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At least 1,243 records · Page 69Linked to original sources
PubMed1999

The effects of reduced agent-area insecticide treatments for rangeland grasshopper (Orthoptera: Acrididae) control on bird densities.

The effects of insecticidal control programs for grasshoppers on the population density of birds were assessed under operational conditions in two rangeland sites in Wyoming during an outbreak (19 to 56 grasshoppers m(-2) on >1,500 ha). Malathion, carbaryl, and fipronil were evaluated using large-scale (>/=260 ha) reduced agent-area treatments (RAAT), in which these chemicals were applied at 50% of the standard rate (except fipronil, for which there is no standard in North America) to 80, 50, and 33% of the areas (alternating treated and untreated swaths), respectively. Grasshopper population densities were reduced by 73 to 99%, at 14 and 28 days after treatment. Significant differences among treatments within the sites were apparent, and despite disparities in the vegetation, topography, and grasshopper populations between sites, some consistent patterns of response by bird populations were found. Relative to pretreatment densities and untreated plots, at 14 days after treatment, bird densities were enhanced at one site and suppressed at the other; at 28 days after treatment bird populations were generally suppressed at both sites. However, absolute densities increased in some plots, indicating that birds still had adequate food. There appeared to be no relationship between posttreatment grasshopper and bird densities, perhaps due to the large initial insect populations. Fipronil plots generally had higher avian population densities (nongregarious insectivores and total birds) than carbaryl plots, which had bird densities greater than or equal to malathion plots. These differences were probably a function of both the toxicological properties of the compounds and the proportion of the infested land that was treated. Based on these findings, we must consider the possibility that compounds with relatively high toxicity to birds and long residual effects applied to widely spaced swaths may cause no more (or perhaps less) environmental impact than less toxic and persistent insecticides that must be applied to large proportions of infested rangeland. http://link.springer-ny. com/link/service/journals/00244/bibs/37n4p519.html</++ +HEA

Animals↗
PubMed2006

Engineered Bacillus thuringiensis GO33A with broad insecticidal activity against lepidopteran and coleopteran pests.

A recombinant plasmid pSTK-3A containing cry3Aa7 gene encoding a coleopteran-specific insecticidal protein was constructed and introduced into wild Bacillus thuringiensis subsp. aizawai G03, which contained cry1Aa, cry1Ac, cry1Ca, and cry2Ab genes and was highly toxic to lepidopteran insect pests. The genetically engineered strain were named G033A. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis demonstrated that the cry3Aa7 gene was expressed normally and produced a 67 kDa protein in G033A, and the flat rectangular crystals of Cry3Aa7 toxin protein was observed under scanning electron microscope. The recombinant plasmid was maintained in bacteria cultured for 180 generations in culture media containing no antibiotics. Synthesis of the Cry3Aa7 toxin conferred high and broad toxicity to the recombinant strain G033A against coleopteran order, elm leaf beetle (Pyrrhalta aenescens) (LC(50) 0.35 mg/ml), for which the parental strain G03 was not toxic. Both the parental strain G03 and recombinant strain G033A showed strong insecticidal activity to lepidopteran pests, beet armyworm (Spodoptera exigua), diamondback moth (Plutella xylostella), and cotton bollworm (Helicoverpa amigera), respectively. The lethal concentration 50% (LC(50)) of G033A against S. exigua, P. xylostella, and H. amigera was 4.26, 0.86, and 1.76 microg/ml, respectively.

Animals↗
PubMed2003

Characterization of flagellar antigens and insecticidal activities of Bacillus thuringiensis populations in animal feces.

In total, 287 Bacillus thuringiensis isolates, recovered from feces of 28 zoo-maintained animal species, were examined for flagellar (H) antigenicity and insecticidal activity. Serologically, 209 isolates (72.8%) were allocated to the 8 H serogroups, 4 were untypable, and 74 were untestable. Among the 8 H serotypes detected, H3abc (serovar kurstaki) predominated at a high frequency of 88.0%, followed by H6 (serovar entomocidus) with a frequency of 7.7%. Insecticidal activity was associated with 67.2% of the fecal populations: 188 isolates were toxic to both Bombyx mori (Lepidoptera: Bombycidae) and Aedes aegypti (Diptera: Culicidae), 2 isolates were specific for B. mori, and 3 isolates were toxic to A. aegypti only. Of the isolates with dual toxicity, 97.9% belonged to the serovar kurstaki, producing bipyramidal parasporal inclusions. All of the H7 (serovar aizawai) isolates were toxic to both insects.

