Hypoglycaemia in African children with severe malaria

Quinine in severe falciparum malaria: evidence of declining efficacy in Thailand

Between 1981 and 1992, 196 Thai adults with severe falciparum malaria were treated with a quinine loading dose regimen. Nineteen patients died (10%) and 6 developed late hypoglycaemia. There was no serious cardiovascular or nervous system toxicity. Although there was no evidence of high grade resistance, and no change in the mortality rate, in recent years an increasing proportion of patients had a delayed clinical and parasitological response to treatment. Since 1988, 78% (29/37) of patients with cerebral malaria were unconscious for > 72 h compared with 41% (11/27) between 1981 and 1987 (P = 0.002). In the past 2 years parasite clearance times have exceeded 96 h in 33% (26/78) of patients compared with 14% (15/102) previously (P = 0.006). Quinine remains an effective treatment for severe multi-drug resistant falciparum malaria in this area, but there is now evidence of a decline in the immediate therapeutic response, and its efficacy will need close monitoring as resistance increases further.

Prognostic indicators in adult cerebral malaria: a study in Burundi, an area of high prevalence of HIV infection

We examined the possible risk factors for poor prognostic in cerebral malaria in 31 adults from Burundi, an area of high prevalence rate of HIV-1 infection. Depth of coma, temperature, vomiting, seizures, parasite load, or anaemia did not modify the outcome. High levels of creatinine, bilirubin, and/or lactates were indicators of poor prognostic. HIV-1 infection did not affect the clinical or biological presentation of cerebral malaria, and did not appear to influence the outcome.

Hypoglycaemia in paediatric admissions in Mozambique

We studied the incidence and clinical associations of hypoglycaemia in an acute medical paediatric service in Maputo, Mozambique. Of 603 children, 43 (7.1%) were hypoglycaemic. 16 of these with Plasmodium falciparum malaria had a shorter illness, and a higher incidence of convulsions and focal neurological signs than those with other diagnoses, but were less likely to die. Hypoglycaemia also complicated protein energy malnutrition, pneumonia, encephalitis, intestinal parasite infection, and nephrotic syndrome. 25 of the 603 children died: 7 (16.3%) of 43 with hypoglycaemia and 18 (3.2%) of 560 who were normoglycaemic, (relative risk of death 5.8 [95% confidence interval 2.25 to 14.93]). Hypoglycaemia is common in children in hospital in Mozambique, and should be suspected in any acutely-ill child regardless of the primary disease.

Lactic acidosis and hypoglycaemia in children with severe malaria: pathophysiological and prognostic significance

Serial clinical and metabolic changes were monitored in 115 Gambian children (1.5-12 years old) with severe malaria. Fifty-three children (46%) had cerebral malaria (coma score < or = 2) and 21 (18%) died. Admission geometric mean venous blood lactate concentrations were almost twice as high in fatal cases as in survivors (7.1 mmol/L vs. 3.6 mmol/L; P < 0.001) and were correlated with levels of tumour necrosis factor (r = 0.42, n = 79; P < 0.0001) and interleukin 1-alpha (r = 0.6, n = 34; P < 0.0001). Admission blood venous glucose concentrations were lower in fatal cases than survivors (3.2 mmol/L, vs. 5.8 mmol/L; P < 0.0001). Treatment with quinine was associated with significantly more episodes of post-admission hypoglycaemia when compared with artemether or chloroquine. After treatment, lactate concentrations fell rapidly in survivors but fell only slightly, or rose, in fatal cases. Plasma cytokine levels fluctuated widely after admission. Sustained hyperlactataemia (raised lactate concentrations, 4 h after admission) proved to be the best overall prognostic indicator of outcome in this series. Lactic acidosis is an important cause of death in severe malaria.

Cerebral malaria in the rhesus monkey (Macaca mulatta): observations on host pathology

Infection was induced in five rhesus monkeys (Macaca mulatta) by intravenous inoculation with a virulent strain of Plasmodium knowlesi. Approximately one week after inoculation, four of the exposed animals developed acute malaria and died or were killed when moribund after varying periods of illness. Post-mortem and light microscopical examination showed marked cerebral vascular congestion and widespread plugging of the brain capillaries and venules (microvessels) by heavily parasitized erythrocytes mixed with uninfected erythrocytes. Electronmicroscopically, the major changes seen were adherence of large numbers of parasitized erythrocytes and macrophages to swollen microvascular endothelial cells; increased numbers of fibroblasts and deposition of collagen bundles in the extracellular matrix around damaged and parasite-packed microvessels were also found in many areas. This animal model may prove useful for further investigation of the pathogenesis of cerebral malaria.

