Neutrophil extracellular traps formation: effect of Leishmania major promastigotes and salivary gland homogenates of Phlebotomus papatasi in human neutrophil culture

BACKGROUND

Leishmaniasis as a neglected tropical disease (NTD) is caused by the inoculation of Leishmania parasites via the bite of phlebotomine sand flies. After an infected bite, a series of innate and adaptive immune responses occurs, among which neutrophils can be mentioned as the initiators. Among the multiple functions of these fighting cells, neutrophil extracellular traps (NETs) were studied in the presence of Leishmania major promastigotes and salivary gland homogenates (SGH) of Phlebotomus papatasi alone, and in combination to mimic natural conditions of transmission.

MATERIAL & METHODS

The effect of L. major and SGH on NETs formation was studied in three different groups: neutrophils + SGH (NS), neutrophils + L. major (NL), neutrophils + L. major + SGH (NLS) along with negative and positive controls in 2, 4 and 6 h post-incubation. Different microscopic methods were used to visualize NETs comprising: fluorescence microscopy by Acridine Orange/ Ethidium Bromide staining, optical microscopy by Giemsa staining and scanning electron microscopy. In addition, the expression level of three different genes NE, MPO and MMP9 was evaluated by Real-Time PCR.

RESULTS

All three microscopical methods revealed similar results, as in NS group, chromatin extrusion as a sign of NETosis, was not very evident in each three time points; but, in NL and especially NLS group, more NETosis was observed and the interaction between neutrophils and promastigotes in NL and also with saliva in NLS group, gradually increased over times. Real-time reveals that, the expression of MPO, NE and MMP9 genes increased during 2 and 4 h after exposure, and then decreased at 6 h in most groups.

CONCLUSION

Hence, it was determined that the simultaneous presence of parasite and saliva in NLS group has a greater impact on the formation of NETs compared to NL and NS groups.

Association Between Wolbachia Infection and Susceptibility to Deltamethrin Insecticide in Phlebotomus papatasi (Diptera: Psychodidae), the Main Vector of Zoonotic Cutaneous Leishmaniasis

Background: Phlebotomus papatasi (Diptera: Psychodidae) is the main vector of zoonotic cutaneous leishmaniasis. Wolbachia is a symbiotic alphaproteobacteria of arthropods that can be involved in susceptibility or resistance. This study aimed to investigate the relationship between Wolbachia and Deltamethrin susceptibility/resistance in Ph. papatasi. Deltamethrin filter papers (0.00002%) were used to test sand fly field collected from southern Iran. After the test, PCR amplification of the Wolbachia surface protein gene (wsp) was used to measure Wolbachia infection rate in the killed, surviving, and control groups. Result: The rates of infection by Wolbachia strain (wPap, super group A) differed between killed (susceptible) and surviving (resistant) Ph. papatasi specimens. The rate of Wolbachia infection in susceptible individuals was more than twice (2.3) (39% vs. 17%) in resistant individuals with the same genetic background. This difference was highly significant (p < 0.001), indicating a positive association between Wolbachia infection and susceptibility to Deltamethrin. In addition, the results showed that Deltamethrin can act as a PCR inhibitor during detection of Wolbachia in Ph. papatasi. Conclusion: Results of this study show that Wolbachia is associated with Deltamethrin susceptibility level in Ph. papatasi. Also, as Deltamethrin has been identified as a PCR inhibitor, great care must be taken in interpreting Wolbachia infection status in infected populations. The results of this study may provide information for a better understanding of the host-symbiont relationship, as well as application of host symbiosis in pest management.

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

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.

Predicting current and future high-risk areas for vectors and reservoirs of cutaneous leishmaniasis in Iran

Climate change will affect the distribution of species in the future. To determine the vulnerable areas relating to CL in Iran, we applied two models, MaxEnt and RF, for the projection of the future distribution of the main vectors and reservoirs of CL. The results of the models were compared in terms of performance, species distribution maps, and the gain, loss, and stable areas. The models provided a reasonable estimate of species distribution. The results showed that the Northern and Southern counties of Iran, which currently do not have a high incidence of CL may witness new foci in the future. The Western, and Southwestern regions of the Country, which currently have high habitat suitability for the presence of some vectors and reservoirs, will probably significantly decrease in the future. Furthermore, the most stable areas are for T. indica and M. hurrianae in the future. So that, this species may remain a major reservoir in areas that are present under current conditions. With more local studies in the field of identifying vulnerable areas to CL, it can be suggested that the national CL control guidelines should be revised to include a section as a climate change adaptation plan.

A Comparative Study on the Biodiversity and Species Richness of Phlebotomine Sand Flies (Diptera: Psychodidae) in Kermanshah and Khuzestan Provinces of Iran

Background: Leishmaniasis is one of the most important vector-borne and neglected tropical diseases in many parts of the world. The main objective of this study was to determine the biodiversity of phlebotomine sand flies (Diptera: Psy­chodidae, Phlebotominae) in Khuzestan and Kermanshah Provinces of Iran. Methods: Sampling was conducted in Khuzestan and Kermanshah Provinces using sticky paper traps and CDC light traps. The samples were then stored in 96% alcohol-containing vials, mounted, and identified. Afterward, the alpha di­versity (using Simpson’s, Shannon-Weiner’s diversity, evenness, Maghalef’s, Menhinick’s, Hill N1 and N2 indices) and beta diversity indices (using Sorensen’s and Jaccard’s coefficients) were calculated. Results: A total of 4302 sand flies were caught and identified which comprised mostly of Phlebotomus papatasi, Ph. alexandri and Ph. sergenti. It was found that among the four counties of Ahvaz, Shush, Shushtar and Dezful in Khuzestan Province, Shush had the lowest, and Shushtar, the highest amount of species diversity and evenness. In the four studied counties of Kermanshah Province, species diversity in Kermanshah County had the lowest amount and Sarpol-e-Zahab, the highest. The species richness in Kermanshah County was the lowest, while Qasr-e-Shirin County had the highest amount. Conclusion: An overview of the biodiversity of phlebotomine sand flies in Kermanshah County in Kermanshah Prov­ince, and Shush County in Khuzestan Province, showed less stability in community structure of these vectors, which can be counted as an alarm for emerging dominant vectors among the studied counties and have the potential to increase the prevalence of leishmaniasis.

First Report of Natural Infection of Phlebotomus mongolensis to Leishmania major and Leishmania turanica in the Endemic Foci of Zoonotic Cutaneous Leishmaniasis in Iran

Background: The primary aim of this study is to determine infection to Leishmania parasites in the wild population of Phlebotomus caucasicus and Phlebotomus mongolensis using molecular methods in some important zoonotic cutaneous leishmaniasis foci in Iran. Methods: Sand flies were collected from active colonies of rodent burrows from 16 trapping sites using sticky trap pa­per. In order to detect and identify of Leishmania parasites in females Ph. caucasicus and Ph. mongolensis, the Nested–PCR amplification of ITS2-rDNA region was performed to generate amplicon with 245bp for Leishmania major, 206bp for L. gerbilli and 141bp for L. turanica. Results: In the current study we found DNA of different gerbil parasites such as L. major and L. turanica, and mixed infection of L. major/L. turanica in Ph. caucasicus and Ph. mongolensis. It should be noted that, in Iran, natural infec­tion with Leishmania parasites is recorded for the first time in this study in Ph. mongolensis. Conclusion: Both species of Ph. caucasicus and Ph. mongolensis not only may participate in the ZCL transmission cycle between reservoir hosts, but also results of this study support the  role of these species as secondary vectors in the transmission of leishmaniasis to humans.

Evaluation of Repellency and Lethal Effects of Ultrasonic Waves on the Blattella germanica (Blattodea: Blattellidae)

Background

The German cockroach, Blattella germanica (Insecta: Blattodea, Blattellidae), which occurs widely in human buildings, is a small cockroach species. Cockroach control chemical pesticides are toxic to the environment, and it is sometimes impossible to prevent them. Controlling Blattella germanica through ultrasonic waves can be efficient and less dangerous for the environment.

Methods

In this study, the repellency and lethal effect of ultrasonic waves on male and female German cockroaches was tested in a twin glass cubic chamber at laboratory condition. The wave frequencies tested ranged from 20 to 100kHz with 5kHz steps. A signal generator generated these frequencies, and the piezoelectric transmitter of these ultrasonic waves was positioned in the chamber's center on the upper side.

