Clinical and parasitological features of P falciparum malaria in splenectomized subjects
| Severity and fatality . | Incidence of “malaria” and febrile symptoms . | Parasite stage distribution on blood smears . | Ultrastructural and molecular studies of iRBCs . |
|---|---|---|---|
| Patients naïve or possibly immune before splenectomy: case reports or series of cases70,83-93 (12 articles 25 patients) | |||
| Overall, 48% of patients had severe malaria and 28% died; 7 of 25 patients had cerebral malaria. | Not relevant (only patients with symptoms were reported) | Mean and median parasitemia = 17% and 5% (13 patients); mature forms accounted for > 3% (often > 20%) of asexual forms in 6 of 10 patients from whom the information was available | Infected erythrocytes allowed to mature in vitro had knobs (electronic microscopy) and were able to cytoadhere in a static assay93 ; no knobs observed on iRBCs in an autopsy study performed after 13 days of antimalarial therapy86 |
| In unsplenectomized travelers, the severity rate is 5%-10% and death rate 0.5%-5%. | In unsplenectomized patients with uncomplicated, severe, and fatal attacks, the mean proportion of mature forms is 0.03%, 0.3%, and 3% of asexual forms, respectively53 | ||
| Immune patients: cohort studies95-97 for 3 articles (69 patients and 83 controls) | |||
| Five deaths in 69 patients followed for 1-10 years | Fever and parasitemia are significantly more frequent in splenectomized subjects95 than in age-, sex-, and exposure-matched controls | Late stages account for > 1/3 of asexual stages in 20.6% of positive smears vs. 0% in controls95 | |
| Acute attack after splenectomy in a chronic carrier: case reports and short series of cases70,94 for 2 articles (3 patients) | |||
| One of 3 patients had severe malaria; none died | Not relevant (only patients with symptoms were reported) | Parasitemia was 0.1%, 2%, and 24%; mature forms accounted for 80% of asexual forms in 1 patient; immature gametocytes were present in 1 patient | Transcription of var, rif A, and stevor gene families was absent just after sampling but reappeared after adaptation of the isolate in culture94 ; same pattern in a static cytoadherence test in vitro94 |
| Severity and fatality . | Incidence of “malaria” and febrile symptoms . | Parasite stage distribution on blood smears . | Ultrastructural and molecular studies of iRBCs . |
|---|---|---|---|
| Patients naïve or possibly immune before splenectomy: case reports or series of cases70,83-93 (12 articles 25 patients) | |||
| Overall, 48% of patients had severe malaria and 28% died; 7 of 25 patients had cerebral malaria. | Not relevant (only patients with symptoms were reported) | Mean and median parasitemia = 17% and 5% (13 patients); mature forms accounted for > 3% (often > 20%) of asexual forms in 6 of 10 patients from whom the information was available | Infected erythrocytes allowed to mature in vitro had knobs (electronic microscopy) and were able to cytoadhere in a static assay93 ; no knobs observed on iRBCs in an autopsy study performed after 13 days of antimalarial therapy86 |
| In unsplenectomized travelers, the severity rate is 5%-10% and death rate 0.5%-5%. | In unsplenectomized patients with uncomplicated, severe, and fatal attacks, the mean proportion of mature forms is 0.03%, 0.3%, and 3% of asexual forms, respectively53 | ||
| Immune patients: cohort studies95-97 for 3 articles (69 patients and 83 controls) | |||
| Five deaths in 69 patients followed for 1-10 years | Fever and parasitemia are significantly more frequent in splenectomized subjects95 than in age-, sex-, and exposure-matched controls | Late stages account for > 1/3 of asexual stages in 20.6% of positive smears vs. 0% in controls95 | |
| Acute attack after splenectomy in a chronic carrier: case reports and short series of cases70,94 for 2 articles (3 patients) | |||
| One of 3 patients had severe malaria; none died | Not relevant (only patients with symptoms were reported) | Parasitemia was 0.1%, 2%, and 24%; mature forms accounted for 80% of asexual forms in 1 patient; immature gametocytes were present in 1 patient | Transcription of var, rif A, and stevor gene families was absent just after sampling but reappeared after adaptation of the isolate in culture94 ; same pattern in a static cytoadherence test in vitro94 |