Glucose turnover in severe falciparum malaria

To investigate glucose metabolism in acute falciparum malaria, [3-3H]glucose turnover was measured in 18 normoglycemic adult Thais (eight males, 10 females; median age, 28 years) with severe infections. Eleven patients were studied before quinine treatment, 15 while receiving quinine, and 10 during convalescence. In paired studies conducted before and after initial intravenous quinine, plasma glucose level decreased from a median (95% confidence limits) of 5.5 (3.0 to 6.6) to 4.6 (2.5 to 6.1) mmol/L (P < or = .027, n = 8), and plasma insulin level increased 9.3 (-3.2 to 30.0) mU/L (P = .02). Glucose turnover decreased during the 4-hour quinine infusion from 3.04 (2.12 to 4.23) to 1.89 (1.20 to 2.54) mg/kg.min-1 (P < .004), as did the metabolic clearance rate for glucose (2.87 [1.88 to 7.83] to 2.50 [1.43 to 4.55) mL/kg.min-1; P = .008). Glucose turnover and clearance measured both after initial quinine treatment and in convalescence were similar (P = .234 and .344, respectively; n = 7). In the series as a whole, there was an inverse association between pretreatment turnover and the simultaneous plasma glucose level (rs = -.76, P < .01; n = 11), a stronger inverse relationship between glucose clearance and plasma glucose level (rs = -.88, P < .001), and a positive association between pretreatment turnover and oral temperature (rs = .65, P < .025; n = 10). These data suggest that, as in other severe illnesses, glucose turnover is high in untreated patients, but that glycolysis by mature parasite forms may accelerate glucose disposal.(ABSTRACT TRUNCATED AT 250 WORDS)

Choice of therapy for imported cases of falciparum malaria in children: a retrospective study of 100 cases seen in Marseilles, France

We have carried out a retrospective study on 100 children in hospital in Marseilles, France with a diagnosis of Plasmodium falciparum malaria. On admission, the main clinical features were anaemia (90 cases), fever (83 cases, > 40 degrees C in 22 cases), hepatomegaly (44 cases), vomiting (29 cases), neurological signs (22 cases), thrombocytopenia (13 cases), hyperparasitaemia (6 cases), jaundice (4 cases), shock (1 case) and hypoglycaemia (1 case). Severe malaria, as defined by the World Health Organization Malaria Action Programme, was rare in our study (only 2 cases) and the prognosis was good (no death, no sequela). The search for neurological signs such as impaired consciousness, prostration or convulsions is an effective and simple way to diagnose potentially severe cases. In the presence of these signs, intravenous quinine treatment resulted in a shortened duration of fever (30 h instead of 63 h) and thereby avoided patients becoming worse. In children without neurological signs or persistent vomiting, oral therapy may be used even if there is high fever or hyperparasitaemia, but close surveillance is required. Patients treated with halofantrine or mefloquine had a shorter stay in hospital than those treated with chloroquine (mean = 4 d instead of 5.7 d). The resistance of some strains to chloroquine may explain this difference.

Intravenous immunoglobulin in the treatment of paediatric cerebral malaria

Hyperimmune globulin can inhibit and reverse the cytoadherence between Plasmodium falciparum-infected erythrocytes and melanoma cells in vitro. Cytoadherence is believed to mediate disease in cerebral malaria. Therefore we studied the efficacy of i.v. immunoglobulin, purified from the plasma of local semi-immune blood donors, as an adjunct to standard treatment for cerebral malaria in Malawian children. The immunoglobulin preparation (IFAT antimalarial antibody titre 1:5120) recognized erythrocyte-associated antigens of each of 22 Malawian P. falciparum isolates studied, and reversed binding of Malawian isolates to melanoma cells. Immunoglobulin did not reverse binding to human monocytes or to cells of the human histiocytic lymphoma cell line U937. Thirty-one children with P. falciparum parasitaemia and unrousable coma were enrolled. All were treated with i.v. quinine dihydrochloride; in addition patients were randomized to receive either immunoglobulin (400 mg/kg by i.v. infusion over 3 h) or placebo (albumen and sucrose by similar infusion) in a double blind trial with sequential analysis. Of 16 patients receiving immunoglobulin, five (31%) died and five survivors had neurological sequelae. Of 15 patients receiving placebo, one (7%) died and two had sequelae. Parasite clearance, fever clearance and coma resolution times in survivors were similar in the two groups. Although the difference in outcome between the two groups was not significant, the trial was stopped because immunoglobulin was demonstrated not to be superior to placebo.

