A Study to Assess Immune Response Status in Patients Before and After Treatment for Visceral Leishmaniasis

Inclusion Criteria: * Aged 12 to 50 years on the day of diagnosis * Have confirmed diagnosis of VL and be judged suitable for treatment using a standard regimen of SSG/PM * Willing and able to give written informed consent * For adolescents aged 12 to 17 years on the day of screening, written informed consent from a parent must be obtained in addition to assent from the patient * Without any other significant health problems as determined by medical history, physical examination, results of screening tests and the clinical judgment of a medically qualified Clinical Investigator * Negative for malaria on blood smear * Judged, in the opinion of a medically qualified Clinical Investigator, to be able and likely to comply with all study requirements as set out in the protocol Exclusion Criteria: The patient may not enter the study if any of the following apply: * Has HIV, HBV or HBC * Has previously had any form of leishmaniasis * Pregnancy or lactating mothers * Any confirmed or suspected immunosuppressive or immunodeficient state, including; asplenia; recurrent, severe infections and chronic (more than 14 days) immunosuppressant medication within the past 6 months * Tuberculosis, leprosy, or severe malnutrition (severe malnutrition in adults defined as a BMI \<18.5, and in adolescents (12-17yrs) as a Z score cut-off value of \<-2 SD) * Any other significant disease, disorder or finding, which, in the opinion of a medically qualified Clinical Investigator, may influence the …