Biological concepts in recurrent Plasmodium vivax malaria

Area of Science:

• Malariology
• Parasitology
• Infectious Disease Research

Background:

• The hypnozoite theory explains malaria relapse, but its universal application is questioned.
• Plasmodium vivax relapse is a significant challenge in malaria eradication efforts.

Purpose of the Study:

• To critically evaluate the prevailing hypnozoite theory of Plasmodium vivax relapse.
• To explore alternative, non-hypnozoite reservoirs for P. vivax recurrence.

Main Methods:

• Review of historical and current malariology literature.
• Analysis of evidence regarding Plasmodium vivax recurrence mechanisms.
• Consideration of potential extra-vascular parasite reservoirs.

Main Results:

• While hypnozoites are a likely cause of relapse, many P. vivax recurrences may be hypnozoite-independent.
• Potential alternative reservoirs include splenic dendritic cells, bone marrow, and skin.
• Overattribution of recurrences to hypnozoites is a growing concern among researchers.

Conclusions:

• Dual or multiple extra-vascular origins for P. vivax recurrences should be considered.
• Identifying these reservoirs is crucial for effective malaria eradication strategies.
• Understanding parasite dormancy is key to addressing malaria relapse.