Systemic endothelial activation occurs in both mild and severe malaria. Correlating dermal microvascular endothelial cell phenotype and soluble cell adhesion molecules with disease severity.

Fatal Plasmodium falciparum malaria is accompanied by systemic endothelial activation. To study endothelial activation directly during malaria and sepsis in vivo, the expression of cell adhesion molecules on dermal microvascular endothelium was examined in skin biopsies and correlated with plasma levels of soluble (circulating) ICAM-1, E-selectin, and VCAM-1 and the cytokine tumor necrosis factor (TNF)-alpha. Skin biopsies were obtained from 61 cases of severe malaria, 42 cases of uncomplicated malaria, 10 cases of severe systemic sepsis, and 17 uninfected controls. Systemic endothelial activation, represented by the up-regulation of inducible cell adhesion molecules (CAMs) on endothelium and increased levels of soluble CAMs (sCAMs), were seen in both severe and uncomplicated malaria and sepsis when compared with uninfected controls. Plasma levels of sICAM-1, sVCAM-1, and sE-selectin correlated positively with the severity of malaria whereas TNF-alpha was raised nonspecifically in malaria and sepsis. Immunohistochemical evidence of endothelial activation in skin biopsies did not correlate with sCAM levels or disease severity. This indicates a background of systemic endothelial activation, which occurs in both mild and severe malaria and sepsis. The levels of sCAMs in malaria are thus not an accurate reflection of endothelial cell expression of CAMs in a particular vascular bed, and other factors must influence their levels during disease.

Blackwater fever in southern Vietnam: a prospective descriptive study of 50 cases.

We prospectively studied 50 Vietnamese patients with blackwater fever (BWF). All patients had fever and hemoglobinuria, 40 (80%) were jaundiced, 25 (50%) had hepatomegaly, 15 (34%) had splenomegaly, and 9 (18%) had hepatosplenomegaly. Twenty-one patients (42%) had impaired renal function, with creatinine clearances of < 50 mL/min/m2; however, only four (8%) developed oliguric renal failure, three (6%) of whom required dialysis. Forty-four patients (88%) developed anemia, which was severe (hematocrit, < 20% in 32 (64%). One patient died, representing a death rate for this once-feared disease that is considerably lower than that reported by earlier investigators. BWF was associated with quinine ingestion in 28 patients (56%), glucose-6-phosphate dehydrogenase (G6PD) deficiency in 27 (54%), and concurrent malaria infection in 16 (32%). There was no statistically significant difference in the severity of BWF associated with each of these three factors, as assessed by creatinine clearance and the hematocrit value on admission and by the number of units of blood transfused. There was considerable overlap in the occurrence of G6PD deficiency, quinine ingestion, and malaria, suggesting that these factors may interact and that it may not be justifiable to regard hemoglobinuria caused by G6PD deficiency as a separate syndrome.

Clearance kinetics of parasites and pigment-containing leukocytes in severe malaria.

In tropical areas, where unsupervised use of antimalarial drugs is common, patients with an illness consistent clinically with severe malaria but with negative blood smears pose a management dilemma. Malaria pigment is evident in peripheral blood leukocytes in greater than 90% of patients with severe malaria. To characterize the clearance kinetics of parasitized erythrocytes and malaria pigment-containing leukocytes, sequential peripheral blood and intradermal smears were assessed in 27 adult Vietnamese patients with severe falciparum malaria. The clearance of parasitized erythrocytes and pigment-containing monocytes (PCMs) followed first order kinetics. The elimination of pigment-containing neutrophils (PCNs) was first order initially, but deviated from this when counts were low. Clearance of peripheral blood PCMs (median clearance time, 216 hours; range, 84 to 492 hours) was significantly slower than that of parasitized erythrocytes (median, 96 hours; range, 36 to 168 hours) or PCNs (median, 72 hours; range, 0 to 168 hours; P < .0001). Intradermal PCM clearance times were the longest of all (median, 12 days; range, 6 to 23 days; significantly longer than peripheral blood PCM clearance, P < .001). Twenty-one (88%) patients still had signs, symptoms, or laboratory features of severe malaria after parasite clearance but before phagocyte pigment clearance. Sixteen of the 23 surviving patients (70%; 95% confidence interval, 50% to 87%) still had intraleukocytic malaria pigment on peripheral blood films 72 hours after parasite clearance. Thus, by determining the distribution of malaria pigment in peripheral blood and intradermal phagocytes, the time since effective antimalarial treatment started can be estimated. Microscopy for intraleukocytic pigment is valuable in the differential diagnosis of severe febrile illnesses in malarious areas where uncontrolled use of antimalarial drugs is widespread.

