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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 Prov- ince, 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, Deltame- thrin, 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 ex-posed with DDT and Deltamethrin shed their leg(s). Conclusion: It is concluded that Ph. papatasi from central Iran is susceptible to DDT, Deltame- thrin, Malathion, and Propoxur.

Background Water pollution due to uncontrolled release of chemical pollutants is an important global problem. Its effect on medically important insects, especially mosquitoes, is a critical issue in the epidemiology of mosquito-borne diseases. Methods In order to understand the effect of water pollutants on the demography of Anopheles stephensi, colonies were reared in clean, moderately and highly polluted water for three consecutive generations at 27 °C, 75% RH, and a photoperiod of 12:12 h (L:D). The demographic data of the 4th generation of An. stephensi were collected and analysed using the age-stage, two-sex life table. Results The intrinsic rate of increase (r), finite rate of increase (λ), mean fecundity (F) and net reproductive rate (R0) of An. stephensi in clean water were 0.2568 d−1, 1.2927 d−1, 251.72 eggs, and 109.08 offspring, respectively. These values were significantly higher than those obtained in moderately polluted water (r = 0.2302 d−1, λ = 1.2589 d−1, 196.04 eggs, and R0 = 65.35 offspring) and highly polluted water (r = 0.2282 d−1, λ = 1.2564 d−1, 182.45 eggs, and R0 = 62.03 offspring). Female adult longevity in moderately polluted (9.38 days) and highly polluted water (9.88 days) were significantly shorter than those reared in clean water (12.43 days), while no significant difference in the male adult longevity was observed among treatments. Conclusions The results of this study showed that An. stephensi can partially adapt to water pollution and this may be sufficient to extend the range of mosquito-borne diseases.

Background While Iran is on the path to eliminating malaria, the disease with 4.9 million estimated cases and 9300 estimated deaths in 2018 remains a serious health problem in the World Health Organization (WHO) Eastern Mediterranean Region. Anopheles stephensi is the main malaria vector in Iran and its range extends from Iraq to western China. Recently, the vector invaded new territories in Sri Lanka and countries in the Horn of Africa. Insecticide resistance in An. stephensi is a potential issue in controlling the spread of this vector. Methods Data were collated from national and international databases, including PubMed, Google Scholar, Scopus, ScienceDirect, SID, and IranMedex using appropriate search terms. Results Indoor residual spaying (IRS) with DDT was piloted in Iran in 1945 and subsequently used in the malaria eradication programme. Resistance to DDT in An. stephensi was detected in Iran, Iraq, Pakistan, and Saudi Arabia in the late 1960s. Malathion was used for malaria control in Iran in 1967, then propoxur in 1978, followed by pirimiphos-methyl from 1992 to 1994. The pyrethroid insecticide lambda-cyhalothrin was used from 1994 to 2003 followed by deltamethrin IRS and long-lasting insecticidal nets (LLINs). Some of these insecticides with the same sequence were used in other malaria-endemic countries of the region. Pyrethroid resistance was detected in An. stephensi in Afghanistan in 2010, in 2011 in India and in 2012 in Iran. The newly invaded population of An. stephensi in Ethiopia was resistant to insecticides of all four major insecticide classes. Different mechanisms of insecticide resistance, including metabolic and insecticide target site insensitivity, have been developed in An. stephensi. Resistance to DDT was initially glutathione S-transferase based. Target site knockdown resistance was later selected by pyrethroids. Esterases and altered acetylcholinesterase are the underlying cause of organophosphate resistance and cytochrome p450s were involved in pyrethroid metabolic resistance. Conclusions Anopheles stephensi is a major malaria vector in Iran and many countries in the region and beyond. The species is leading in terms of development of insecticide resistance as well as developing a variety of resistance mechanisms. Knowledge of the evolution of insecticide resistance and their underlying mechanisms, in particular, are important to Iran, considering the final steps the country is taking towards malaria elimination, but also to other countries in the region for their battle against malaria. This systematic review may also be of value to countries and territories newly invaded by this species, especially in the Horn of Africa, where the malaria situation is already dire.

