Evaluation of susceptibility status of Phlebotomus papatasi, the main vector of zoonotic Cutaneous Leishmaniasis, to different WHO recommended insecticides in an endemic focus, Central Iran

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

Laboratory Evaluation of a Rodenticide-insecticide, Coumavec®, against Rhombomys opimus, the Main Reservoir Host of Zoonotic Cutaneouse Leishmaniasis in Iran.

Background: Zoonotic cutaneous leishmaniasis is a growing health problem in many rural areas of Iran. Rhombomys opimus, the great gerbil, is the main animal reservoir of ZCL in the northeast and central part of Iran. The aim of the current study was to evaluate the rodenticidal effect of Coumavec® (a mixture of Coumatetralyl 0.5% and Etofenprox 0.5%) on R. opimus under laboratory condition. Methods: Great gerbils were collected from Sejzi rural district, Esfahan Province, Iran. Four groups of 19 great ger- bils were treated with the poisoned baits of different concentrations and one group was considered as control. The bating procedure was conducted in three stages: first, second (a week after first) and third (a month after first stage), in each stage baits were offered in 1 day, based on national protocol for rodent control operation in purpose of ZCL control. Results: The mortality rate for 0.03, 0.0625, 0.125 and 0.25% concentrations in the first stage of baiting were ob- tained 36.8%, 31.5%, 52.6% and 36.8%, in the second stage 47.3%, 52.6%, 68.4% and 52.6%, and in the third stage 52.6%, 63.1%, 68.4% and 57.8% respectively. The maximum and minimum mortality has occurred in 5-6 days and 31-40 days intervals consequently. Conclusion: The results of this study showed that, Coumavec® has some rodenticidal effects on R. opimus in labo- ratory condition. For the appropriate rodenticide-insecticide contamination of the rodent body and also considering to the economic issues, we suggest the use of 0.125% concentration for rodent control operation in the field condition

Molecular epidemiological study of cutaneous leishmaniasis in the focus of bushehr city, southwestern iran.

Background: Cutaneous leishmaniasis (CL) represents the most frequent vector borne parasitoses in Iran. The ob-jective of this study was to determine the epidemiological features of CL including human infection and the reservoir host in the city of Bushehr, Bushehr Province, Iran during 2010–2011. Methods: Studies on human infection was carried out on 2962 school children aged 7–14 years old from 60 primary schools and among 400 households with a total population of 1568 in four infected districts of the city in December 2010. Serosity materials from patients on glass slides were collected for molecular identification of causative agent. Rodents were caught by Sherman traps and examined for identification of the parasite. Results: Prevalence of scars and ulcers among the inhabitants were 5.86% and 0.12% respectively. Molecular study indicated the presence of two coexisting species: Leishmania major and L. tropica among patients. The scar rate was 1.24% but no ulcers were seen among the students. Nineteen rodents were caught and identified as Tatera indica (47.4%) and Rattus norvegicus (52.6%). Specimens from 7 T. indica and 9 R. norvegicus were examined by two techniques, microscopic examination and nested-PCR. Out of 7 T. indica, 14.3% were infected with L. major and 42.9% with L. turanica by nested-PCR. Out of 9 R. norvegicus 22.2% were infected with L. turanica and 11.1% with L. gerbilli. Conclusion: Based on this survey L. major and L. tropica are the causative agents of the disease among patients and T. indica plays a predominant role in the dissemination of L. major in the city

Rodenticide Comparative Effect of Klerat® and Zinc Phosphide for Controlling Zoonotic Cutaneous Leishmaniasis in Central Iran

Background: Zoonotic cutaneous leishmaniasis (ZCL) is a neglected disease with public health importance that is common in many rural areas of Iran. In recent years, behavioral resistance and/or bait shyness against the common rodenticide among reservoir hosts of ZCL have been reported. The aim of this study was to evaluate the effectiveness of Klerat® and zinc phosphide against natural reservoir of ZCL. Methods: This survey was carried out in four villages located 45 to 95 km far from Esfahan City Esfahan province, central Iran from April to November 2011. The rodent burrows were counted destroyed and reopened holes baited around all villages. Effect of rodent control operation on the main vector density and incidence of ZCL were evaluated. Results: The reduction rate of rodent burrows after intervention calculated to be at 62.8% in Klerat® and 58.15% in zinc phosphide treated areas. Statistical analysis showed no difference between the densities of the vector in indoors and outdoors in intervention and control areas. The incidence of the disease between treated and control areas after intervention was statistically different (P< 0.05). Conclusion: Klerat® could be a suitable alternative for zinc phosphide in a specific condition such as behavior resistance or occurrence of bait shyness