Results

Fisher's test showed that there was the greatest repellency effect in both male and female at frequencies of 35 and 40kHz. According to the results of the regression test, the most lethal effect is at the frequencies of 40 and 75kHz.

Conclusion

The operating ultrasonic frequencies investigated in this study can be used to repel and kill German cockroaches as pests endangering human health and environment.

The therapeutic effect of larval saliva and hemolymph of Lucilia sericata on the treatment of Leishmania major lesion in BALB/c mice946

BACKGROUND

Treatment of cutaneous leishmaniasis (CL) remains a major challenge for the public health and medical community. It has been claimed that natural compounds derived from fly larvae have anti-leishmania properties against some species of Leishmania. The present study aimed at assessing the in vitro effects of larval products of Lucilia sericata against the promastigote and intracellular amastigote forms of Leishmania major. Also, the therapeutic effect of larval products on lesions induced by L. major infection was evaluated in BALB/c mice models.

METHODS

Parasite specimens and macrophage cells were exposed to varying concentrations of larval products for 24-120 h. Lesion progression and parasite load were investigated in the models to assess the therapeutic effects of the products.

RESULTS

The larval products displayed more potent cytotoxicity against L. major promastigotes. The IC₅₀ values for larval saliva and hemolymph were 100.6 and 37.96 ug/ml, respectively. The IC₅₀ of glucantime was 9.480 ug/ml. Also, the saliva and hemolymph of L. sericata exhibited higher cytotoxicity against the promastigotes of L. major but were less toxic to the macrophage cells. Treatment with leishmanicidal agents derived from larvae of L. sericata decreased the infection rate and the number of amastigotes per infected host cell at all concentrations. Lesion size was significantly (F _{(7, 38)} = 8.54, P < 0.0001) smaller in the treated mice compared with the untreated control group. The average parasite burden in the treated mice groups (1.81 ± 0.74, 1.03 ± 0.45 and 3.37 ± 0.41) was similar to the group treated with a daily injection of glucantime (1.77 ± 0.99) and significantly lower (F _{(7, 16)} = 66.39, P < 0.0001) than in the untreated control group (6.72 ± 2.37).

CONCLUSIONS

The results suggest that the larval products of L. sericata were effective against L. major parasites both in vivo and in vitro. However, more clinical trial studies are recommended to evaluate the effects of these larval products on human subjects.

Bioecological Study on the Sand Flies (Diptera: Psychodidae, Phlebotominae) in Sari County, North of Iran

Background: Phlebotomine sand flies are vectors of Leishmania species, the causative agents of leishmaniasis in the world. Present study aimed to evaluate the bioecological aspects of sand flies in different ecotopes in Sari County, north of Iran.        Methods: Sand flies were collected from four villages in mountainous, forest, plain and peri-urban areas monthly using sticky traps in May–October 2016. Mounted specimens were identified using valid identification keys under optical microscope. The Arc GIS 10.5 software was applied for showing the distribution of sand flies. Shannon-Weiner, Simp­son and Evenness species diversity indices were calculated. Results: Generally, 334 specimens were captured and identified, namelly Phlebotomus kandelakii, Ph. papatasi, Ph. major, Ph. sergenti, Ph. longiductus, Ph. halepensis, Ph. tobbi, Sergentomyia dentata, Se. theodori, Se. sintoni, Se. an­tennata and Se. sumbarica. The most common species was Ph. kandelakii (n= 128, 38.32 %). The highest Simpson in­dex (0.81) and abundance (N= 141) were recorded in the mountaineous area. Shannon diversity index was higher in the forest (H'= 1.53) and the highest evenness index was in the plain area (J'= 0.93). The highest richness (S= 9) and Shan­non indices (H'= 1.57) were observed in June. Conclusions: Phlebotomus kandelakii, Ph. sergenti, Ph. tobbi, Ph. longiductus, Se. theodori, Se. antennata and Se. sumbarica were recorded for the first time in the study area. Since some species are incriminated for leishmaniasis transmission, further studies are required in the northern regions of Iran to timely control measures planning.

PCR Positivity of Gerbils and Their Ectoparasites for Leishmania Spp. in a Hyperendemic Focus of Zoonotic Cutaneous Leishmaniasis in Central Iran

Background: Various arthropods, including Rhipicephalus sanguineus and Ctenocephalides felis felis have been sug­gested as secondary vectors of Leishmania spp. many years ago. This study was conducted to determine zoonotic cuta­neous leishmaniasis (ZCL) PCR positivity of reservoir hosts and their ectoparasites for Leishmania spp. in Segzi plain in Esfahan Province from October 2016 to October 2017. Methods: Microscopic examination and nested PCR were used to detect and identify Leishmania spp. isolated from rodents' ears and ectoparasites, and then, the results were confirmed by two methods, PCR-restriction fragment length polymorphism and sequencing. Results: Totally, 93 rodents (92 Rhombomys opimus and one Nesokia indica) and nine different species of ectoparasites (n=527) including fleas, mites, and ticks were collected during different seasons in the study area. Fourteen R. opimus were positive for Leishmania spp. by microscopic examination while one N. indica and 77 R. opimus were positive by nested PCR. The infection rate of rodents with Leishmania major and Leishmania turanica was 39.79% (n=37) and 15.05% (n=14), respectively. Mixed natural infections with L. major and L. turanica were seen in rodents. Moreover, 72.22% of fleas (39/54), 75.0% of mites (5/8), and 100% of tick nymph (1/1) were PCR positive for Leishmania parasites. Conclusions: The highest rate of infection with L. major and L. turanica in R. opimus populations was observed in summer and spring, respectively. It is suggested that the role of L. turanica and the probable role of ectoparasites in the epidemiology of disease should be investigated. A Xenodiagnostic test is recommended for future study.  

Molecular and Biochemical Detection of Insecticide Resistance in the Leishmania Vector, Phlebotomus papatasi (Diptera: Psychodidae) to Dichlorodiphenyltrichloroethane and Pyrethroids, in Central Iran

The aim of the present study was to explore resistance markers and possible biochemical resistance mechanisms in the Phlebotomine sand fly Phlebotomus papatasi in Esfahan Province, central Iran. Homogenous resistant strains of sand flies were obtained by exposing P. papatasi collected from Esfahan to a single diagnostic dose of DDT. The adults from the colony were tested with papers impregnated with four pyrethroid insecticides: Permethrin 0.75%, Deltamethrin 0.05%, Cyfluthrin 0.15%, and Lambdacyhalothrin 0.05% to determine levels of cross-resistance. To discover the presence of mutations, a 440 base pair fragment of the voltage gated sodium channel (VGSC) gene was amplified and sequenced in both directions for the susceptible and resistant colonies. We also assayed the amount of four enzymes that play a key role in insecticide detoxification in the resistant colonies. A resistance ratio (RR) of 2.52 folds was achieved during the selection of resistant strains. Sequence analysis revealed no knockdown resistance (kdr) mutations in the VGSC gene. Enzyme activity ratio of the resistant candidate and susceptible colonies were calculated for α-esterases (3.78), β-esterases (3.72), mixed function oxidases (MFO) (3.21), and glutathione-S-transferases (GST) (1.59). No cross-resistance to the four pyrethroids insecticides was observed in the DDT resistant colony. The absence of kdr mutations in the VGSC gene suggests that alterations in esterase and MFO enzymes are responsible for the resistant of P. papatasi to DDT in central Iran. This information could have significant predictive utility in managing insecticide resistant in this Leishmania vector.

