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Table 1 Glossary of terms relevant to Plasmodium vivax relapse

From: Geographical variation in Plasmodium vivax relapse

Term Definition
Infection Presence of parasites in any of its forms of incubation, prepatency, patency, subpatency or latency.
Incubation The period between inoculation of sporozoites and release of merozoites into the blood stream (primary exo-erythrocytic cycle).
Prepatency The period prior to a primary attack where asexual parasites in the blood are both not detectable and asymptomatic, though present.
Patency The period of clinical attack with demonstration of asexual parasites in blood as the cause of illness.
Subpatency The period following a primary attack where asexual parasites are both not detectable and asymptomatic, though present.
Recrudescence An event following sub-patency when parasites are both demonstrated to be present and the cause of another clinical attack or asymptomatic patency.
Latency The period between a primary attack and a relapse; in some strains also the period between inoculation of sporozoites and the occurrence of a patent primary attack, typically six months or more.
Relapse Patent asexual parasitaemia originating from activation of latent hypnozoites.
Re-infection Patency by asexual blood stage parasites deriving from a new inoculation of sporozoites.
Recurrence A newly patent parasitaemia occurring at any point after clearance of sub-patency of a primary parasitaemia where the origin is not known with certainty as being a reinfection, recrudescence or relapse.
  1. Definitions are presented in chronological order of events.