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1.
PLoS Negl Trop Dis ; 18(4): e0011451, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38630832

ABSTRACT

Systems for disease vector control should be effective, efficient, and flexible to be able to tackle contemporary challenges and threats in the control and elimination of vector-borne diseases. As a priority activity towards the strengthening of vector control systems, it has been advocated that countries conduct a vector-control needs assessment. A review was carried out of the perceived needs for disease vector control programs among eleven countries and subnational states in South Asia and the Middle East. In each country or state, independent teams conducted vector control needs assessment with engagement of stakeholders. Important weaknesses were described for malaria, dengue and leishmaniases regarding vector surveillance, insecticide susceptibility testing, monitoring and evaluation of operations, entomological capacity and laboratory infrastructure. In addition, community mobilization and intersectoral collaboration showed important gaps. Countries and states expressed concern about insecticide resistance that could reduce the continued effectiveness of interventions, which demands improved monitoring. Moreover, attainment of disease elimination necessitates enhanced vector surveillance. Vector control needs assessment provided a useful planning tool for systematic strengthening of vector control systems. A limitation in conducting the vector control needs assessment was that it is time- and resource-intensive. To increase the feasibility and utility of national assessments, an abridged version of the guidance should focus on operationally relevant topics of the assessment. Similar reviews are needed in other regions with different contextual conditions.


Subject(s)
Vector Borne Diseases , Middle East/epidemiology , Humans , Vector Borne Diseases/prevention & control , Vector Borne Diseases/transmission , Asia/epidemiology , Animals , Needs Assessment , Dengue/prevention & control , Dengue/epidemiology , Dengue/transmission , Malaria/prevention & control , Malaria/epidemiology , Insecticides , Disease Vectors , Asia, Southern
2.
Parasit Vectors ; 17(1): 34, 2024 Jan 25.
Article in English | MEDLINE | ID: mdl-38273349

ABSTRACT

BACKGROUND: Aedes aegypti is the main vector of arboviral diseases worldwide. The species invaded and became established in southern Iran in 2020. Insecticide-based interventions are primarily used for its control. With insecticide resistance widespread, knowledge of resistance mechanisms is vital for informed deployment of insecticidal interventions, but information from Iranian Ae. aegypti is lacking. METHODS: Fifty-six Ae. aegypti specimens were collected from the port city of Bandar Lengeh in Hormozgan Province in the South of Iran in 2020 and screened for kdr mutations. The most common kdr mutations in Latin America and Asia (V410L, S989P, V1016G/I and F1534C), especially when present in combinations, are highly predictive of DDT and pyrethroid resistance were detected. Phylogenetic analyses based on the diversity of S989P and V1016G/I mutations were undertaken to assess the phylogeography of these kdr mutations. RESULTS: Genotyping all four kdr positions of V410L, S989P, V1016G/I and F1534C revealed that only 16 out of the 56 (28.57%) specimens were homozygous wild type for all kdr mutation sites. Six haplotypes including VSVF (0.537), VSVC (0.107), LSVF (0.016), LSIF (0.071), VPGC (0.257) and LPGC (0.011) were detected in this study. For the first time, 11 specimens harbouring the V410L mutation, and 8 samples with V1016I mutation were found. V410L and V1016I were coincided in 8 specimens. Also, six specimens contained 1016G/I double mutation which was not reported before. CONCLUSIONS: The relatively high frequency of these kdr mutations in Iranian Ae. aegypti indicates a population exhibiting substantial resistance to pyrethroid insecticides, which are used widely in control operations and household formulations. The detection of the 410L/1016I kdr mutant haplotype in Iranian Ae. aegypti suggests possible convergence of invasive populations from West Africa or Latin America. However, as Iran has very limited maritime/air connections with those African countries, a Latin American origin for the invasive Ae. aegypti in Iran is more plausible.


