Leishmania in Immune Cells (image) Washington University School of Medicine Share Print E-Mail Caption For many infectious diseases, a single bout of the illness protects a person against contracting it again. In some cases, the infecting microbe persists in the body long after symptoms resolve, and can cause disease later in life. Now, researchers studying the tropical parasite Leishmania have found a clue to explain the link between long-term immunity and long-term infection: The parasite (shown in green) is constantly multiplying and being killed by immune cells (pink and blue), keeping the immune system alert and prepared for any new encounters with the parasite. Credit M. Mandell and S. Beverley Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.