Rodents as vehicle for delivery of transgenic bacteria to make paratransgenic sand fly vectors of cutaneous leishmaniasis in field condition

Abstract Vector-borne diseases, among them leishmaniasis, cause more than 700,000 deaths annually. The lack of an effective vaccination and the increasing resistance of sand flies to insecticides require the urgent development of innovative approaches to contain the disease. The use of engineered bacteria that express anti-parasite molecules (paratransgenesis) shows much promise. However, a challenge for implementation of this strategy is to devise means to introduce modified bacteria into sand flies in the field. In this study, we use rodent food bait as a delivery strategy to introduce two mCherry-fluorescent bacteria, Serratia AS1 and Enterobacter cloacae, into adult sand flies in field settings. Bacteria-infected food was provided to Rhombomys opimus rodents. These bacteria transiently pass through the rodent alimentary tract and are delivered to larval habitats with the rodent feces. The feces are ingested by sand fly larvae and, in the case of Serratia AS1, are trans-stadially transmitted to adults. This is the first report of targeting delivery of Serratia AS1 in a paratransgenic system to control transmission of leishmaniasis under field condition. This novel strategy shows promise for delivering transgenic bacteria to Leishmania vectors in the field

An Eco-Epidemiological Study on Zoonotic Cutaneous Leishmaniasis in Central Iran

Background: Leishmaniasis is an expanding neglected tropical disease in the world reporting from 98 countries including Iran. This study focused on eco-epidemiological determinants of the disease following a rapid and unexpected increase of leishmaniasis incidence in a strategic residential district in North-East of Isfahan County, Iran. Methods: This study was accomplished from Apr 2012 to Jan 2014 in a strategic residential zone in North-East of Isfahan County, Esfahan, Iran. Monthly activity, parity, Leishmania infection and susceptibility tests, were determined on sand flies. Some portion of inhabitants and school children were surveyed to find active or passive cases of leishmaniasis and also wild rodents were collected to determine reservoir host. Results: Totally 5223 sand flies belonging to Phlebotomus and Sergentomyia genus were collected and identified; Ph. papatasi was the dominant species and started to appear in May and disappeared in Oct. The majority of living dissected sand flies were unfed and parous. Ph. papatasi showed 4.6% Leishmania infection through direct examination and 39.54% by nested-PCR respectively. Phlebotomus papatasi was susceptible against deltametrin 0.05%. Totally 2149 people were surveyed and incidence and prevalence of zoonotic cutaneous leishmaniasis estimated as 45.39 and 314.40 per 1000 population. Rodents showed 73.91% and 80% Leishmania infection by direct examination and nested-PCR respectively. Conclusion: Cutaneous leishmaniasis due to L. major has been established in this area. Rodent control operation and personal protection are highly recommended to control the disease in this focus

Biodiversity of Aquatic Insects of Zayandeh Roud River and Its Branches, Isfahan Province, Iran.

Background: Aquatic insects are the  major groups of arthropods that spend  some parts of their life cycle in the water. These insects play an important role for transmission of some human and animal diseases. There is few information about the aquatic insects fauna of Iran. Methods: To study the aquatic insects fauna, adult, nymphal and larval collections were carried out from different habitats using the standard technique in Zayandeh Roud River, Isfahan Province,central Iran, during summer 2011. Results: In total, 741 speimens of aquatic insects were collected and morphologically identified. They include 7 families and 12 genera representing 2 Orders. The order of  Diptera (92.31%) and Coleoptera (7.69%). The families Culicidae, Syrphidae and Chironomidae from Diptera order, Gyrinidae, Dytiscidae, Haliplidae, Hydrophilidae from Coleoptera order were identified. Conclusion: Some aquatic insects play an important role for transmission of human and animal diseases. These insects also are important for biological control. Therefore ecological study on aquatic insects can provide information about ecology of insects in an area for any decision making