Subject(s)
Aedes , Insecticides , Pyrethrins , Voltage-Gated Sodium Channels , Animals , Aedes/genetics , Iran , Genotype , Phylogeny , Insecticides/pharmacology , Pyrethrins/pharmacology , Mutation , Voltage-Gated Sodium Channels/genetics , Insecticide Resistance/genetics , Mosquito Vectors/genetics
3.
Sci Rep ; 14(1): 1116, 2024 01 11.
Article in English | MEDLINE | ID: mdl-38212448

ABSTRACT

Vector-borne diseases emergence, particularly malaria, present a significant public health challenge worldwide. Anophelines are predominant malaria vectors, with varied distribution, and influenced by environment and climate. This study, in Ghana, modelled environmental suitability for Anopheles stephensi, a potential vector that may threaten advances in malaria and vector control. Understanding this vector's distribution and dynamics ensures effective malaria and vector control programmes implementation. We explored the MaxEnt ecological modelling method to forecast An. stephensi's potential hotspots and niches. We analysed environmental and climatic variables to predict spatial distribution and ecological niches of An. stephensi with a spatial resolution of approximately 5 km2. Analysing geospatial and species occurrence data, we identified optimal environmental conditions and important factors for its presence. The model's most important variables guided hotspot prediction across several ecological zones aside from urban and peri-urban regions. Considering the vector's complex bionomics, these areas provide varying and adaptable conditions for the vector to colonise and establish. This is shown by the AUC = 0.943 prediction accuracy of the model, which is considered excellent. Based on our predictions, this vector species would thrive in the Greater Accra, Ashanti Central, Upper East, Northern, and North East regions. Forecasting its environmental suitability by ecological niche modelling supports proactive surveillance and focused malaria management strategies. Public health officials can act to reduce the risk of malaria transmission by identifying areas where mosquitoes may breed, which will ultimately improve health outcomes and disease control.


Subject(s)
Anopheles , Malaria , Animals , Humans , Mosquito Vectors , Ghana , Malaria/epidemiology , Malaria/prevention & control , Ecosystem
4.
Microorganisms ; 11(11)2023 Nov 11.
Article in English | MEDLINE | ID: mdl-38004764

ABSTRACT

Phleboviruses are classified into two main groups: the sandfly fever group (transmitted by sandflies and mosquitoes) and the Uukuniemi group (transmitted by ticks). Old World sandfly-borne viruses (SBVs) are classified into four main serocomplexes; sandfly fever Naples viruses (SFNVs), sandfly fever Sicilian viruses (SFSVs), Karimabad viruses (KARVs), and Salehabad viruses (SALVs). This study addresses current knowledge gaps on SBVs in Iran by focusing on identification and molecular epidemiology. We used PCR to examine DNA/RNA extracts to identify sandfly species and evaluate for SBV presence. We identified five specimens positive for phleboviruses: one Ph. sergenti for Tehran virus (TEHV), one Ph. papatasi for SFSV, and two Ph. papatasi and one Ph. perfiliewi for KARV. A phylogenetic tree indicated that the TEHV isolate from this study formed a cluster with previous isolates of TEHV, Zerdali virus, and Fermo virus. Meanwhile, the identified SFSV isolate fell in lineage I and was grouped with previous isolates of SFSVs and Dashli virus in Iran. Finally, the KARV isolates from this study formed a monophyletic clade in a sister relationship with other viruses in KARV lineages I and II. This comprehensive study on SBVs in Iran provided new insights into the molecular epidemiology of TEHV, SFSVs and KARVs in this country.

5.
J Arthropod Borne Dis ; 17(1): 72-82, 2023 Mar.
Article in English | MEDLINE | ID: mdl-37609566

ABSTRACT

Background: Anopheles stephensi is a major vector of malaria in some parts of the world. A standard method for determining resistance in adult mosquito populations is the bioassay test recommended by the world health organization (WHO). The papers used in this method have an expiry date. This study aimed to determine the effectiveness of outdated susceptibility test papers for use in insecticide resistance monitoring programs. Methods: Beech and Bandar Abbas strains of An. stephensi were reared in the insectary. Permethrin 0.75%, Deltamethrin 0.05%, and Bendiocarb 0.1% impregnated test papers prepared by Universiti Sains Malaysia were used. Probit analysis was used to analyze the results and prepare time-mortality regression lines of LT50 and LT90. Results: There was a difference in the mortality of both tested strains of An. stephensi was exposed to all tested insecticides. Both expired and not expired Permethrin and Deltamethrin papers induced 100% mortality at the diagnostic time (60min), but their insecticidal properties were reduced gradually in serial times. The highest efficacy of test papers was in the first trimester after the expiry date and decreased over time. Conclusion: At the diagnostic time of 60 minutes, the mortality rate of both dated and expired papers was 100% in the pyrethroid insecticides, even three years after expiry dates, if stored in the package provided by the producer, in a refrigerator. This value was reduced to less than 100% in the expired papers of Bendiocarb comparing the dated papers that induced 100% mortality.

