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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In many African populations, the prevalences of both iron deficiency and malarial infection exceed 50%. The control of iron deficiency anemia is of urgent public health importance, but assessment of iron status in these contexts has been controversial because of the effects of malarial disease on common iron status indicators. We assessed iron status in 3605 school children in Zanzibar by measuring hemoglobin, erythrocyte protoporphyrin (EP) and serum ferritin concentrations. Malaria parasitemia was quantified by counting against leukocytes. Iron deficiency was highly prevalent: 62.4% of hemoglobin concentrations were <110 g/L, 59.7% of EP values were >80 micromol/mol heme, and 41.5% of ferritin concentrations were <12 microg/L. Prevalence of Plasmodium falciparum parasitemia was 60.6%, but <1% of children had densities above 5000 parasites/microL blood. Neither hemoglobin nor EP concentration was associated with malaria parasite density, but prevalence of abnormal values increased by < or = 25% with parasite density. Erythrocyte protoporphyrin and hemoglobin were strongly inversely related regardless of parasite density. The relationship of EP to hemoglobin was slightly attenuated when parasite density exceeded 1000 parasites/microL blood. Ferritin rose by 1.5 microg/L per 1000 parasites/microL for parasite densities >1000 parasites/microL, but the relationship of ferritin to hemoglobin or EP was strong even when parasite densities exceeded this cutoff. The population prevalences of iron deficiency were not significantly biased by malarial infection. In this population of school children, iron status assessment using these indicators was not seriously influenced by malarial infection. We hypothesize that these indicators perform reliably in populations in which malarial infection is infrequently associated with disease; namely older children and adults in holoendemic environments.
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PMID:Serum ferritin, erythrocyte protoporphyrin and hemoglobin are valid indicators of iron status of school children in a malaria-holoendemic population. 903 30

The control of anemia in women of childbearing age is essential to prevent low birth weight and perinatal and maternal mortality. To help identify appropriate intervention strategies for the control of iron deficiency anemia in Burkina Faso, cluster sampling of women 15-49 years of age was conducted in Bobo-Dioulasso. Of the 251 women selected, 56 were pregnant and 123 were breast feeding. Chronic nutritional deficiency (defined as a body mass index under 19 kg/m2) was present in 18% of women. The overall prevalence of anemia was 58.6% (71.4% among pregnant women, 64.2% among breast-feeding women, and 38.9% among non-pregnant/non-lactating women). Although health service utilization was high (91% for prenatal care and 72% for delivery) in this sample, only 11% had taken iron tablets. Ignorance about the benefits of iron supplements, the black color of feces associated with use of the tablets, and the tablets' unpleasant odor were the main reasons for non-compliance. When health workers addressed these concerns, women were compliant. Examination of conjunctival pallor had low sensitivity (16%) as a screening mechanism for anemia, while the portable hemoglobinometer was both acceptable and accurate. Recommended are programs to prevent malaria and malnutrition--the two main causes of anemia in Burkina Faso.
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PMID:Anaemia among women of reproductive age in Burkina Faso. 906 Feb 33

There is growing evidence of considerable burden of morbidity and mortality due to infectious diseases and undernutrition in school children. This study describes the nutritional status and parasitic infections of school children in two areas of rural Sri Lanka. All children in four primary schools in the Moneragala district of Sri Lanka were included in the study. The height and weight of children were measured and anthropometric indices calculated. Stool and blood samples were examined for evidence of intestinal helminthiasis, malaria and anaemia. A greater proportion of boys than girls were underweight, wasted and stunted. Over 80% of the children were anaemic but did not apparently have iron deficiency anaemia according to their blood picture. The prevalence of parasitic infections such as hookworm and Plasmodium spp that may contribute to anaemia was low.
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PMID:The health and nutritional status of school children in two rural communities in Sri Lanka. 1092 46

The diagnosis of iron deficiency anemia in malaria endemic areas is complicated by the influence of the infection on the laboratory tests conventionally used to assess iron status. Determination of soluble transferrin receptor (sTfR) levels has been shown to be a sensitive indicator of iron deficiency in adults and is not affected by a range of infectious and inflammatory conditions. The utility of sTfR levels in the diagnosis of iron deficiency in malaria endemic areas remains unresolved. Three hundred and fourteen infants in a rural area of southern Tanzania living under conditions of intense and perennial malaria transmission were studied to determine the utility of sTfR plasma levels in the assessment of iron deficiency anemia. Independent of the presence of anemia, malaria parasitemia was associated with a significant increase in sTfR plasma levels that were even higher than those found in iron deficiency anemia. We conclude that the measurement of sTfR levels does not have a role in the diagnosis of iron deficiency anemia in young children exposed to malaria infection.
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PMID:Effect of malaria on soluble transferrin receptor levels in Tanzanian infants. 1150 89