Leishmania spp. infection in Rhombomys opimus and Meriones libycus as main reservoirs of zoonotic cutaneous leishmaniasis in central parts of Iran: Progress and implications in health policy

Rodents from the subfamily Gerbillinae are the principal reservoir of cutaneous leishmaniasis (CL) caused by Leishmania major in the center and northeast of Iran. This study was conducted to determine both naturally occurring Leishmania infection rates and the distribution of Leishmania species in the central parts of Iran during 2019-2020. In this regard, presence of Leishmania parasites were confirmed by microscopic examination and the species were identified by nested-PCR using the Internal Transcribed Spacer2- Ribosomal DNA (ITS2-rDNA). Finally, some samples were sequenced and, the blast analysis of L. major samples, showed a 92.45-100% homology to the L. major sequence. Of the 181 wild gerbils collected (Rhombomys opimus=157 and Meriones lybicus=24), 88 (48.6%) tested positive for Leishmania sp. by microscopic examination whereas 162 (89.5%) were positive by nested-PCR. Of the 162 infected gerbils, 103 showed single strain infections (30 L. major, 28 L. gerbilli and 45 L. turanica), 43 showed dual infections with only the non-human species (L. gerbilli and L. turanica), and 16 were mixed infections of L. major and L. turanica (n = 14) or L. gerbilli (n = 2). All single or mixed L. major infections were detected in gerbils from areas with reports of human CL during the last decade. These findings suggest that Rhombomys opimus and Meriones libycus have a potential role in the maintenance of human and non-human transmission of Leishmania species in the CL foci.

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 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.

A Feasibility Study on Using the Facilities of Health Centers for Developing a Laboratory Network on Vectors and Reservoir Hosts of Cutaneous Leishmaniasis in Iran

Background

Cutaneous leishmaniasis is an ancient endemic disease in Iran and continues to be a growing health threat to community development and the environment. This paper explains how to use the facilities of health centers for developing a laboratory network on vectors and reservoir hosts of cutaneous leishmaniasis in Iran.

Methods

A literature search was performed of the relevant multiple databases to include studies on vectors and reservoirs of cutaneous leishmaniasis in Iran. A team of experienced experts was performed. After holding several meetings, field visits and organizing workshops, the activities of laboratories were determined at three levels.

Results

Entomological studies showed that 5 species of the genus Phlebotomus and 10 species of the genus Sergentomyia are active in the south, 4 species of the genus Phlebotomus and one species of the genus Sergentomyia in the central part and 5 species of the genus Phlebotomus and 2 species of the genus Sergentomyia in the north east. Reservoir hosts were identified in the study areas. The tasks of laboratories were regulated at different levels.

Conclusion

The Iranian Ministry of Health and Medical Education should prioritize the employment of capable persons in the field of Medical Entomology and Vector Control. The survival of this laboratory network depends on hiring and employing interested and persistent people. The universities of Medical Sciences that have the facilities to set up this network will be a very effective partner in the control of the disease in high risk areas. The results can be used in neighboring countries.

Climate change and its effect on the vulnerability to zoonotic cutaneous leishmaniasis in Iran

Zoonotic cutaneous leishmaniasis (ZCL) is an important vector-borne disease with an incidence of 15.8 cases per 100,000 people in Iran in 2019. Despite all efforts to control the disease, ZCL has expanded into new areas during the last decades. The aim of this study was to predict the best ecological niches for both vectors and reservoirs of ZCL under climate change scenarios in Iran. Several online scientific databases were searched. In this study, various scientific sources (Google Scholar, PubMed, SID, Ovid Medline, Web of Science, Irandoc, Magiran) were searched. The inclusion criteria for this study included all records with spatial information about vectors and reservoirs of ZCL which were published between 1980 and 2019. The bioclimatic data were downloaded from online databases. MaxEnt model was used to predict the ecological niches for each species under two climate change scenarios in two periods: the 2030s and 2050s. The results obtained from the model were analysed in ArcMap to find the vulnerability of different provinces for the establishment of ZCL foci. The area under the curve (AUC) for all models was >0.8, which suggests the models are able to make an accurate prediction. The distribution of all studied species in different climatic conditions showed changes. The variables affecting each of the studied species are introduced in the article. The predicted maps show that by 2050 there will be more suitable areas for the co-occurrence of vector and reservoir(s) of ZCL in Iran compared to the current climate condition and RCP2.6 scenario. An area in the northwest of Iran is predicted to have suitable environmental conditions for both vectors and reservoirs of ZCL, although the disease has not yet been reported in this area. These areas should be considered for field studies to confirm these results and to prevent the establishment of new ZCL foci in Iran.

Comparative Testing of Susceptibility Levels of Phlebotomus sergenti, the Main Vector of Anthroponotic Cutaneous Leishmaniasis, to Conventional Insecticides Using Two Capture Methods in Kerman City, Southeastern Iran

Background:

Collecting live sand flies from indoor sites is a major challenge for researchers in large cities due to the reluctance of families to survey their homes. This study was conducted to assess the efficacy of two methods for collecting sand flies for use in susceptibility tests in the urban area of Kerman, southeastern Iran.

Methods:

Sandflies were mainly collected using both baited traps and hand catch methods from outdoor and indoor sites. Susceptibility tests were separately done according to the standard World Health Organization testing protocol on Phlebotomus sergenti, including 60-minute exposure to DDT 4.0%, propoxur 0.1%, deltamethrin 0.05%, and malathion 5.0%.

Results:

During this research, the natural habitats and suitable indoor sites were selected to predict the density of live sand fly with perfect accuracy. The number of live Ph. sergenti caught by hand catch and baited traps methods was 42 and 361 in indoor and outdoor sites, respectively. The mortality rate of Ph. sergenti exposed to DDT 4%, deltamethrin 0.05, malathion 5%, and propoxur was 100%.

Conclusion

The baited traps showed a significant efficiency compared to hand catch for collecting live Ph. sergenti for use in susceptibility tests in urban areas. The Ph. sergenti collected from both indoor and outdoor sites were susceptible to all insecticides.

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. papa-tasi 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.

The leishmanicidal effect of Lucilia sericata larval saliva and hemolymph on in vitro Leishmania tropica

Background

Leishmaniasis is a major parasitic disease worldwide, except in Australia and Antarctica, and it poses a significant public health problem. Due to the absence of safe and effective vaccines and drugs, researchers have begun an extensive search for new drugs. The aim of the current study was to investigate the in vitro leishmanicidal activity of larval saliva and hemolymph of Lucilia sericata on Leishmania tropica.

Methods

The effects of different concentrations of larval products on promastigotes and intracellular amastigotes of L. tropica were investigated using the mouse cell line J774A.1 and peritoneal macrophages as host cells. The 3-(4.5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and direct observation and counting method were used to assess the inhibitory effects and cell cytotoxicity of the larval products. The effects of larval products on the amastigote form of L. tropica were quantitatively estimated by calculating the rate of macrophage infection, number of amastigotes per infected macrophage cell, parasite load and survival index.

Results

The 50% cytotoxicity concentration (CC₅₀) value of both larval saliva and hemolymph was 750 µg/ml, and the 50% inhibitory concentration (IC₅₀) values were 134 µg/ml and 60 µg/ml for larval saliva and larval hemolymph, respectively. The IC₅₀ for Glucantime, used a positive control, was (11.65 µg/ml). Statistically significant differences in viability percentages of promastigotes were observed for different doses of both larval saliva and hemolymph when compared with the negative control (p ≤ 0.0001). Microscopic evaluation of the amastigote forms revealed that treatment with 150 µg/ml larval hemolymph and 450 µg/ml larval saliva significantly decreased the rate of macrophage infection and the number of amastigotes per infected macrophage cell.

Conclusion

Larval saliva and hemolymph of L. sericata have acceptable leishmanicidal properties against L. tropica.

Graphical Abstract

Emerging of Cutaneous Leishmaniais Due to Leishmania major in a New Focus in Esfahan Province, Central Iran

Background:

Esfahan Province is considered as one of the main focus of zoonotic cutaneous leishmaniasis (ZCL) in Iran. Recently, ZCL distribution is expanding through this province leading to report of new cases in non-endemic areas. In the current study epidemiological aspects of ZCL has been investigated in Naein County in Esfahan Province.

Methods:

Adult sand flies were collected from beginning to the end of their seasonal activity. Rodents were caught by Sherman live traps once a month for one year. To active case detection, a hundred households in each selected village were visited in November and December 2016. Nested-PCR was employed to detect Leishmania parasite in the vector, reservoir and human.

Results:

Totally 1562 sand flies including Phlebotomus sergenti, Phlebotomus papatasi, Sergentomyia sintoni and Sergentomyia mervinae were collected and identified. No Leishmania infection was detected in the collected sand flies. All of the 30 collected rodents were identified as Rhombomys opimus, and of these 3.3% and 26.7% were infected by Leishmania major using microscopic and molecular technique respectively. Totally, 914 individuals were investigated and the ulcer and scar rates of ZCL calculated to be at 1.1 and 15.3 per 1000 population, respectively. Molecular results confirmed L. major infection in human and reservoir samples.