Animals↗
PubMed2003

Biological monitoring of workers after the application of insecticidal pyrethroids.

OBJECTIVES: Pyrethroids are applied as insecticides throughout the world. Human metabolism of pyrethroids results in urinary metabolites that are suitable for biological monitoring. The aim of the study was to evaluate individual exposure due to occupational application of pyrethroids as a precondition for the assessment of health risks. METHODS: Thirty-six workers who applied insecticides and other pesticides in Germany collected samples of their urine (24 h) after having used various pyrethroids (alpha-cypermethrin, cypermethrin, cyfluthrin, deltamethrin, tau-fluvalinate, permethrin, lambda-cyhalothrin) in agriculture, greenhouses or indoor pest control. Biological monitoring was carried out and metabolites were analysed in 61 urine samples by GC-MS: cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid ( cis-Cl(2)CA and trans-Cl(2)CA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid ( cis-Br(2)CA), 3-phenoxybenzoic acid (3-PBA) and 4-fluoro-3-phenoxybenzoic acid (FPBA). Forty-five urine specimens collected (24 h) from persons with no occupational exposure to pyrethroids served as controls. Concentrations were related to creatinine content and expressed as microgrammes per gramme creatinine. RESULTS: Control urine samples revealed a considerable background excretion of pyrethroid metabolites by the general population. The 95th percentile of the concentrations of Cl(2)CA and cis-Br(2)CA were 2.1 and 0.1 microg/g creatinine, respectively. FPBA was not detected in any control urine and was found in only one sample within the complete study. After occupational application of pyrethroids the highest concentrations of metabolites in urine samples were detected within the group of indoor pest-control operators. The maximum concentrations (median values) of Cl(2)CA, 3-PBA, and cis-Br(2)CA were 92.4 microg/g (1.8 microg/g), 57.5 microg/g (1.4 microg/g) and 1.1 microg/g (median below detection limit), respectively. Workers in greenhouses excreted metabolites with median concentrations as follows: 2.9 microg/g Cl(2)CA, 0.5 microg/g cis-Br(2)CA and 2.9 microg/g 3-PBA. Medians of the metabolite concentrations in specimens from agricultural workers were below the detection limit with regard to Cl(2)CA and cis-Br(2)CA, but the value was 0.6 microg/g for 3-PBA. Pest-control operators excreted significantly higher concentrations of Cl(2)CA and 3-PBA than workers in agriculture on a collective basis. Comparison of the excreted concentrations of metabolites with values of acceptable daily intake (ADI) of pyrethroids set by WHO revealed that the amount of pyrethroids that had been taken up during occupational application was not considerably higher than the ADI. CONCLUSIONS: As a consequence, we conclude that adverse health effects are not to be expected after workers' occupational exposure to pyrethroids in Germany, provided that the application is carried out properly. Good working practices need to be supported by adequate supervision with regard to occupational hygiene and medicine.

Agriculture↗
PubMed1996

Susceptibility of Hydrotaea aenescens (Wiedemann) (Diptera: Muscidae) to selected insecticides and its importance in integrated fly management.

The doses lethal to 50% of the insects (LD50 values) obtained for a strain of Hydrotaea aenescens (Wiedemann) adults from a layer farm revealed higher sensitivity to 16 insecticides than those recorded for the susceptible WHO/SRS strain of the housefly. Because H. aenescens adults are about half the size of the housefly, the chemical compounds used for adult control may jeopardize the survival of Hydrotaea populations released in animal confinement houses. An efficient and economical combined application of biological and chemical control methods is possible only if the local management conditions and the dissimilar behavior of the adults of the two species are taken into consideration during the use of insecticides. Other suggestions and implications are further discussed.

Animals↗
PubMed1998

Duplication of the Rdl GABA receptor subunit gene in an insecticide-resistant aphid, Myzus persicae.