6.
Front Public Health ; 11: 1129056, 2023.
Article in English | MEDLINE | ID: mdl-37469697

ABSTRACT

Background: Dengue fever is a rapidly emerging infection worldwide with a high public health burden. Adequate training of healthcare workers is essential to warrant the timely provision of health services to improve the outcome of dengue management. Methods: This is an analytical cross-sectional study, conducted to assess the knowledge, attitudes and practice (KAP) of healthcare workers regarding dengue from April 2021 to March 2022 in Mazandaran Province, northern Iran. Data was collected using a researcher-made structured questionnaire, prepared as Google Forms, and sent to target groups through social media and email. Data analysis was performed by SPSS 22 software using descriptive and inferential statistics (Chi-square) at a significant level of 5%. Results: Most of the respondents had heard about dengue (83.8%); media (32.7%) and academic education (25%) were the main sources of information. Respondents had less knowledge associated with dengue symptoms (52%) than prevention and control (69%), transmission (72.2%) and clinical management (81%). Based on the 70% cut-off point, the majority of the participants had a good attitude (81%) and practice (73%). However, only 49.6% of the respondents showed good practice regarding dengue local transmission. A significant difference was observed between participants knowledge on clinical management with occupation; attitude with gender and occupation; and practice with gender (p < 0.05). Conclusion: The results of this study revealed gaps in some dimensions of KAP in healthcare workers, therefore, a greater focus should be placed on future training programs to raise knowledge and attitude leading to sound practice and behavior for adequate management of dengue.


Subject(s)
Dengue , Health Knowledge, Attitudes, Practice , Humans , Cross-Sectional Studies , Iran , Dengue/prevention & control , Health Personnel
7.
Sci Rep ; 13(1): 8683, 2023 05 29.
Article in English | MEDLINE | ID: mdl-37248286

ABSTRACT

Mosquitoes are the most important vectors of serious infectious diseases in the world. Dengue, Zika, chikungunya and yellow fever are emerging and re-emerging infectious diseases, associated with the distribution of two key vectors i.e. Aedes aegypti and Aedes albopictus throughout the world including countries neighbouring Iran. Entomological surveillance was planned and performed monthly from May to December during 2014-2020 in selected counties of Mazandaran Province, North of Iran, by ovitrap, larval collection, hand catch and human baited trap. Overall, 4410 Aedes specimens including 2376 larvae (53.9%) and 2034 (46.1%) adults belonging to six species, namely Aedes vexans, Aedes geniculatus, Aedes caspius, Aedes echinus, Aedes pulcritarsis and Aedes flavescence were collected and morphologically identified. Over the seven years of surveillance, Ae. aegypti and Ae. albopictus were not found by any sampling method. Aedes vexans and Ae. geniculatus were the most abundant species, their populations peaked in October and November and was positively correlated with precipitation and relative humidity. Aedes flavescence was a new species record for the province. A flowchart for planning and implementation of invasive mosquito surveillance for provincial health authorities in the country is proposed. These surveillance efforts provide basic and timely information for the health system to act promptly on integrated and intensified surveillance and control programs should Ae. aegypti and Ae. albopictus detected in the province.


