Iranian Journal of Arthropod-borne Diseases最新文献

Background: There is a little data on Coxiella burnetii (Q fever agent) in Iran. Ticks may play a significant role in the transmission of C. burnetii among animals. The aim of this study was to use polymerase chain reaction for the detection of C. burnetii in ticks collected in Southeast Iran.

Methods: One hundred and sixty ticks were collected from domestic animals in three localities of Kerman Province, Southeast Iran from November to June 2009. The collected ticks were divided into 35 pools and examined by Trans-PCR for C. burnetii.

Results: Three pools, each consisting of five female of Hyalomma anatolicum anatolicum and one pool (6 ticks) of Rhipicephalus sanguineus ticks collected from goats and sheep were found to be positive by Trans-PCR.

Conclusion: This paper documents the first molecular detection of C. burnetii in ticks, which shows their role as putative vectors and reservoirs for this pathogenic agent.

Background: Visceral leishmaniasis is caused by Leishmania infantum, transmitted to humans by bites of phlebotomine sand flies and is one of the most important public health problems in Iran. To identify the vector(s), an investigation was carried out in Bilesavar District, one of the important foci of the disease in Ardebil Province in northwestern Iran, during July-September 2008.

Methods: Using sticky papers, 2,110 sand flies were collected from indoors (bedroom, guestroom, toilet and stable) and outdoors (wall cracks, crevices and animal burrows) and identified morphologically. Species-specific amplification of promastigotes revealed specific PCR products of L. infantum DNA.

Results: SIX SAND FLY SPECIES WERE FOUND IN THE DISTRICT, INCLUDING: Phlebotomus perfiliewi transcaucasicus, P. papatasi, P. tobbi, P. sergenti, Sergentomyia dentata and S. sintoni. Phlebotomus perfiliewi transcaucasicus was the dominant species of the genus Phlebotomus (62.8%). Of 270 female dissected P. perfiliewi transcuacasicus, 4 (1.5%) were found naturally infected with promastigotes.

Conclusion: Based on natural infections of P. perfiliewi transcaucasicus with L. infantum and the fact that it was the only species found infected with L. infantum, it seems, this sand fly could be the principal vector of visceral leishmaniasis in the region.

Background: Plant extracts and oils may act as alternatives to conventional pesticides for malaria vector control. The aim of this study was to evaluate the larvicidal activity of essential oils of three plants of Apiaceae family against Anopheles stephensi, the main malaria vector in Iran.

Methods: Essential oils from Heracleum persicum, Foeniculum vulgare and Coriandrum sativum seeds were hydro distillated, then their larvicidal activity were evaluated against laboratory-reared larvae of An. stephensi according to standard method of WHO. After susceptibility test, results were analysis using Probit program.

Results: Essential oils were separated from H. persicum, F. vulgare and C. sativum plants and their larvicidal activities were tested. Result of this study showed that F. vulgare oil was the most effective against An. stephensi with LC(50) and LC(90) values of 20.10 and 44.51 ppm, respectively.

Conclusion: All three plants essential oil can serve as a natural larvicide against An. stephensi. F. vulgare oil exhibited more larvicidal properties.

Background: The cutaneous leishmaniasis (CL) has been occurred in Dehbakri County, located 46 km of Bam District, Kerman Province since 2004-2005. Phlebotomus papatasi is an important vector of zoonotic cutaneous leishmanisis (ZCL) as well as sand fly fever and P. sergenti is considered as main vector of anthroponotic cutaneous leishmaniasis (ACL) in Iran. There are several measures for vector control with emphasizing on insecticides. The objective of this study was to determine the baseline susceptibility of leishmaniasis vectors to the DDT and deltamethrin in an endemic focus of CL in southern Iran.

Methods: Baseline susceptibility tests were carried out on field collected strains of P. papatasi and P. sergenti and tested with WHO impregnated papers with DDT 4.0% and deltamethrin 0.05% in the focus of disease in Dehbakri County during summer 2010. The values of LT(50) and LT(90) were determined using probit analysis and regression lines.

Results: The LT(50) value of DDT 4.0% and deltamethrin 0.05% against P. papatasi was 20.6 and 13.6 minutes respectively. The same data for P. sergenti were ranged between 21.8 and 17.7 minutes.

Conclusion: The results of tests will provide a guideline for implementation of vector control using pesticides such as impregnated bed nets, indoor residual spraying and fogging.

