Biodiversity of culicid mosquitoes in rural Neka township of Mazandaran province, northern Iran.

BACKGROUND & OBJECTIVES: This paper presents the results of a study on ecological parameters including diversity indices applied on populations of Culicidae mosquitoes (Diptera: Culicidae) from three rural areas (Darvishan, Chalmardi and Khairabad) of Neka township in Mazandaran province, northern Iran. METHODS: Adult and larval stages of mosquitoes were systematically sampled to obtain data required for measuring diversity of mosquitoes in these areas. Alfa and beta indices were analyzed to compare mosquito diversity. A total of 5270 specimens belonging to four genera and 14 different species were collected and identified. RESULTS: Evaluation of dominance structure of species showed that culicid mosquitoes of Neka rangelands include one eudominant species, two dominant species, two subdominant species, two rare species and eight subrare species when Heydemann classification was used. INTERPRETATION & CONCLUSION: Data analysis revealed a higher diversity of mosquitoes in Khairabad with a low degree of interspecific dominance, while Darvishan and Chalmardi recorded the lowest observed diversity and a high degree of interspecific dominance. The cluster analysis based on Jaccard's index indicated the relationship between the categories and indicates that Darvishan and Khairabad are the closest categories in their specific composition.

Field evaluation of phostoxin and zinc phosphide for the control of zoonotic cutaneous leishmaniasis in a hyperendemic area, central Iran.

BACKGROUND & OBJECTIVES: ZCL is a growing threat in many rural areas of Iran which involves 17 out of 31 provinces. This study was conducted from April to November 2011 for evaluation of the efficacy of phostoxin and zinc phosphide against rodents. METHODS: Rodent control operations were carried out using phostoxin and zinc phosphide. To evaluate the effect of rodent control operation on the main vector density, an entomological survey was carried out. The effects of the operation on the disease incidence were also evaluated. RESULTS: After intervention, the reduction rate of rodent burrows was 32.68% in the village treated with phostoxin and 58.14% in the village treated with zinc phosphide. The number of rodent holes in the control area showed 6.66-fold increase at the end of the study. The incidence of the disease decreased to 19.23 and 11.40 in areas treated with phostoxin and zinc phosphide, respectively. A total of 4243 adult sandflies were collected and identified. The most common and dominant species was Phlebotomus papatasi. In the village treated with phostoxin, the density of P. papatasi in outdoors was lower than indoors. Nevertheless, the density of P. papatasi in the village treated with zinc phosphide was higher in outdoors. INTERPRETATION & CONCLUSION: It is concluded that phostoxin is less effective and has low safety in comparison with zinc phosphide, so that this rodenticide can be used only in special situations such as lack or ineffective rodenticides and only in the colonies far from human and animal dwelling places in small scales.

Baseline insecticide susceptibility data of Phlebotomus papatasi in Iran.

BACKGROUND & OBJECTIVES: Phlebotomine sandflies (Diptera: Psychodidae) play main role in the transmission of different forms of leishmaniasis in the world. Phlebotomus papatasi is the main vector of zoonotic cutaneous leishmaniasis (ZCL) in Iran. There are several control measures for vector control using different classes of insecticides. The aim of this study was to breed the sandflies which were collected from a hyperendemic focus of the disease in central Iran in the laboratory condition and to determine its baseline susceptibility to commonly used insecticides. METHODS: Sandflies were collected from the field and were reared in insectary. Susceptibility tests were carried out on their generation. Baseline susceptibility of sandflies to DDT and pyrethroids was evaluated based on LT50 values. A total of 1305 specimens were tested using different time intervals. The LT50 and LT90 values were measured according to the WHO standard tests. The results were plotted using probit analysis and regression lines. RESULTS: The results against female sandflies revealed the LT50 values of 1312.66, 253.66, 36.04, 9.38 and 6 sec to DDT (4%), permethrin (0.75%), deltamethrin (0.1%), cyfluthrin (0.15%) and lambda-cyhalothrin (0.05%), respectively. The figures for male sandflies were 1200.97, 310.10, 18.63, 6.08 and 0.77 sec respectively to the above insecticides. CONCLUSION: The results of this study could help to provide a clue for implementation of currently used insecticides. Furthermore, a specific guideline is needed for monitoring and evaluation of insecticide susceptibility test against sandflies.

Dynamics of Leishmania infection rates in Rhombomys opimus (Rodentia: Gerbillinae) population of an endemic focus of zoonotic cutaneous leishmaniasis in Iran.

