Method for diagnosing visceral leishmaniasis in a patient by identification of a new key marker namely 9-O-acetylated sialoglycoconjugate

A hemaglutination method for diagnosing and assessing acute visceral leishmaniasis in a patient suspected of suffering from said visceral leishmiasis, which method comprises:

• a. collecting an anticoagulated blood sample from said patient;
• b. separating erythrocytes from said anticoagulated blood sample and preparing an erythrocyte suspension by washing and resuspending said separated erythrocytes in an isotonic balanced salt solution;
• c. providing serial dilutions of a known initial concentration of Achatinin-H which specifically binds 9-O-acetylsialic acid;
• d. reacting each dilution with an equal sized aliquot of said erythrocyte suspension at a temperature from 4.degree.-35.degree. C. in the presence of calcium ions for a time sufficient for said Achatinin-H to bind to and thereby agglutinate any erythrocytes having said 9-O-acetylsialic acid on their surfaces;
• and
• e. determining a hemagglutination titer by taking the reciprocal of the highest serial dilution that produced a visible agglutination wherein positive hemagglutination indicates a positive diagnosis of said acute visceral leishmaniasis and said titer indicates the level of circulating leishmania parasites.