Subject(s)
Aedes , Ochlerotatus , Zika Virus Infection , Zika Virus , Adult , Animals , Humans , Iran , Mosquito Vectors , Larva
8.
PLoS One ; 18(4): e0284240, 2023.
Article in English | MEDLINE | ID: mdl-37053214

ABSTRACT

Cutaneous leishmaniasis (CL) is a prevalent infectious disease with considerable morbidity annually. Here, we aimed to investigate the likely variations in gene expression of glycoprotein63 (gp63), heat shock protein 70 (HSP70), histone, arginase, cysteine protease B (CPB), Leishmania homologue of receptors for activated C kinase (LACK), small hydrophilic endoplasmic reticulum-associated protein (SHERP) in metacyclic promastigotes of L. major isolated from Phlebotomus papatasi sand flies and promastigotes excessively cultured in culture medium. The parasites were collected from suspected CL cases in Pasteur Institute of Iran, cultured and inoculated into the female BALB/c mice (2×106 promastigotes). Sand flies were trapped in Qom province, fed with the blood of euthanized infected mice and subsequently dissected in order to isolate the midgut including stomodeal valve. The metacyclic promastigotes were isolated from Ph. papatasi (Pro-Ppap) using peanut agglutinin test (PNA), then continuously cultured in RPMI-1640 medium enriched with fetal bovine serum, penicillin (100 U/ml) and streptomycin (100 mg/ml) to reach stationary phase (Pro-Stat). The gene expression was evaluated in both parasitic stages (Pro-Ppap and Pro-Stat) using qRT-PCR. Out results showed a significant increased gene expression at Pro-Ppap stage for gp63 (P = 0.002), SHERP (P = 0.001) and histone (P = 0.026) genes, in comparison with Pro-Stat stage. Noticeably, significant changes were, also, demonstrated in 10th to 15th passages [gp63 (P = 0.041), arginase (P = 0.016), LACK (P = 0.025)] and in 5th to 20th passage (SHERP) (P = 0.029). In conclusion, the findings of the present study seem to be essential in designing Leishmania studies, in particular regarding host-parasite interaction, immunization and infectivity studies.


Subject(s)
Leishmania major , Leishmaniasis, Cutaneous , Phlebotomus , Psychodidae , Female , Animals , Mice , Phlebotomus/genetics , Phlebotomus/parasitology , Leishmania major/genetics , Virulence/genetics , Histones , Arginase , Psychodidae/parasitology , Leishmaniasis, Cutaneous/parasitology
9.
Iran J Parasitol ; 17(1): 70-78, 2022.
Article in English | MEDLINE | ID: mdl-36046563

ABSTRACT

Background: We aimed to evaluate the rate of infection by endoparasites amongst rodents in the western regions of Iran to enhance the level of knowledge amongst health authorities in this entity. Methods: This study was conducted in the west and southwest of Kurdistan Province, including the cities of Sanandaj, Marivan, and Sarvabad. The field mission of this work was performed in three seasons' spring, summer, and autumn. The rodents were captured alive and their gastrointestinal tracts were evaluated for the worm endoparasites. Results: Herein, 208 rodents from 15 types of seven species, including Apodemus, Meriones, Mus, Sciurus, Cricetulus, Microtus, and Dryomys, were captured. In addition, 67 (32.21%) rodents were infected with endoparasites and 10 types of worms endoparasites, including Syphacia muris, Streptophagus spp., Mastophorus muris, Skrjabinema spp., Trichostrongylus spp., Trichuris muris, Hymenolepis nana, Hymenolepis dimimuta, Heligmosomoide spp., and other oxiuros were isolated from their gastrointestinal tracts. Most of these parasites (60%) were isolated from their small intestine whereas they were least (10%) found in their stomach and cecum. Conclusion: Having compared the results of this study with other studies in different regions of Iran, there is a higher variety of rodents and worm parasites in these regions of Iran.