Conclusion:

It is concluded that ZCL is established in the area in low endemicity, and it is extrapolated the disease will not be a serious increasing health problem in the near future in this region.

Molecular Identification of Leishmania Species in Phlebotomus alexandri (Diptera: Psychodidae) in Western Iran

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.

Human immune response to Phlebotomus sergenti salivary gland antigens in a leishmaniasis-endemic focus in Iran

Salivary proteins specific antibodies have been shown to be useful biomarkers of exposure to sand fly bites. This study aimed to investigate the level, duration, and dynamics of the human immune response against the SGL of Phlebotomus sergenti Parrot, 1917 (Diptera: Psychodidae), and to assess the immunoreactivity of human sera with SGL components in an endemic area of anthroponotic cutaneous leishmaniasis (ACL) in Iran. The study was carried out in 2-phase; longitudinal and cross-sectional. Sand flies were collected monthly from indoors and outdoors. In the longitudinal study, sera from healthy volunteers were collected monthly, and in the cross-sectional study, sera from healthy volunteers and patients with ACL lesion/s, were collected for immunoassay studies. The level of anti-P. sergenti saliva IgG was detected using the ELISA. Immunoreactivity of individual human sera with saliva components was also assessed by western blotting. Phlebotomus sergenti was the predominant sand fly species in the study area. The maximum and minimum percentages of IgG responses were seen in October (66%) and March (29%), respectively. Additionally, the cross-sectional study showed that 59.3% of the healthy volunteers and 80% of the patients were IgG positive. The antibody response against P. sergenti salivary gland was high during the sand fly active season and declined by the end of the activity of the vectors.  Antibody response against the SGL components of P. sergenti was transient and individual-specific. Some individuals shared a strong reaction against certain individual antigens, which could be considered as vector exposure markers for further investigation.

LIST OF ABBREVIATIONS

ELISA: Enzyme-Linked Immunosorbent Assay; SDS PAGE: Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis; SGL: Salivary Gland Lysate; ACL: Anthroponotic Cutaneous Leishmaniasis; PBS: Phosphate Buffered Saline; BCA: Bicinchoninic Acid; PBS-T: Phosphate Buffered Saline Tween; FBS: Fetal Bovine Serum; HRP: Horseradish Peroxidase; TMB: 3,3',5,5'-Tetramethylbenzidine; PVDF: Polyvinylidene Difluoride; SGA: Salivary Gland Antigens; OD: Optical Density; KDa: Kilodalton; VL: Visceral Leishmaniasis; CL: Cutaneous Leishmaniasis; SGs: Salivary glands.

Evaluation of Different Attractive Traps for Capturing Sand Flies (Diptera: Psychodidae) in an Endemic Area of Leishmaniasis, Southeast of Iran

Background:

The attraction of phlebotomine sand flies to plant and animal hosts is due to the produced chemical compounds, affecting the olfactory receptors of the insects. Therefore, novel and effective methods, such as Attractive Toxic Sugar Baits (ATSB) and Attractive Toxic Baits (ATB), are based on the effective materials that attract sand flies toward the host. The present study was designed to identify the attractive materials in plants and animals for using in ATSB and ATB.

Methods:

This cross-sectional study was carried out in July 2018 on endemic areas of leishmaniasis in Iran. Different baits, including mango, nectarine, grape, banana, melon and watermelon, defibrinated blood of cattle, sheep, goat and chicken, urine of cattle, sheep, goat and ultimately, simple and complex chemicals, such as CO₂, 1-octanol, lactic acid and human sweat were placed inside the traps, and the rate of the sand flies attraction to these materials was studied. Furthermore, data were analyzed using the Kruskal-Wallis test and Mann Whitney U test.

Results:

There was a significant difference in the sand flies attraction between the traps containing watermelon, urine of cattle, and sheep, and chemicals such as CO₂ and human sweat and the control trap (p< 0.05).

Conclusion:

This study showed that watermelon and CO₂ are the potential candidates for using in ATSB and ATB, respectively.

Epidemiological survey on Cutaneous Leishmaniasis in southwestern Iran

BACKGROUND & OBJECTIVES

Cutaneous leishmaniasis (CL) is still a public health threat in many rural areas of Iran. It causes considerable morbidity among a huge number of people in the endemic areas. Khuzestan is considered as a CL focus in Iran and recently several cases have been reported from Shush County. The aim of the current study was to determine different aspects of CL epidemiology in this County.

METHODS

The study was conducted in four villages in the rural district of Shush County. In order to survey the scar and acute rate of the disease, 100 inhabitants were questioned in each village. In addition, to determine the reservoir host and vector of the disease, rodents were captured using Sherman traps, and sandflies were collected from around the rodent burrows using sticky paper traps.

RESULTS

The scar and acute lesion rates were reported as 5.26 and 0.57% among inhabitants, respectively. Fifty-four rodents including Tatera indica (55.5%), Nesokia indica (33.3%), Mus musculus (9.3%) and Rattus norvegicus (1.9%) were captured and identified. Nested PCR showed 3 out of 54 rodents infected with Leishmania major. In total, 1122 sandflies were collected, and Leishmania major detected in Phlebotomus papatasi (4.35%), Sergentomyia dentata (23%), and Sergentomyia clydei (10%).

INTERPRETATION & CONCLUSION

Zoonotic cutaneous leishmaniasis due to L. major prevailed in this area. The common and the main vector was Ph. papatasi and, T. indica seems to be the main while N. indica as a secondary reservoir host of the disease in this area.

Epidemiology of Visceral Leishmaniasis with Emphasis on the Dynamic Activity of Sand Flies in an Important Endemic Focus of Disease in Northwestern Iran

Background

Leishmaniasis diseases are known to be one of the most important public health problems in World and Iran. Visceral leishmaniasis is considered to be the most serious form and transmitted by sand flies species. The aim of this study was to investigate the dynamic activities of sandflies in northwestern Iran.

Methods

This crass-sectional study was conducted from April to December 2018 in Meshkinshahr County, Ardabil Province. Sticky traps have been used to collect sand flies. They are stored in 70% alcohol and finally identified using valid keys. The aspects of the synoptic information were inquired from the Meshkin Shahr weather department and results analyzed for SPSS24.

Results

Totally 259 sandflies were collected during study period. From collected samples 78.7% were male and 21.3% female. There were 8 different species. Phlebotomus kandelakii was the most prevalent one (30.8%). The average temperature, relative humidity, and average wind speed was 13.5 °C, 84%, and 2 meters per hour on the onset of sandflies' activity, respectively. These values were 18.3 °C, 85% and 1.5 meters per hour at the peak of their activity and 16 °C, 62% and 5 meters per hour at the final stage of their activity. Sand flies had one peak in July which is strongly influenced by temperature and humidity conditions. Two species of Ph. kandelakii and Phlebotomus perfilewi transcaucasicus, had the highest activity in this endemic area.

Conclusion

The results of current study will provide a guideline for control of diseases in the country.

Monitoring of Laboratory Reared of Phlebotomus papatasi (Diptera: Psychodidae), Main Vector of Zoonotic Cutaneous Leishmaniasis to Different Imagicides in Hyper endemic Areas, Esfahan Province, Iran

Background:

In domestic and per domestic area, insecticides such as DDT, malathion, fenitrothion, propoxur and, more recently, synthetic pyrethroids such as deltamethrin and lambda-cyhalothrin, have been successfully used to control sand flies in many countries. The present study reports the results of time-mortality bioassay to DDT 4%, lambda-cyhalothrin 0.05%, permethrin 0.75%, cyfluthrin 0.15% and deltamethrin 0.05% in recently colonized Phlebotomus papatasi populations in Iran.

Methods:

The insecticide susceptibility status of P. papatasi laboratory population was assessed during 2016–2017, following the standard WHO technique for mosquito (WHO, 2013) based on diagnostic dose. Sand flies collected from rural area of Badrood (Matin Abad), Natanz County, Esfahan Province, using aspirator.