Aerobic bacterial flora of biotic and abiotic compartments of a hyperendemic Zoonotic Cutaneous Leishmaniasis (ZCL) focus

Abstract Background Identification of the microflora of the sand fly gut and the environmental distribution of these bacteria are important components for paratransgenic control of Leishmania transmission by sand flies. Methods Biotic and abiotic bacterial communities of four compartments of a hyper-endemic focus of Zoonotic Cutaneous Leishmaniasis (ZCL) were investigated using 16S ribosomal DNA sequencing and phylogenetic tree construction. These compartments include Phlebotomus papatasi’s gut, skin and intestinal tract of great gerbil Rhombomys opimus, the gerbil nest supplies, and plant food sources of the vectors and reservoirs. Results Sequence homology analysis using nine available 16S rDNA data bases revealed 40, 24, 15 and 14 aerobic bacterial species from the vector guts, the gerbil bodies, the gerbil nests, and the plants, respectively. The isolated bacteria belong to wide ranges including aerobic to facultative anaerobic, pathogen to commensals, sand fly oviposition inducers, land to air and ocean habitats, animal and human probiotics, and plant growth-promoting rhizobacteria. Matching data analysis suggested that the adult P. papatasi gut bacteria could be acquired from three routes, adult sugar feeding on the plant saps, adult blood feeding on the animal host, and larval feeding from nest supplies. However, our laboratory experiment showed that none of the bacteria of the reservoir skin was transmitted to female sand fly guts via blood feeding. The microflora of sand fly guts were associated with the sand fly environment in which the predominant bacteria were Microbacterium, Pseudomonas, and Staphylococcus in human dwellings, cattle farms, and rodent colonies, respectively. Staphylococcus aureus was the most common bacterium in sand fly guts. Presence of some sand fly ovipoisition inducers such Bacillus spp. and Staphylococcus saprophyticus support association between gut flora and oviposition induction. Conclusions Results of this study showed that Bacillus subtilis and Enterobacter cloacae particularly subsp. dissolvens are circulated among the sand fly guts, the plants, and the sand fly larval breeding places and hence are possible candidates for a paratransgenic approach to reduce Leishmania transmission

Sand Flies of the Subgenus Adlerius (Diptera: Psychodidae) in an Endemic Focus of Visceral Leishmaniasis and Introduction of Phlebotomus (Adlerius) comatus as a New Record for Iran.

Background: Sand flies of subgenus Adlerius has a wide geographical distribution in Iran and are mostly found in wild form in mountainous areas. They are always considered as probable vectors of visceral leishmaniasis. The ob- jective of this study was to determine the Adlerius species and its composition in an endemic focus of zoonotic vis- ceral leishmaniasis in northwest of the country. Methods: Sand flies were collected from 6 different areas of Azarbaijan-e-Sharqi Province using sticky paper traps from August to September which is active season for sand flies in this area, in 2009. The flies were mounted and identified. The length of third antennal segments, ascoid, labrum, coxite, surstyle, style, aedeagus, genital filament, genital pump, width of style, and the end of aedeagus were measured and the number of costal hairs group was also counted as the morphological characters. Results: A total of 30 adult sand flies, (26 males and 4 females) including Phlebotomus halepensis (46.8%), P. longiductus (13.3%), P. balcanicus (23.3%), P. comatus (3.3%), and Adlerius spp. (13.3%) belong to subgenus Adlerius were identified respectively in 6 counties. One P. comatus male was captured in front of a cave located in the hillside of a mountain covered with the vegetation in Varzeqan area. Conclusion: The presence of at least 5 species of the subgenus Adlerius in Azarbaijan-e-Sharqi Province, an en- demic focus of zoonotic visceral leishmaniasis in Iran, shows that the risk of parasite transmission among man and reservoir animals is high during the active season of sand flies. P. comatus is a new record for Iran and needs to be added to the list of Iranian phlebotomines of subgenus Adlerius