Journal of Arthropod-Borne Diseases
Volume:1 Issue: 1, Jun 2007

Reports from the health center of Kerman Province, southern Iran showed an increasing of cutaneous leishmaniasis cases in Orzuieh Rural District, southwest of the province in 2003. The report encouraged the team to carry out an epidemi ological survey in the district during 2003-2004. The objectives were to determine the ecology of sand flies, potential reser voir hosts and human infection. A total of 1075 sand flies were collected by sticky traps and 7 species of sand flies were identified. They comprised 3 species of the genus Phlebotomus (P. papatasi, P. mongolensis and P. bergeroti) and 4 species of the genus Sergentomyia (S. sintoni, S. clydei, S. tiberiadis and S. baghdadis). P. papatasi was the predominant species of the genus Phlebotomus in indoors (90.3%) and outdoors (50.2%). Susceptibility tests on P. papatasi with DDT 4%. Showed that the species was susceptible to this insecticide. A total of 13 rodents consist of Tatera indica (76.9%) and Nesokia indica (23.1%) were collected. A study of prevalence among 2441 inhabitants in four villages showed a rate of 1.1% for active lesions and 10.4% for scars during November- December 2003. In a separate study examination of 1662 school children aged 6-12 years old showed 1.14% for ulcers and 14.7% for scars at the same time. The Leishmania parasites were isolated from man and characterized as Leishmania major using RAPD-PCR method. It seems that cutaneous leishmaniasis due to L. major (CLM) has been prevailed in the district.

An investigation was carried out during April to December 2000 to study mosquito fauna and ecology in Guilan Prov ince of northern Iran. The mosquito larvae were collected by dipping method and larval habitat characteristics recorded ac cording to hydro-ecological features. In total, 3937 larvae of the genus Culex from 92 larval breeding sites were collected. Six spe cies of the genus Culex; Cx. mimeticus, Cx. pipiens, Cx. theileri, Cx. tritaeniorhynchus, Cx. hortensis, and Cx. terri tans were identified in the province and respectively comprised 10.3%, 47.2%, 2.2%, 31%, 6.5%, and 2.8% of the samples. Most of the larvae were collected from the natural habitats (75.6%) such as river edges (6.5%), riverbed pools (28.2%), rain pools (47.8%), stream edges (9.4%), grasslands (1.9%), marshes (2.8%), and hoof-prints (3.4%) and others from artificial habitats (24.4%) including rice fields (32.1%), irrigation channels (7.1%), wells (16.4%), discarded concrete tubes (33.1%), dis carded tires (11.0%), and agricultural water-storage pools (0.3%). The ecology of Cx. pipiens and Cx. tritaeniorhynchus, which are the most prevalent species and potentially involved in the transmission of many pathogens to humans and domes ticated animals, must be extensively studied.

Ecology of Anopheles dthali was studied in Bandar Abbas County, where there is indigenous malaria. Anopheles dthali plays as a secondary malaria vector in the region. It is active throughout the year in mountainous area with two peaks of activity, whereas in coastal area it has one peak. There is no report of hibernation or aestivation for this species in the re gion. Precipitin tests on specimens from different parts showed that 15.6-20.8% were positive for human blood. This species usually rests outdoors. It has different larval habitats. Insecticides susceptibility tests on adult females exhibited susceptibil ity to all insecticides recommended by WHO. LT50 for the currently used insecticide, lambda-cyhalothrin, is measured less than one minute. The irritability tests to pyrethroid insecticides, showed that permethrin and lambda-cyhalothrin had more irritancy compared to deltamethrin and cyfluthrin. Larval bioassay using malathion, chlorpyrifos, temephos and fenithrothion did not show any sing of resistance to these larvicides at the diagnostic dose. It is recommended that all the decision makers should consider the results of our study for any vector control measures in the region.

The members of Anopheles maculipennis subgroup (Diptera: Culicidae) are the most important vectors of malaria in the north, west, and central plateau of Iran. This study was carried out to differentiate the species composition of this subgroup based on morphometric variation seta 2-IV and V (antepalmate hair) among 149 larval specimens that were deposited at the Medical Arthropods Museum, the School of Public Health, Tehran University of Medical Sciences by using the light micro scope. The mean numbers of larval seta 2-IV and V of the specimens belong to different locations of Iran, were calculated by SPSS (11.5) software package, followed by cluster analysis, and four different groups (clusters) were identified. The means were compared with the similar and available published data. After analyzing, four clusters recognized. The first cluster was fitted in ten localities in Esfahan, East Azarbaijan, West Azarbaijan, Khorassan, Kurdistan, and Mazandaran Provinces with its mean and standard deviation (SD) of 14.89±1.13 (n= 79); the second group with one location in Gilan Province (11±1.58, no= 5); the third one with two locations in Fars and Western Azarbaijan Provinces (27.43±0.31, n=20), and the final group with four locations in Khuzestan, West Azarbaijan, and Qazvin Provinces (36.84±1.91, n= 45) were identified and corresponded to Anopheles messeae, An. atroparvus, An. melanoon, and An. sacharovi respectively. This work provides comparative information on the Maculipennis Subgroup based on morphometric examination at the larval stage in Iran.

