Are up to 80% or more of detectable Plasmodium vivax malarial recurrences relapses (a relapse being a hypnozoite-mediated recurrence)? This is a topical matter and a very interesting question.
Miles Markus's blog
Attention has been drawn to the use of serology for revealing subclinical Plasmodium vivax malaria that can lead to ongoing transmission of the disease in human communities if parasite carriers are not treated .
A Blog by Pierre Lutgen in the MalariaWorld Newsletter (https://malariaworld.org/search/site/Malaria%20inhibits%20Covid) refers to the high overall Immunoglobulin E (IgE) levels that have been found in human populations in areas where malaria is endemic. Further to what is explained in his Blog, but on a different subject:
Only a "few" hypnozoites occur in patients who have Plasmodium vivax infections, compared to the large, non-circulating merozoite biomass that is now known to be present.
Therefore, to readily ascribe P. vivax malarial recurrences to hypnozoite activation, as is currently common practice, is no longer appropriate without good reasons for doing so. Forget about what you were taught at university in this context and keep an open mind.
As is well known, long-term malarial recurrences are a feature of human infections caused by species of Plasmodium. The frequency of recurrence varies. In P. falciparum malaria, long-term recurrence is rare, but not (contrary to popular belief) non-existent. P. malariae [Pm] and P. vivax [Pv] only will be considered below; and with reference to only the bone marrow as a site of parasite occurrence.
The quality of literature on malaria occasionally leaves something to be desired, with lack of attention to detail in one way or another being evident. Note the following selected matters:
Malariologists have recently reiterated, in more than one paper, the notion that the non-bloodstream origin of Plasmodium vivax malarial recurrence is both hypnozoites (a term coined by me long ago ) and merozoites, not hypnozoites only. It has happened without any acknowledgement relating to the existing literature on the subject. Although the glaring omissions might have been inadvertent, let us nevertheless not become confused as to the background here. What needs to be pointed out is that this is not an original (new) idea.
The progression to schizont formation of individual activated hypnozoites has been reported for the first time. This means that it is probably no longer appropriate to use the words "theory" and "hypothesis" when talking about hypnozoites in relation to malarial relapse. The link to the important publication concerned (by Voorberg-van der Wel et al.) is:
Attention is drawn to a paper (by G. Franken, J. Richter, and A. Labisch) which points out, quite rightly, that it would be appropriate for more research on aspects of the life cycle of Plasmodium species that infect humans to be carried out, using modern techniques. The current "liver and blood" concept of the life cycle should not be regarded as the final "word" on the subject.
Link to the publication:
In relation to some biological and epidemiological implications of the killing of Plasmodium vivax by hydrogen peroxide, discussed in a November 2019 publication (click on the first link below and, in turn, click on the "Free Download" link that comes up in a Tweet), see the comments in the MalariaWorld Newsletter by Pierre Lutgen concerning hydrogen peroxide. Find his blog via the second link provided below.