Does a One Health Approach to Human African Trypanosomiasis Control Hasten Elimination? A Stochastic Compartmental Modeling Approach

Background: In response to large strides in the control of human African trypanosomiasis (HAT), in the early 2000s the WHO set targets for elimination of both the gambiense (gHAT) and rhodesiense (rHAT) forms as a public health (EPHP) problem by 2020, and elimination of gHAT transmisson (EOT) by 2030. While global EPHP targets have been met, and EOT appears within reach, there is ample evidence that current control strategies will not achieve gHAT EOT in the presence of animal reservoirs, the role of which is currently uncertain. Furthermore, rHAT is not targeted for EOT due to the known importance of animal reservoirs for this form. Methods: To evaluate the utility of a One Health approach to gHAT and rHAT EOT, we built and parameterized a compartmental stochastic model, using the Institute for Disease Modeling's Compartmental Modeling Software, to six HAT epidemics: the national rHAT epidemics in Uganda and Malawi, the national gHAT epidemics in Uganda and South Sudan, and two separate gHAT epidemics in Democratic Republic of Congo distinguished by dominant vector species. In rHAT foci the reservoir animal sub-model was stratified on four species groups, while in gHAT foci domestic swine were assumed to be the only competent reservoir. The modeled time horizon was 2005-2045, with calibration performed using HAT surveillance data from 2000-2004 and Optuna. Interventions included insecticide and trypanocide treatment of domestic animal reservoirs at varying coverage levels. Results: Validation against HAT surveillance data indicates favorable performance overall, with the possible exception of DRC. EOT was not observed in any modeled scenarios for rHAT, however insecticide treatment consistently performed better than trypanocide treatment in terms of rHAT control. EOT was not observed for gHAT at 0% coverage of domestic reservoirs with trypanocides or insecticides, but was observed by 2030 in all test scenarios; again, insecticides demonstrated superior performance to trypanocides. Conclusions: EOT cannot be achieved for rHAT without control of wildlife reservoirs, however insecticide treatment of domestic animals holds promise for improved control. In the presence of domestic animal reservoirs, gHAT EOT will not be achieved under current control strategies.

Insecticidal Efficacy of Medicines During Cat Flea Infestations in Tyumen

From time immemorial people began to domesticate wild animals and throughout many generations, they are kept by people genetically isolated from external pathogens. In the prevailing era, every pet owner is trying to breed and protect his animal from contagious and noncontagious diseases. Having said that, lack and inadequacy of knowledge and mass media on simple preventive measures results in the widespread occurrence of infectious and invasive diseases, including flea, Ctenocephalides felis infestation among dogs as well as cats. The present paper primarily attempts to present the results of therapeutic efficiency of Komfortis, Foresto, and Fitoelita medical agents used during flea infestation among domestic cats. In order to meet the purpose of the study, research was carried out within the framework of study and analysis of the epizootic state of invasive diseases of agricultural and unproductive animals, bees, and birds. Studies of changes in the species composition, and bioecological patterns of the development cycle of parasites under shifting boundaries of their ranges were also done. For the study, the animals were divided into three groups of 10 animals each. Standard clinical and hematological research methods were used during the study. Blood sampling included three stages: before insecticide treatment, the intermediate interval of 15 days, and the final stage. Based on the results obtained, it was found that Komfortis and Foresto have 100% therapeutic efficacy at all stages of flea development and possess a long-lasting action duringa flea infestation. The morphological blood analysisshowed that the proposed medical agents have no toxic orsideeffects.

MATING DISRUPTION OF GRAPHOLITA MOLESTA BUSCK. TO IMPROVE QUALITY AND HEALTHY OF PEACH FRUITS

In Bulgarian fruit growing agriculture mainly chemical plant protection is applied. Applications with organophosphates and pyrethroids are carried out to control the economically most important peach pest - the oriental fruit moth (Grapholita molesta Busck.). Annually during the vegetation season 7-8 insecticide treatments are applied. This leads to contamination of fruit products and the environment, which is a prerequisite for seeking other approaches. Regarding to fruit moth, sex pheromones are one of the most widely used environmental control methods, but they are most commonly used in apples. Their introduction in the monitoring of the main peach pest can lead to a reduction of chemical treatments and production with less pesticide residues. A promising direction is the use of pheromones to control the pests through sexual disorientation of males. The trial of mating disruption in the present study were carried out with ISOMATE® OFM TT dispensers in 0.9 ha peach orchard in 2020 and 2021. Pheromone traps type "Delta" of the Hungarian company CSALOMON® were used. The ISOMATE OFM TT dispensers, installed before the first flight of OFM at the rate of 250 units per ha, efficiently reduced fruit damages - down to 0.1-0.2% at harvest. In the reference orchard with 6 insecticide treatment against OFM, the damages reached 3.0-3.6%. The results indicate that mating disruption for control of Grapholita molesta Busck. can be used in production of quality and healthy peach fruits.