10.
J Arthropod Borne Dis ; 16(4): 340-349, 2022 Dec.
Article in English | MEDLINE | ID: mdl-37159598

ABSTRACT

Background: Dengue fever as a mosquito-borne disease, has rapidly spread due to climate change, globalization, and human behavior. Iran is prone to dengue fever, as its vector recently has been found in the country. This study aimed to assess predictors of dengue preventive practices based on Precaution Adoption Process Model (PAPM) factors in West Azerbaijan province, northwest of Iran. Methods: This cross-sectional study conducted on 405 health professionals of communicable disease sector who were interested in study participation. Data-gathering instrument was an online researcher-made questionnaire consisting of demographic characteristics (11 items), questions based on PAPM, and dengue preventive practices (85 items). Content validity and reliability of the instrument, content validity ratio, content validity index, and Cronbach α were utilized, respectively. Descriptive, analytical, and regression analysis using SPSS and STATA were examined. Results: Regression analysis revealed that awareness of appropriate actions for dengue prevention was a stronger predictor of preventive practice in borderline and appropriate categories (ß= 4.09, p< 0.001) and (ß= 4.42, p< 0.001), respectively. Among factors of PAPM, beliefs about precaution effectiveness and difficulty in borderline (ß= 1.04, p= 0.04) and appropriate (ß= 1.12, p= 0.03) groups had direct and significant relation with dengue preventive practice. Conclusion: The highest mean score of beliefs about hazard likelihood and severity factor was related to dengue prevention. Therefore, theory-based interventions that address beliefs about precaution effectiveness and difficulty can lead to assistance in acting. To improve dengue preventive practices, a well-designed promotive intervention that addresses associated factors in a context-specific manner is essential.

11.
Iran J Public Health ; 50(8): 1668-1677, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34917538

ABSTRACT

BACKGROUND: Mosquito species are highly considering as disease transmission as well as nuisance insects. One of the principal strategy to protect human from the mosquito bites is repellent agents. This study aimed to assess repellency of two organic essential oils, Eucalyptus globulus and Syzygium aromaticum from bites of malaria vector, Anopheles stephensi. METHODS: The study was conducted in 2019-2020. The components of essential oils of E. globulus and S. aromaticum was determined using gas chromatography/mass spectrometry. The unfed female mosquitoes aged 2-5 d old were used in all experiments. In vivo Klun and Debboun module bioassays were utilized on human-volunteer skin. The essential oils at serial concentrations were used to find repellent efficacy against Anopheles landings and bites. To find the synergistic effect, four combinations of the essential oils were tested. RESULTS: The main composition of E. globulus essential oil was 1,8-Cineol (78.20%), whereas that of S. aromaticum essential oil was 2-methoxy-3-(2-propenyl) (77.04%). Based on minimum effective dose (≤1% biting), 10% (v/v) of E. globulus showed high landing repellency (77.78%), whereas minimum effective dose of S. aromaticum at concentration of 1% had high landing repellency (88.89%). Among four combinations, the ratio of 1:1 of E. globulus (10%):S. aromaticum (1%) showed the most landing repellency (94.44%). CONCLUSION: The combinations of two essential oils had the most potential repellency effect against landing of mosquitoes. As essential oils are eco-friendly with less irritation for human skin, E. globulus and S. aromaticum essential oils are recommended as effective and safe mosquito repellents.

12.
Heliyon ; 7(12): e08477, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34934829

ABSTRACT

Meteorological parameters, have been identified as an important factor involved in the transmission of vector-borne diseases. Mosquitoes are extremely sensitive to weather conditions. The aim of this study was investigate the correlation between meteorological parameters and the abundance of mosquitoes in Kashan County. Mosquitoes were collected using four different traps, including hand catch, animal baited bed net trap (usually a cow), human baited bed net trap and BG-Sentinel trap with CO2 from May to December 2019. A total number of mosquitoes collected were 1756 out of which 1621 (92.31%) were Culex, 22 (1.25%) Culiseta and 113 (6.44%) Anopheles in nine species. Most mosquitoes were collected by BG-Sentinel trap with CO2 (63.78%). Monthly distribution of the mosquitoes indicated different monthly peaks. Their high density were recorded in September and were low in December. The spearman's correlation of the mosquito abundance and the meteorological parameters shows that correlation of the number of total collected mosquitoes with relative humidity and precipitation (Rainfall) was weak negative, and there was week correlation with wind speed, and positive strong correlation with temperature. Data collected with various trap types and mosquito correlation with meteorological parameters in this study can be used for mosquito surveillance and control programs. However, meteorological parameters affect the abundance of mosquitoes, but their impact is complex and most of these variables are species specific.