Zoonotic cutaneous leishmaniasis (ZCL) due to Leishmania major is a great public health problem in the Old World. Leishmania major is widely distributed in populations of rodents in arid and savannah regions. In this study, seasonal variation of natural infection with Leishmania parasites in Rhombomys opimus (Rodentia: Gerbillinae) population of an endemic focus of ZCL in Iran was monitored. The study was conducted from October 2007 to October 2008 in the central part of the country. Nested polymerase chain reaction (PCR) assay was used for the detection and identification of Leishmania parasites, and the results were confirmed by PCR-restriction fragment length polymorphism (RFLP). The results showed that Leishmania infection rate was 55.8% (29 out of 52 gerbils) using nested PCR. The highest and lowest Leishmania infection rates were observed in fall and summer, respectively. Gerbils that were found to be infected only with L. major were 5.8%, and that with Leishmania turanica were 23.1%. A mixed natural infection was seen in the rodents with L. major and L. turanica (21.2%), with L. major and L. gerbilli (1.9%), and with all the three species (3.9%). Leishmania major infection alone was seen in fall and winter whereas mixed infection of L. major and L. turanica was observed in all seasons except in summer. Leishmania turanica infection was observed throughout the year. It is concluded that L. major, L. gerbilli, and L. turanica circulate in the population of R. opimus in central part of Iran. Leishmania major infection is usually accompanied by L. turanica in naturally infected gerbils with the highest rate in fall. It is recommended that the role of L. turanica in the epidemiology and transmission of ZCL should be reconsidered.

Distribution and ecology of mosquitoes in a focus of dirofilariasis in northwestern Iran, with the first finding of filarial larvae in naturally infected local mosquitoes.

A study of the distribution and ecology of mosquitoes (Diptera: Culicidae) in Ardebil Province of northwestern Iran, with special reference to the known dirofilariasis focus in Meshkinshahr County, was carried out in July-August 2005 and April-October 2006. In total, 17,533 adult mosquitoes and 3090 third- and fourth-instar larvae were collected on 14 occasions and identified using morphological characters and DNA sequence data. Twenty species belonging to seven genera were found: Anopheles claviger (Meigen), An. hyrcanus (Pallas), An. maculipennis Meigen, An. pseudopictus Grassi*, An. sacharovi Favre, An. superpictus Grassi, Aedes vexans (Meigen)*, Coquillettidia richiardii (Ficalbi)*, Culex hortensis Ficalbi, Cx. modestus Ficalbi, Cx. pipiens Linnaeus, Cx. theileri Theobald, Cx. torrentium Martini*, Cx. tritaeniorhynchus Giles, Culiseta longiareolata (Macquart), Cs. annulata (Schrank)*, Cs. subochrea (Edwards), Ochlerotatus caspius (Pallas) s.l.* (= Aedes caspius sensu auctorum), Oc. geniculatus (Olivier)* (= Aedes geniculatus sensu auctorum) and Uranotaenia unguiculata Edwards (asterisks indicate new occurrence records for the province). The most prevalent species in adult catches were An. maculipennis (52%), Cx. theileri (45%) and Cx. hortensis (1%); the most prevalent species caught as larvae were Cx. theileri (27%), Cx. hortensis (21%) and An. maculipennis (19%). Anopheles maculipennis, Cx. pipiens and Cx. theileri were most widely distributed in the province. The occurrence of Cx. torrentium in Iran is verified based on differential characters of fourth-instar larvae. Anopheles maculipennis and An. sacharovi of the Maculipennis Group were identified from their diagnostic ITS2 sequences. For the first time, cytochrome c oxidase I (COI) sequences were obtained from Iranian specimens of An. hyrcanus, An. pseudopictus, Cx. theileri and Oc. caspiuss.l. Culex theileri and An. maculipennis were found naturally infected with third-stage (infective) larvae of Dirofilaria immitis (Leidy) and Setaria labiatopapillosa (Alessandrini) (Spirurida: Onchocercidae), respectively, for the first time in Iran.

Population structure and geographical subdivision of the Leishmania major vector Phlebotomus papatasi as revealed by microsatellite variation.

