**1.1 Leishmaniasis**

The neglected tropical diseases (NTDs) are a group of about 17 parasitic diseases. The NTDs are prevalent in many tropical and subtropical countries that present the most common illness of the poorest people worldwide [1]. *Leishmania* infection constitutes a foremost public health issue with a rising burden over the last decade and is the second main cause of disease and death [2]. Leishmaniasis is prevalent in 102 countries/areas worldwide [3]. *Leishmania* infection affects approximately 1.5–2 million people, while 350 million are at risk of this pathogen [4, 5]. The causative agent of leishmaniasis is parasite protozoa of the genus *Leishmania* and is transferred via vector sandfly bite belongs to genus *Lutzomyia* and *Phlebotomus* [6].

Three clinical forms of leishmaniasis have been reported concerning parasite location in the infected tissues, that is, visceral leishmaniasis (VL) which is a less common type of leishmaniasis and it causes spleen and liver destruction and causes death if does not receive timely treatment; cutaneous leishmaniasis (CL), which affect only localized skin parts; and mucocutaneous leishmaniasis (MCL), which has the ability of mucus tissue destruction [7, 8]. About 0.7–1.2 million CL and 0.2–0.4 million VL cases are reported annually. Approximately CL cases (90%) are spread across three main areas, that is, (a) Syria, Afghanistan, Saudi Arabia, and Iran; (b) Tunisia and Algeria; and (c) Peru and Brazil [9, 10]. Annual visceral leishmaniasis (VL) cases are estimated to be less than 100,000, down from 400,000 in previous estimates [11], with more than 95% of cases reported to the World Health Organization (WHO) from Brazil, China, Ethiopia, India, Kenya, Nepal, Somalia, and Sudan. Currently, 54 *Leishmania* spp. are known and twenty-one are human's pathogenic [8].