13.
Malar J ; 20(1): 393, 2021 Oct 09.
Article in English | MEDLINE | ID: mdl-34627243

ABSTRACT

BACKGROUND: Due to the effect of synthetic and commercial insecticides on non-target organisms and the resistance of mosquitoes, non-chemical and environmentally friendly methods have become prevalent in recent years. The present study was to isolate entomopathogenic fungi with toxic effects on mosquitoes in natural larval habitats. METHODS: Larvae of mosquitoes were collected from Central, Qamsar, Niasar, and Barzok Districts in Kashan County, Central Iran by standard dipping method, from April to late December 2019. Dead larvae, live larvae showing signs of infection, and larvae and pupae with a white coating of fungal mycelium on the outer surface of their bodies were isolated from the rest of the larvae and sterilized with 10% sodium hypochlorite for 2 min, then washed twice with distilled water and transferred to potato-dextrose-agar (PDA) and water-agar (WA) media and incubated at 25 ± 2 °C for 3-4 days. Larvae and fungi were identified morphologically based on identification keys. RESULTS: A total of 9789 larvae were collected from urban and rural areas in Kashan County. Thirteen species were identified which were recognized to belong to three genera, including Anopheles (7.89%), Culiseta (17.42%) and Culex (74.69%). A total of 105 larvae, including Anopheles superpictus sensu lato (s.l), Anopheles maculipennis s.l., Culex deserticola, Culex perexiguus, and Culiseta longiareolata were found to be infected by Nattrassia mangiferae, Aspergillus niger, Aspergillus fumigatus, Trichoderma spp., and Penicillium spp. Of these, Penicillium spp. was the most abundant fungus isolated and identified from the larval habitats, while An. superpictus s.l. was the most infected mosquito species. CONCLUSIONS: Based on the observations and results obtained of the study, isolated fungi had the potential efficacy for pathogenicity on mosquito larvae. It is suggested that their effects on mosquito larvae should be investigated in the laboratory. The most important point, however, is the proper way of exploiting these biocontrol agents to maximize their effect on reducing the population of vector mosquito larvae without any negative effect on non-target organisms.


Subject(s)
Anopheles/microbiology , Fungi/isolation & purification , Mosquito Vectors/microbiology , Animals , Culex/microbiology , Fungi/classification , Fungi/pathogenicity , Iran , Larva/microbiology , Pupa/microbiology
14.
J Arthropod Borne Dis ; 15(1): 69-81, 2021 Mar.
Article in English | MEDLINE | ID: mdl-34277857

ABSTRACT

BACKGROUND: Mosquitoes are responsible for spreading devastating parasites and pathogens causing some important infectious diseases. The present study was done to better understand and update the fauna of Culicidae and to find out the distribution and the type of their larval habitats in Kashan County. METHODS: This study was done in four districts of Kashan County (Central, Qamasr, Niasar and Barzok). Mosquito larvae were collected from 23 active larval habitats using a standard 350ml capacity mosquito dipper from April to late December 2019. The collected larvae were transferred to containers containing lactophenol, and after two weeks individually mounted in Berlese's fluid on a microscope slide and identified to species by morphological characters and valid keys. RESULTS: In this study, a total of 9789 larvae were collected from urban and rural areas in Kashan County. The identified genera were Anopheles, Culiseta and Culex. In this study larvae of An. turkhudi, Cx. perexiguus, Cx. mimeticus, Cx. deserticola and Cs. subochrea were collected for the first time from Kashan County. CONCLUSION: The results of this study indicate the presence and activity of different mosquito species in Kashan County that some of them are vectors of arbovirus and other vector-borne diseases.

15.
J Environ Health Sci Eng ; 19(1): 1025-1034, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34150290

ABSTRACT

PURPOSE: There is a growing need to use green and efficient larvicidal as alternatives for conventional chemicals in vector control programs. Nanotechnology has provided a promising approach for research and development of new larvicides. Larvicidal potential of a nanoemulsion of Cinnamomum zeylanicum essential oil reports against Anopheles stephensi. METHODS: The nanoemulsion of was formulated in various ratios comprising of C. zeylanicum oil, tween 80, span 20 and water by stirrer. It was characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). All components of C. zeylanicum essential oil were identified by GC-MS analysis. The larvicidal potential of the oil and its nanoformulation were evaluated against larvae of An. stephensi. The stability and durability of nanoemulsion was observed over a period of time. RESULTS: Sixty one components in the oil were identified, cinnamaldehyde (56.803%) was the main component. The LC90 and LC50 values of C. zeylanicum essential oil were calculated as 49 ppm and 37 ppm, respectively. The nanoemulsion droplets were found spherical in shape. It was able to kill 100% of larvae in up to 3 days. It was stable after dilution and increased its larvicidal activity up to 32% compared with the essential oil. CONCLUSIONS: A novel larvicide based on nanotechnology introduced. This experiment clearly showed increasing larvicidal activity and residual effect of the nanoformulation in comparison with the bulk essential oil. It could be concluded that this nanoemulsion may be considered as safe larvicide and should be subject of more research in this field.