Multi-locus microsatellite typing (MLMT) has been employed to infer the population structure of Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae) sandflies and assign individuals to populations. Phlebotomus papatasi sandflies were collected from 35 sites in 15 countries. A total of 188 P. papatasi individuals were typed using five microsatellite loci, resulting in 113 different genotypes. Unique microsatellite signatures were observed for some of the populations analysed. Comparable results were obtained when the data were analysed with Bayesian model and distance-based methods. Bayesian statistic-based analyses split the dataset into two distinct genetic clusters, A and B, with further substructuring within each. Population A consisted of five subpopulations representing large numbers of alleles that were correlated with the geographical origins of the sandflies. Cluster B comprised individuals collected in the Middle East and the northern Mediterranean area. The subpopulations B1 and B2 did not, however, show any further correlation to geographical origin. The genetic differentiation between subpopulations was supported by F statistics showing statistically significant (Bonferroni-corrected P < 0.005) values of 0.221 between B2 and B1 and 0.816 between A5 and A4. Identification of the genetic structure of P. papatasi populations is important for understanding the patterns of dispersal of this species and to developing strategies for sandfly control.

First detection of Leishmania infantum in Phlebotomus (Larroussius) major (Diptera: Psychodidae) from Iran.

Ghir-Karzin district is one of the most important endemic foci of visceral leishmaniaisis (VL) in Fars province of southern Iran. To identify the vector(s) of Leishmania in this focus, a total of 2,539 sand flies were collected during June to September 2005. Eleven species (six Phlebotomus and five Sergentomyia) were identified, of which Phlebotomus papatasi Scopoli and Phlebotomus major Annandale were the first (37.4%) and third (11.2%) most common species, respectively. Natural leptomonad infections were observed in two P. papatasi (4.25%) and three P. major (6.65%) specimens on dissection and microscopic examination. Using a Leishmania genus-specific standard polymerase chain reaction (PCR; primers RV1-RV2) and a species-specific nested-PCR (primers LINR4, LIN17, and LIN 19), Leishmania infantum and Leishmania major kinetoplast minicircle DNA was detected in 6 of 72 P. major (8.3%) and 4 of 65 P. papatasi (6.1%), respectively. This is the first detection of L. infantum in P. major, implicating this sand fly as a probable vector of VL in Iran.

Genetic Population Diversity of Aedes caspius in Southern Provinces of Iran.

Aedes caspius has a wide distribution throughout the world and can transmit Chikungunya virus, West Nile Virus (WNV), Tahyna virus and the bacterium Francisella tularensis. Sequences of the mitochondrial cytochrome C-oxidase subunit 1 (COI) and cytochrome C-oxidase subunit 2 (COII) genes have been widely used to estimate phylogenetic relationships at different taxonomic levels among this species. Adult collections were carried out by human bait, Center for Deseases Control Light Traps (CDC-LT) and aspirator during February/April, June and October/December 2013-2015 from different southern provinces of Iran and then identified morphologically with reliable keys. A total of 3,570 adult mosquitoes were collected and identified as belonging to three genera, including five species of Culex, six species of Aedes and one species of Culiseta. In this study, 1,796 specimens of Aedes caspius were identified from four provinces. Based on the COI and COII sequences obtained for Ae. caspius population, 12 and 11 haplotypes were identified, respectively. The present study evidenced a high degree of intraspecific variation among these populations of Ae. caspius.

Aedes caspius largement distribué dans le monde est le vecteur du virus du chikungunya, du virus West Nile, du virus Tahyna et de la bactérie Francisella tularensis. Les séquences des gènes mitochondriaux COI et COII sont généralement utilisées pour estimer les relations phylogénétiques entre les différents niveaux taxonomiques de cette espèce. Des moustiques adultes ont été collectés sur appâts humains, à l'aide de pièges lumineux de type « CDC/light-trap ¼ et d'aspirateurs en février/avril, juin et octobre/décembre 2013­2015 dans les provinces au sud de l'Iran. Les moustiques ont ensuite été identifiés d'un point de vue morphologique. Trois mille cinq cent soixante-dix moustiques adultes ont été collectés et identifiés comme appartenant à trois genres, dont cinq espèces de Culex, six espèces d'Aedes et une espèce de Culiseta. Dans cette étude, 1 796 spécimens d'Aedes caspius ont été identifiés dans quatre provinces. Les séquences COI et COII des populations d'Ae. caspius ont permis d'identifier respectivement 12 et 11 haplotypes. Les résultats de cette étude ont démontré qu'il existe une forte variation intraspécifique dans ces populations d'Ae. caspius.

Geographical variation in populations of Phlebotomus (Paraphlebotomus) caucasicus (Diptera: Psychodidae) in Iran.

