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Background & Objective: Despite their very wide geographical distribution in the Mediterranean region, most Leishmania infantum strains belong to zymodeme MON-1. As different Leishmania species are known to cause different clinical symptoms and may require different treatment protocols, therefore this study was done to identify and characterize the leishmania agents causing visceral, Leishmaniasis (VL) in humans, reservoirs and vectors in the north-west of Iran by Isoenzyme analyses. Materials & Methods: In this descriptive and cross sectional study, The samples collected from 12 VL confirmed patients (bone marrow aspirates), 26 dogs (spleen and hepatic aspirates) and more than 100 sand flies from northwest of Iran between 2005 and 2006. All aspirated material from human, canine and sandflies demostrated growth of Leishmania parasite in NNN and αMEM media. The above species compared with WHO reference strains, Leishmania (Leishmania) donovani (DD8), L (L) infantum (IPT-1), L (L) tropica (K-27), and L(L) major (5-ASKH), using thin layer starch gel electrophoresis. The enzymes investigated in this study were ALAT, ASAT, SOD, ES,NH, MPI, GPI, MDH, 6PGD, PGM, PEPD, and PDK. Results: In this study L.infuntum. MON-1 was the only zymodeme present in all samples of dogs and human sandflies. Conclusion: We concluded that the visceral Leishmania (VL) focus in northwest of Iran is evidently Mediterranean type, which extends from Portugal and Morocco to Pakistan and the Central Asia and domestic doges act as the reservoir host in northwest of Iran, where the complete life cycle of zymodeme MON-1 has been identified.

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Background and Objective: Epidemiology of Visceral Leishmaniasis is affected by combination quality and interaction of Parasite-Vector-Host and environmental conditions. So, disease cycle related and eco-social factors and environmental risk factors co-analyzing, help to understanding these interactions, prognosis and orientation in disease control and treatment. This study was done to determine the role of nomadic and non-nomadic lifestyle in transmission of Kala-Azar in the Northwest of Iran.

Materials and Methods: In this case-control study, firstly the prevalence of Kala-Azar among people living in selected villages were determined by both serological test (Direct Agglutination Test: DAT) and immunological test (Montenegro Skin Test: MST) in the Northwest of Iran, on the way of Shahsavan tribe travelling in summer/winter quarters villages. Then DAT was conducted on the dogs presenting in those villages during 2006. One year later Seroconversion rate was calculated through collection of the individual’s negative sera and re-analyzing them via DAT. Finally, occurrence of Visceral Leishmaniasis in relation with various involving factors like dog density/abundance and nomadic and non-nomadic lifestyle using Chi-Square test were determined.

Results: Both MST and DAT were significantly higher in the nomadic lifestyle than in the non-nomadic lifestyle (P<0.05). Three values of prevalence (5.5%), seropositivity (2.7%) and seroconversion (2.5%) were higher in nomads than non-nomads. The GIS studies and electronically prepared maps showed that the endemicity and the infection rate are higher in nomads than non-nomads. There were a negative correlation between general distribution of Visceral Leishmaniasis in relation with environmental conditions altitude, mean temperature and rainfall.

Conclusion: This study indicated that Nomadic lifestyle can play as a risk factor in transmission of Visceral Leishmaniasis due to nomads/dog contacting, their entering in the wild cycle of disease and travelling.