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prepatent period

[prē-păt′nt, -pāt′nt]
n.
  1. The interval between infection of an individual by a parasitic organism and the first ability to detect from that host a diagnostic stage of the organism.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.