A comparative morphological and molecular study was carried out on 11 different populations of Phlebotomus (Paraphlebotomus) caucasicus Marzinovsky 1917 caught in 7 provinces in Iran (2004-2005). Differences in the implantation level of the two distal spines of the style, the number of setae of the basal lobe of coxite, and the length of the third antennal segment, revealed the existence of two morphotypes within P. (Pa) caucasicus, a species having a confused history if we take into account an unclear synonymisation with Phlebotomus (Paraphlebotomus) grimmi Porchinsky 1874. Sequencing of mtDNA (a fragment of cytchromeB gene, tRNA for serine gene and a fragment of NADH1 gene) and Neighbour-Joining analysis showed a partial correlation between morphotypes and haplotypes. We also found a correlation between the latter and the geographical origin of the specimens. These results need further studies in order to appreciate the role of each morphotype/haplotype in the transmission of Leishmania major.

Morphological studies on adult mosquitoes (Diptera: Culicidae) and first report of the potential Zika virus vector Aedes (Stegomyia) unilineatus (Theobald, 1906) in Iran.

Beside numerous extensive studies on Anophelinae mosquitoes of Iran, little is known on Aedes species in the country and existing reports are dispersed. The objective of this study was to identify adults of Culicinae species occurring in the Sistan and Baluchestan Province, southeast of Iran, during 2012-2014. Mosquito collections were carried out three times (May-June, September, October-November) in four counties by Centers for Diseases Control (CDC) light traps and human landing catches outdoors and under bed nets baited with carbon dioxide. These trapping were carried out two consecutive nights during the field studies. Several mosquito collections were also conducted with aspirator and pyrethrum spray space catches during the day. A total of 1885 mosquitoes were collected, belonging to 10 species of genus Culex including Cx. pipiens Complex, Cx. laticinctus, Cx. sinaiticus, and Cx. tritaeniorhynchus, one species of the genus Culiseta, Cs. longiareolata, and five species of the genus Aedes, Ae. caspius, Ae. vexans, Ae. detritus, Ae. albopictus, and Ae. unilineatus. Ae. vexans was the dominant species in the area (77.7%). During the study, seven Ae. unilineatus were collected in two villages near the city of Chabahar located in a coastal area; this is the first record for Iran and identification was confirmed by Cytochrome oxidase (COI) sequences analysis. Confirmation of the presence of Ae. unilineatus in the country raises the number of species of the genus Aedes to 12. The detection of this species reveals its probable establishment in the southeast of the country, which has implications for public health such as dengue and Zika infections and requires active entomological surveillance and implementation of adapted vector control measures in the area.

Evaluation of deltamethrin-impregnated bed nets and curtains for control of zoonotic cutaneous leishmaniasis in a hyperendemic area of Iran.

In the study carried out in the rural district of Borkhar (Isfahan, Iran) from March 2003 to March 2004 efficacy of deltamethrin impregnated bed nets (IBs) and curtains (ICs), polyester mesh size 156 holes/ inch2, (25 holes/cm2) were compared to that of non-impregnated bed nets (NIBs) and curtains (NICs), in relation to zoonotic cutaneous leishmaniasis (ZCL) control. Deltamethrin impregnated bed nets and curtains at 25 mg a.i./m2 were distributed among 168 households in one of the villages and NIBs plus NICs among the same number of households in another village. In the third village similar numbers of households were used as control. Health education messages were disseminated to ensure the population's compliance with the proper use of bed nets and curtains in the two intervention areas. Entomological surveys using sticky paper traps were carried out in ten households in each village for the collection of sand flies from indoors and outdoors, every two weeks to assess the impact of insecticide impregnated bed nets and curtains on the density of Phlebotomus papatasi. Deltamethrin susceptibility tests and also bioassay tests were carried out on this species by WHO standard method. Case findings were done by house-to-house visits once a season and all the inhabitants of the selected households in each village were examined. The results showed that IBs and ICs can provide a definite personal protection against sand fly bites and interrupted the transmission of ZCL in the intervention village. NIBs and NICs did not provide any protection against the disease. There was no significant difference in monthly density of P. papatasi in indoors and outdoors among the villages (P > 0.05). Susceptibility tests showed that this species was susceptible to deltamethrin in the field population in the area. Bioassays confirmed that the treated nets with deltamethrin remain effective for more than three months and was an excellent mean of individual protection. It is recommended that IBs and ICs can be used widely in the control of ZCL in other similar foci such as hyperendemic and mesoendemic areas of Iran.