Toxicity studies were performed with a chemically defined mixture of 25 groundwater contaminants, using dose levels considered to have environmental relevance. The mixture contained 19 organic compounds and six metals (shown below); the selection of these compounds was based primarily on the frequency of their occurrence in United States Environmental Protection Agency surveys of groundwater contamination in the vicinity of hazardous waste disposal sites. This report focuses primarily on 26-week drinking water toxicity studies with male and female F344/N rats and B6C3F(1) mice. The endpoints evaluated included histopathology, clinical pathology, neurobehavioral studies, and reproductive toxicity. Additional studies using this same chemical mixture are briefly reviewed in this report and include an evaluation of spermatogenesis in B6C3F(1) mice exposed to the chemical mixture for 13 weeks, a continuous breeding study with Sprague-Dawley rats and CD-1(R) Swiss mice, studies of myelotoxicity in B6C3F(1) mice exposed to the chemical mixture for up to 31.5 weeks, studies of immunosuppression in B6C3F(1) mice exposed for up to 13 weeks, in vitro mutagenicity assays in Salmonella typhimurium and Escherichia coli, and measures of genetic damage in bone marrow and peripheral blood of F344/N rats and B6C3F(1) mice in 2-week drinking water studies. In a 26-week drinking water study in which rats were administered the chemical mixture at composite contaminant concentrations of 0, 11, 38, 113, or 378 ppm, no deaths occurred and the body weight gain of high-dose males was slightly less than that of the controls. Water consumption decreased with dose and was 24% to 28% less than that of the controls at the highest concentration. Changes in organ weights occurred primarily in high-dose rats and included increased absolute and relative liver and kidney weights in females, increased relative kidney weight in males, and decreased absolute and relative thymus weights in males and females. Hematologic assessments indicated that rats receiving 378 ppm developed a microcytic anemia consistent with that accompanying iron depletion. Multiple foci of inflammation occurred in the liver of exposed rats. In high-dose females, these liver lesions were especially prominent and included bile duct and oval cell hyperplasia. Inflammation also occurred in the mesenteric lymph nodes, the adrenal gland, and the spleen. The amount of hemosiderin in the spleens of rats receiving the higher concentrations of the chemical mixture was less than normal. Components of a chemical mixture of 25 groundwater contaminants include acetone, aroclor 1260, arsenic, benzene, cadmium, carbon tetrachloride, chlorobenzene, chloroform, chromium, 1,1-dichloroethane, 1,2-dichloroethane, 1,1-dichloroethylene, 1,2-trans-dichloroethylene, di(2-ethylhexyl) phthalate, ethylbenzene, lead, mercury, methylene chloride, nickel, phenol, tetrachloroethylene, toluene, 1,1,1-trichloroethane, trichloroethylene, xylenes. In a 26-week study in which mice were exposed to the chemical mixture at concentrations of 0, 11, 38, 113, and 378 ppm in drinking water, there were no clear adverse effects noted in survival, weight gain, clinical pathology parameters, or histopathologic evaluations. Water consumption decreased with increasing dose, and water consumption by high-dose mice was approximately 40% less than that by the controls. In neurobehavioral assessments, no clear treatment-related effects were observed in measures of forelimb and hindlimb grip strength, hindlimb footsplay, motor activity, response to a thermal stimulus, or startle response in rats or mice evaluated at 6-week intervals throughout the 26- week drinking water studies. There were no effects on sperm morphology or motility or on estrous cycle length in rats or mice receiving the chemical mixture during the 26-week studies. Sperm concentration was decreased in F(1) CD-1(R) Swiss mice during continuous breeding studies, although there were no clear adverse effects on the fertility of Sprague-Dawley rats or CD-1(R) Swiss mice in th CD-1&reg; Swiss mice in these studies. Pup weight, the number of live males, and the number of male pups per litter were slightly decreased in dosed rats in the continuous breeding study in rats; the number of live female mouse pups in litters born of the F(0) and F(1) generations was decreased in the 378 ppm group. The significance of these observations, if any, is not known. F(1) mice receiving 378 ppm had increased incidences of hepatic inflammation compared to the controls. In female B6C3F(1) mice that received the chemical mixture in drinking water at concentrations as high as 756 ppm for 2 weeks or 378 ppm for 13 weeks, assessments of immune function showed suppression of hematopoietic stem cells and antigen-induced antibody-forming cells. This was manifested by impaired resistance to challenge with a nonlethal strain of mouse malaria, Plasmodium yoelii. Additional evidence of an adverse effect on hematopoietic stem cells was demonstrated by decreases in the in vitro colony-forming ability of granulocyte-macrophage progenitor cells and erythroid precursor cells isolated from female mice that had received the chemical mixture at a concentration of 378 or 756 ppm in 31.5 week studies. Potential genotoxic effects of the chemical mixture to the bone marrow of F344/N rats and B6C3F(1) mice were assessed in 2-week drinking water studies with concentrations as high as 756 ppm. Small increases in sister chromatid exchanges and micronucleated polychromatic erythrocytes occurred in the bone marrow of dosed male mice, and micronucleated polychromatic erythrocytes were also increased in dosed female mice. The chemical mixture did not induce mutations in Salmonella typhimurium strains TA98 and TA100 and did not induce DNA damage in Escherichia coli with or without metabolic activation. In summary, rats receiving drinking water containing a mixture of 25 common groundwater contaminants at levels of potential environmental relevance developed inflammatory lesions in the liver, spleen, lymph nodes, and adrenal gland, as well as evidence of an iron deficiency anemia. The inflammatory lesions could not be predicted based on the known toxic effects of the individual components of the chemical mixture. Mice exposed to similar concentrations of the chemical mixture did not show adverse effects in a standard toxicity study but developed deficits in bone marrow function, evidence of genetic damage, hepatic inflammation, and immunosuppression in other studies that generally included exposures to higher concentrations or exposures of longer duration. A no-observed-adverse-effect level for histologic injury (granulomatous inflammation of the liver) was 11 ppm in rats; however, no clear evidence for histologic injury was seen in mice exposed to concentrations of the chemical mixture as high as 378 ppm in a standard 26-week study. NOTE: These studies were supported in part by funds from the Comprehensive Environmental Response, Compensation, and Liability Act trust fund (Superfund) by an interagency agreement with the Agency for Toxic Substances and Disease Registry, U.S. Public Health Service.
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PMID:NTP technical report on the toxicity studies of a Chemical Mixture of 25 Groundwater Contaminants Administered in Drinking Water to F344/N Rats and B6C3F(1) Mice. 1220 89