Results:

Susceptibility test to DDT and pyrethroids was assessed on 3534 laboratory-reared P. papatasi (1746 females and 1788 males). The LT ₅₀ and LT ₉₀ values were measured using probit analysis and regression lines. The test results against males of P. papatasi revealed that LT ₅₀ values to DDT 4%, Permethrin 0.75%, Deltamethrin 0.05%, Cyfluthrin 0.15% and Lambdacyhalothrin 0.05% were 439.28, 108.90, 97.75, 5.00 and 57.84 seconds. The figures for females were 641.62, 136.15, 146.44, 8.71 and 72.69 seconds, respectively.

Conclusion:

According to presented results, the reared population of sand flies collected from a hyper-endemic region of Esfahan Province is still susceptible to prethroids and Resistance candidate to DDT 4%.

Modelling and evaluating the risk of zoonotic cutaneous leishmaniasis in selected areas of Kerman Province, south of Iran

Cutaneous leishmaniasis (CL) remains a public health problem in the world, particularly in tropical and sub-tropical countries. This study aimed to determine the hotspots of CL in Kerman Province of Iran and model their potential for the establishment of new disease foci. All documents related to studies conducted in Kerman Province on CL published between 1978 and 2017 were retrieved and categorized. Spatial distributions of the vector, reservoir and human infection of CL were mapped. MaxEnt ecological model was used to predict the environmental suitability of the vector and reservoir(s) of zoonotic cutaneous leishmaniasis (ZCL). The most hazardous sites with the potential for the establishment of new disease foci were determined for field operations. Statistics of new cases of CL was obtained from the Center for Disease Control (CDC) of the ministry of health for the period 2011-2016. A total of 6,056 cases of CL were recorded, while we found a decreasing pattern in the incidence of CL from 46.48 per 100,000 inhabitants to 22.97. The best ecological niches for Phlebotomus papatasi are located in the central, western, northwest and southwest regions of the province. Also, environmental suitability for the reservoirs was highest in the central, southern and southwestern regions. The model predicted the gerbils can be present in some foci of anthroponotic cutaneous leishmaniasis (ACL). However, this result should be confirmed through a precise field study, and if validated, plans should be made to prevent the emergence of new foci of ZCL in the risk areas.

Comparative Performance of Different Traps for Collection of Phlebotominae Sand Flies and Estimation of Biodiversity Indices in Three Endemic Leishmaniasis Foci in North Khorasan Province, Northeast of Iran

  Background: Phlebotominae sand flies (Diptera: Psychodidae) are the vectors of leishmaniasis. There are different methods for sand fly collection with different performance. The purpose of the current study was to compare the effect of different traps for collection of Phlebotominae sand flies in three endemic leishmaniasis foci in North Khorasan Prov-ince, northeast of Iran. Methods: Sand flies were collected using seven different traps from three villages, three times each twenty days during peak periods of seasonal activity in 2016. Results: A total of 7253 sand flies were collected. The specimens belonged to19 species. Phlebotomus sergenti was the most predominant species in the study area. Light trap baited with Carbon dioxide (CLT) and sticky paper trap (SPT) caught 22.6% and 22.3% of sand flies respectively. Animal baited trap (ABT) and white Shannon trap (WST) caught significantly fewer sand flies than the other traps. The sex ratio was different by phlebotominae sand fly species and collection methods. The sex ratio was highest in SPT and lowest in black Shannon trap (BST). Species diversity and species richness in SPT were more than other traps. Conclusion: Our findings confirm that CLT and SPT are the most efficient sand fly collection methods. CLT is higher attractive for females and Phlebotomus genus and is an ideal method for monitoring the population of Phlebotomus ge-nus during surveillance. SPT is an inexpensive, convenient and easy to be used to detect the presence of sand flies at low densities and provide a more realistic estimation of sand flies biodiversity.

Comparative Performance of Different Traps for Collection of Phlebotominae Sand Flies and Estimation of Biodiversity Indices in Three Endemic Leishmaniasis Foci in North Khorasan Province, Northeast of Iran

BACKGROUND

Phlebotominae sand flies (Diptera: Psychodidae) are the vectors of leishmaniasis. There are different methods for sand fly collection with different performance. The purpose of the current study was to compare the effect of different traps for collection of Phlebotominae sand flies in three endemic leishmaniasis foci in North Khorasan Province, northeast of Iran.

METHODS

Sand flies were collected using seven different traps from three villages, three times each twenty days during peak periods of seasonal activity in 2016.

RESULTS

A total of 7253 sand flies were collected. The specimens belonged to19 species. Phlebotomus sergenti was the most predominant species in the study area. Light trap baited with Carbon dioxide (CLT) and sticky paper trap (SPT) caught 22.6% and 22.3% of sand flies respectively. Animal baited trap (ABT) and white Shannon trap (WST) caught significantly fewer sand flies than the other traps. The sex ratio was different by phlebotominae sand fly species and collection methods. The sex ratio was highest in SPT and lowest in black Shannon trap (BST). Species diversity and species richness in SPT were more than other traps.

CONCLUSION

Our findings confirm that CLT and SPT are the most efficient sand fly collection methods. CLT is higher attractive for females and Phlebotomus genus and is an ideal method for monitoring the population of Phlebotomus genus during surveillance. SPT is an inexpensive, convenient and easy to be used to detect the presence of sand flies at low densities and provide a more realistic estimation of sand flies biodiversity.

Prone Regions of Zoonotic Cutaneous Leishmaniasis in Southwest of Iran: Combination of Hierarchical Decision Model (AHP) and GIS

Background: Cutaneous leishmaniasis due to Leishmania major is an important public health problem in the world. Khuzestan Province is one of the main foci of zoonotic cutaneous leishmaniasis (ZCL) in the southwest of Iran. We aimed to predict the spatial distribution of the vector and reservoir(s) of ZCL using decision-making tool and to pre­pare risk map of the disease using integrative GIS, RS and AHP methods in endemic foci in Shush (plain area) and Khorramshahr (coastal area) counties of Khuzestan Province, southern Iran from Mar 2012 to Jan 2013. Methods: Thirteen criteria including temperature, relative humidity, rainfall, soil texture, soil organic matter, soil pH, soil moisture, altitude, land cover, land use, underground water depth, distance from river, slope and distance from human dwelling with the highest chance of the presence of the main vector and reservoir of the disease were chosen for this study. Weights of the criteria classes were determined using the Expert choice 11 software. The pres­ence proba­bility maps of the vector and reservoir of the disease were prepared with the combination of AHP method and Arc GIS 9.3. Results: Based on the maps derived from the AHP model, in Khorramshahr study area, the highest probability of ZCL is predicted in Gharb Karoon rural district. The presence probability of ZCL was high in Hossein Abad and Benmoala rural districts in the northeast of Shush. Conclusion: Prediction maps of ZCL distribution pattern provide valuable information which can guide policy mak­ers and health authorities to be precise in making appropriate decisions before occurrence of a possible disease out­break.

Conducting International Diploma Course on Leishmaniasis and its Control in the Islamic Republic of Iran

Background: Leishmaniasis represents the important public health problem in the world. One of the main objectives of World Health organization is capacity building of managers and authorities who are involved with diseases control ac­tivities. Methods: The course was conducted in Esfahan Health Research and Training Center (E.H.R.T.C) in summer 2005 and 2009. The course carried out jointly by the Ministry of Health and Medical Education (MOH) of Iran, World Health Or­ganization-Eastern Mediterranean Regional Office (WHO-EMRO) and School of Public health, Tehran University of Med­ical Sciences (SPH-TUMS) and designed for medical officers, senior technicians and managers involved in leish­mania­sis control. Prior to initiate the course, pre-test evaluations including different subjects on leishmaniasis and its control were carried out. The examinations include multiple choice questions. The duration of the course was 3 weeks. A total of 206 contact hours were taught. The main subjects were Basic epidemiology, Leishmaniasis parasitology, Leishmaniasis en­tomology, control of vectors and reservoirs, principles of integrated pest management, Field work and Planning. Dif­ferent methods of teaching including lecture, laboratory, workshop, team work, field exercise and presen­tation were used. Requirement for achievement of the course was to have at least 60% of the total mark for awarding the diploma certificate. Results: A total of 45 participants from Iraq, Afghanistan and Iran graduated from this course. Conclusion: The course is providing the skill for managers, how to combat against disease in their country and is paral­lel to the policy of the leishmaniasis control for capacity building in endemic areas of their countries.