Resistance to cyclodiene insecticides is associated with replacements of a single amino acid (alanine 302) in a gamma-aminobutyric acid (GABA) receptor subunit encoded by the single-copy gene Resistance to dieldrin (Rdl). Alanine 302 is predicted to reside within the second membrane-spanning region of the Rdl receptor, a region that is thought to line the integral chloride ion channel pore. In all cyclodiene-resistant insects studied to date, this same alanine residue is replaced either by a serine, or, in some resistant strains of Drosophila simulans, a glycine residue. Therefore, individuals can carry only two different Rdl alleles. In contrast, here we report the presence of up to four different Rdl-like alleles in individual clones of the green peach aphid, Myzus persicae. In addition to the wild-type copy of Rdl gene (encoding A302 or allele A), M. persicae carries three other alleles with the following amino acid replacements: A302-->Glycine (allele G), A302-->SerineTCG (allele S) and A302-->SerineAGT (allele S'). Evidence from direct nucleotide sequencing and Single Stranded Conformational Polymorphism (SSCP) analysis shows that at least three of these different Rdl alleles (i.e. A, G and S) are commonly present in individual aphids or aphid clones. Southern analysis using allele-specific probes and analysis of sequences downstream of the exon containing the resistance-associated mutation confirm the presence of two independent Rdl-like loci in M. persicae. One locus carries the susceptible alanine (A) and/or resistant glycine (G) allele while the other carries the two serine alleles (S or S'). Whereas resistance levels are correlated with the glycine replacement, the S allele was present in all aphid clones, regardless of their resistance status. These results suggest that target site insensitivity is associated with replacements at the first (A/G) but not the second (S/S') locus. Phylogenetic analysis of nucleotide sequences indicates that both putative aphid Rdl loci are monophyletic with respect to other insect Rdl genes and may have arisen through a recent gene duplication event. The implications of this duplication with respect to insecticide resistance and insect GABA receptor subunit diversity are discussed.

Alanine↗
PubMed2007

Insect sodium channels and insecticide resistance.

Voltage-gated sodium channels are essential for the generation and propagation of action potentials (i.e., electrical impulses) in excitable cells. Although most of our knowledge about sodium channels is derived from decades of studies of mammalian isoforms, research on insect sodium channels is revealing both common and unique aspects of sodium channel biology. In particular, our understanding of the molecular dynamics and pharmacology of insect sodium channels has advanced greatly in recent years, thanks to successful functional expression of insect sodium channels in Xenopus oocytes and intensive efforts to elucidate the molecular basis of insect resistance to insecticides that target sodium channels. In this review, I discuss recent literature on insect sodium channels with emphases on the prominent role of alternative splicing and RNA editing in the generation of functionally diverse sodium channels in insects and the current understanding of the interactions between insect sodium channels and insecticides.

Action Potentials↗
PubMed2006

Estimating the rate of poisoning by insecticide-treated seeds in a bird population.

Poisonings of granivorous birds by cereal seed treatments have been reported in the UK, but the true frequency of poisonings is unknown. We aimed to measure the rate of mortality due to poisoning by seed treatments in woodpigeons (Columba palumbus) in an area of East Anglian farmland where the risk from these compounds appeared high. Woodpigeons were fitted with temperature-sensing radio-tags and monitored daily during the winters of 1994/95 and 1995/96. Birds' deaths were detected and attempts made to retrieve carcasses for post-mortem examination including, where possible, analysis for pesticide residues. Ninety-one woodpigeons were monitored. Eleven birds died, but the causes of their deaths were uncertain: one contained a low residue of insecticide and in the other ten cases, no carcass was recovered, so no analysis was possible. Therefore, the number poisoned by pesticides could lie anywhere between zero and eleven. During 1994/95, estimated mortality ranged from 0% to 52%, depending on how many (if any) of the 11 casualties were poisoned. During 1995/96 there were no casualties. Using conservative diagnostic rules for classifying birds as poisoned by OP seed treatments, no link was found between the availability of treated fields in the study area and the rate of poisonings, and there were no significant differences between the two study years. For reasons discussed in the paper, true mortality resulting from exposure to insecticide seed treatments was considered likely to lie in the range 0-5%.

Animals↗
PubMed2005

Persistence and dissipation of readymix formulations of insecticides in/on okra fruits.