Background: Ecological data are important in the vector control management of mosquitoes. There is scattered published information about the larval habitat characteristics and ecology of the genus Anopheles (Diptera: Culicidae) in Iran and most of available data is in relation to malaria vectors in southern Iran.

Methods: This cross sectional investigation was carried out to study the mosquito fauna and ecology in Guilan Province, northern Iran, during April-December 2000. Larvae were collected using the standard dipping technique. Larval habitat characteristics were recorded according to water situation (clear or turbid), vegetation, substrate type, sunlight situation, habitat situation (transient or permanent, running or stagnant), habitat type (natural or artificial), and water temperature.

Results: In total, 1547 third- and fourth-instar larvae of Anopheles from 90 habitats were collected and morphologically identified. Five species; Anopheles claviger, An.'hyrcanus', An. maculipennis s.l., An. plumbeus, and An. superpictus were identified and respectively comprised 6.3%, 22.4%, 54.4%, 13.0%, and 3.9% of the samples. The mean and range temperatures of the larval habitat water were 19.6°C (n=14) (16-25°C), 22.6°C (n=53) (12-33°C), 23.8°C (n=52) (10-33°C), 11.5°C (n=12) (9-21°C), and 20.4°C (n=7) (12-26°C), respectively. There was a significant difference in the mean water temperatures (11.5-23.5°C) of the larval habitats of different species (P=0.000). Most of the genus larvae were collected from natural habitats (86.9%) such as river bed pools (46.4%) and rain pools (33.1%) with transient (98.3%), stagnant (99.5%) and clear (95.3%) water, with vegetation (69.9%), mud (42.0%) or gravel (39.7%) substrate in full sunlight (69.6%) or shaded (22.7%) area. A checklist of the province mosquitoes including 30 species and seven genera has been provided.

Conclusion: The main larval habitats of the most abundant species, An.'hyrcanus' and An. maculipennis s.l., in Guilan Province are: river bed pools, rain pools, and rice fields.

Background: Metarhizium anisopliae strain IRAN 437C is one of the most virulent fungal isolates against house fly, Musca domestica. The objective of this study was to determine the interaction of this isolate with sublethal doses of spinosad against housefly.

Methods: In adult bioassay, conidia of entomopathogenic fungus were applied as inoculated bait at 10(5) and 10(7) spore per gram and spinosad at 0.5, 1 and 1.5 μg (A.I.) per gram bait. In larval bioassay, conidia were applied as combination of spore with larval bedding at 10(6) and 10(8) spore per gram and spinosad at sublethals of 0.002, 0.004 and 0.006 μg (AI) per gram medium.

Results: Adult mortality was 48% and 72% for fungus alone but ranged from 66-87% and 89-95% in combination treatments of 10(5) and 10(7) spore/g with sublethal doses of spinosad respectively. The interaction between 10(5) spore/g with sublethals exhibited synergistic effect, but in combination of 10(7) spore in spite of higher mortality, the interaction was additive. There was significant difference in LT(50) among various treatments. LT(50) values in all combination treatments were smaller than LT(50) values in alone ones. Larval mortality was 36% and 69% for fungus alone but ranged from 58%-78% and 81%-100% in combination treatments of 10(6) and 10(8) spore/g medium with sublethals of spinosad respectively. The interaction was synergistic in all combination treatments of larvae.

Conclusion: The interaction between M. anispliae and spinosad indicated a synergetic effect that increased the house fly mortality as well as reduced the lethal time.

Background: There are several plant extractions which are being used for mosquito control. The aim of this study was to evaluate the efficacy of Olea vera, Linum usitatissimum and Piper nigera against Anopheles stephensi and Aedes aegypti under laboratory conditions.

Methods: These tests were carried out using WHO recommended bioassay method for adult mosquitoes.

Results: The extracts from black pepper was more effective as adulticide with lowest LC(50) values (2.26% and 8.4%) against Aedes aegypti and Anopheles stephensi after 24 h of exposure while after 48h (1.56% and 5.11%) respectively. In terms of LC(90) value black pepper was best with (8.66% and 30.1%) against Ae. aegypti and An. stephensi after 24 h of exposure while after 48h (4.59% and 17.3%) respectively. In terms of LT(50) black pepper took 15 h to kill 50% tested population of Ae. aegypti while against An. stephensi it took more than 2 days. In terms of percentage mortality black pepper kill 84% of the population of Ae. aegypti and 44.75% of the An. stephensi population.

