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Falciparum Infection (falciparum + infection)
Kinds of Falciparum Infection Selected AbstractsAcalculous Cholecystitis in a Patient With Plasmodium falciparum Infection: A Case Report and Literature ReviewJOURNAL OF TRAVEL MEDICINE, Issue 3 2006Jean C. Yombi MD Acute acalculous cholecystitis (AAC) can occur without gallstones in critically ill or injured patients and has also been associated with various infectious agents.1,4 We report here a case of AAC in a patient with Plasmodium falciparum malaria. [source] Experimental cerebral malaria progresses independently of the Nlrp3 inflammasomeEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2010Thornik Reimer Abstract Cerebral malaria is the most severe complication of Plasmodium falciparum infection in humans and the pathogenesis is still unclear. Using the P. berghei ANKA infection model of mice, we investigated a potential involvement of Nlrp3 and the inflammasome in the pathogenesis of cerebral malaria. Nlrp3 mRNA expression was upregulated in brain endothelial cells after exposure to P. berghei ANKA. Although ,-hematin, a synthetic compound of the parasites heme polymer hemozoin, induced the release of IL-1, in macrophages through Nlrp3, we did not obtain evidence for a role of IL-1, in vivo. Nlrp3 knock-out mice displayed a delayed onset of cerebral malaria; however, mice deficient in caspase-1, the adaptor protein ASC or the IL-1 receptor succumbed as WT mice. These results indicate that the role of Nlrp3 in experimental cerebral malaria is independent of the inflammasome and the IL-1 receptor pathway. [source] Automated detection of malaria-associated intraleucocytic haemozoin by Cell-Dyn CD4000 depolarization analysisINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 2 2003C.S. Scott Summary Laboratory tests for malaria are only performed if there is clinical suspicion of the disease, and a missed diagnosis contributes substantially to morbidity and mortality. Malaria parasites produce haemozoin, which is able to depolarize light and this allows the automated detection of malaria during routine complete blood count analysis (CBC) with some Abbott Cell-Dyn instruments. In this study, we evaluated the Cell-Dyn CD4000 with 831 blood samples submitted for malaria investigations. Samples were categorized as malaria negative (n = 417), convalescent malaria (n = 64) or malaria positive (n = 350) by reference to thin/thick film microscopy, ,rapid test' procedures, polymerase chain reaction analysis and clinical history. With regard to CD4000 depolarization analysis, a malaria positive CD4000 pattern was ascribed to samples that showed one or more abnormal depolarizing purple events, which corresponded to monocytes containing ingested malaria pigment (haemozoin). Positive CD4000 patterns were observed in 11 of 417, 50 of 64 and 281 of 350 of malaria negative, convalescent malaria and malaria positive samples respectively. The specificity and positive predictive values for malaria (active and convalescent) were very high (97.4 and 96.8%, respectively), while sensitivity and negative predictive values were 80.0 and 83.0% respectively. Depolarization analysis was particularly effective for Plasmodium falciparum malaria but there was lower detection sensitivity for White compared with Black African patients. CD4000 90° depolarization vs 0° analysis revealed a proportion of samples with small nonleucocyte-associated depolarizing particles. Appearance of such events in the form of a discrete cluster was associated with P. vivax rather than P. falciparum infection. [source] Erythrocytapheresis for Plasmodium falciparum infection complicated by cerebral malaria and hyperparasitemiaJOURNAL OF CLINICAL APHERESIS, Issue 1 2001Y. Zhang Abstract In malaria due to Plasmodium falciparum, life-threatening complications are in part related to the degree of parasitemia. Whole blood exchange and red blood cell exchange (RCE) have been used for the rapid removal of parasites from the circulation of patients with a high parasite load complicated by cerebral, pulmonary, and renal dysfunction. We have treated three 5,45-year-old patients with hyperparasitemia and end-organ dysfunction with red cell exchange by automated apheresis as an adjunct to specific anti-malarial chemotherapy. Parasitemia dropped more than 80% in all three patients immediately after the exchange, and all patients had an uneventful and full recovery. In combination with effective anti-malarial chemotherapy, apheresis RCE is a safe and rapid approach to treat complicated malaria due to P. falciparum. J. Clin. Apheresis. 16:15-18, 2001. © 2001 Wiley-Liss, Inc. [source] Malaria in Brazilian Military Personnel Deployed to AngolaJOURNAL OF TRAVEL MEDICINE, Issue 5 2000COL L. Jose Sanchez Background: Malaria represents one of the most important infectious disease threats to deployed military forces; most personnel from developed countries are nonimmune personnel and are at high risk of infection and clinical malaria. This is especially true for forces deployed to highly-endemic areas in Africa and Southeast Asia where drug-resistant malaria is common. Methods: We conducted an outbreak investigation of malaria cases in Angola where a total of 439 nonimmune Brazilian troops were deployed for a 6-month period in 1995,1996. A post-travel medical evaluation was also performed on 338 (77%) of the 439 soldiers upon return to Brazil. Questionnaire, medical record, thick/thin smear, and serum anti- Plasmodium falciparum antibody titer (by IFA) data were obtained. Peak serum mefloquine (M) and methylmefloquine (MM) metabolite levels were measured in a subsample of 66 soldiers (42 cases, 24 nonmalaria controls) who were taking weekly mefloquine prophylaxis (250 mg). Results: Seventy-eight cases of malaria occurred among the 439 personnel initially interviewed in Angola (attack rate = 18%). Four soldiers were hospitalized, and 3 subsequently died of cerebral malaria. Upon return to Brazil, 63 (19%) of 338 soldiers evaluated were documented to have had clinical symptoms and a diagnosis of malaria while in Angola. In addition, 37 (11%) asymptomatically