Dissipation behaviour of ready mix polytrin C 44EC (profenophos 40% + cypermethrin 4%) and spark 36EC (triazophos 35% + deltamethrin 1%) applied at 1 L/ha in okra crop during Kharif in year 2000 was studied at 0, 1, 3, 5 and 7 days after treatment. Dissipation on 7th day was found to be maximum (98.4%) for profenophos followed by triazophos (86.2%), cypermethrin (73.5%) and deltamethrin (55.7%). Half life (t1/2) values for the above insecticides were 1.35, 2.55, 4.11 and 7.60 days, respectively. All the insecticides followed a first order kinetics. Profenophos and triazophos followed a biphasic dissipation pattern with faster dissipation in phase I (0-1 days) and manifesting slower rate of dissipation in phase II (1-7 days).

Abelmoschus↗
PubMed1991

The effects of density fluctuations on the partitioning of foreign molecules into lipid bilayers: application to anaesthetics and insecticides.

An extensive computer-simulation study is performed on a simple but general molecular model recently proposed (Jørgensen et al. (1991) Biochem. Biophys. Acta 1062, 277-238) to describe foreign molecules interacting with lipid bilayers. The model is a multi-state lattice model of the main bilayer transition in which the foreign molecules are assumed to intercalate at interstitial lattice positions. Specific as well as non-specific interactions between the foreign molecules and the lipid acyl chains are considered. Particular attention is paid to the fluctuating properties of the membrane and how the presence of the foreign molecules modulates these fluctuations in the transition region. By means of computer-stimulation techniques, a detailed account is given of the macroscopic as well as microscopic consequences of the fluctuations. The macroscopic consequences of the fluctuations are seen in the thermal anomalies of the specific heat and the passive trans-membrane permeability. Microscopically, the fluctuations manifest themselves in lipid-domain formation in the transition region which implies an effective dynamic membrane heterogeneity. Within the model it is found that certain anaesthetics and insecticides which are characterised by specific interactions with the lipids have a strong effect on the heterogeneity of the membrane inducing regions of locally very high concentration of the foreign molecules. This leads to a broadening of the specific heat peak and a maximum in the membrane/water partition coefficient. These results are in accordance with available experimental data for volatile general anaesthetics like halothane, local anaesthetics like cocain derivatives, and insecticides like lindane.

Anesthetics↗
PubMed1993

Effect of fenvalerate, a pyrethroid insecticide on membrane fluidity.

Fenvalerate is a commonly used pyrethroid insecticide, used to control a wide range of pests. We have studied its interaction with the membrane using fluorescence polarization and differential scanning calorimetry (DSC) techniques. Fenvalerate was found to decrease the DPH fluorescence polarization value of synaptosomal and microsomal membrane, implicating that it makes the membrane more fluid. At different concentrations of fenvalerate, the activation energy of the probe molecule in the membrane also changes revealed from the change in slope of the Arrhenius plot. At higher concentrations the insecticide slowly saturates the membrane. The effects of fenvalerate on model membrane were also studied with liposomes reconstituted with dipalmitoylphosphatidylcholine (DPPC). Fenvalerate decreased the phase transition temperature (Tm) of DPPC by 1.5 C degrees at 40 microM concentration, but there was no effect on the cooperativity of the transition as interpreted from the DSC thermogram. From the change in the thermogram profile with fenvalerate it has been interpreted that it localizes in the acyl chain region of the lipid, possibly between C10 and C16 region and weakens the acyl chain packing. Fenvalerate was also found to interact with DPPC liposomes containing cholesterol to fluidize it.

Animals↗
PubMed1982

Differential alterations of cholinergic muscarinic receptors during chronic and acute tolerance to organophosphorus insecticides.

