The invention encompasses flow cytometric methods for detecting intracellular pathogens in cells at extremely low levels of infection. In particular, the method provides for the early and accurate detection of Leishmania-infected monocytes in peripheral blood and other body fluids and liquid suspensions of tissue-derived cells. This specific and highly sensitive flow cytometric method is useful as a technique for assessment of parasites in blood, and may also identify persons and animals who are undergoing active infections with Leishmania sp. or other intracellular pathogens.