Conclusion: Black pepper showed best results in term of LC(50), LC(90), LT(50) and percentage mortality against Ae. aegypti and An. stephensi. Our study suggested that the plant extracts have potential to kill adult mosquitoes, are environment friendly and can be used for the control of mosquitoes.

Background: Malaria and leishmaniasis are two most significant parasitic diseases which are endemic in Iran. Over the past decades, interest in botanical repellents has increased as a result of safety to human. The comparative efficacy of essential oils of two native plants, myrtle (Myrtus communis) and marigold (Calendula officinalis) collected from natural habitats at southern Iran was compared with DEET as synthetic repellent against Anopheles stephensi on human subjects under laboratory condition.

Methods: Essential oils from two species of native plants were obtained by Clevenger-type water distillation. The protection time of DEET, marigold and myrtle was assessed on human subject using screened cage method against An. stephensi. The effective dose of 50% essential oils of two latter species and DEET were determined by modified ASTM method. ED(50) and ED(90) values and related statistical parameters were calculated by probit analysis.

Results: The protection time of 50% essential oils of marigold and myrtle were respectively 2.15 and 4.36 hours compared to 6.23 hours for DEET 25%. The median effective dose (ED(50)) of 50% essential oils was 0.1105 and 0.6034 mg/cm(2) respectively in myrtle and marigold. The figure for DEET was 0.0023 mg/cm(2).

Conclusion: This study exhibited that the repellency of both botanical repellents was generally lower than DEET as a synthetic repellent. However the 50% essential oil of myrtle showed a moderate repellency effects compared to marigold against An. stephensi.

Background: Zoonotic cutaneous leishmaniasis (ZCL) is an increasing public health problem in some endemic regions. Horseradish peroxidase (HRP) conjugated rabbit anti-Rhombomys opimus (R. opimus) Ig is needed for immunoblotting and ELISA tests used to explore the immune response of the rodents against the sand fly saliva. In this study, the production of HRP conjugated rabbit anti-R. opimus Ig was conducted for the first time.

Methods: Rhombomys opimus Ig was purified from serum by protein G affinity chromatography column and injected into rabbit to produce anti-R. opimus Ig antibody. The titration of antibody against R. opimus Ig in rabbit serum was checked using indirect ELISA. Rabbit anti-R. opimus Ig was purified by Sepharose-4B-R. opimus Ig column. Reactivity of this antibody was assessed by indirect ELISA and was conjugated to HRP by periodate method.

Results: Approximately 3.5 mg Ig was purified from 1 ml R. opimus serum using protein G affinity chromatography column. The molecular weight of purified R. opimus Ig was estimated about 150 kDa by SDS-PAGE. Nearly 2.3 mg rabbit anti-R. opimus Ig was purified from 1 ml immunized rabbit serum. The purified antibody was conjugated to HRP and the optimum titer of HRP conjugated rabbit anti-R. opimus Ig was determined as 1:8000 using direct ELISA.

Conclusion: HRP conjugated rabbit anti-Gerbil IgG has been produced by a few companies, but to our knowledge HRP conjugated rabbit anti-R. opimus Ig is not commercially available. Production of HRP conjugated rabbit anti-R. opimus Ig is considerably helpful for immunological studies of R. opimus, the main reservoir host of ZCL in Iran as well as some other countries.

Background: The aim of his study was to determine development time and thermal requirements of three myiasis flies including Chrysomya albiceps, Lucilia sericata, and Sarcophaga sp.

Methods: Rate of development (ROD) and accumulated degree day (ADD) of three important forensic flies in Iran, Chrysomya albiceps, Lucilia sericata, and Sarcophaga sp. by rearing individuals under a single constant temperature (28° C) was calculated using specific formula for four developmental events including egg hatching, larval stages, pupation, and eclosion.

Results: Rates of development decreased step by step as the flies grew from egg to larvae and then to adult stage; however, this rate was bigger for blowflies (C. albiceps and L. sericata) in comparison with the flesh fly Sarcophaga sp. Egg hatching, larval stages, and pupation took about one fourth and half of the time of the total pre-adult development time for all of the three species. In general, the flesh fly Sarcophaga sp. required more heat for development than the blowflies. The thermal constants (K) were 130-195, 148-222, and 221-323 degree-days (DD) for egg hatching to adult stages of C. albiceps, L. sericata, and Sarcophaga sp., respectively.

Conclusion: This is the first report on thermal requirement of three forensic flies in Iran. The data of this study provide preliminary information for forensic entomologist to establish PMI in the area of study.