NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.

This study was supported by Contract No. SAQMPD04C1166 between the National Academy of Sciences and U.S. Department of State. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the organizations or agencies that provided support for this project.

Additional copies of this report are available in limited quantities from the Committee for the Evaluation of PEPFAR Implementation; Board on Global Health; Institute of Medicine; 500 Fifth Street, N.W., Washington, DC 20001. The full text is available online at http://www.nap.edu.

For more information about the Institute of Medicine, visit the IOM home page at: www.iom.edu.

The serpent has been a symbol of long life, healing, and knowledge among almost all cultures and religions since the beginning of recorded history. The serpent adopted as a logotype by the Institute of Medicine is a relief carving from ancient Greece, now held by the Staatliche Museen in Berlin.