PROJECT SUMMARY In this application, we propose to continue our training program to achieve a critical mass of researchers in Bolivia, where we are building local expertise. We will employ a successful progressive stepwise method of selecting and training young investigators in Bolivia. This stepwise training method permits screening of candidates at multiple levels and ensures that we invest in the most highly qualified and motivated individuals. The proximity of Bolivia to Peru provides us with a unique opportunity to leverage the human capacity and infrastructure that we have built in Peru over the last 25 years, using a South-South training approach to more cost-effectively begin to build a scientific research community in Bolivia.1 Several infectious diseases affect public health in Bolivia, and we plan to focus our training on a few of the most important to the country: Chagas disease, cysticercosis, tuberculosis (TB), pneumonia, and HIV neurological co-infections. Over the past 25 years, we have developed a training network of developing and developed country institutions that is remarkable for its breadth, depth, and sustainability. This program began with a focus on Peru and has trained more than 95 Peruvian graduate and post-graduate students and 500 students of other nationalities. The collaborative network of individuals and institutions tied to this grant has produced more than 500 original research articles in peer-reviewed journals. This network and infrastructure developed in our original program in Peru was used as the model to train researchers in Bolivia. We will continue the South-South training approach used in the first five years of the program to train researchers in Bolivia. We have the following steps in our program that will be completed under this D43 grant: Step 1. We will train 20+ students each year in infectious disease and research methods seminars in Bolivia, for a total of 100+ students during the five-year grant. Step 2. We will train four students per year in laboratory rotations at the UPCH, for a total of 20 trainees during the 5-year grant. Step 3. We will train six students per year in laboratory rotations in Bolivia, for a total of 30 trainees during the 5-year grant. Step 4. We will train two Bolivian students per year in a master’s degree program at UPCH, for a total of ten trainees during the five-year grant. Step 5. We will support 10 Bolivian students to attend the Tropical Medicine and Public Health Summer Institute at JHSPH during the five-year grant. Step 6. Four Ph.D. candidates at USA or U.K during the five-year grant.