PROS1 and parasitic infectious disease: The 40S ribosomal protein S12 sandwich ELISA could detect the target antigen from Peripheral Blood Mononuclear Cell (PBMC) samples in 68% of VL patients and post-kala-azar dermal leishmaniasis (PKDL) patients, providing an estimation of parasitemia ranging from 15 to 80 amastigotes per ml of blood.