An audit of the management of malaria in a Tanzanian district hospital

An audit of the management of falciparum malaria was carried out over a 12 month period in a north-west Tanzanian district hospital; 1494 patients were studied, 75% being children under 5 years. Chloroquine was effective in 1128 cases (79%), 68 patients died, of whom 64 were aged under 5 years; 30 of them died fewer than 2 d after admission; 14 had received quinine chemotherapy. Management can be improved by better diagnosis of anaemia and hypoglycaemia, changing the dose of injectable chloroquine, earlier use of quinine, and enabling doctors to see very ill patients earlier.

Malaria--a neglected disease?

In situations where malaria eradication is not an option in the foreseeable future the emphasis must be on the control of morbidity and mortality due to malaria. Under such circumstances drawing a distinction between malarial parasitization and malarial disease may be important for workers in both field and laboratory. This concept is explored from the points of view of the epidemiological picture of malaria in endemic populations, the factors which may influence progression to disease and the processes which mediate disease.

Falciparum malaria-induced hypoglycaemia in a diabetic patient

We report a patient with diabetes mellitus who suffered severe falciparum malaria complicated by profound and persistent hypoglycaemia. The hypoglycaemia evolved before therapy with quinine was begun and resolved with eradication of the parasitaemia. The patient reverted to her baseline hyperglycaemia despite continuation of quinine. This case illustrates the critical role of falciparum malaria in the pathogenesis of malaria-associated hypoglycaemia, rather than quinine-mediated mechanisms. Anticipation of hypoglycaemia in falciparum malaria and its vigorous treatment may improve the poor prognosis associated with this complication.

Neurological manifestations of malaria

The involvement of the nervous system in malaria is reviewed in this paper. Cerebral malaria, the acute encephalopathy which complicates exclusively the infection by Plasmodium falciparum commonly affects children and adolescents in hyperendemic areas. Plugging of cerebral capillaries and venules by clumped, parasitized red cells causing sludging in the capillary circulation is one hypothesis to explain its pathogenesis. The other is a humoral hypothesis which proposes nonspecific, immune-mediated, inflammatory responses with release of vasoactive substances capable of producing endothelial damage and alterations of permeability. Cerebral malaria has a mortality rate up to 50%, and also a considerable longterm morbidity, particularly in children. Hypoglycemia, largely in patients treated with quinine, may complicate the cerebral symptomatology. Other central nervous manifestations of malaria include intracranial hemorrhage, cerebral arterial occlusion, and transient extrapyramidal and neuropsychiatric manifestations. A self-limiting, isolated cerebellar ataxia, presumably caused by immunological mechanisms, in patients recovering from falciparum malaria has been recognized in Sri Lanka. Malaria is a common cause of febrile seizures in the tropics, and it also contributes to the development of epilepsy in later life. Several reports of spinal cord and peripheral nerve involvement are also available. A transient muscle paralysis resembling periodic paralysis during febrile episodes of malaria has been described in some patients. The pathogenesis of these neurological manifestations remains unexplored, but offers excellent perspectives for research at a clinical as well as experimental level.

Comparative trial of oral versus intramuscular chloroquine in children with cerebral malaria

One hundred and thirteen children aged 12 years or less with cerebral malaria in Accra, Ghana were treated with chloroquine either with a low dose regime of 3.5 mg/kg 8-hourly intramuscularly, or orally by nasogastric tube, in a standard regime, both to a total of 25 mg/kg body weight. There was no obvious difference in outcome in the 2 treatment groups. The overall mortality of 5.3% (5.9% and 4.4% in the oral and intramuscular treatment groups respectively) was similar to that seen 10 years ago in this hospital. The average parasite clearance time had increased to 61 h, compared to 41 h noted 10 years ago. The incidence of hypoglycaemia (3%) was very low compared to studies in other malaria endemic areas. The reason for this is not clear but it could have contributed to the low mortality. Neurological deficits were seen on day 14 in 7.8% of patients. Parasitaemia recurred within 14 d in 22% of surviving patients, confirming the presence of RI/RII chloroquine resistance in Accra.