Predicted Distribution of Visceral Leishmaniasis Vectors (Diptera: Psychodidae; Phlebotominae) in Iran: A Niche Model Study.

Visceral leishmaniasis (VL) is an important vector-borne disease in Iran. Till now, Leishmania infantum has been detected from five species of sand flies in the country including Phlebotomus kandelakii, Phlebotomus major s.l., Phlebotomus perfiliewi, Phlebotomus alexandri and Phlebotomus tobbi. Also, Phlebotomus keshishiani was found to be infected with Leishmania parasites. This study aimed at predicting the probable niches and distribution of vectors of visceral leishmaniasis in Iran. Data on spatial distribution studies of sand flies were obtained from Iranian database on sand flies. Sample points were included in data from faunistic studies on sand flies conducted during 1995-2013. MaxEnt software was used to predict the appropriate ecological niches for given species, using climatic and topographical data. Distribution maps were prepared and classified in ArcGIS to find main ecological niches of the vectors and hot spots for VL transmission in Iran. Phlebotomus kandelakii, Ph. major s.l. and Ph. alexandri seem to have played a more important role in VL transmission in Iran, so this study focuses on them. Representations of MaxEnt model for probability of distribution of the studied sand flies showed high contribution of climatological and topographical variables to predict the potential distribution of three vector species. Isothermality was found to be an environmental variable with the highest gain when used in isolation for Ph. kandelakii and Ph. major s.l., while for Ph. alexandri, the most effective variable was precipitation of the coldest quarter. The results of this study present the first prediction on distribution of sand fly vectors of VL in Iran. The predicted distributions were matched with the disease-endemic areas in the country, while it was found that there were some unaffected areas with the potential transmission. More comprehensive studies are recommended on the ecology and vector competence of VL vectors in the country.

Some Epidemiological Aspects of Cutaneous Leishmaniasis in a New Focus, Central Iran.

Following the epidemic of cutaneous leishmaniasis in Khatam County, Yazd Province, this study was carried out to determine vector, and animal reservoir host(s) and investigate the human infection during 2005-2006. Four rural districts where the disease had higher prevalence were selected. Sticky paper traps were used to collect sand flies during April to November, biweekly. Meanwhile rodents were captured using Sherman traps from August to November. Households and primary schools were visited and examined for human infection in February 2006. The parasite was detected by RAPD-PCR method. The rate of ulcers and scars among the inhabitants was 4.8% and 9.8%, respectively. Three rodent species were captured during the study: Meriones libycus, Rhombomys opimus, and Tatera indica. Six sand fly species were also collected and identified; among them Phlebotomus papatasi had the highest frequency. Leishmania major was detected as the agent of the disease in the area. It was detected from R. opimus and native people.

Meriones libycus and Rhombomys opimus (Rodentia: Gerbillidae) are the main reservoir hosts in a new focus of zoonotic cutaneous leishmaniasis in Iran.

Following an epidemic of zoonotic cutaneous leishmaniasis (ZCL) around Badrood city, central Iran, Meriones libycus were found to be naturally infected with Leishmania major zymodeme MON-26 (= LON-1) in the villages of Matinabad and Fami, 12 km north-west of Badrood. This is the first isolation and characterization of L. major from M. libycus in Iran, in an area where ZCL has been present recently. M. libycus is probably the principal reservoir host in this area, but the main reservoir host further east is Rhombomys opimus. Parasites were not found in Hemiechinus auritis. The main, proven vector to humans and gerbils is Phlebotomus (Phlebotomus) papatasi. The close contact between vectors and reservoirs creates a very efficient cycle for the transmission of the disease.

The isolation of Leishmania major from Phlebotomus (Paraphlebotomus) caucasicus, in Isfahan province, Islamic Republic of Iran.

As part of a general survey of leishmaniasis and sandflies in the focus of zoonotic cutaneous leishmaniasis (ZCL) at Borkhar, a rural district north of the city of Isfahan, central Iran, Phlebotomus (Paraphlebotomus) caucasicus Marzinowsky from gerbil and jird burrows were found naturally infected with Leishmania major, zymodeme MON-26 (= LON-1). This is the first characterized isolate of L. major from a sandfly vector in Iran.

Bionomics of Anopheles sacharovi in Ardebil province, northwestern Iran during a larval control program.

