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Background: Dengue fever (DF) is increasingly recognized as one of the world's major mosquito-borne diseases and causes significant morbidity and mortality in tropical and subtropical countries. Appropriate and timely diagnosis and risk stratification for severe disease are crucial in the appropriate management of this illness. Healthcare providers (HCPs) play a key role in dengue fever diagnosis, management and prevention. The present study was conducted to determine the knowledge, attitudes and practices (KAP) among HCPs in East Azerbaijan Province, Iran. Methods: A cross-sectional survey among 948 HCPs, using a structured questionnaire, was conducted in East Azerbaijan Province from May to July 2022. Data analysis was undertaken using descriptive methods, the Chi-square test or Fisher's exact test, and logistic regression. A P-value <0.05 was considered for statistical significance. Results: Out of the 948 (68.5% female) respondents, 227 were physicians and 721 were health professionals. The knowledge level of DF was found to be largely inadequate in the present study population (80.4%). The physician vs. health professional were a significant factor in differentiating attitude scores. The mean practice score regarding DF prevention and control measures among respondents was 8.40±1.97. Conclusion: The findings call for urgent continuous education and training courses to increase KAP levels and increased capacity and capability for DF prevention and control. This is of outmost importance for the first point of care of DF patients. [ABSTRACT FROM AUTHOR]

Objective: To compare the efficacy of seven pyrethroid insecticides for impregnation of mosquito nets, six currently recommended by WHO and one candidate (bifenthrin), under laboratory conditions. Methods: Tests were conducted using pyrethroid-susceptible and pyrethroid-resistant strains of Anopheles gambiae and Culex quinquefasciatus. Knock-down effect, irritancy and mortality were measured using standard WHO cone tests. Mortality and blood-feeding inhibition were also measured using a baited tunnel device. Findings: For susceptible A. gambiae, alpha-cypermethrin had the fastest knock-down effect. For resistant A. gambiae, the knock- down effect was slightly slower with alpha-cypermethrin and much reduced following exposure to the other insecticides, particularly bifenthrin and permethrin. For susceptible C. quinquefasciatus, the knock-down effect was significantly slower than in A. gambiae, particularly with bifenthrin, and no knock-down effect was observed with any of the pyrethroids against the resistant strain. Bifenthrin was significantly less irritant than the other pyrethroids to susceptible and resistant A. gambiae but there was no clear ranking of pyrethroid irritancy against C. quinquefasciatus. In tunnels, all insecticides were less toxic against C. quinquefasciatus than against A. gambiae for susceptible strains. For resistant strains, mortality was significant with all the pyrethroids with A. gambiae but not with C. quinquefasciatus. Inhibition of blood-feeding was also high for susceptible strains of both species and for resistant A. gambiae but lower for resistant C. quinquefasciatus; bifenthrin had the greatest impact. Conclusions: Efficacy for impregnation of mosquito nets against A. gambiae was greatest with alpha-cypermethrin. Bifenthrin is likely to have a significant comparative advantage over other pyrethroids in areas with pyrethroid resistance because of its much stronger impact on the nuisance mosquito, C. quinquefasciatus, despite its slower knock-down effect and irritancy. Selection of pyrethroids for mosquito vector control and personal protection should take into account the different effects of these insecticides, the status of pyrethroid resistance in the target area, and the importance of nuisance mosquitoes, such as C. quinquefasciatus.

BACKGROUND: Data on insecticide use for vector control are essential for guiding pesticide management systems on judicious and appropriate use, resistance management, and reduction of risks to human health and [...]