The metabolic response to rapid intravenous glucose injection in acute falciparum malaria

Because hypoglycaemia is common in severe malaria, intravenous glucose is often given empirically to patients on admission to hospital. To investigate the metabolic response to rapid glucose injection in acute malaria, 50 ml of 50% w/v (25 g) dextrose was given over 5 min to 10 adult patients (7 males, 3 females; mean age 30 years) with acute falciparum malaria. Five patients with severe infections were studied between doses of intravenous quinine; 5 cases were uncomplicated and previously untreated. The patients with severe malaria had lower pre-injection plasma glucose concentrations than patients with uncomplicated infections (mean +/- standard deviation, 4.2 +/- 0.9 vs 5.8 +/- 1.1 mmol/litre, 2P less than 0.015). However, peak glucose concentrations (18.6 +/- 4.8 vs 17.0 +/- 2.4 mmol/litre) and integrated responses (AUC0-245 min) were similar in the groups (2P greater than 0.1 in each case), and pre- and post-injection plasma insulin concentrations and AUC0-245 min values were also not significantly different (2P greater than 0.05 in each case). No 'rebound' hypoglycaemia was observed. The patients with severe malaria had higher peak plasma lactate concentrations than the uncomplicated patients (2.5 +/- 0.7 vs 1.5 +/- 0.9 mmol/litre, 2P less than 0.05), but the highest plasma lactate achieved and the greatest maximum post-injection rise were only 3.8 and 0.8 mmol/litre respectively. The average maximum reduction in plasma potassium after injection was 0.2 mmol/litre at 35 min. These data suggest that injections of hypertonic dextrose given empirically in conventional doses to non-acidotic patients with acute, severe malaria are not harmful, but the metabolic response in patients with an established acidosis remains unknown.

Plasmodium berghei: lactic acidosis and hypoglycaemia in a rodent model of severe malaria; effects of glucose, quinine, and dichloroacetate

Fulminant malaria infections are characterised by hypoglycaemia and potentially lethal lactic acidosis. In young adult Wistar rats (n = 26) infected with Plasmodium berghei (ANKA strain), hyperparasitaemia (greater than 50%), anaemia (PCV 19.6 +/- 5.3%; mean +/- SD) hypoglycaemia (1.04 +/- 0.74 mmol/litre), hyperlactataemia (13.2 +/- 2.20 mmol/litre), hyperpyruvicaemia (0.51 +/- 0.12 mmol/litre) and metabolic acidosis (arterial pH 6.96 +/- 0.11) developed after approximately 14 days of infection. Hypoglycaemia was associated with appropriate suppression of plasma insulin concentrations. In a second series of experiments the metabolic effects of treatment with glucose (500 mg/kg/hr), quinine (5 mg/kg bolus followed by 10 mg/kg over 1 hr) and a potent activator of pyruvate dehydrogenase, dichloroacetate (300 mg/kg) were studied over a 1-hr period. In control animals quinine had no measurable effects, but dichloroacetate significantly reduced arterial blood lactate (74%) and pyruvate (80%). In infected animals, glucose infusion attenuated the rise in lactate (38% compared with 82%; P less than 0.01) but quinine had no additional metabolic effects. Dichloroacetate further attenuated the rise in lactate (14%; P less than 0.01).