An estimated 50% of pregnant women in Africa are anemic-- a condition that has been linked to intrauterine growth retardation, increased perinatal mortality, low birthweight, compromised immunity, and possible psychomotor and cognitive impairments. In tropical Africa, iron and folate deficiencies and malaria are the major causes of anemia in pregnancy. Iron deficiency anemia results from a combination of dietary insufficiency, excessive requirements associated with multiparity, and chronic blood loss from hookworm infestation. An essential component of maternal-child health services in Africa is prevention of anemia and therapeutic management once severe anemia is documented. Since 35% of nonpregnant African women are anemic, many women will enter pregnancy with inadequate iron stores. Thus, the prophylactic dose of iron should be at least 120 mg/day rather than the usual 60 mg dose. Unfortunately, increased dosages of iron increase the side effects of constipation and nausea, so careful counseling is necessary to ensure compliance. Folic acid, which has no side effects, should be administered in doses of 1.5 mg/day. To reduce the risk of malaria, a therapeutic dose of chloroquine should be administered at the 1st prenatal visit (600 mg for 2 days and 300 mg on the 3rd day) followed by proguanil (100 mg/day) until delivery. In cases where anemia persists or emerges, the iron dose should be increased to 200 mg of ferrous sulfate 3 time/day (180 m,g of elemental iron) and 5 mg of folic acid should be provided. Blood transfusion should be used sparingly and only in severe cases, given the risk of transmission of human immunodeficiency virus.
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PMID:Towards a more effective management of pregnancy related anaemias in Africa. 1231 81

Thalassemia (thal) is one of the most prevalent congenital disorders in a world, especially in an endemic area of Plasmodium falciparum. The thal is relatively rare in northeast Asia including Japan where malaria is uncommon. However, thal in Japan has peculiar mutation spectrum and characteristics. Most b-thal patients in Japan are heteorozygote and thal minor as a phenotype. They are prone to be misdiagnosed as iron deficiency anemia. Thirty-four mutations of b-thal were thus far identified, and ten of which comprise 80% of beta-thal carriers. Among them 60% are unique to Japanese and 40% possibly from abroad. The exception is homozygote for -31G-A which leads to thal intermedia by beta(+)-thal phenoytpe. More than a half of patients with alpha-thal are of Southeast Asian type, but mutations of the remaining patients seem to be unique to Japanese and yet undetermined. Thus, Japanese thal's have dual origin. The frequency of beta-thal is one in 600 to approximately 1,000 of general population, and that of alpha(+)-thal (- alpha/) is one in 400. Thus, alpha-thal trait (- alpha/- alpha) is extremely rare. Another alpha-thal trait (- -/alpha alpha) would be one fifth of beta-thal. Seventeen families of HbH disease (- -/- alpha) were found. Many of them are related to Southeast Asian. Cases of non-iron deficient microcytosis and positive in the screening for hemoglobinopathies are subjected to gene analysis using allele-specific PCR, SSCP, direct sequencing and gap PCR. Precise breakpoints with large deletion are being identified by gene dosage and PCR instead of conventional Southern blotting and cloning. Most Japanese thal's are asymptomatic (or not hemolytic) except for microcytosis. However, dominant-type b-thal (or Heinz body beta-thal) are found, and their clinical phenotype vary with mutations. Some of them become symptomatic transiently. This is also seen in beta-thal coexisting with alpha-triplication. Acute exacerbation or transient appearance of Heinz body is seen in ordinary thal mutations on physical conditions such as pregnancy.
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PMID:Thalassemia mutations and their clinical aspects in Japan. 1243 Sep 6

