This study was funded by Consejo Nacional de Ciencia y Tecnologia (CONCYTEC), Lima, Peru. We thank Dr. Peter Schantz for constructive comments and review of the manuscript.

This study was funded in part by NIH grant no.U01A135894-01 and funds by CONCYTEC, Lima, Peru.The authors thank J.D. Moro, N. Perez-Palma, J.B. Phu, D.Sara, Amanda Chavez and Eva Casas for editorial help.We also thank Armando Gonzales, Cesar Gavidia, NestorFalcon for helpful comments and M. Gamarra and R.Zarate from Tupac Amaru for their cooperation.

Financial support for this study was received from Consejo Nacional de Ciencia y Tecnología (CONCYTEC), Lima, Peru. The methods used in the present study comply with current Peruvian law governing the participation of human subjects in biomedical research.

This study was funded in part by the National Institutes of Health (grant no. U01-A135894, awarded to The Johns Hopkins University), the RG-ER Fund, and Consejo Nacional de Ciencia y Tecnologı´a (CONCYTEC; Lima, Peru).

This study was funded by Consejo Nacional de Ciencia y Tecnolog ??a (CONCYTEC).We wish to thank Dr. Peter Schantz for manuscript review and the people and authoritiesof the farming cooperative of Tupac Amaru in Junin, Peru.