Glucose metabolism in quinine-treated patients with uncomplicated falciparum malaria

To investigate host and drug effects on glucose metabolism in acute falciparum malaria, 10 previously untreated, fasting Thai males with uncomplicated infections were given a 2-h intravenous glucose infusion (5 mg/kg ideal body weight min) with an infusion of quinine dihydrochloride (10 mg/kg body weight) during the second hour. Eight patients were restudied in convalescence. Fasting plasma glucose (mean +/- SD) and insulin (geometric mean (-SD to + SD] were higher during acute illness (5.5 +/- 1.0 mmol/l and 6.2 (5.0-7.7) mU/l) than in convalescence (4.2 +/- 0.25 mmol/l and 3.7 (2.1-6.7) mU/l; P less than 0.001 and P = 0.058 respectively). After 1 h, both plasma glucose (9.3 +/- 1.4 vs 7.5 +/- 0.8 mmol/l, P less than 0.001) and insulin (21.2 (13.8-32.5) vs 15.2 (11.2-20.8) mU/l, P = 0.089) remained higher during acute illness; mathematical model (CIGMA) assessment of these values indicated lower tissue insulin sensitivity on admission (97% (71-134] than in convalescence (139% (109-178), P less than 0.025) but normal beta-cell function on both occasions. Two-hour plasma glucose (9.5 +/- 2.0 mmol/l) and insulin (81.8 (51.5-129.9) mU/l) concentrations during acute illness were also significantly higher than in convalescence (7.2 +/- 1.2 mmol/l and 40.1 (23.5-68.4) mU/l, P less than or equal to 0.025) despite similar end-infusion free plasma quinine concentrations (P greater than 0.5). Basal plasma free fatty acid concentrations were increased in acute illness (0.68 +/- 0.24 vs 0.21 +/- 0.12 mmol/l, P less than 0.001) but fell to low levels at 2 h in both studies. These data suggest tissue insulin resistance and augmented quinine-stimulated insulin secretion in acute falciparum malaria, factors which are likely to influence the clinical situation in which malaria-associated hypoglycaemia occurs.

Cerebral malaria in children

Cerebral malaria is a rapidly progressive encephalopathy with up to 50% mortality. A cardinal feature is the massing of red cells containing mature Plasmodium falciparum within the cerebral capillaries. Adhesion of these parasitised red cells to endothelium, an event which may initiate cerebral malaria, is being studied at the molecular level. However, the relevance of these studies to the pathophysiology and treatment of human cerebral malaria is uncertain. Although chloroquine is still widely used to treat falciparum malaria, resistance has spread to most of the endemic zone. Quinine is emerging as the only effective treatment for cerebral malaria, though resistance to this drug threatens to become a problem. Alternative drugs are urgently needed.

Neurological sequelae of cerebral malaria in children

Out of 604 Gambian children admitted with falciparum malaria to one hospital between September and December, 1988, 308 had cerebral malaria and 203 were severely anaemic (haemoglobin less than 60 g/l). 14% of those with cerebral malaria died, as did 7.8% of those with severe anaemia. 32 (12%) of children surviving cerebral malaria had residual neurological deficit. 69 other children were admitted with clinical features strongly suggestive of cerebral malaria but with negative blood films; 16 of these died and 3 had residual neurological deficits. The commonest sequelae of cerebral malaria were hemiplegia (23 cases), cortical blindness (11), aphasia (9), and ataxia (6). Factors predisposing to sequelae included prolonged coma, protracted convulsions, severe anaemia, and a biphasic clinical course characterised by recovery of consciousness followed by recurrent convulsions and coma. At follow up 1-6 months later over half these children had made a full recovery, but a quarter were left with a major residual neurological deficit. Cerebral malaria in childhood may be an important cause of neurological handicap in the tropics.

Specificity of hypoglycaemia for cerebral malaria in children

Glycaemic status on hospital admission was compared in 97 children with severe falciparum malaria (36 with cerebral malaria) and 89 children with other serious illnesses (32 in coma; 57 with acute pneumonia, not in coma). The frequency of hypoglycaemia (blood glucose below 2.2 mmol/l) did not differ significantly between malarial and control patients (5.2% vs 11.2%) nor between the comatose (11.1% vs 18.8%) and conscious (1.6% vs 7.0%) malarial and control subgroups. Compared with normoglycaemic patients, hypoglycaemic patients had appropriately low serum insulin (3.0 vs 8.2 mU/l) and C-peptide (0.13 vs 0.42 mmol/l) and high plasma non-esterified fatty acids (1.42 vs 0.83 mmol/l). Hypoglycaemia, the level of consciousness, and death were all significantly associated with the time since the last meal. Hypoglycaemia is not a specific complication of malaria but is found in severely ill fasted children, resulting from glycogen depletion and perhaps impaired hepatic gluconeogenesis. It should be sought in all severely sick children. A single bolus dose of glucose may not be enough to correct it.