Infections with 3 species of malaria parasites are rarely encountered and observed in less than 0.05% of cases. We came across such an infection in four year-old, monozygote twin sisters, coming from Kinshasa (Democratic Republic of Congo). In both of them, parasitemia was low or very low for P. falciparum and P. ovale and of 0.1-0.2% for P. malariae. The twin sisters presented with an iron deficiency anaemia, associated with an heterozygous sickle-cell anaemia and a moderate splenomegaly. The biological tests results were similar. They responded well to treatment. We point out the difficulty in recognizing the concomitant presence of several species of hematozoaire on blood smear.
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PMID:[Triple malaria infection in twin sisters from the Democratic Republic of Congo]. 1283 24

The intraerythrocytic Plasmodium falciparum parasite converts most of host hemoglobin heme into a nontoxic heme crystal. Erythrocyte zinc protoporphyrin IX, normally present at 0.5 microM, which is a ratio of 1:40,000 hemes, can elevate 10-fold in some of the anemias associated with malaria disease protection. This work examines a binding mechanism for zinc protoporphyrin IX inhibition of heme crystallization similar to the antimalarial quinolines. Zinc protoporphyrin IX neither forms crystals alone nor extends on preformed heme crystals. Inhibition of both seed heme crystal formation and crystal extension occurs with an inhibitory concentration (IC)50 of 5 microM. Field emission in-lens scanning electron microscopy depicts the transition and inhibition of heme monomer aggregates to heme crystals with and without seeding of preformed hemozoin templates. In vitro zinc protoporphyrin IX, like the quinolines, binds to heme crystals in a saturable, specific, pH, and time-dependent manner. The ratio at saturation is approximately 1 zinc protoporphyrin IX per 250 hemes of the crystal. Unlike the quinolines, zinc protoporphyrin IX binds measurably in the absence of heme. Isolated ring and trophozoite stage parasites have an elevated zinc protoporphyrin IX to heme ratio 6 to 10 times that in the erythrocyte cytosol, which also corresponds to elevated ratios found in heme crystals purified from Plasmodium parasites. This work implicates protection from malaria by a mechanism where elevated zinc protoporphyrin IX in anemic erythrocytes binds to heme crystals to inhibit further crystallization. In endemic malaria areas, severe iron deficiency anemia should be treated with antimalarials along with iron replenishment.
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PMID:Zinc protoporphyrin IX binds heme crystals to inhibit the process of crystallization in Plasmodium falciparum. 1457 25

Iron deficiency is the most common nutritional disorder in the world. Pregnant women are at especially high risk for iron deficiency and iron deficiency anemia. A considerable proportion of pregnant women in both developing and industrialized countries become anemic during pregnancy. The prevalence of anemia in pregnant women has remained unacceptably high worldwide despite the fact that routine iron supplementation during pregnancy has been almost universally recommended to prevent maternal anemia, especially in developing countries over the past 30 years. The major problem with iron supplementation during pregnancy is compliance. Despite many studies, the relationship between maternal anemia and adverse pregnancy outcome is unclear. However, there is now sufficient evidence that iron supplements increase hemoglobin and serum ferritin levels during pregnancy and also improve the maternal iron status in the puerperium, even in women who enter pregnancy with adequate iron stores. Recent information also suggests an association between maternal iron status in pregnancy and the iron status of infants postpartum. The necessity of routine iron supplementation during pregnancy has been debated in industrialized countries and routine supplementation is not universally practiced in all these countries. In view of existing data, however, routine iron supplementation during pregnancy seems to be a safe strategy to prevent maternal anemia in developing countries, where traditional diets provide inadequate iron and where malaria and other infections causing increased losses are endemic.
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PMID:Iron supplementation in pregnancy. 1460 Dec 65


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