The effect of application of control techniques to the population, damage intensity of onion caterpillar (Spodoptera exigua hubner) and yield of shallots

Shallot is an important cash crop in Indonesia. However, its productivity is relatively low, due to the attack of the onion caterpillar (Spodoptera exigua Hubner). This study aimed to identify the effect of the application of control techniques on the population, damage intensity, and shallots yield. This research was conducted by field experiment. Control treatment consisted of covering shallots by using gauze/net and insecticide treatment with active ingredients of profenofos, metomil, and carbosulfan. The research variables consisted of the population and the damage intensity of S. exigua, as well as the yield of shallots. The results showed that the caterpillars population of S. exigua was found at 16 DAP and increased up to before harvest at 44 DAP. Covering shallots with gauze effectively suppressed the population of S. exigua (0.0 per hills), followed by treatment with profenofos (0.14 per hills), carbosulfan (0.15 per hills), and methomyl 0.32 per hills). The damage intensity of S. exigua in the plot gauze covered was 0%, lower than 32%, 25%, 12%, 10%, respectively, in the control plot, treatment of metomil, carbosulfan, and profenofos. Covering shallots with gauze also increased the weight of wet-harvested tubers (50.83 g per hills).

Effectiveness of a long-lasting insecticide treatment kit (ICON® Maxx) for polyester nets over three years of household use: a WHO phase III trial in Tanzania

Background ICON® Maxx (Syngenta) is an insecticide treatment kit of pyrethroid and binding agent for long-lasting treatment of mosquito nets. Interim recommendation for use on nets was granted by the World Health Organization (WHO) after successful evaluation in experimental huts following multiple washes. A full WHO recommendation is contingent upon demonstration of continued bio-efficacy after 3 years of use. Methods A household-randomized prospective study design was used to assess ICON Maxx-treated nets over 3 years in north-eastern Tanzania. Conventional treated nets (with lambda-cyhalothrin, but without binder) served as a positive control. At 6-monthly intervals, cross-sectional household surveys monitored net use and physical integrity, while cone and tunnel tests assessed insecticidal efficacy. Pyrethroid content was determined after 12 and 36 months. A parallel cohort of nets was monitored annually for evidence of net deterioration and attrition. Results After 12 months’ use, 97% of ICON Maxx-treated nets but only 67% of CTN passed the WHO efficacy threshold for insecticidal durability (> 80% mortality in cone or tunnel or 90% feeding inhibition in tunnel). After 24- and 36-months use, 67% and 26% of ICON Maxx treated nets met the cone criteria, respectively, and over 90% met the combined cone and tunnel criteria. Lambda-cyhalothrin content after 36 months was 17% (15.8 ± 4.3 mg/m2) of initial content. ICON Maxx nets were used year-round and washed approximately 4 times per year. In cross-sectional survey after 36 months the average number of holes was 20 and hole index was 740 cm2 per net. Cohort nets had fewer holes and smaller hole index than cross-sectional nets. However, only 15% (40/264) of cohort nets were not lost to follow-up or not worn out after 36 months. Conclusions Because more than 80% of nets met the WHO efficacy criteria after 36 months use, ICON Maxx was granted WHO full recommendation. Cross-sectional and cohort surveys were complementary and gave a fuller understanding of net durability. To improve net usage and retention, stronger incentives and health messaging should be introduced in WHO LLIN longitudinal trials. Untreated polyester nets may be made long-lastingly insecticidal in Africa through simple household treatment using ICON Maxx pyrethroid-binder kits.