Male mice treated for 2 weeks with the anticholinesterase insecticide disulfoton (O,O-diethyl S-[2-(ethylthio)-ethyl] phosphorodithioate; 10 mg per kg per day) became tolerant to the hypothermic and antinociceptive effects of disulfoton itself and of oxotremorine, a muscarinic cholinergic agonist. Homogenates of brain and ileum from tolerant animals exhibited reduced binding of the specific muscarinic antagonist [3H]quinuclidinyl benzilate ([3H]QNB). In forebrains of tolerant animals, the number of receptors (Bmax) was decreased 40% with no change in the affinity constant. Acetylcholinesterase (AChE) activity was 15% of control. Forty-eight hours after a single injection of disulfoton (10 mg/kg) mice were more resistant than their controls to the hypothermic and antinociceptive effects of a second administration of the same insecticide and of oxotremorine. Tolerance was not present 96 hr after a single administration of disulfoton. A single injection of disulfoton produced 74, 65 and 27% inhibition of AChE activity after 4, 48 and 96 hr respectively. Four hours after a second injection at 49 and 96 hr, 73 or 72% inhibition was found. [3H]QNB binding of animals treated with a single injection of disulfoton and of controls did not differ at either time point. An increase in the Ki for inhibition of [3H]QNB binding by unlabeled oxotremorine was observed in forebrain from mice killed 48 hr after a single injection of disulfoton, indicating a decreased affinity of the muscarinic receptor for agonists. Binding of [3H]oxotremorine-M was decreased significantly 48 hr after a single injection of disulfoton and after chronic treatment. It is suggested that a differential down-regulation of muscarinic receptors occurs in acute and chronic tolerance, involving agonist and antagonist binding sites and depending on duration of exposure.

Acetylcholinesterase↗
PubMed1984

Chronic administration of an organophosphorus insecticide to rats alters cholinergic muscarinic receptors in the pancreas.

Male rats were treated for 10 days with the organophosphorus insecticide, acetylcholinesterase inhibitor, O,O-diethyl S-[2-(ethylthio)ethyl] phosphorodithioate (disulfoton, 2 mg/kg/day by gavage). At the end of the treatment, binding of [3H]quinuclidinyl benzilate ( [3H]QNB) to cholinergic muscarinic receptors and cholinesterase (ChE) activity were assayed in the pancreas. Functional activity of pancreatic muscarinic receptor was investigated by determining carbachol-stimulated secretion of alpha-amylase in vitro. ChE activity and [3H]QNB binding were significantly decreased in the pancreas from disulfoton-treated rats. The alteration of [3H]QNB binding was due to a decrease in muscarinic receptor density with no change in the affinity. Basal secretion of amylase from pancreas in vitro was not altered, but carbachol-stimulated secretion was decreased. The effect appeared to be specific since pancreozymin was able to induce the same amylase release from pancreases of control and treated rats. The results suggest that repeated exposures to sublethal doses of an organophosphorus insecticide lead to a biochemical and functional alteration of cholinergic muscarinic receptors in the pancreas.

Animals↗
PubMed1983

Mechanism of action of Bacillus thuringiensis var israelensis insecticidal delta-endotoxin.

Bacillus thuringiensis var israelensis delta-endotoxin protein active against mosquitoes was inactivated by prior incubation with lipids extracted from Aedes albopictus cells. Experiments with lipid dispersions and multilamellar liposomes showed that the toxin binds to phosphatidyl choline, sphingomyelin and phosphatidyl ethanolamine provided these lipids contain unsaturated fatty acids. Phosphatidyl serine binds toxin less efficiently and phosphatidyl inositol, cardiolipin, cerebroside and cholesterol show no affinity for the toxin. The results suggest an insecticidal mechanism in which interaction of toxin with affinity for the toxin. The results suggest an insecticidal mechanism in which interaction of toxin with specific plasma membrane lipids causes a detergent-like rearrangement of the lipids, leading to disruption of membrane integrity and eventual cytolysis.

Aedes↗
PubMed1990

Response of nuclear polyhedrosis virus-resistant Spodoptera frugiperda larvae to other pathogens and to chemical insecticides.

Selection in the laboratory for Spodoptera frugiperda (Sf) resistant to nuclear polyhedrosis virus (NPV) affected the susceptibility of the insect to certain other mortality agents, including a chemical insecticide. Median lethal concentrations (LC50S) and associated statistics were compared for several mortality agents between colonies of NPV-resistant and -susceptible (control) insects. Compared to the susceptible insects, the NPV-resistant insects were cross-resistant to the S. frugiperda granulosis virus and to the Autographa californica NPV based on nonoverlap of 95% fiducial limits of the LC50S. The NPV-resistant insects were significantly more susceptible to methyl parathion than the control insects. The two colonies of S. frugiperda did not differ significantly in their response to Bacillus thuringiensis, Vairimorpha necatrix, or carbaryl. The cross-resistance experiments were based on per os exposure of the insects to the pathogens and insecticides; the susceptibility of the resistant and control insects did not differ significantly when the Sf NPV was injected into the hemocoel or when methyl parathion was applied topically.