Post-malaria neurological syndrome.

BACKGROUND: Neurological signs and symptoms are common in malaria, but observations in Vietnam and Thailand have pointed to a discrete transient neurological syndrome after recovery from severe infections. METHODS: A prospective study of the post-malaria neurological syndrome (PMNS) was conducted at two centres in Vietnam over four years. Criteria for inclusion were recent symptomatic malaria infection with parasites cleared from blood (and in cases of cerebral malaria full recovery of consciousness), and development of neurological or psychiatric symptoms within two months after the acute illness. Half of the patients with severe falciparum malaria had been taking part in a randomised trial of antimalarials. FINDINGS: Of 18,124 patients with falciparum malaria treated (1176 of whom had severe infections) 19 adults and three children had subsequent PMNS; in one patient it followed uncomplicated malaria and in 21 it followed severe malaria. The overall incidence (95% confidence interval) of PMNS after falciparum malaria at the main study centre was 1.2 per 1000 (0.7 to 1.8 per 1000) and relative risk (95% CI) for developing PMNS after severe versus uncomplicated falciparum malaria was 299 (40 to 2223). 13 patients had an acute confusional state or psychosis, six had one or more generalised convulsions, two had generalised convulsions followed by a long period of acute confusion, and one developed a fine tremor. At the time of PMNS diagnosis all patients were aparasitaemic. The syndrome was self-limiting, median duration 60 h (range 24-240). PMNS was associated with the use of oral mefloquine. In the randomised trial 4.4% (10/228) of patients with severe malaria who received mefloquine after parenteral treatment developed PMNS compared with 0.5% (1/210) of those who received quinine; relative risk 9.2 (95% CI 1.2 to 71.3, p = 0.012). INTERPRETATION: Mefloquine is not the only risk factor for PMNS but it is a strong one. Where an effective alternative drug is available, mefloquine should not be used after treatment of severe malaria.

A controlled trial of artemether or quinine in Vietnamese adults with severe falciparum malaria.

BACKGROUND: Artemisinin (qinghaosu) and its derivatives are rapidly effective antimalarial drugs derived from a Chinese plant. Preliminary studies suggest that these drugs may be more effective than quinine in the treatment of severe malaria. We studied artemether in Vietnam, where Plasmodium falciparum has reduced sensitivity to quinine. METHODS: We conducted a randomized, double-blind trial in 560 adults with severe falciparum malaria. Two hundred seventy-six received intramuscular quinine dihydrochloride (20 mg per kilogram of body weight followed by 10 mg per kilogram every eight hours), and 284 received intramuscular artemether (4 mg per kilogram followed by 2 mg per kilogram every eight hours). Both drugs were given for a minimum of 72 hours. RESULTS: There were 36 deaths in the artemether group (13 percent) and 47 in the quinine group (17 percent; P = 0.16; relative risk of death in the patients given artemether, 0.74; 95 percent confidence interval, 0.5 to 1.11). The parasites were cleared more quickly from the blood in the artemether group (mean, 72 vs. 90 hours; P < 0.001); however, in this group fever resolved more slowly (127 vs. 90 hours, P < 0.001), the time to recovery from coma was longer (66 vs. 48 hours, P = 0.003), and the hospitalization was longer (288 vs. 240 hours, P = 0.005). Quinine treatment was associated with a higher risk of hypoglycemia (relative risk, 2.7; 95 percent confidence interval, 1.7 to 4.4; P < 0.001), but there were no other serious side effects in either group. CONCLUSIONS: Artemether is a satisfactory alternative to quinine for the treatment of severe malaria in adults.