern Saudi Arabia, the resting of Anopheles stephensi on recently sprayed surfaces suggested the development of resistance in this species to DDT, and this suspicion has been confirmed by tests carried out from 1955 to 1958.DDT was replaced by dieldrin in 1955 and malaria rates, which had been rising, were again reduced. No dieldrin-resistance has been found in local. A. stephensi strains, and no A. stephensi have been collected from treated villages since the wide use of dieldrin.A. pulcherrimus, A. coustani var. tenebrosus, A. fluviatilis and A. sergenti have proved susceptible to DDT, but the first two have developed resistance to dieldrin. A. pulcherrimus was rarely collected before and during the use of DDT but has become increasingly frequent since the introduction of dieldrin. Its possible role in transmitting malaria in the area is discussed.Egg measurements and ratios on several series of eggs obtained from locally collected A. stephensi fall within the limits of the range set for A. stephensi mysorensis, not previously recorded outside India.

Topics: Animals; Anopheles; DDT; Dieldrin; India; Insecticide Resistance; Insecticides; Malaria; Mosquito Control; Saudi Arabia; Seasons

Topics: Dieldrin; Insecticides; Malaria

Topics: DDT; Dieldrin; Humans; Insecticides; Malaria; Venezuela

Topics: Animals; Culicidae; Dieldrin; Eswatini; Hexachlorocyclohexane; Humans; Insecticides; Malaria; Rural Population

Topics: Animals; Chemistry, Pharmaceutical; Culicidae; DDT; Dieldrin; Hexachlorocyclohexane; Insecticides; Malaria

Topics: Dieldrin; Humans; Insecticides; Malaria; Venezuela

Topics: Dieldrin; Humans; Insecticides; Malaria

Topics: Animals; Culicidae; Dieldrin; Insecticides; Malaria

Topics: Animals; Chemistry, Pharmaceutical; Culicidae; Dieldrin; Insecticides; Malaria; Research Design