Table 1 Onset of gametocyte production and recurrence in human malaria
From: Plasmodium—a brief introduction to the parasites causing human malaria and their basic biology
Causative species | Onset of gametocyte production | Recurrence | |
|---|---|---|---|
Relapse | Recrudescence | ||
P. falciparum | After several rounds of intraerythrocytic asexual reproduction (“gametocytes may make their appearance in small numbers on or about the 10th day following the first day of fever, and their numbers increase rapidly day by day for 2 or 3 weeks” [40]) | Unknown (hypnozoites not observed yet) | Known to occur (latent period usually < 2 months, but can be > 2 years [41]) |
P. vivax | Continuous from early rounds of intraerythrocytic asexual reproduction (“sexual forms may occur as early as the 6th or 7th day, reaching their maximum number on or about the 10th day” [40]) | Well documented (latency period ranges from < 2 weeks to > 1 year and varies systematically by geographic region [42]; hypnozoites in liver observed [43]; estimated to be majority of recurrence [44]) | Unknown |
P. malariae | Probably continuous from early rounds of intraerythrocytic asexual reproduction (after a prepatent period (16–59 days [45]), gametocytes emerges in patient’s blood together with intraerythrocytic parasites [46]) | Unknown (hypnozoites not observed yet) | Known to occur (latent period can be > 40 years [47]) |
P. ovale | Continuous from early rounds of intraerythrocytic asexual reproduction (“[gametocytes] appear in the peripheral blood a little earlier than in B.T. [benign tertian]” [40]) | Clinical cases reported [48]; molecular evidence for a causal relationship between dormant liver stages and subsequent relapses unavailable [49]; hypnozoites not observed yet [50] | Unknown |
P. knowlesi | Unknown (gametocytes identified in some of the naturally infected malaria patients [22]) | Unknown (hypnozoites not observe [51]) | Unknown |