Effect of interleukin-1 and tumor necrosis factor/cachectin on glucose turnover in the rat

We studied the effect of recombinant human interleukin-1 beta (IL-1) and recombinant human tumor necrosis factor alpha/cachectin (TNF) on glucose kinetics in healthy rats by means of a primed constant infusion of D-(6-3H)glucose and D-[U-14C]glucose. During the isotope (6-hour) and monokine (4-hour) infusion, plasma levels of glucagon and insulin were determined and correlated with changes in glucose metabolism. The rates of glucose appearance (Ra) and disappearance (Rd) were elevated only with IL-1 and were associated with an increase in glucagon and a concomitant decrease in the ratio of insulin to glucagon. Plasma glucose concentration was increased early after IL-1 administration and coincided with the peak in the Ra. The augmentation of the metabolic clearance rate (MCR) and percent of flux oxidized by IL-1 suggest that this monokine induces the utilization of glucose as a substrate. TNF administration failed to modify the Ra or Rd, percent of flux oxidized, or MCR. TNF-treated rats increased the percent of glucose recycling, but not the total rate of glucose production. The results of this experiment suggest that endogenous macrophage products participate in the diverse alterations of carbohydrate metabolism seen during injury and/or infection.

Hypoglycemia during diarrhea in childhood. Prevalence, pathophysiology, and outcome

To determine the frequency and outcome of hypoglycemia during diarrhea in childhood, we screened 2003 consecutive patients less than 15 years of age who were admitted to a diarrhea treatment center in Dhaka, Bangladesh. Hypoglycemia, defined as a blood glucose concentration less than 2.2 mmol per liter, was found in 91 patients (4.5 percent), 39 (42.9 percent) of whom died. We also measured the plasma concentrations of glucoregulatory hormones and gluconeogenetic substrates in 46 of the patients with hypoglycemia who were 2 to 15 years old and in 25 normoglycemic patients matched with them for age and weight. The patients with hypoglycemia had had diarrhea for less time than the normoglycemic patients (median, 12 vs. 72 hours; P less than 0.05), and their last feeding had been 18 hours before admission, as compared with 9 hours for the normoglycemic patients (P less than 0.05). The groups were similar in terms of nutritional status, the proportion of patients who had fever, and the types of pathogens recovered from stool samples. The plasma C-peptide concentrations were low (less than 0.30 nmol per liter) in all the hypoglycemic patients. As compared with the normoglycemic patients, the patients with hypoglycemia had elevated median plasma concentrations of glucagon (44 vs. 11 pmol per liter; P = 0.001), epinephrine (3400 vs. 1500 pmol per liter; P = 0.012), norepinephrine (7500 vs. 2900 pmol per liter; P = 0.002), and lactate (3.5 vs. 2.1 mmol per liter; P = 0.020) and similar alanine and beta-hydroxybutyrate concentrations. Eighteen hypoglycemic patients with severe malnutrition had been ill longer than 26 better-nourished patients with hypoglycemia (median duration of illness, 18 vs. 10 hours; P = 0.023) and had lower median plasma concentrations of lactate (1.9 vs. 3.9 mmol per liter; P = 0.021) and alanine (173 vs. 293 micromol per liter; P = 0.040). We conclude that hypoglycemia is a major cause of death in association with diarrhea. Because the glucose counterregulatory hormones were appropriately elevated in the children with diarrhea and hypoglycemia, whereas the gluconeogenetic substrates were inappropriately low, we further conclude that the hypoglycemia observed in such patients is most often due to the failure of gluconeogenesis.

Open comparison of intramuscular chloroquine and quinine in children with severe chloroquine-sensitive falciparum malaria

An open paired randomised comparison of intramuscular chloroquine (3.5 mg base/kg every 6 h) and intramuscular quinine (20 mg salt/kg followed by 10 mg/kg every 12 h) was carried out in 50 Gambian children with severe falciparum malaria. 8 children died, 6 from the quinine-treated and 2 from the chloroquine-treated group. Chloroquine reduced parasitaemia significantly more rapidly than did quinine, but other measures of the therapeutic response were similar in the two groups. Quinine injections were painful. These findings do not support the proposition that quinine is intrinsically superior to chloroquine in the treatment of severe drug-sensitive falciparum malaria.

