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Abstract. Malaria remains the most important parasitic cause of mortality in humans. Its presentation is thought to vary according to the intensity of Plasmodium falciparum transmission. However, detailed descriptions of presenting features and risk factors for death are only available from moderate transmission settings. Such descriptions help to improve case management and identify priority research areas. Standardized systematic procedures were used to collect clinical and laboratory data on 6,624 children admitted to hospital over a 1-year period in an intensely malarious part of Tanzania. Frequencies of signs and symptoms were calculated and their association with a fatal outcome was assessed using multivariate logistic regression. There were 72 deaths among 2,432 malaria cases (case fatality rate [CFR] ϭ 3.0%); 44% of the cases and 54% of the deaths were in individuals less than 1 year of age. There was no association between level of parasitemia and CFR. Increased risk of dying was independently found in all children with hypoglycemia (odds ratio [OR] ϭ 6.7, 95% confidence interval [CI] ϭ 3.9-11.7), in children 1-7 months of age with tachypnea (OR ϭ 8.8, 95% CI ϭ 2.6-30.5) and dehydration (OR ϭ 5.0, 95% CI ϭ 1.9-14.2), and in children 8 months to 4 years of age with chest indrawing (OR ϭ 4.7, 95% CI ϭ 2.0-11.2) and inability to localize a painful stimulus (OR ϭ 6.9, 95% CI ϭ 2.9-16.5). Children in the bottom quartile of weight-for-age were more likely to die (OR ϭ 2.1, 95% CI ϭ 1.3-3.5). Eight percent of the malaria cases had severe anemia (packed cell volume Ͻ 15%) but 24% received a blood transfusion. The epidemiology of malaria disease may be more complex than previously thought. Improved case management in a wide variety of health facilities may result from adequate identification and treatment of dehydration and hypoglycemia. Transfusion-requiring anemia is a major problem and sustainable, effective preventive measures are urgently needed.More than half of the world's population lives in areas endemic for Plasmodium falciparum malaria, resulting in more than 400 million clinical cases and between one and three million deaths every year. 1 Young children living in sub-Saharan Africa carry the largest part of this burden. 2 Although the epidemiology of P. falciparum infection has been well described in a variety of settings, the description of malaria as a life-threatening disease is less complete. Such descriptions can improve case management by identifying children at highest risk of dying; focusing scarce resources on such patients may reduce case fatality rates. Furthermore, these studies provide valuable insights into underlying pathophysiologic processes.Common manifestations of severe malaria in children include cerebral malaria and severe anemia. The relative importance of each presentation is thought to vary according to the intensity of transmission, with severe anemia being increasingly important as transmission intensity increases and cerebral malaria more common at lower transmission inten...

SummaryA longitudinal study of Plasmodium falciparum malaria in infants in Idete village, south-eastern Tanzania, was conducted over a period of 14 months in order to determine the incidence of P. falciparum infection and clinical malaria in the first year of life. Of 1356 blood slides from cross-sectional surveys, 52.1% were positive for asexual stages of P. falciparum. There were marked increases in P. falciparum prevalence, parasite densities, overall fever incidence and the incidence of malaria fevers with age for the first 6 months of life. The average attack rate, estimated from a reversible catalytic model, was 0.029 per day with a slight increase with age but there was no initial period of protection against infection in neonates. Estimated average duration of infections was 64 days, with infections in older infants lasting much longer than those contracted during the first 2 months of life.These results support the hypotheses that the main effect of passively transferred maternal immunity to malaria is in the control of asexual stage parasites, and that the level of clinical immunity depends upon the extent of recent exposure to parasites. Infants as young as 4 months of age are at high risk of clinical attacks. Intervention programmes against malaria in areas of the highest transmission should therefore be designed to include this group.

SummaryMalaria control continues to rely on the diagnosis and prompt treatment of both suspected and con®rmed cases through the health care structures. In south-eastern Tanzania malaria is one of the leading causes of morbidity and mortality. The absence of microscopic examination in most of the health facilities implies that health workers must rely on clinical suspicion to identify the need of treatment for malaria. Of 1558 randomly selected paediatric consultations at peripheral health facilities throughout Kilombero District, 41.1% were diagnosed by the attending health worker as clinical malaria cases and 42.5% prescribed an antimalarial. According to our malaria case de®nition of fever or history of fever with asexual falciparum parasitaemia of any density, 25.5% of all children attending the health services had malaria. This yielded a sensitivity of 70.4% (IC95% 65.9±74.8%) and a speci®city of 68.9% (IC95% 66.2±71.5%). Accordingly, 30.4% of con®rmed cases left with no antimalarial treatment. Among malaria-diagnosed patients, 10% were underdosed and 10.5% were overdosed. In this area, as in many African rural areas, the low diagnostic accuracy may imply that the burden of malaria cases may be overestimated. Greater emphasis on the functioning and quality of basic health services in rural endemic areas is required if improved case management of malaria is to help roll back this scourge.