Anti-pest protection of two-year old alfalfa grown for seeds

Purpose. To evaluate the effectiveness of different insecticides against pests on two-year old alfalfa grown for seeds. Materials and methods. The study was conducted in the experimental field of the Institute of Irrigated Agriculture of NAAS in 2017–2019. The filed experiments were laid out in split plots. The main plots (factor A) were for water supply conditions (no irrigation vs. irrigation); sub-plots (factors B and C) were for application of insecticides. Seeds were sown in wide rows with interrows of 70 cm. Results and discussion. When the two-year old alfalfa canopy (budding onset) was inspected before insecticide treatment, the average numbers of pests were as follows: alfalfa plant bug – 3.0 specimens/10 sweeps, alfalfa aphid – 20.0 specimens/10 sweeps, beet webworm – 3.0 specimens/10 sweeps, alfalfa weevil (imagoes/grubs) – 1.0/3.0 specimens/10 sweeps, and alfalfa seed weevil – 1.0 specimens/10 sweeps. Treatment 1 reduced the pest numbers in the canopy: alfalfa plant bug – by 70.0–93.3%, alfalfa aphid – by 93.0–97.5%, beet webworm – by 80.0–96.7, alfalfa weevil (imagoes/grubs) – by 60.0–90.0%/73.3–93.3%, and alfalfa seed weevil – by 76.0–94.0%, depending on the insecticide. Treatment 2 helped to reduce the pest numbers in the canopy. Insecticide containing active substances chlorpyrifos 500 g/L and cypermethrin 50 g/L applied at a dose of 1.00 L/ha was the most effective. The highest seed yield was achieved after treatment 1 with insecticide containing active ingredients chlorpyrifos 500 g/L and cypermethrin 50 g/L applied at a dose of 1.00 L/ha and treatment 2 with insecticide containing active ingredients chlorantraniliprole 200 g/L and lambda-cyhalothrin 50 g/L applied at a dose of 0.17 L/ha and 0.15 L/ha, respectively. Conclusions. The highest seed yield was achieved after treatment 1 with insecticide containing active ingredients chlorpyrifos 500 g/L and cypermethrin 50 g/L applied at a dose of 1.00 L/ha and treatment 2 with insecticide containing active ingredients chlorantraniliprole 200 g/L and lambda-cyhalothrin 50 g/L applied at a dose of 0.17 L/ha and 0.15 L/ha, respectively

Effectiveness of a Long-Lasting Insecticide Treatment Kit (ICON® Maxx) for Polyester Nets Over Three Years of Household use: A WHO Phase III Trial in Tanzania

BackgroundICON® Maxx (Syngenta) is an insecticide treatment kit of pyrethroid and binding agent for long-lasting treatment of mosquito nets. Interim recommendation for use on nets was granted by WHO after successful evaluation in experimental huts following multiple washes. A full WHO recommendation is contingent upon demonstration of continued bio-efficacy after 3 years of use. MethodsA household-randomised prospective study design was used to assess ICON Maxx treated nets over 3 years in north-eastern Tanzania. Conventional treated nets (with lambda-cyhalothrin but without binder) served as a positive control. At 6-monthly intervals, cross-sectional household surveys monitored net use and physical integrity, while cone and tunnel tests assessed insecticidal efficacy. Pyrethroid content was determined after 12 and 36 months. A parallel cohort of nets was monitored annually for evidence of net deterioration and attrition. ResultsAfter 12 months’ use, 97% of ICON Maxx treated nets but only 67% of CTN passed the WHO efficacy threshold for insecticidal durability (>80% mortality in cone or tunnel or 90% feeding inhibition in tunnel). After 24- and 36-months use, 67% and 26% of ICON Maxx treated nets met the cone criteria respectively and over 90% met the combined cone and tunnel criteria. Lambda-cyhalothrin content after 36 months was 17% (15.8 ± 4.3 mg/m2) of initial content. ICON Maxx nets were used year-round and washed approximately 4 times per year. In cross-sectional survey after 36 months the average number of holes was 20 and hole index was 740 cm2 per net. Cohort nets had fewer holes and smaller hole index than cross-sectional nets. However, only 15% (40/264) of cohort nets were not lost to follow-up or not worn out after 36 months.ConclusionsBecause more than 80% of nets met the WHO efficacy criteria after 36 months use, ICON Maxx was granted WHO full recommendation. Cross-sectional and cohort surveys were complementary and gave a fuller understanding of net durability. To improve net usage and retention, stronger incentives and health messaging should be introduced in WHO LLIN longitudinal trials. Untreated polyester nets may be made long-lastingly insecticidal in Africa through simple household treatment using ICON Maxx pyrethroid-binder kits.