International trade of tires has been responsible for the introduction of invasive Aedes species into many countries. The present study aimed to determine the sources and volume of such trading in Iran and to establish and map points of entry for entomological surveillance.A list of tire importers, type and number of tires and source of their shipment was compiled, and the map of the main location(s) of their depot in the country was produced from 2017 to 2018. Contamination of imported tires with mosquito eggs or larvae was also determined. The samples from all parts of the warehouse were taken randomly from 4 to 20 tires every 15 days. In tires with a trace of water inside, the existence of the egg and larva of Aedes mosquitoes was investigated by sticking the glue band to the hot spot of left water inside the unpacked tires.Approximately one-third of the annual tire requirements of Iran were imported from 15 countries, most of which were endemic to Aedes aegypti and or Ae. albopictus. It is obligatory to import only wrapped tires. About 10% of total country consumption is imported through informal markets and smuggled. However, the unofficially imported tires are usually not wrapped. The majority of tire imports were made through the southern ports of the country. The main sites for depots of imported tires were located in four Iranian provinces, namely Tehran, Isfahan, Fars, and Sistan and Baluchestan. The latter is extremely important given its border with Pakistan. Depot locations were mostly unstructured, and tires were kept in the open air. All these depot locations were at the edge of towns and residential areas. Priority areas for routine entomological surveillance were established. Such as the previous studies, surveillance of imported tires for the presence of Aedes eggs or larvae was negative in this study.Mapping the entry points of imported tires and their origin is crucial to determine and prioritize sites for entomological surveillance of invasive mosquito species. Strengthening collaboration with customs authorities and the association of tire importers is imperative in this effort. The development of national rules and regulations for tire import is necessary to minimize the danger of the introduction of invasive vector species into the country.

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.

Background: West Nile Virus, a mosquito-borne flavivirus, causes a variety of symptoms in human, from asymptomatic infection to neuroinvasive disease. Several studies have been conducted on the seroprevalence of WNV infection in different areas from Iran. This study was performed to find the presence of antiviral antibodies in human serum among some high risk population and awareness of health care staff about symptom of the WNV infection. Methods: Study performed in five geographical districts based on high population of immigrant and domestic birds and prevalence of the antiviral antibodies in horses which was reported previously. Totally 150 human blood samples were collected during 2018. The samples collected from patients referred to the clinics. The ELISA method used to detect IgG and IgM antibody against WNV. Logistic regression models used to analyze the effect of sex, age, keeping birds and urban/rural residence on the risk of infection. The awareness of health care staff about symptom of infection surveyed. Results: From all blood donors, 41 samples (27.33%) showed positive to IgG antibody. From which 56.10% were males and remaining females. None of the mentioned factors had a significant relationship. Health care staff had less attention to the infection. Conclusions: Although the prevalence of antibodies was relatively high, due to the similarity to other viral diseases, health care staff had less attention to the disease. The study showed that people in these areas have been exposed to the virus. Further research activities are recommended for control of this arbovirus.

Background Public health pesticides has been the mainstay control of vectors of malaria and other diseases, and public health pests, but there is increasing concern over how these pesticides are being managed. Poor pesticide management could lead to risks to human health and the environment, or diminish the effectiveness of interventions. Strategies for strengthening the management of public health pesticides, from manufacture to disposal, should be evaluated to propose future directions. Methods The process and outcomes of three strategies were studied in five regions of the WHO (African Region, Eastern Mediterranean Region, South-East Asia Region, Western Pacific Region, and American Region) and 13 selected countries. These strategies are: regional policy development, in-depth country support and thematic support across countries. Results Consensus, frameworks and action plans on public health pesticide management were developed at regional level. Country support for situation analysis and national action planning highlighted weaknesses over the entire spectrum of pesticide management practices, mainly related to malaria control. The thematic support on pesticide quality control contributed to structural improvements on a priority issue for malaria control across countries. Conclusions The three strategies showed promising and complementary results, but guidelines and tools for implementation of the strategies should be further improved. Increased national and international priority should be given to support the development of policy, legislation and capacity that are necessary for sound management of public health pesticides.