Background: Among neglected zoonotic diseases, leishmaniases caused by Leishmania parasite through infected female sand fly bite, are a group of diseases found in 98 countries and territories representing a critical burden of disease worldwide. Vector management plays a crucial role in reducing the burden of vector-borne diseases by WHO’s global plan. The objective of the current study was to assess the susceptibility status of wild phlebotomine sand flies from Esfahan Province, central Iran, to the recommended insecticides by WHO. Methods: Sand flies were collected by mouth aspirator in Matin Abad desert Eco-resort and were tested using WHO adult mosquito test kit against Dichlorodiphenyltrichloroethane (DDT) 4%, Deltamethrin 0.05%, Malathion 5% and Propoxur 0.1%. The number of knockdown sand flies were recorded during exposure time in ten minutes interval for DDT and Deltamethrin and they were allowed to recover for 24 hours. Knockdown Time50 (KD50) and KD90 were generated for them using Probit software. They were mounted and identified by valid keys. Results: Among the tested insecticides against female Phlebotomus papatasi, DDT, Deltamethrin, and Malathion recorded the highest mortality rate of 100%, followed by Propoxur with 92.2% mortality for a one-hour exposure. For DDT, KD50 and KD90 were calculated 21.87 and 42.93 and for Deltamethrin, they were 23.74 and 56.50 minutes respectively. Total sand flies exposed with DDT and Deltamethrin shed their leg(s). Conclusion: It is concluded that Ph. papatasi from central Iran is susceptible to DDT, Deltamethrin, Malathion, and Propoxur. [ABSTRACT FROM AUTHOR]

Summary Points * Recent developments have highlighted the urgency of sound management of public health pesticides in vector-borne-disease-endemic countries. * Major shortcomings are evident in national-level management practices throughout the pesticide life cycle from production to disposal; these shortcomings will adversely affect the cost-effectiveness and increase the risks of pesticides used. * A major thrust has occurred towards developing international standards for improvement of public health pesticide management and towards expanding WHO's global network on pesticide evaluation. * However, to face current and future challenges, such as insecticide resistance in malaria vectors, the global capacity for evaluation of new insecticide products and vector-control tools should be further enhanced. * Another area requiring urgent attention is the actual adoption and implementation of the recommended standards, calling for support to strengthen policy, legislation, and capacity., Introduction Pesticide use has been the mainstay control of disease vectors and pests of importance to public health [1-3]. However, three recent developments have raised concern over how pesticides used [...]

Abstract Background It is critical that vector control pesticides are used for their acceptable purpose without causing adverse effects on health and the environment. This paper provides a global overview of the current status of pesticides management in the practice of vector control. Methods A questionnaire was distributed to WHO member states and completed either by the director of the vector-borne disease control programme or by the national manager for vector control. In all, 113 countries responded to the questionnaire (80% response rate), representing 94% of the total population of the countries targeted. Results Major gaps were evident in countries in pesticide procurement practices, training on vector control decision making, certification and quality control of pesticide application, monitoring of worker safety, public awareness programmes, and safe disposal of pesticide-related waste. Nevertheless, basic conditions of policy and coordination have been established in many countries through which the management of vector control pesticides could potentially be improved. Most countries responded that they have adopted relevant recommendations by the WHO. Conclusions Given the deficiencies identified in this first global survey on public health pesticide management and the recent rise in pesticide use for malaria control, the effectiveness and safety of pesticide use are being compromised. This highlights the urgent need for countries to strengthen their capacity on pesticide management and evidence-based decision making within the context of an integrated vector management approach.

Background: Southeastern Iran has been established as an area with the potential to harbor Asian tiger mosquito populations. In 2013, a few numbers of Aedes albopictus were detected in three sampling sites of this region. This field study was aimed to evaluate the efficacy of various traps on monitoring mosquitoes and status of this dengue vector, in five urban and 15 suburban/rural areas. Methods: For this purpose, four adult mosquito traps (BG-sentinel 2, bednet, Malaise, and resting box trap) were used and their efficacy compared. In addition, large numbers of CDC ovitraps were employed, within 12 months. Results: A total of 4878 adult samples including 22 species covering five genera were collected and identified from traps. It was not revealed any collection of Ae. albopictus. Statistical analysis showed no significant difference in meteorological variables between the two periods, the previous report and the current study. There were significant differences in the total number of mosquitoes collected by various traps in the region across different months. Conclusion: The resulting data collected here on the efficiency of the various trap types can be useful for monitoring the densities of mosquito populations, which is an important component of a vector surveillance system. While the presence of Ae. albopictus was determined in this potential risk area, there is no evidence for its establishment and further monitoring needs to be carried out. [ABSTRACT FROM AUTHOR]

