 The efficacy of LtSTA as a skin test antigen depends upon the sensitivity and specificity of the product. This study has been designed to measure the skin test responses to 15, 30, or 50μg doses of LtSTA. The measurements of non-specific reactivity due to components of the antigen solution and the products ability to sensitize lymphocytes of Leishmania naïve persons when administered intradermally. The presence or absence of a local inflammatory response to the first skin test with each of three doses of LtSTA will provide insight on the specificity of the antigen in a naïve population. The local inflammatory response to LtSTA following the first and second repeat skin tests will indicate if the antigen is sensitizing after intradermal administration. 