Conducting International Diploma Course on Leishmaniasis and Its Control in the Islamic Republic of Iran

BACKGROUND

Leishmaniasis represents the important public health problem in the world. One of the main objectives of World Health organization is capacity building of managers and authorities who are involved with diseases control activities.

METHODS

The course was conducted in Esfahan Health Research and Training Center (E.H.R.T.C) in summer 2005 and 2009. The course carried out jointly by the Ministry of Health and Medical Education (MOH) of Iran, World Health Organization-Eastern Mediterranean Regional Office (WHO-EMRO) and School of Public health, Tehran University of Medical Sciences (SPH-TUMS) and designed for medical officers, senior technicians and managers involved in leishmaniasis control. Prior to initiate the course, pre-test evaluations including different subjects on leishmaniasis and its control were carried out. The examinations include multiple choice questions. The duration of the course was 3 weeks. A total of 206 contact hours were taught. The main subjects were Basic epidemiology, Leishmaniasis parasitology, Leishmaniasis entomology, control of vectors and reservoirs, principles of integrated pest management, Field work and Planning. Different methods of teaching including lecture, laboratory, workshop, team work, field exercise and presentation were used. Requirement for achievement of the course was to have at least 60% of the total mark for awarding the diploma certificate.

RESULTS

A total of 45 participants from Iraq, Afghanistan and Iran graduated from this course.

CONCLUSION

The course is providing the skill for managers, how to combat against disease in their country and is parallel to the policy of the leishmaniasis control for capacity building in endemic areas of their countries.

Prone Regions of Zoonotic Cutaneous Leishmaniasis in Southwest of Iran: Combination of Hierarchical Decision Model (AHP) and GIS

BACKGROUND

Cutaneous leishmaniasis due to Leishmania major is an important public health problem in the world. Khuzestan Province is one of the main foci of zoonotic cutaneous leishmaniasis (ZCL) in the southwest of Iran. We aimed to predict the spatial distribution of the vector and reservoir(s) of ZCL using decision-making tool and to prepare risk map of the disease using integrative GIS, RS and AHP methods in endemic foci in Shush (plain area) and Khorramshahr (coastal area) counties of Khuzestan Province, southern Iran from Mar 2012 to Jan 2013.

METHODS

Thirteen criteria including temperature, relative humidity, rainfall, soil texture, soil organic matter, soil pH, soil moisture, altitude, land cover, land use, underground water depth, distance from river, slope and distance from human dwelling with the highest chance of the presence of the main vector and reservoir of the disease were chosen for this study. Weights of the criteria classes were determined using the Expert choice 11 software. The presence probability maps of the vector and reservoir of the disease were prepared with the combination of AHP method and Arc GIS 9.3.

RESULTS

Based on the maps derived from the AHP model, in Khorramshahr study area, the highest probability of ZCL is predicted in Gharb Karoon rural district. The presence probability of ZCL was high in Hossein Abad and Benmoala rural districts in the northeast of Shush.

CONCLUSION

Prediction maps of ZCL distribution pattern provide valuable information which can guide policy makers and health authorities to be precise in making appropriate decisions before occurrence of a possible disease outbreak.

Designing and Introducing a New Artificial Feeding Apparatus for Sand Fly Rearing

Background: Due to strict ethical rules, the risk of accidental disease transmission and the most importantly, inconven­ience regarding using of live animals, artificial feeding apparatus has been developed for colonization of haematophagous insects. Rearing of sandfly is more difficult than other haematophagous insects. Methods: In the current study, a new apparatus for membrane feeding of Phlebotomus papatasi was designed, made and compared with available apparatus in Sand Fly Insectary, Tehran University of Medical Sciences, Tehran, Iran, in 2014. Results: In comparison to other apparatus designed for artificial feeding of other arthropods, our designed apparatus had the highest performance which after up to 1h, the majority of sand flies landed and took blood and among tested membranes, chicken skin was proved the most efficient membrane. Conclusion: Sand fly artificial feeding apparatus can be used at least for rearing of Ph. papatasi.

Designing and Introducing a New Artificial Feeding Apparatus for Sand Fly Rearing

BACKGROUND

Due to strict ethical rules, the risk of accidental disease transmission and the most importantly, inconvenience regarding using of live animals, artificial feeding apparatus has been developed for colonization of haematophagous insects. Rearing of sandfly is more difficult than other haematophagous insects.

METHODS

In the current study, a new apparatus for membrane feeding of Phlebotomus papatasi was designed, made and compared with available apparatus in Sand Fly Insectary, Tehran University of Medical Sciences, Tehran, Iran, in 2014.

RESULTS

In comparison to other apparatus designed for artificial feeding of other arthropods, our designed apparatus had the highest performance which after up to 1h, the majority of sand flies landed and took blood and among tested membranes, chicken skin was proved the most efficient membrane.

CONCLUSION

Sand fly artificial feeding apparatus can be used at least for rearing of Ph. papatasi.

The Potential Role of Humans in the Transmission Cycle of Leishmania major (Kinetoplastida: Trypanosomatidae), the Causative Agent of the Old World Zoonotic Cutaneous Leishmaniasis

Zoonotic cutaneous leishmaniasis (ZCL) due to Leishmania major (Yakimoff and Schokhor, 1914) is known as a neglected tropical disease, transmitted by Phlebotomus papatasi (Scopoli, 1786) in North Africa and the Middle East. The main reservoirs of ZCL are desert gerbils and the role of humans as a reservoir host of the disease is not clearly defined and is therefore investigated in this study. In order to achieve this objective, Ph. papatasi sand flies were allowed to take blood through indirect blood sources (human, Rhombomys opimus (Lichtenstein, 1823) (great gerbil), and BALB/c mice) using artificial feeding or direct xenodiagnoses from ZCL patients. To detect Leishmania promastigotes inside digestive canal, blood-fed sand flies were dissected and examined under light microscope and then confirmed by nested-PCR. In indirect xenodiagnoses, promastigote forms of Leishmania parasite were observed in 7.1%, 12%, and 13.6% of sand flies which fed on Rh. opimus, BALB/c mice, or human blood sources, respectively. In direct xenodiagnoses, among 93 female lab-reared sand flies which fed on active L. major lesion(s), 2.1% Leishmania infection was subsequently observed in the sand flies. No infection was detected in those sand flies that fed on nonlesioned skin of CL patients. Humans can serve as a reservoir of ZCL since the data indicate that Ph. papatasi is able to acquire L. major parasites from an active lesion of ZCL patients and the parasites can complete metacyclogenesis in the sand fly.

Richness and Diversity of Phlebotomine Sand Flies (Diptera: Psychodidae) in North Khorasan Province, Northeast of Iran

Background: We aimed to determine the species composition, richness and diversity indices of the Phlebotomine sand flies at different topographic condition in visceral (VL) and cutaneous leishmaniasis (CL) foci in the northeast of Iran. Methods: This cross-sectional study was conducted during 2016 in North Khorasan Province. The sampling was focused on rural regions, where human cases of VL and/or CL were diagnosed and reported during last 5 years. Sand flies were collected three times each twenty days during peak periods of seasonal activity. Seven collection methods were used. Some Alpha and Beta diversity indices were calculated. Results: Overall, 7253 sand flies were collected and identified. They were from 19 species of Phlebotominae sand­flies. Phlebotomus sergenti and Ph. papatasi were the most prevalent (84.9%) species in the study area. Species rich­ness (S) was very different in three areas and were18, 8, and 4 respectively but Evenness (E) were 0.357, 0.345, and 0.380, so evenness was almost equal in the study areas. Shannon Index (H ) and Margalef Richness Index were cal­culated 1.033, 0.718, 0.527 and 2.117, 0.8998, 0.4006 respectively. Conclusion: The sand fly fauna in North Khorasan Province was very rich and often included some of the most im­portant proven or suspected vectors of leishmaniasis. Species diversity indices (Shannon index, and Simpson’s in­dex) were not high due to decreasing in evenness. The Margalef richness index could accurately reflect the biodiver­sity of sand flies between three subtidal locations.

