The frequent difficulty of establishing a parasitologic diagnosis in American leishmaniasis has established the need for a reliable serologic test, which has not been available up to this time. Preliminary attempts to adapt the indirect fluorescent antibody test were unsuccessful when promastigote forms of a recent human isolate of Leishmania braziliensis from culture were used as antigen. However, the use of intracellular amastigote forms. freed from Vero tissue culture cells by osmotic disruption, resulted in reproducible specific reactions in 89% of 75 sera of leishmaniasis patients. Reactions up to a dilution of 1:1,024 were obtained, with a mode at 1:16. In comparison, 93% of control sera from 100 healthy persons and 75 hospital patients with other diseases gave completely negative reactions, and the great majority of those nonspecific reactions which did occur were at a dilution of 1:8. This test has proved to be a useful adjunct to other diagnostic procedures.
Colonel, Medical Service Corps, U.S. Army; Chief, Parsitic Diseases Section, MARU.
Requests for reprints should be sent to Colonel Walton at U.S. Army Medical Research Unit, Panama, Box 2011, Balboa Heights, Canal Zone.
Master Sergeant, Army Medical Department, U.S. Army.