[Prevalence of IL18-607A/C polymorphism in patients with visceral leishmaniasis]

Visceral leishmaniasis [VL] is a parasitic disease caused by a protozoan of Leishmania genus and in Iran by Leishmania infantum. The protective immune response against VL is cellular immunity through Th1 CD4+, which dominant chemokiens are IL12, IFN-alpha and IL18 and lead to Th1 response. Single nucleotide polymorphism [SNP] on IL-18 gene and its relation to IL18 levels in blood and IL18 function have been studied in many inflammatory diseases such as Behcect's disease and tuberculosis. According to the important role of IL-18 in immunity against visceral leishmaniasis, this study was conducted to demonstrate the prevalence of genotypes on-607A/C in promoter region of IL-18 gene. This descriptive and cross-sectional study was done on 91 pateints with confirmed VL, 105 healthy sero-negative controls and 78 seropositive controls during 1999-2009. Salting out method was used to extract DNA and ARMS-PCR was used to determine the genotype of-607A/C allele of individuals. Statistical analysis of genotypes was performed using Chi-Square test. According to the results,-607C/C was the dominant genotype among the groups [35.8%]. Distribution of genotypes among groups had not any significant difference. The lowest genotype among healthy sero-positive and patients were-607A/C and-607A/A, respectively. Statistical analysis of distribution of genotypes, did not reveal any significant difference among groups. The dominant genotypes of VL patients, healthy sero-negatives and healthy seropositives were-607C/C [38.5%],-607A/C [37.1%] and-607C/C [35.9%] respectively

[Comparison of nomadic and non-nomadic lifestyles in transmission of visceral leishaniasis]

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. 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. Both MST and DAT were significantly higher in the nomadic lifestyle than in the nonnomadic 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. 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