Studies on Drug Sensitivity in Leishmania donovani Field Isolates and Differential Gene Expression Analysis in Miltefosine Resistant Parasites

Abstract

Leishmaniasis is a group of diseases with wide epidemiological and clinical newlinediversity caused by protozoan parasite, Leishmania. The disease is endemic in large areas newlineof the tropics, subtropics and the Mediterranean basin. Leishmaniasis is characterized by newlineboth diversity and complexity (Herwaldt, 1999): it is caused by more than 20 Leishmania newlinespecies and is transmitted to humans by more than 30 different species of Phlebotomine newlinesandflies (Pearson and Sousa, 1996). newlineThe two major clinical forms of Leishmaniasis, cutaneous and visceral, are the newlineresult of infection by different species of the parasite. However, in addition to the newlineinfecting species, the clinical outcome of Leishmaniasis also depends on the immune newlineresponse of the host (Rivas et al., 2004). Environmental risk factors such as massive newlinedisplacement of populations, urbanization, deforestation, new irrigation plans and newlineindividual risk factors such as HIV, malnutrition and genetic susceptibility make newlineLeishmaniasis an important public health problem (Desjeux, 2004).Visceral Leishmaniasis (VL) is a lethal, disseminated form of this infection newlinecaused by L donovani/ L infantum and stands second only to malaria as a parasitic cause newlineof death. Prevalent in 70 countries, 90% of the VL cases occur in India, Bangladesh, newlineNepal, Brazil and Sudan (Desjeux, 2004). India alone shares almost 50 % of the world`s newlineglobal VL burden. In India, states of Bihar, Uttar Pradesh and West Bengal are highly newlineendemic foci of VL or kala azar (KA) where periodic epidemics are common (Adhya et newlineal., 2002). The official estimate of 430,000 VL cases in Bihar state over the past 11 years newlinemay represent only a fraction of the real numbers.