Effectivity of Bacillus thuringiensis from Soil in Freshwater Swamps against Epilachna sp. Larvae

Bacillus thuringiensis is an entomopathogenic bacterium isolated from the soil and has been widely used as an active ingredient in the manufacture of bioinsecticides. The target insects are very specific and depend on the type of protein content. Epilachna sp. are important insect pests because both larvae and adults as plant-eating pests. The research aimed was to investigate the effectivity of B. thuringiensis against the larvae of Epilachna sp.. B. thuringiensis- bio-insecticide was prepared using isolates originally from freshwater swamp soil of South Sumatra (SMR04). Epilachna sp larvae were mass-reared with Solanum torvum leaf feed in the laboratory. The design used was a completely randomized design, with 6 treatments and 5 replications. Treatments were spore concentration contained in the bioinsecticide solution included: 1 x 108, 1 x 107, 1 x 106, 1 x 105 spores/mL, commercial bio-insecticide and without treatment as a control. Each replication used 10 individual of the 2nd larvae. Statistical test results showed larval mortality in B. thuringiensis treatment was significantly different from commercial bio-insecticide treatment. The highest mortality of bio-insecticide treatment occurred at a concentration of 108 spores/ml (40.00 %) and the lowest was at a concentration of 105 spores/mL (18.01 %). The lowest LT50 value of bio-insecticide treatment was at a concentration of 108 spores/mL, namely 79.37 hours. The control of larvae included in the Coleoptera order was still not satisfactory yet, considering the presence of protein content in B. thuringiensis strain SMR04 which did not match the type of protein required.

Developmental and reproductive effects of clothianidin exposure in monarch butterflies (Lepidoptera: Nymphalidae)

Neonicotinoid insecticides are used to reduce crop damage caused by insect pests, but sublethal levels could affect development and reproduction in nontarget insects, such as monarch butterflies (Danaus plexippus) (Lepidoptera: Nymphalidae). To investigate the impact of field-realistic concentrations of the neonicotinoid clothianidin on monarch butterflies, we grew swamp milkweed (Asclepias incarnata) (Apocynaceae) in either low (15 ng/g of soil) or high (25 ng/g of soil) levels of clothianidin, or in a control (0 ng/g), then raised monarchs on the milkweed. Morphological traits of monarch caterpillars were measured during development and, once they eclosed, were mated as adults to quantify egg size and mass and the number of eggs laid. Although the effects of the treatment had complex effects on caterpillar length, width and volume of late-instar caterpillars were negatively affected. Fifth-instar caterpillars from the high-dose insecticide treatment had lower mass than other groups. Adult monarch butterflies raised on treated milkweed were larger than controls, but clothianidin exposure did not affect the number of eggs laid or egg size. Although the magnitude of the effect depends on clothianidin concentration, our results suggest that exposure to clothianidin during early life can impact monarch caterpillar development but is unlikely to reduce female reproductive output.

Effect of Imidacloprid and Acephate for Tobacco Thrips (Thysonaptera: Thripidae) Management on Flumioxazin Injured Peanut

Experiments were conducted in 2016 and 2017 in Stoneville, MS and Starkville, MS to determine the impact of different insecticide management options for thrips on herbicide injured peanut. Insecticide treatments included imidacloprid in-furrow at-planting, one or two foliar applications of acephate, and an untreated control with and without an application of flumioxazin. In Stoneville, herbicide applications were made immediately following planting, and in Starkville, applications were made as plants were emerging to maximize herbicide injury. The Stoneville experiment also had an additional factor in which plots were flooded or not flooded to simulate a heavy rainfall in order to maximize herbicide injury and also to give added stress from saturated soils. Thrips counts, thrips injury ratings, plant vigor ratings, plant biomass, width between plant canopies, and yield were recorded. Few interactions were observed, but temporary flooding, herbicide injury, and thrips injury affected peanut growth as measured by biomass and canopy. Imidacloprid was the most consistent insecticide treatment for reducing thrips numbers and injury, but acephate provided some protection. Temporary flooding during the seedling stage, flumioxazin injury, and thrips injury all reduced peanut pod yield. Based on these results, every attempt should be made to minimize early season stress in peanuts including the use of an effective in-furrow insecticide.