Treatment of severe malaria in the United States with a continuous infusion of quinidine gluconate and exchange transfusion

During the past decade the incidence of Plasmodium falciparum malaria in the United States has increased 10-fold. Treatment may be delayed because the therapy recommended for severe or complicated disease, intravenous quinine dihydrochloride, is available only from the Centers for Disease Control. We studied 17 patients who were treated for severe or complicated P. falciparum malaria in the United States between 1985 and 1987. Five patients were treated with a continuous infusion of quinidine gluconate, 10 with an exchange transfusion in addition to the continuous infusion of quinidine gluconate, and 2 with intermittently administered intravenous quinine dihydrochloride and an exchange transfusion. All 16 patients with P. falciparum malaria (1 patient had P. vivax malaria) had hyperparasitemia at the time of diagnosis (6 to 54 percent of the erythrocytes infected; median, 13 percent). Three patients with marked hyperparasitemia (54, 38, and 30 percent) and multiple other indicators of a poor prognosis, including advanced age, died. The 13 patients who completed their courses of quinidine with or without exchange transfusion had a parasitemia level of 1.1 percent or less 28 to 72 hours (mean, 44.4 hours) after the start of therapy. Side effects of quinidine treatment were observed in only two patients, one of whom had a serum quinidine concentration above the toxic level. We conclude that the continuous infusion of quinidine gluconate is well tolerated alone and with exchange transfusion and is effective in the treatment of severe and complicated malaria.

Tumor necrosis factor and disease severity in children with falciparum malaria

To investigate the role of tumor necrosis factor in Plasmodium falciparum infections, we measured serum concentrations of this cytokine in 65 Malawian children with severe falciparum malaria. Of these children (mean age, 5.3 years), 55 were unconscious and 10 had hypoglycemia at presentation. Although there was considerable overlap, the mean (+/- SEM) initial serum concentration of tumor necrosis factor was significantly higher in the 10 patients who died (709 +/- 312 pg per milliliter) than in the 55 who survived (184 +/- 32 pg per milliliter; P less than 0.02). The mortality rate increased with the concentration of tumor necrosis factor: at a level of less than 100 pg per milliliter, 1 of 24 patients died; at 100 to 500 pg per milliliter, 6 of 34 patients; and at more than 500 pg per milliliter, 3 of 7 patients. High concentrations of tumor necrosis factor were also associated with hypoglycemia (P less than 0.02), hyperparasitemia (P less than 0.002), age under three years (P less than 0.03), and severity of illness as measured by a prognostic index (P less than 0.0005). The highest serum concentrations of tumor necrosis factor were found in patients who died shortly after admission. The concentrations in cerebrospinal fluid were within the normal range in all patients. In serum samples obtained from 38 convalescent patients, the concentration of tumor necrosis factor declined to a mean of 16 +/- 3 pg per milliliter. We conclude that the level of tumor necrosis factor is frequently increased in patients with severe falciparum malaria, particularly in those with cerebral malaria or hypoglycemia. To determine whether it is important in the pathogenesis of the signs and symptoms of the disease requires further study.

Malaria--an overview

The epidemiology, clinical features, diagnosis, prognosis, management, chemotherapy and chemoprophylaxis of malaria are reviewed.

Chloroquine treatment of severe malaria in children. Pharmacokinetics, toxicity, and new dosage recommendations

Although empirical regimens of parenteral chloroquine have been used extensively to treat severe malaria for 40 years, recent recommendations state that parenteral chloroquine should no longer be used because of potential toxicity. We studied prospectively the pharmacokinetics and toxicity of seven chloroquine regimens in 58 Gambian children with severe chloroquine-sensitive falciparum malaria. In all regimens the total cumulative dose was 25 mg of chloroquine base per kilogram of body weight. Chloroquine was rapidly absorbed after either intramuscular or subcutaneous administration (5 mg of base per kilogram every 12 hours), producing high peak blood concentrations but transient hypotension in 5 of 18 patients (28 percent). Intermittent intravenous infusion (5 mg of base per kilogram over 4 hours, repeated every 12 hours) also produced wide fluctuations in chloroquine levels, suggesting incomplete distribution from a small central compartment. Continuous infusion (0.83 mg of base per kilogram per hour for 30 hours) and smaller, more frequent intramuscular or subcutaneous injections of chloroquine (3.5 mg of base per kilogram every 6 hours) produced smoother blood-concentration profiles with lower early peak levels and no adverse cardiovascular or neurologic effects. Chloroquine given by nasogastric tube (initial dose, 10 mg of base per kilogram) was absorbed well, even in comatose children. We conclude that simple alterations in dosage and frequency of administration can give parenteral chloroquine an acceptable therapeutic ratio and reinstate it as the treatment of choice for severe malaria in areas where chloroquine resistance is not a major problem.

