A case of Plasmodium malariae recurrence: recrudescence or reinfection?

Abstract

Background Plasmodium malariae is the most neglected of the six human malaria species and it is still unknown which is the mechanism underlying the long latency of this Plasmodium . Case presentation A case of PCR-confirmed P. malariae recurrence in a 52-year old Italian man was observed 5 months after a primary attack. In the interval between the two observed episodes of malaria the patient denied any further stay in endemic areas except for a visit to Libya, a country considered malaria-free. Genomic DNA of the P. malariae strain using five microsatellites (PM2, PM9, PM11, PM25, PM34) and the antigen marker of circumsporozoite ( csp ) was amplified and sequenced. Analysis of polymorphisms of the P. malariae csp central repeat region showed differences between the strains responsible of the first and second episode of malaria. A difference in the allele size was also observed for the sequence analysis of PM2 microsatellites. Conclusions Plasmodium malariae is a challenging human malaria parasite and even with the use of molecular techniques the pathogenesis of recurrent episodes cannot be precisely explained. Electronic supplementary material The online version of this article (10.1186/s12936-019-2806-y) contains supplementary material, which is available to authorized users.

Evidence of Plasmodium falciparum infection after 12 years from the exposure: cryptic malaria or recrudescence?

“…As is well known, hypnozoite production is the most common cause of malaria relapses, but it is not the only condition that leads to malaria recurrence after primary infection. For example, Plasmodium malariae is incapable of producing a liver dormant stage but can remain with a low parasitaemia for a long time (maximum 50 years) even in the absence of symptomatic infection, especially after inadequate antimalarial treatment [6]. In addition, Plasmodium falciparum has been documented in the literature to cause episodes of suspected recrudescence at least a decade after the last exposure, even though this species is not capable of producing hypnozoites [7].…”

Malaria

“…Die Erfahrung der untersuchenden Person spielt hierbei eine große Rolle. Ein negatives Untersuchungsergebnis schließt eine Erkrankung nicht sicher aus, zumal zu Beginn der klinischen Erscheinungen und bei semi-immunen Personen die Parasitendichte im peripheren Blut gering sein kann [38] [6,11,19,20].…”

Safety and Efficacy of Tafenoquine for Plasmodium vivax Malaria Prophylaxis and Radical Cure: Overview and Perspectives

“…Whereas many post-28-day recurrences will no doubt indeed be relapses, it is also possible, if not likely, 30 that some long-term recurrences of P. vivax malaria have the same presumed non-hypnozoite origin as long-term recurrences of P. malariae infection (P. malariae is not known to have a hypnozoite form), whatever the non-hypnozoite origin concerned may be. 30,[54][55][56] For that matter, presumed non-hypnozoite P. falciparum and P. ovale sensu lato parasites can persist for long periods too. 54,57,58 To summarize, the point being made above is that, as I recently hypothesized elsewhere, 34 TQ may help to prevent not only hypnozoite-derived relapses but possibly also recrudescences which have a splenic, bone marrow, or some other non-circulating merozoite origin.…”