Abstract Background Pyrethroid resistant mosquitoes are becoming increasingly common in parts of Africa. It is important to identify alternative insecticides which, if necessary, could be used to replace or supplement the pyrethroids for use on treated nets. Certain compounds of an earlier generation of insecticides, the organophosphates may have potential as net treatments. Methods Comparative studies of chlorpyrifos-methyl (CM), an organophosphate with low mammalian toxicity, and lambdacyhalothrin (L), a pyrethroid, were conducted in experimental huts in Côte d'Ivoire, West Africa. Anopheles gambiae and Culex quinquefasciatus mosquitoes from the area are resistant to pyrethroids and organophosphates (kdr and insensitive acetylcholinesterase Ace.1R). Several treatments and application rates on intact or holed nets were evaluated, including single treatments, mixtures, and differential wall/ceiling treatments. Results and Conclusion All of the treatments were effective in reducing blood feeding from sleepers under the nets and in killing both species of mosquito, despite the presence of the kdr and Ace.1R genes at high frequency. In most cases, the effects of the various treatments did not differ significantly. Five washes of the nets in soap solution did not reduce the impact of the insecticides on A. gambiae mortality, but did lead to an increase in blood feeding. The three combinations performed no differently from the single insecticide treatments, but the low dose mixture performed encouragingly well indicating that such combinations might be used for controlling insecticide resistant mosquitoes. Mortality of mosquitoes that carried both Ace.1R and Ace.1S genes did not differ significantly from mosquitoes that carried only Ace.1S genes on any of the treated nets, indicating that the Ace.1R allele does not confer effective resistance to chlorpyrifos-methyl under the realistic conditions of an experimental hut.

Background: Data on insecticide use for vector control are essential for guiding pesticide management systems on judicious and appropriate use, resistance management, and reduction of risks to human health and the environment. Objective: We studied the global use and trends of insecticide use for control of vector-borne diseases for the period 2000 through 2009. Methods: A survey was distributed to countries with vector control programs to request national data on vector control insecticide use, excluding the use of long-lasting insecticidal nets (LNs). Data were received from 125 countries, representing 97% of the human populations of 143 targeted countries. Results: The main disease targeted with insecticides was malaria, followed by dengue, leishmaniasis, and Chagas disease. The use of vector control insecticides was dominated by organochlorines [i.e., DDT (dichlorodiphenyltrichloroethane)] in terms of quantity applied (71% of total) and by pyrethroids in terms of the surface or area covered (81% of total). Global use of DDT for vector control, most of which was in India alone, was fairly constant during 2000 through 2009. In Africa, pyrethroid use increased in countries that also achieved high coverage for LNs, and DDT increased sharply until 2008 but dropped in 2009. Conclusions: The global use of DDT has not changed substantially since the Stockholm Convention went into effect. The dominance of pyrethroid use has major implications because of the spread of insecticide resistance with the potential to reduce the efficacy of LNs. Managing insecticide resistance should be coordinated between disease-specific programs and sectors of public health and agriculture within the context of an integrated vector management approach. [ABSTRACT FROM AUTHOR]