Animals↗
PubMed1991

Pyrethroid insecticides indirectly inhibit GABA-dependent 36Cl- influx in synaptoneurosomes from the trout brain.

Rainbow trout (Oncorhynchus mykiss) are extremely sensitive to the neurotoxic activity of pyrethroid insecticides. One possible target for pyrethroids is the GABA(A) receptor of brain of the trout, the function of which can be tested by measurement of influx of 36Cl- into synaptoneurosomes, in response to the application of agonists. gamma-Aminobutyric acid produced a time- and concentration-dependent increase in influx of 36Cl- in synaptoneurosomes from the brain of the trout, which exhibited the pharmacology characteristic of a response mediated by activation of a GABAA receptor. Deltamethrin, (1R alpha S)-cis-cypermethrin and permethrin produced a dose-dependent increase in the basal uptake and a corresponding decrease in GABA-dependent influx, with a maximum inhibition of 70-82%. This effect of pyrethroid was stereospecific, of high potency and inhibited by tetrodotoxin (TTX) and t-butylbicyclophosphorothionate (TBPS). The sensitivity of the effect of the pyrethroid to TTX suggested an activation by pyrethroid of the voltage-dependent sodium channel. Veratridine, a sodium channel activator, elicited similar changes in the basal uptake of chloride, which were TTX-sensitive. Neither deltamethrin nor veratridine had a measurable effect on the efflux of 36Cl- from synaptoneurosomes. Thus, pyrethroid insecticides may interfere with the function of GABAA receptors indirectly through an interaction with the voltage-dependent sodium channel in the brain of the trout and consequently perturb chloride influx, possibly through a voltage-dependent chloride channel.

Animals↗
PubMed1993

A malaria control trial using insecticide-treated bed nets and targeted chemoprophylaxis in a rural area of The Gambia, west Africa. 3. Entomological characteristics of the study area.

Baseline entomological surveillance was carried out in a rural area of The Gambia during the rainy season in 1988, one year before the implementation of a malaria control programme using insecticide-impregnated nets and targeted chemoprophylaxis in villages with a primary health care (PHC) system. Mosquito collections took place in 6 pairs of settlements each with untreated bed nets; within each pair there was a large PHC village with a resident village health worker (VHW) and traditional birth attendant (TBA) and a smaller non-PHC village without either a VHW or a TBA. The most common vectors in the study area were Anopheles gambiae sensu stricto and, to a lesser extent, An. arabiensis. These mosquitoes were found in appreciable numbers for at least 4 months of the year (geometric mean/bedroom/night = 32.5, 95% confidence interval 18.2-57.3). Numbers of mosquitoes collected in PHC villages or non-PHC villages were not significantly different. Greater numbers of mosquitoes were found in villages closer to the River Gambia than in those further away. Evidence for DDT resistance due to elevated glutathione S-transferase activity was found in one of the 12 villages, but there was no evidence of resistance to organophosphate or carbamate insecticides as suggested by the low esterase levels and carbamate sensitive acetylcholinesterase.

Animals↗
PubMed1993

A malaria control trial using insecticide-treated bed nets and targeted chemoprophylaxis in a rural area of The Gambia, west Africa. 6. The impact of the interventions on mortality and morbidity from malaria.

The effects of insecticide-impregnated bed nets on mortality and morbidity from malaria have been investigated during one malaria transmission season in a group of rural Gambian children aged 6 months to 5 years. Sleeping under impregnated nets was associated with an overall reduction in mortality of about 60% in children aged 1-4 years. Mortality was not reduced further by chemoprophylaxis with Maloprim given weekly by village health workers throughout the rainy season. Episodes of fever associated with malaria parasitaemia were reduced by 45% among children who slept under impregnated nets. The addition of chemoprophylaxis provided substantial additional benefit against clinical attacks of malaria; 158 episodes were recorded among 946 children who slept under impregnated nets but who also received chemoprophylaxis. Chemoprophylaxis reduced the prevalence of splenomegaly and parasitaemia at the end of the malaria transmission season by 63% and 83% respectively. Thus, insecticide-impregnated bed nets provided significant protection in children against overall mortality, mortality attributed to malaria, clinical attacks of malaria, and malaria infection. The addition of chemoprophylaxis provided substantial additional protection against clinical attacks of malaria and malaria infection but not against death.

Antimalarials↗