Blood glucose levels in Malawian children before and during the administration of intravenous quinine for severe falciparum malaria

Hypoglycemia may develop in patients with severe untreated malaria and can complicate the course of treatment with parenteral quinine as a result of quinine-induced hyperinsulinemia. Intravenous quinine is used increasingly as the therapy of choice in patients with severe malaria, most of whom are children. To assess the importance of both pretreatment and quinine-related hypoglycemia in children in an area in which the disease is endemic, we prospectively studied 95 Malawian children with falciparum malaria and altered consciousness who were treated with intravenous quinine. Nineteen patients had hypoglycemia before treatment. Seven (37 percent) died, and five of the survivors (26 percent) had neurologic sequelae. The corresponding values for patients who were initially normoglycemic were 4 percent and 4 percent, respectively (P less than 0.0001). Hypoglycemia was associated with low plasma insulin concentrations and with elevated plasma concentrations of lactate, alanine, and 5'-nucleotidase--a finding that suggests that impaired hepatic gluconeogenesis but not hyperinsulinemia contributes to the pathogenesis of pretreatment hypoglycemia. All patients were given quinine dihydrochloride in a 5 percent dextrose infusion, and those with hypoglycemia received 50 percent dextrose. Hypoglycemia recurred in seven of the patients with pretreatment hypoglycemia, but these episodes were also not associated with hyperinsulinemia. Of the 76 children who were initially normoglycemic, none became hypoglycemic during the course of treatment with intravenous quinine. We conclude that hypoglycemia is a frequent complication of falciparum malaria in children and that it reflects severe disease and is associated with a poor prognosis. We did not find it to be a complication of quinine treatment.

Hypoglycaemia in severe falciparum malaria

The incidence of hypoglycaemia and the role of quinine in its causation was assessed in 46 patients with severe Plasmodium falciparum malaria. Plasma glucose and immunoreactive insulin were estimated before, during and after quinine therapy. In 5 patients the plasma glucose was in the hypoglycaemic range, the lowest value being 0.67 mmol/litre (12 mg/dl) in a pregnant patient. Most of the remaining patients showed a significant fall in plasma glucose (P less than 0.05), but not to the hypoglycaemic range, and an increase in plasma insulin after quinine (P less than 0.01). A good correlation was found between these changes (r = 0.79, P less than 0.01). Patients with severe P. falciparum malaria, particularly those on quinine therapy, should be watched carefully for developing hypoglycaemia.

High incidence of hypoglycaemia in African patients treated with intravenous quinine for severe malaria

Changes in plasma glucose and insulin concentrations were monitored over 24 hours in 28 African patients receiving quinine intravenously in an average dose of 8.5 mg base/kg over one hour eight hourly for severe malaria. The patients (nine children and 19 adults) were moderately undernourished; none was pregnant or had renal insufficiency. Plasma insulin concentrations rose during the infusion and then declined. Plasma glucose concentrations were decreased at two, three, and four hours after the start of the infusion. Insulin: glucose ratios were raised between half an hour and two hours after the start of the infusion. The three infusions of quinine increased plasma insulin concentrations in a similar way. In nine patients, including four children, plasma glucose concentrations fell below 2.8 mmol/l on one or two occasions. At the time of the hypoglycaemia plasma insulin concentrations were inappropriately high as shown by a consistent and often considerable increase in the insulin:glucose ratio. Hypoglycaemia that may pass unnoticed in comatose patients is thus a common complication of treating severe malaria with quinine, in particular in children. Its high incidence calls for attentive monitoring and preventive measures.