Studies were conducted on the ecology of Anopheles sacharovi over a period of 12 months in Parsabad and Germi counties, Ardebil province, Iran. The species was active from June to late November with one peak of activity in early August on the plain of Parsabad, and from late June to late November with one peak of activity in late August in mountainous areas of Germi. Chemical analysis of the water in larval habitats showed that the water contained calcium bicarbonate and sodium sulphate, and the limit of salinity was 263--414 mg/l. Dissection of A. sacharovi from three villages during July in Parsabad indicated a very low parity rates all were found negative for sporozoites. ELISA testing of 210 blood meals of the species, showed that few of those found in cowsheds or chicken coops had fed on humans, but of those found in bedrooms 38.5% had fed on humans. Insecticide susceptibility tests showed that the species is susceptible to malathion and propoxur but resistant to DDT and dieldrin.

Host preference pattern of phlebotomine sandflies of Borkhar rural district, Isfahan province, Iran.

Blood meals from 400 engorged Phlebotomine sandflies belonging to three species collected in 6 villages from Borkhar rural district were identified by enzyme linked immunosorbent assay (ELISA). Out of 388 blood meals of Phlebotomus papatasi 29.6-44.6% were human blood, 8.4% dogs' blood and 0.6% cows' blood, indicating a strong preference for man. Double blood meals of human-dog and human-cow were observed in 0.9% and 3.08% P. papatasi respectively. Phlebotomus caucasicus was relatively anthropophilic and the human blood index in this species was 20%. Sergentomyia sintoni was negative for man and cow blood. Phlebotomus papatasi appears to be predominantly anthropophilic and makes the central part of Iran an area of high risk for leishmaniasis.

Entomological survey of sandflies (Diptera: Psychodidae) in a new focus of zoonotic cutaneous leishmaniosis in Iran.

A total of 22,982 sandflies representing six species were collected using sticky (oiled) paper traps in Badrood rural district, Natanz county from May 1995 to May 1996. Phlebotomus papatasi was the predominant species. The average indoor resting density of P. papatasi ranged from 11.8 (May 1995) to 135.8 per 10 traps (September 1995). The average indoor resting density of this species varied between 39.7-701.3 per 10 traps in May and September, respectively in 1995. The activity of P. papatasi starts from late April or early May and extends to mid October with two peaks, one in mid or late June and the second one in early or mid September. Natural leptomonad infection was found in P. papatasi and Sergentomyia sintoni. P. papatasi could be a vector of humans and gerbils and it is susceptible to DDT in this area.

Leishmania major MON-26 isolated from naturally infected Phlebotomus papatasi (Diptera: Psychodidae) in Isfahan Province, Iran.

In a survey of leishmania infections in phlebotomine sandflies in one of the most important focus of zoonotic cutaneous leishmaniasis (ZCL) at Borkhar, a rural district north of the city of Isfahan, central Iran, Phlebotomus (phlebotomus) papatasi Scopoli from gerbil and jird burrows were naturally infected with Leishmania major zymodeme MON-26. This is the first isolation and characterization of L. major from P. papatasi in Iran, from an area where human and rodent infections with L. major have been present for a very long time.

Epidemiological study in a new focus of cutaneous leishmaniosis due to Leishmania major in Ardestan town, central Iran.

An endemic focus of zoonotic cutaneous leishmaniosis caused by Leishmania major zymodeme MON-26 was identified in Ardestan town central Iran, during 1998-99. Among 1960 school children examined over a 1-year period of time, 0.92% had evidence of active lesions and 1.53% had scar indicative of past infection. The incidence of the disease among school children was 3.2 per thousand in 1998. In a separate study, the incidence of infection among 100 households in an area with a population of 460 persons showed 3.26% for scars and 1.3% for ulcers. The most highly infected age group was 10-14 with a rate of 2.74%. Meriones libycus (93.3%) and Nesokia indica (6.7%) were present around the town of Ardestan. Both were found to be infected with Leishmania. Two out of 28 M. libycus (7.1%) and one out of two N. indica had positive results. M. libycus is probably the principal reservoir host of zoonotic cutaneous leishmaniosis in this area. Fourteen dogs appeared to be uninfected because examination showed no active lesion or scar. Most probably Phlebotomus papatasi is the vector because about 93% of indoor sandflies were of this species. The active season of sandflies was from late May to late October. Economic changes in this area of Iran may have contributed to this outbreak of cutaneous leishmaniosis.