Richness and Diversity of Phlebotomine Sand Flies (Diptera: Psychodidae) in North Khorasan Province, Northeast of Iran

BACKGROUND

We aimed to determine the species composition, richness and diversity indices of the Phlebotomine sand flies at different topographic condition in visceral (VL) and cutaneous leishmaniasis (CL) foci in the northeast of Iran.

METHODS

This cross-sectional study was conducted during 2016 in North Khorasan Province. The sampling was focused on rural regions, where human cases of VL and/or CL were diagnosed and reported during last 5 years. Sand flies were collected three times each twenty days during peak periods of seasonal activity. Seven collection methods were used. Some Alpha and Beta diversity indices were calculated.

RESULTS

Overall, 7253 sand flies were collected and identified. They were from 19 species of Phlebotominae sand-flies. Phlebotomus sergenti and Ph. papatasi were the most prevalent (84.9%) species in the study area. Species richness (S) was very different in three areas and were18, 8, and 4 respectively but Evenness (E) were 0.357, 0.345, and 0.380, so evenness was almost equal in the study areas. Shannon Index (H) and Margalef Richness Index were calculated 1.033, 0.718, 0.527 and 2.117, 0.8998, 0.4006 respectively.

CONCLUSION

The sand fly fauna in North Khorasan Province was very rich and often included some of the most important proven or suspected vectors of leishmaniasis. Species diversity indices (Shannon index, and Simpson's index) were not high due to decreasing in evenness. The Margalef richness index could accurately reflect the biodiversity of sand flies between three subtidal locations.

Spatial Distribution of Phlebotomine Sand Flies (Diptera: Psychodidae) as Phlebovirus Vectors in Different Areas of Iran

Sand fly fever is caused by Naples (SFNV) and Sicilian viruses (SFSV) and the closely related Toscana virus of the Phlebovirus genus in the family Bunyaviridae, and transmitted by Phlebotomine sand flies. Phlebotomus papatasi Scopoli, 1786 is known as the main vector of the disease. This study aimed to investigate the distribution of Phlebotomine sand flies as vector of sand fly fever viruses, and the effects of some environmental variables on their potential dispersion to new areas in some provinces of Iran. Sand flies were collected during their active season in the region using CDC light traps. Ecological parameters were recorded for each collection site. Arc GIS 10.3 software was used for data analysis and mapping the distribution of sand flies. Sampling in the study areas was carried out in six different climatic zones. Seventeen sand fly species were collected including eight species of genus Phlebotomus and nine species of genus Sergentomyia. The Medium Semi-Arid climatic zone had the highest species diversity. Fourteen species of sand flies were collected at altitude between 2 and 325 m, and seven species were collected between 326 and 1380 m above sea level. There was significant correlation between sand fly density and all tested environmental variables. Phlebotominae sand flies have wide distribution in Iran and have a major public health concern in the country. P. papatasi and Sergentomyia sintoni Pringle, 1933 prefers hot summers and rainfall. This poses a threat of transmission of sand fly fever caused by SFSV and SFNV across the country.

Susceptibility status of wild population of Phlebotomus sergenti (Diptera: Psychodidae) to different imagicides in a endemic focus of cutaneous leishmaniasis in northeast of Iran

BACKGROUND & OBJECTIVES

Phlebotomine sandflies (Diptera: Psychodidae) transmit several important zoonotic diseases to humans and leishmaniasis is one of them. Two types of leishmaniasis, viz. visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) are endemic in Iran. The main vector of anthroponotic cutaneous leishmaniasis (ACL) is Phlebotomus sergenti. The aim of the present study was to determine the susceptibility status of wild strain of P. sergenti to different imagicides of DDT, bendiocarb and permethrin at the median lethal time, LT50 level.

METHODS

Sandflies were collected from selected village in North Khorasan Province, northeast of Iran from indoors using CDC light-traps. Susceptibility test was carried out against DDT (4%), bendiocarb (0.1%) and permethrin (0.75%) for all the females according to WHO method, and mortality was calculated. Species identification was carried out using the morphological keys. Data were analysed using probit regression analysis to determine the LT50 and LT90 values.

RESULTS

In total, 851 female P. sergenti sandflies were tested. LT50 values to DDT (4%), Bendiocarb (0.1%) and permethrin (0.75%) were 15.4, 19.2 and 6.3 min respectively. The values for LT90 were 51.1, 47.4 and 18.6 min respectively. The mortality rates for 1 h exposure time to DDT, bendiocarb and permethrin were 89.8 ± 1.4; 93.6 ± 1.4; and 95.6 ± 1.7%, respectively.

INTERPRETATION & CONCLUSION

The suscesptibility studies revealed development of resistance against DDT (4%) in the wild strain of P. sergenti population. Monitoring and mapping of insecticide resistance in the region is recommended for vector control.

Modeling of Environmental Factors Affecting the Prevalence of Zoonotic and Anthroponotic Cutaneous, and Zoonotic Visceral Leishmaniasis in Foci of Iran: a Remote Sensing and GIS Based Study

BACKGROUND

Leishmaniasis is a re-emerging serious international public health problem, and both visceral and cutaneous types of leishmaniasis became important endemic diseases in Iran. In this study, the relationships between environmental factors (vegetation and elevation) and the prevalence of diseases have been investigated.

METHODS

All international and national online databases were searched by terms such as leishmaniasis, incidence, prevalence and other related words attributed to Iran and published until first quarter of 2015. The developed database in Excel, later imported to the ArcMap for spatial analyst and mapping. Afterwards, the software was used for modeling the relationship between the prevalence/incidence and environmental variables (vegetation and elevation) by both linear and nonlinear regression.

RESULTS

After mapping the prevalence data from 144 studies, considering non-parametric ANOVA, the tendency of zoonotic visceral leishmaniasis to presence in high elevation and high vegetation was more than Anthroponotic and zoonotic cutaneous leishmaniasis. While linear regression showed weaker results for modeling, however, additive nonparametric regression analysis suggested that 10km buffers for elevation, and 10 as well as 50km buffers for vegetation could contribute in better fitness in modeling of these variables.

CONCLUSION

The detailed maps for distribution of disease concluded. The nonlinear regression is a reliable predictor of the relationship between environmental factors and disease incidence, although more and wide researchers are needed to confirm it.

Rearing and Biology of Phlebotomus sergenti, the Main Vector of Anthroponotic Cutaneous Leishmaniasis in Iran

BACKGROUND

Establishment of sand flies laboratory colonies is essential to understand various biological aspects of Phlebotominae sand flies. The aims of the current study were to establish the colony of Phlebotomus sergenti Parrot (1917), the main vector of anthroponotic cutaneous leishmaniasis in old world, and to study biological parameters of this species.

METHODS

The sand flies were reared at 26-28 °C temperature, 14:10 (light: dark) photoperiod and 70-80% relative humidity. Larval diet was a composted mixture of rabbit faces and rabbit pellets which is prepared through a special process. First to fifth generations of P. sergenti were used to define biological parameters.

RESULTS

Results showed that, P. sergenti blood feeding percentage were 42% on chicken, 21% on BALB/c and 37% on golden hamster. Average time of blood digestion, egg incubation, 1^st instar larva, pupa and adult emerging was recorded at 3.4, 8.7, 15, 33.3 and 41.2 days after blood feeding, respectively. Mean number of laid eggs was 55.1 and retained eggs were 35 per a female. Fecundity and production rate were 61.6%, and 42.2% respectively. Average longevity recorded at 15.2 days for females and 14.8 days for males.

CONCLUSION

Colony of P. sergenti has been established for the first time in Iran. Average interval time from egg to adult of this species was 32.5 days. Chicken and golden hamster were recommended as a blood source for colony initiation and routine blood feeding, respectively.