Background: High frequency of insecticide used to control German cockroaches may lead to insecticide resistance development. We aimed to compare the level of insecticide resistance and heterogeneity in insecticide resistance of field-collected German cockroaches in eight selected zones of Mashhad City, Razavi Khorasan Province, Iran., Methods: The present study was conducted from October 2019 to May 2021. Adult and nymphs of German cockroaches were collected from infested restaurants or hotels in eight zones of Mashhad City and then colonized in an insectarium. The cockroaches were subjected to bioassay against cypermethrin insecticide. In addition, the genomic DNA of each cockroach population was analyzed in the region where the kdr mutations reside in the German cockroach., Results: The LT 50 values against cypermethrin in the susceptible strain (SS) and eight field-collected strains so varied from 17.52 to 95.36 min. The resistance ratio of the strains was also different in response to the insecticide. The similarity of multiple sequence alignments at the amino acid level was 97.5%-100%. An exon 20 transversion mutation and a nonsynonymous substitution were found. The L1014F substitution was detected in 83.4% of the cockroach samples., Conclusion: The field-collected strains were resistant to cypermethrin at different levels. Furthermore, the molecular study confirms the heterogeneity in the level of resistance among eight strains. Therefore, eight strains might have a different history of insecticide treatment., (Copyright© 2024 Dashti et al. Published by Tehran University of Medical Sciences.)

Background: Pyrethroid resistant mosquitoes are becoming increasingly common in parts of Africa. It is important to identify alternative insecticides which, if necessary, could be used to replace or supplement the pyrethroids for use on treated nets. Certain compounds of an earlier generation of insecticides, the organophosphates may have potential as net treatments., Methods: Comparative studies of chlorpyrifos-methyl (CM), an organophosphate with low mammalian toxicity, and lambdacyhalothrin (L), a pyrethroid, were conducted in experimental huts in Côte d'Ivoire, West Africa. Anopheles gambiae and Culex quinquefasciatus mosquitoes from the area are resistant to pyrethroids and organophosphates (kdr and insensitive acetylcholinesterase Ace.1R). Several treatments and application rates on intact or holed nets were evaluated, including single treatments, mixtures, and differential wall/ceiling treatments., Results and Conclusion: All of the treatments were effective in reducing blood feeding from sleepers under the nets and in killing both species of mosquito, despite the presence of the kdr and Ace.1R genes at high frequency. In most cases, the effects of the various treatments did not differ significantly. Five washes of the nets in soap solution did not reduce the impact of the insecticides on A. gambiae mortality, but did lead to an increase in blood feeding. The three combinations performed no differently from the single insecticide treatments, but the low dose mixture performed encouragingly well indicating that such combinations might be used for controlling insecticide resistant mosquitoes. Mortality of mosquitoes that carried both Ace.1R and Ace.1S genes did not differ significantly from mosquitoes that carried only Ace.1S genes on any of the treated nets, indicating that the Ace.1R allele does not confer effective resistance to chlorpyrifos-methyl under the realistic conditions of an experimental hut.

Toxic and feeding inhibition effect of cyfluthrin treated nets was assessed and compared with the activity of deltamethrin impregnated nets, before and after 2 and 4 washes against Phlebotomus papatasi. Impregnated cyfluthrin nets (50, 25, 12.5 mg active ingredient (a.i.)/m2) caused knock down and mortality rates higher than 90%, being of 100% at the highest dose, while the nets impregnated with deltamethrin (25, 12.5, 6.25 mg a.i./m2) showed low mortality rates (13.3-43.5%). Also after washing cyfluthrin at the dose of 50 mg a.i./m2 provided higher activity than deltamethrin (25 mg a.i./m2), being mortality rates within 24 hs of 66.7 and 48.9% for cyfluthrin and 38.0 and 2.1% for deltamethrin, respectively after 2 and 4 washes. Before washing, cyfluthrin (50 mg a.i./m2) significantly prevented blood feeding, with respect to both untreated (88.6%) and deltamethrin impregnated nets (56.8%). Deltamethrin (25 mg a.i./m2) showed low feeding inhibition (48.4%), although it was significantly higher than control. The washing of cyfluthrin impregnated nets (50 mg a.i./m2) produced a decrease of the feeding inhibition, being the reduction of 26.6% and 41.3%, respectively after 2 and 4 washes. Two washes of deltamethrin impregnated nets (25 mg a.i./m2) yielded a very high reduction of antifeeding inhibition (68.8%). These laboratory results if confirmed by field evaluation indicate cyfluthrin as good candidate for treatment of mosquito nets to be used against phlebotomine sandflies.