Authors

M B Markus¹;  ¹ University of Witwatersrand, South Africa

Discussion

This presentation is compatible with the theme of the 2017 BSP Autumn Symposium in that it is concerned with a host-parasite association as well as a control matter involving a vector. Accumulation of erythrocytic stages of P. vivax in bone marrow/spleen has been reported by various authors. Earlier this year, the bone marrow was, in fact, described as “a major hub for P. vivax infection”. The question therefore arises as to whether erythrocytic forms in bone marrow/spleen are part of the hidden P. vivax reservoir in people who are asymptomatic. Do they cause or contribute to renewed or increased peripheral parasitaemia? Such non-circulating, blood-stage parasites might well be a source of relapse-like, homologous, P. vivax malarial recurrences (“pseudorelapses”, to coin a word); at present probably over-attributed to hypnozoite activation in my opinion (which opinion so far, surprisingly, seems to be unique!). Erythrocytic schizogony, wherever it occurs (e.g. in bone marrow), will presumably be accompanied by gametocyte production and, in turn, by ongoing transmission of P. vivax malaria by mosquitoes. As a result, the post-2007 goal of eradicating the disease globally might not be achievable.