From what I've learnt by browsing the Internet since seeing this topic, there are different types of leishmaniasis and not all respond to the same type of treatment.
I have also seen emphasis given to early analysis and diagnosis of leishmaniasis, followed by appropriate treatment.
With symptoms showing after a sandfly bite, if I would even know that it was a sandfly, I would not trust myself to self-analyse, self-diagnose and initiate self-treatment.