Leishmaniasis includes two major diseases, cutaneous leishmaniasis and visceral leishmaniasis, caused by more than 20 different leishmanial species. Cutaneous leishmaniasis, the most common form of the disease, causes skin ulcers, and is the form upon with the Sabin PDP focuses. Visceral leishmaniasis is more rare, but causes a severe systemic disease that is usually fatal without treatment. Leishmaniasis is transmitted by the bite of  a sand fly. Many leishmanial species infect animals as well as humans. The distribution is worldwide, but 90% of visceral leishmaniasis cases occur in India, Bangladesh, Nepal, Sudan, Ethiopia and Brazil, while 90% of cutaneous leishmaniasis cases occur in Afghanistan, Algeria, Iran, Saudi Arabia, Syria, Brazil, Colombia, Peru and Bolivia.