Assessing the insecticide susceptibility status of field population of Phlebotomus papatasi (Diptera: Psychodidae) in a hyperendemic area of zoonotic cutaneous leishmaniasis in Esfahan Province, Central Iran

Leishmaniasis is a Neglected Tropical Disease (NTD) and emerging parasitic infection that affect mainly poor regions around the world. This study aimed to determine the baseline susceptibility of Phlebotomus papatasi to commonly used insecticides in a hyper endemic area using WHO standard procedure in central Iran. A total of 4-5 replicates containing 120-200 sand flies were used for each insecticide. Baseline susceptibility to DDT and pyrethroids was assessed on 5326 specimens collected from the study area. The LT₅₀ and LT₉₀ values were measured according to the World Health Organisation test using probit analysis and regression lines. The test results against males P. papatasi revealed that LT₅₀ values to DDT 4%,Permethrin 0.75%, Deltamethrin 0.05%, Cyfluthrin 0.15% and Lambdacyhalothrin 0.05% were 564.07, 38.08, 1.95, 0.60 and 9.78s and the figures for females were 584.44, 110.10, 11.64, 1.53 and 16.91s, respectively. Our results indicated that P. papatasi as the main cutaneous leishmaniasis vector was susceptible to Cyfluthrin 0.15%, Lambdacyhalothrin 0.05%, Permethrin 0.75% and Deltamethrin 0.05% and tolerant to DDT 4%. This study was carried out in one out of many Leishmaniasis foci in Iran. We recommend that future studies incorporate other regions and use the same procedure for monitoring and evaluating sand fly resistance. Also, WHO can provide a specific guideline and create a test kit for sand fly resistance monitoring and for applying susceptibility test because the tubes prepared for mosquitoes are not actually fit for sand flies.

Epidemiological Study on Cutaneous Leishmaniasis in an Endemic Area, of Qom Province, Central Iran

BACKGROUND

Cutaneous leishmaniasis (CL) is one of the most important health problems in many areas of Iran. There are two forms of the disease in Iran, anthroponotic and zoonotic CL. This study conducted to assess the epidemiological situation of CL in an endemic area of Qom Province, central Iran from Apr to Nov 2015.

METHODS

The sticky paper traps and aspirating tubes were used for collecting adult sand flies. Sherman traps and small insect nets were used to capture rodents and small mammals. Giemsa staining was used for preparing the expanded smear and followed by PCR for identifying the causative agent in human, vectors, and reservoirs. In this study, relative frequency of CL was also calculated.

RESULTS

Fourteen species of Phlebotomine sand flies were collected. Phlebotomus papatasi (61.74%) was the predominant species through the period of activity. Overall, 62 Meriones libycus, 8 Nesokia indica, 4 Mus musculus, 16 Allactaga elater and 2 Hemiechinus auritis were caught. PCR technique showed 6 out of 150 P. papatasi (2%), two out of 62 M. libycus (3.23%) and all of suspected human's skin tissue samples (100%) were infected with Leishmania major. The relative frequency of CL was 0.30%.

CONCLUSION

This is the first detection of L. major within P. papatasi, M. libycus and human in Kahak District in Qom Province of Iran. Zoonotic cycle of CL exists in this area, L. major is the causative agent, P. papatasi is the main vector and M. libycus is the main reservoir of the disease.

Assessing the Ovarian Accessory Glands to Determine the Parity of Phlebotomus papatasi, Vector of Zoonotic Cutaneous Leishmaniasis, under Laboratory Condition

BACKGROUND

Zoonotic cutaneous leishmaniasis (ZCL) is a neglected tropical disease prevailed in many rural areas of 17 out of 31 provinces in Iran. The main vector of the disease is Phlebotomus papatasi and the causative agent is Leishmania major in ZCL foci of Iran. In the current study we investigated the validity of accessory glands secretions as an indicator to recognize parous from nulliparous Ph. papatasi females under laboratory conditions.

METHODS

Over 235 laboratory-reared females of Ph. papatasi were dissected in 6 groups including: newly emerged, one hour, one day, two days, and three days after blood feeding and also after oviposition under stereo microscope for their parity in 2014-2015.

RESULTS

Transparent glands were compatible with nulliparous only in newly emerged sand flies. In sand flies dissected after oviposition, accessory glands were rather large as a result of oviposition though they were transparent.

CONCLUSION

The accessory glands secretions could not be as an indicator for distinguishing parous from nulliparous of Ph. papatasi females.

Predicting the Distribution of Phlebotomus papatasi (Diptera: Psychodidae), the Primary Vector of Zoonotic Cutaneous Leishmaniasis, in Golestan Province of Iran Using Ecological Niche Modeling: Comparison of MaxEnt and GARP Models

Zoonotic cutaneous leishmaniasis (ZCL) is a prevalent vector-borne disease in the Golestan province of Iran, with Phlebotomus papatasi (Scopoli, 1786) serving as the main vector. The aim of this study was to model the probability of presence of this species in the study area, and to determine the underlying factors affecting its distribution. Three villages were selected from each county of the province and visited monthly for investigating ZCL. Sticky paper traps were used for collecting the sand flies to determine the species present. The presence of Ph. papatasi was modeled using genetic algorithm for rule-set production (GARP) and maximum entropy (MaxEnt) techniques. Both models showed the central and northern parts of the province with lowland areas were more vulnerable to Ph. papatasi propagation, in comparison with the southern parts with mountainous and forest areas. The area under curve (AUC) of MaxEnt model for the training points was calculated as 0.90, indicating excellent performance of the model in predicting Ph. papatasi distribution. Jackknife test showed that the factors with the greatest influence in vector distribution were slope, vegetation cover, annual mean temperature, and altitude. By using ecological niche models, it is possible to identify areas with higher probability of presence of Ph. papatasi, which guides public health policy makers for planning better vector control interventions.

Spatial Distribution of Phlebotomine Sand Fly Species (Diptera: Psychodidae) in Qom Province, Central Iran

Zoonotic cutaneous leishmaniasis (ZCL) is transmitted to humans by phlebotomine sand fly bites. ZCL is a major health problem in Iran, where basic knowledge gaps about sand fly species diversity persist in some ZCL-endemic areas. This paper describes the richness and spatial distribution of sand fly species, collected with sticky traps, in Qom province, a ZCL-endemic area in central Iran, where sand fly fauna has been poorly studied. Collected species were mapped on urban and rural digital maps based on a scale of 1/50,000. All analyses were undertaken with rural- and urban-level precision, i.e., rural and urban levels were our basic units of analysis. After identifying the sand flies, high-risk foci were determined. For spatial analysis of vector species population, the entomological sampling sites were geo-referenced using GPS. Arc GIS 9.3 software was used to determine the foci with leishmaniasis vector species. Following the analyses, two genera (Phlebotomus and Sergentomyia) and 14 species were identified. Based on the mapping and sand fly dispersion analysis, the rural districts were categorized into three groups-infection reported, without infection, and no report. Based on Geographical Information System analyses, Kahak and Markazi districts were identified as high-risk foci with leishmaniasis vector species. These findings can act as a help guide to direct active control measures to the identified high-risk foci and, eventually, lead to reduction in incidence of the disease.

Bioassay evaluation of residual activity of attractive toxic sugar-treated barrier fence in the control of Phlebotomus papatasi (Diptera: Psychodidae)

BACKGROUND & OBJECTIVES

Phlebotomus papatasi is the main vector of the zoonotic cutaneous leishmaniasis (ZCL) in Qom Province and many other provinces of Iran. Attractive toxic sugar baits (ATSB) treated barrier fence is one of the new methods for controlling the vectors such as sandflies. The present study was designed to evaluate the residual activity of ATSB-treated barrier fence that was used in control of P. papatasi.

METHODS

Following the selection of villages in Markazi district of Qom Province, central Iran during 2015 for ATSB and ASB (bait containing no active ingredient) methods; barrier fences on the ground in front of the rodent's colony were installed. A total of four conical tubes were installed and fixed on surfaces of treated barrier net of dimension 25 Χ 25 cm at biweekly interval. In each conical tube, 10 sand flies were released and after 3 min of exposure they were transferred to sterile cups. After 24 h, the obtained results were recorded according to the survival and mortality rate of sandflies. These tests were carried out five days after the installation of barrier fences, and repeated every 15 days until the mortality rate decreased to 60-65%.

RESULTS

The bioassay tests results showed that the mortality rate of P. papatasi on ATSB-treated barrier fence for 5, 15, 30 and 45 days after spraying was 100, 95.83, 88.18 and 66.67% respectively, which decreased to 50.83% after 60 days.

INTERPRETATION & CONCLUSION

Persistence and residual activity of the active ingredient of the bait in the hot and dry climatic conditions of Qom Province remained significantly effective for at most 45 days, which subsequently decreased at a high rate. Hence, every 45 days barrier fences need to be impregnated with ATSB bait. The method also appeared cost-effective and could be practical in implementation of vector control programmes against ZCL.