16.
J Arthropod Borne Dis ; 15(3): 333-346, 2021 Sep.
Article in English | MEDLINE | ID: mdl-36579001

ABSTRACT

Background: Extensive use of chemical larvicides to control larvae, has led to resistance in vectors. More efforts have been conducted the use of natural products such as plant essential oils and their new formulations against disease vectors. Nanoformulation techniques are expected to reduce volatility and increase larvicidal efficacy of essential oils. In this study for the first time, a larvicide nanoemulsion from the essential oil of Acroptilon repens was developed and evaluated against Anopheles stephensi larvae under laboratory conditions. Methods: Fresh samples of A. repens plant were collected from Urmia, West Azarbaijan Province, Iran. A clevenger type apparatus was used for extracting oil. Components of A. repens essential oil (AEO) were identified by gas chromatography-mass spectrometry (GC-MS). All larvicidal bioassay tests were performed according to the method recommended by the World Health Organization under laboratory condition. Particle size and the morphologies of all prepared nanoformulations determined by DLS and TEM analysis. Results: A total of 111 compounds were identified in plant. The LC50 and LC90 values of AEO calculated as 7 ppm and 35 ppm respectively. AEO was able to kill 100% of the larvae in 4 days. Conclusion: The nanoemulsion of AEO showed a weak effect on the larvar mortality. It may therefore be suggested that this kind of nanoemulsion is not appropriate for the formulation as a larvicide. It is important to screen native plant natural products, search for new materials and prepare new formulations to develop alternative interventions with a long-lasting impact.

17.
J Arthropod Borne Dis ; 15(4): 397-404, 2021 Dec.
Article in English | MEDLINE | ID: mdl-36644308

ABSTRACT

Background: Fauna and larval habitat characteristics studies on mosquitoes are important tools to identify the breeding places of the vectors and management of the control strategies. This study was done to provide data on Culicidae fauna, larval habitat characteristics and identifying potential vectors of West Nile virus in Lorestan Province, west of Iran. Methods: Culicidae mosquitoes were collected at three counties and nine site stations from Lorestan Province, west of Iran in 2017. Adult mosquitoes were collected using human and animal bite collection methods, New Jersey and CDC light traps and pit shelters by aspirator. Larva were collected by dipping method. RT-PCR technique was employed for detection of the West Nile virus among mosquito's samples. Results: 4805 mosquitoes were collected from three counties and nine sites in Lorestan Province during June-October 2017, including 4363 adults and 442 larvae. The most abundant species collected from all counties in both adult and larval stages were Culex pipiens (49.10%), Cx. theileri (31.82%), Anopheles maculipennis (11.09%), An. superpictus (2.66%), An. stephensi (2.12%), Cx. perexiguus (1.89%), An. dthali (1.17%) and An. sacharovi (0.15%) respectively. West Nile virus was detected in none of mosquitoes examined. Conclusion: The results of this study revealed that arbovirus vectors such as Cx. pipiens along with Cx. theileri and Cx. perexiguus are well adapted to a broad range of habitats and different climatic conditions in Lorestan Province. That necessitates further routine surveillance of arboviral infections.