Most insecticides used against pests and vectors of human disease (e.g. fleas, flies and mosquitoes) are spin-offs from agrochemical research and development. The arsenal of safe and cost-effective public health insecticides is being depleted by restrictions for various reasons (e.g. insecticide resistance, unacceptable side effects and non re-registration) and the number of new products launched is dwindling. Mobilizing public resources and establishment of partnerships to support research and development of public health insecticides is crucial in the post-DDT and post-pyrethroid era.

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.

Because pyrethroid, organophosphate, and carbamate resistance is more and more developed in mosquitoes of medical importance, there is an urgent need for alternative insecticides for vector control. Dinotefuran, a new neonicotinoid insecticide commercialized by Mitsui Chemicals (Tokyo, Japan), could be a useful candidate in public health because it shows low mammalian toxicity and great insecticidal activity against a broad range of pests. In this study, the intrinsic toxicity of dinotefuran was evaluated by larval bioassay and topical application against different mosquito strains of Anopheles gambiae Giles, Culex quinquefasciatus Say, and Aedes aegypti L. having none, one, or several resistance mechanisms, respectively, to insecticides. The results showed that dinotefuran was less toxic than most of the commonly used insecticides (e.g., deltamethrin, carbosulfan, and temephos) against the susceptible mosquitoes tested (between 6- and 100-fold at the LD50 level). However, the toxicity of dinotefuran was not strongly affected by the presence of common resistance mechanism, i.e., kdr mutation and insensitive acetylcholinesterase (resistance ratio [RR] from 1.3 to 2.3). More interestingly, the carbamate-resistant strain of Cx. quinquefasciatus was significantly more affected by dinotefuran than the susceptible strain (RR = 0.70), probably because the insensitive acetylcholinesterase is less efficient to degrade nicotinic substrates than normal acetylcholinesterase. Despite the relatively low toxicity of dinotefuran against susceptible mosquitoes, the absence of cross-resistance with common insecticides (pyrethroids, carbamates, and organophosphates) makes neonicotinoids potential candidates for disease vector control, especially in area where mosquitoes are resistant to insecticides.

Bifenthrin, a pyrethroid insecticide already used in agriculture was evaluated in laboratory conditions against susceptible and pyrethroid resistant mosquitoes, as a potential insecticide for treatment of mosquito nets. Two laboratory strains of Anopheles gambiae s.s. Giles, the major malaria vector in Africa, and two of Culex quinquefasciatus Say, a major pest mosquito in urban areas, were used. Compared with other pyrethroids such as permethrin and deltamethrin, the intrinsic toxicity of bifenthrin, measured by topical application with susceptible strains, was intermediate. By forced tarsal contact on filter papers (cylinder tests) or on netting materials (cone tests), bifenthrin was found slightly more effective against A. gambiae than against C. quinquefasciatus, in terms of mortality and knock-down effect. With free flying mosquitoes (tunnel tests), bifenthrin was very efficient in killing mosquitoes and inhibiting blood feeding. Against the two pyrethroid resistant strains, bifenthrin was relatively efficient against A. gambiae but the impact of resistance was greater with C. quinquefasciatus. In tunnel tests, blood feeding remained almost entirely inhibited with the two species despite resistance. The high mortality of susceptible mosquitoes and excellent blood feeding inhibition of susceptible and resistant strains makes bifenthrin a good candidate for treatment of netting materials, particularly in areas where C. quinquefasciatus, the main nuisance in urban areas, is resistant to pyrethroids. The slower knock-down and lower irritant effect also makes this insecticide especially attractive when a mass killing effect on mosquito populations is expected.

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. Comparative studies of chlorpyrifos-methyl (CM), an organophosphate with low mammalian toxicity, and lambdacyhalothrin (L), a pyrethroid, were conducted in experimental huts in Cote d'Ivoire, West Africa. Anopheles gambiae and Culex quinquefasciatus mosquitoes from the area are resistant to pyrethroids and organophosphates (kdr and insensitive acetylcholinesterase Ace.1 R ). Several treatments and application rates on intact or holed nets were evaluated, including single treatments, mixtures, and differential wall/ceiling treatments. 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.1 R 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.1 R and Ace.1 S genes did not differ significantly from mosquitoes that carried only Ace.1 S genes on any of the treated nets, indicating that the Ace.1 R allele does not confer effective resistance to chlorpyrifos-methyl under the realistic conditions of an experimental hut.