**5. Vector control using PDT**

The field of insect photo-killing by administration of photosensitizer molecules and light exposition (usually sun light) is one of the areas of possible PDT application that has received smallattentionofthescientific community[60-63].Thefewstudies,whichweremainlyreported by Jori and co-authors, sustain thatthere is indeed great potential on this area. There are reports showing that the PS activity is a function of its log POW value and of its amphiphilic character [62,63]. PDT was also shown to be efficient for Larva control of dengue vector *Aedes aegypti*[60]. However, there is no scientific report on the use of PDT to control the vector (*Phlebotomus* sand flies) and its larva, which are responsible forthe transmission the leishmania parasites.It is also important to emphasize that the amount of information available concerning larva develop‐ ment of phlebotomine sand flies is much less than what is known for the mosquitoes whose control have been studied by PDT. Nevertheless, for the matter of bringing new ideas to the field of *Leishmania* treatment, the concentration of photosensitizers that are needed to neutral‐ ize larva and to killthose mosquitoes is several orders of magnitude smallerthan the concentra‐ tions of chemical insecticides, which are currently used for vectors control, causing great disturbance in the whole ecosystem. Therefore, it is up to our community to develop and test strategies to control vectors of *Leishmania* parasites using PDT.

## **6. Blood purification**

CG: control group / GA: group A / GB: group B

400 Leishmaniasis - Trends in Epidemiology, Diagnosis and Treatment

tegumentary leishmaniasis in murine models

**Table 1.** Parameters used in PDT to the treatment of Old World tegumentary leishmaniasis and New World

The purification of blood products is critical to avoid disease transmittance through blood transfusion. Although this is not the main route of transmission of leishmaniasis, it is a possible one, and cases have been reported in the literature [64]. The focus of the disinfection strategy is to kill microorganisms without harming the cellular and plasma components. PDT offers great potential to be successful in blood disinfection, because it is a multi–target strategy, i.e, the reactive species that are formed (after light absorption and photosensitization reaction) are effective against viruses, bacteria, fungi, and parasites [37-40]. This strategy has even been proved effective to promote pathogen inactivation in the presence of fragile blood components, such as stem cells from blood of embryo's cord [65-68]. It is better than UV treatments, because it does not cause direct damage to blood components. Several PS have been used for blood disinfection including MB, CV and RF (Figure 2). Molecules that have intracellular targets such as MB and CV can be used to treat plasma derivatives but not whole cell blood, because they will cause extensive hemolysis. RF, however, is an aqueous based photosensitiser, which do not enter cells and can be used to disinfect whole blood derivatives. RF reacts either by type I or by type II mechanisms and is already in use. Several companies commercialize kits for blood and plasma decontamination, like Macopharma, whose technology for plasma decontamina‐ tion is based on MB photosensitization (http://www.macopharmausa.com/). In the case of leishmaniasis, parasites remain mostly in the intracellular environment, except when they are in transit from a lysed cell to infect a macrophage or other phagocytic cell. We could think of using PDT to remove parasites in the plasma or to develop strategies to target PSs to destroy only infected cells of contaminated blood.