18.
J Arthropod Borne Dis ; 14(2): 214-227, 2020 Jun.
Article in English | MEDLINE | ID: mdl-33365349

ABSTRACT

BACKGROUND: Southern part of the country is a high risk for mosquito transmitted Arboviruses. This study was carried out to determine the base line susceptibility of the Aedini mosquitoes to the WHO-recommended insecticide. METHODS: Larval collection was carried out by dipping method and adult collection occurred by suction tube from January to December 2017. The adult susceptibility test was assessed to Bendiocarb 0.1%, DDT 4%, Deltamethrin 0.05%, Lambda-cyhalothrin 0.05%, Malathion 5% and, Permethrin 0.75% at different interval times as well as at discriminative dose recommended by WHO. The larval susceptibility test was occurred using Temephos and Bacillus thuringiensis serotype H-14, at different concentrations. The LT50, LT90 and LC50, LC90 values were calculated for plotting the regression line using Microsoft office Excel software ver. 2007. RESULTS: Aedes caspius was quite resistant to DDT, Malathion, Bendiocarb and showed susceptible or tolerant to other insecticides.The LT50 and LT90 values to DDT in this species were 157.896, and 301.006 minutes, respectively. The LC50 and LC90 values of Ae. caspius to Temephos were 0.000068, and 0.000130ppm, the figures for B. thuringiensis was 111.62 and 210.2ppm, respectively. CONCLUSION: A routine and continuous study for monitoring and evaluation of different species of Aedes to insectides is recommend at different parts of country for decision making.

19.
Viruses ; 12(12)2020 12 16.
Article in English | MEDLINE | ID: mdl-33339336

ABSTRACT

Using molecular techniques and bioinformatics tools, we studied the vector-host interactions and the molecular epidemiology of West Nile virus (WNV) in western Iran. Mosquitoes were collected during 2017 and 2018. DNA typing assays were used to study vector-host interactions. Mosquitoes were screened by RT-PCR for the genomes of five virus families. WNV-positive samples were fully sequenced and evolutionary tree and molecular architecture were constructed by Geneious software and SWISS-MODEL workspace, respectively. A total of 5028 mosquito specimens were collected and identified. The most prevalent species was Culex (Cx.) pipiens complex (57.3%). Analysis of the blood-feeding preferences of blood-fed mosquitoes revealed six mammalian and one bird species as hosts. One mosquito pool containing non-blood-fed Cx. theileri and one blood-fed Culex pipiens pipiens (Cpp.) biotype pipiens were positive for WNV. A phylogram indicated that the obtained WNV sequences belonged to lineage 2, subclade 2 g. Several amino acid substitutions suspected as virulence markers were observed in the Iranian WNV strains. The three-dimensional structural homology model of the E-protein identified hot spot domains known to facilitate virus invasion and neurotropism. The recent detection of WNV lineage 2 in mosquitoes from several regions of Iran in consecutive years suggests that the virus is established in the country.


Subject(s)
Disease Vectors , Host-Pathogen Interactions , West Nile Fever/transmission , West Nile Fever/virology , West Nile virus/physiology , Amino Acid Sequence , Animals , Evolution, Molecular , Genome, Viral , Genomics/methods , Geography, Medical , Humans , Iran/epidemiology , Mosquito Vectors/virology , Phylogeny , Population Dynamics , Prevalence , Protein Conformation , Viral Structural Proteins/chemistry , Viral Structural Proteins/metabolism , Virulence , Virulence Factors , Whole Genome Sequencing
20.
J Arthropod Borne Dis ; 14(1): 8-16, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32766344

ABSTRACT

BACKGROUND: Visceral and cutaneous leishmaniasis are common in some areas of Iran and consider as health problems. Phlebotomus alexandri has been incriminated as a suspected vector for the both form of leishmaniasis. METHODS: This study was carried out in 4 western provinces of Iran. Sand flies were collected using sticky traps and light traps from indoor and outdoor resting places. Nested PCR was employed to detect Leishmania parasites among collected sand flies. RESULTS: Seven hundred and twenty two P. alexandri females were collected and pooled in 179 batches. Results of nested PCR showed, out of 9 samples from East Azerbaijan Province, only one sample was infected by Leishmania infantum. Of 34 individual and pooled samples from Kermanshah Province, only one pooled sample was infected with Leishmania major and among 30 individual and pooled samples in Fars Province, five specimens were infected by L. major, L. infantum, Leishmania donovani and Leishmania tropica. Furthermore, out of 108 individual and pooled samples from Khuzestan Province, 10 samples showed infection with L. major and L. infantum. CONCLUSION: The results of this study showed that P. alexandri is more active in hot zones than in moderate zones and this species may be considered as a permissive species.

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