Visceral Leishmaniasis (Kala-azar) is a serious health problem in some northern and south western parts of Iran. The incidence of kala-azar caused by Leishmania infantum has recently increased in Nourabad-Mamassani district of Fars Province, in the south of the country. This study was designed to determine the role of asymptomatic dogs as host reservoir of L. infantum in this new formed focus and detection of prevalence of infection near them. A total of 20 as ymptomatic stray and sheep dogs were randomly sampled. The Buffy coat layer of their peripheral blood was used for DNA extraction and PCR. A species specific seminested PCR was used for DNA amplification using LINR4, LIN17 and LIN19 primers. These primers amplified variable area of the minicircle kDNA of Leishmania parasites. Of the 20 sampled dogs checked for leishmanial kDNA, six (30%) were found naturally infected. It is concluded that, dogs (Canis familiaris) even if asympto matic, is considered as the domestic host reservoir of kala-azar in this endemic focus.

A field trial was carried out in the Chabahar District of Sistan and Baluchistan Province, southeastern Iran on the efficacy of mosquito nets treated with a suspension formulation of deltamethrin (K-O THRIN®) against malaria vectors. Treated nets were used in three villages, and in the two control villages, one used untreated nets and the other used indoor spraying with deltamethrin (WP 10%), without nets. Treatment of polyester mosquito net with a target dose of 25 mg/m2 active ingredi ent, carried out in mid-April 2005. Bioassays repeated on domestically used nets over 7 months showed persistence of al most 100% mortality of Anopheles. stephensi over this period. Adult mosquitoes were collected by pyrethroid space spray catch of living quarters and stables, cattle bait and pit shelter catches. Overall, An. culicifacies Giles s.l predominated (49.8%), followed by An. stephensi Liston s.l.(36.9%), An. pulcherrimus Theobald (7.3 %), An. dthali Patton (5.7%) and An. fluviatilis James (0.3%). Acknowledge, Attitude and Practice (KAP) study showed that about 97% of respondents in communities agreed that they would like to participate in malaria control activities such as personal protection using im pregnation bed net. Therefore, in planning for future large scale trials, comparison of new compounds and formulations such as tablets and long lasting insecticides impregnated bed net is recommended.

Following the hospitalization of 195 individuals due to the spider bite in 1995 and three cases of recorded death in the year of 1993 which were referred to Emam Reza Hospital in Mashad, the present study was undertaken on bionomics and medical importance of Lathrodectus spp in Khorasan Province, during 1995-2005. A total cases of 195 bites were studied composing of 70.8 % males and 29.2% females. The most prevalence cases were observed in mid age (20-55 years old) and par ticularly among farmers (36.4%). A total number of 216 adult widow spiders and 258 egg sacs were collected from their habitats in different localities of 15 counties in the province. The following species have been recognized: Lathrodectus tredecimgottatus (62%), L. dahli (32%), L. geometricus (5%) and L. pallidus (1%). Here is the first report on the occurrence of males of L. pallidus as well as both sexes of L. trdecimgottatus and L. geometricus in the country. The sex ratio among collected specimens was 88% and 12% female and male, respectively. Summer provides the most suitable and favorable climatic condition for the activities of these spiders. However 65% of spiders were collected in this season. Among different cit ies, Mashad had (60%) the most reported cases in the study area. Foot was more injured than other parts. 96.5% of pa tients exhib ited localized pain from which only 2% had no pain in the bitten part and 87% had a generalized pain in whole body.

Ectoparasites of various species of rodents were examined from Sarepole Zehab, Kermanshah Province Iran during 2005. This city is bordered with Iraq. A total of 139 rodents included 6 species of hosts were captured during all different seasons and examined for ectoparasites using live trap. The area of study was mainly plateu (70%) and mountanous. The hosts including: Microtus socialis, Mus musculus, Rattus rattus, Nesokia indica, Meriones persicus and Tatera indica. The 9 species of ectoparasites recovered included 3 fleas (Pulex irritans, Xenopsylla buxtoni, Nosopsyllus medus), one sucking lice (Polyplax spinolosa), two ticks (Rhipicephalus sp., Hyalomma sp.), and 3 mites (Lealaps nuttalli, Dermanysus sanguineus, Ornithonussus bacoti). Among all arthropod collected, the lice and flea had the most and least frequency, i.e. 77.7% and 4.4%, respectivelly. The data showed that the ectoparasites on some rodent hosts tend to prefer particular host body sites, and that some ectoparasite species sites may overlap owing to their inaccessibility to the host.