Miles Markus's blog
Attention is drawn to the following three publications that are relevant to the preparation of manuscripts on malaria:
Markus, M.B. 2019. Plasmodium – Yet More Don’ts. Trends in Parasitology 35 (2): 101–102.
McFadden, G.I. 2019. Plasmodium – More Don’ts. Trends in Parasitology 35 (1): 4–6.
An article on vivax malarial recurrences was highlighted in the "Global Malaria News" section of last week's MalariaWorld Newsletter. Below (in the next paragraph) is a relevant explanation concerning the article (http://theconversation.com/why-does-malaria-recur-how-pieces-of-the-puzz...):
The amount of time that passes between a symptomatic vivax malarial episode and a subsequent recurrence has in the past often been regarded as an indication as to whether the recurrence is a relapse (hypnozoite origin) or a recrudescence (merozoite origin). It should be noted that in the light of new knowledge and understanding, the time factor is not a valid criterion. (Link to first paper). (Link to second paper).
We talk about asymptomatic, submicroscopic plasmodial infections as potentially being a threat to the elimination of malaria. This is, of course, partly because such infections are not normally treated; especially not in rural endemic areas where laboratory facilities are limited. An aggravation of the situation is when parasitaemias are so low that they cannot be detected by molecular diagnosis (where available) either. But obstacles to elimination are probably even greater than has been realized.
The two links below did not come up in the original "Comment" on a paper but should do so in this "Blog" version, which appears in full below. It was speculated in detail for the first time in two recent publications (particularly the second one) that in addition to a hypnozoite origin of relapse-like vivax recurrences, parasites in bone marrow might be a source. (Link to first paper). (Link to second paper).
UPDATE COMMENTARY: Acquisition of novel insights has been taking place (reflected especially in 2018 reports) in relation to where plasmodial parasites go in the mammalian body. This new understanding has led to the hypnozoite hypothesis of relapse in malaria becoming partly out of date insofar as it is now a theory that is (in the way it has been applied since 1980) too restrictive. To elucidate:
Was P.G. Shute’s “X Body” the same plasmodial stage that is now called a “hypnozoite”? The short answer is “No”. The malariologist who has just put this question to me has suggested that the whole reply (see below) be made available in the MalariaWorld Newsletter, considering the current topicality of the enigmatic hypnozoite; particularly in regard to the concept of malaria eradication.
As shown by the record of historical events listed in Table 1 in a recent review of biological concepts in recurrent vivax malaria, the question of a hypnozoite-independent, non-circulating origin(s) of recurrences was first raised approximately 7 years ago. (Link to the paper and Table 1 [click here]). More specifically, parasites in bone marrow as a possible contributing source are discussed in this 2018 article, the matter having initially been debated in a 2017 publication cited therein.