infected individuals were detected upon return (< 1% parasitemia). Elevated, post-travel anti- P. falciparum IFA titers (, 1:64) were seen in 101 (35%) of 292 soldiers tested, and was associated with a prior history of malaria in-country (OR = 3.67, 95% CI 1.98,6.82, p < .001). Noncompliance with weekly mefloquine prophylaxis (250 mg) was associated with a malaria diagnosis in Angola (OR = 3.75, 95% CI 0.97,17.41, p = .03) but not with recent P. falciparum infection (by IFA titer). Mean peak levels (and ratios) of serum M and MM were also found to be lower in those who gave a history of malaria while in Angola. Conclusions: Malaria was a significant cause of morbidity among Brazilian Army military personnel deployed to Angola. Mefloquine prophylaxis appeared to protect soldiers from clinical, but not subclinical, P. falciparum infections. Mefloquine noncompliance and an erratic chemoprophylaxis prevention policy contributed to this large outbreak in nonimmune personnel. This report highlights the pressing need for development of newer, more efficacious and practical, prophylactic drug regimens that will reduce the malaria threat to military forces and travelers. [source] Distinct pattern of class and subclass antibodies in immune complexes of children with cerebral malaria and severe malarial anaemiaPARASITE IMMUNOLOGY, Issue 6-7 2008E. K. MIBEI SUMMARY Plasmodium falciparum infection can lead to deadly complications such as severe malaria-associated anaemia (SMA) and cerebral malaria (CM). Children with severe malaria have elevated levels of circulating immune complexes (ICs). To further investigate the quantitative differences in antibody class/subclass components of ICs in SMA and CM, we enrolled 75 children with SMA and 32 children with CM from hospitals in western Kenya and matched them to 74 and 52 control children, respectively, with uncomplicated symptomatic malaria. Total IgG IC levels were always elevated in children with malaria upon enrolment, but children with CM had the highest levels of any group. Conditional logistic regression showed a borderline association between IgG4-containing IC levels and increased risk of SMA (OR = 3·11, 95% CI 1·01,9·56, P = 0·05). Total IgG ICs (OR = 2·84, 95% CI 1·08,7·46, P = 0·03) and IgE-containing ICs (OR = 6·82, OR 1·88,24·73, P , 0·01) were associated with increased risk of CM. These results point to differences in the contribution of the different antibody class and subclass components of ICs to the pathogenesis of SMA and CM and give insight into potential mechanisms of disease. [source] Antigenic cross-reactivity between different alleles of the Plasmodium falciparum merozoite surface protein 2PARASITE IMMUNOLOGY, Issue 11-12 2003Ingrid Felger SUMMARY The polymorphic domain of the gene encoding Plasmodium falciparum merozoite surface protein 2 (MSP2) was PCR amplified from blood of malaria patients, genotyped, and 19 distinct fragments were cloned and expressed in E. coli. The reactivity of naturally occurring antibodies against this panel of recombinant MSP2 antigens was tested using 67 homologous or heterologous sera from a serum bank of travel clinic patients. Sera from semi-immune individuals strongly recognized almost all recombinant antigens. Sera from primary infected patients either did not react at all (9 sera), or reacted weakly against varying numbers of antigens (39 sera). The antigens that showed reactions were mostly of the allelic family corresponding to the infecting clone, but in very few cases also of the alternative allelic family. Single clone infections and repeated samples from the same individual were analysed in greater detail. Thus, we were able to quantify cross-reactivity induced by a single P. falciparum infection. Within the two allelic families of MSP2, cross-reactivity was observed between some but not all alleles of the same family, whereas antibodies cross-reactive between variants belonging to different allelic families were detected in only a few cases. [source] ,+ -Thalassaemia and pregnancy in a malaria endemic region of Papua New GuineaBRITISH JOURNAL OF HAEMATOLOGY, Issue 2 2006A. O'Donnell Summary The effect of maternal ,+ -thalassaemia on pregnancy was assessed in the north coastal region of Papua New Guinea (PNG), where malaria is hyperendemic and ,+ -thalassaemia is extremely common. In a prospective study of 987 singleton hospital deliveries, we correlated maternal , -globin genotype with markers of reproductive fitness (age in primigravidae, gravidity, pregnancy interval and the number of miscarriages and stillbirths), Plasmodium falciparum(P. falciparum) infection of the mother and placenta, maternal haemoglobin, preterm delivery and birthweight. The frequency of the ,, genotype in mothers was 0·61. Markers of reproductive fitness were similar in women with and without ,+ -thalassaemia. Median haemoglobin concentration during pregnancy and after delivery was about 1·0 g/dl lower in homozygous ,+ -thalassaemia than in women with a normal , - globin genotype (P , 0·001). The frequency of placental P. falciparum infection and systemic malaria infection after delivery showed no consistent relationship to , -globin genotype. The frequency of preterm delivery and low birthweight did not vary significantly according to maternal , -globin genotype. Maternal ,+ -thalassaemia does not affect reproductive fitness or susceptibility to malaria during pregnancy. Although median haemoglobin concentration was significantly lower in mothers homozygous for ,+ -thalassaemia than those with a normal , -globin genotype, this did not result in an adverse outcome of pregnancy. [source] Plasmodium falciparum infection of the placenta affects newborn immune responsesCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2003J. ISMAILI SUMMARY The effects of exposure to placental malaria infection on newborn immunological responses, in particular Th1/Th2 cytokines and antigen-presenting cell (APC) function, were compared between cord blood mononuclear cells (CBMC) from parasitized and non-parasitized placentas of Gambian women. Cells were analysed in vitro for their ability to respond to mitogens [phorbol myristate acetate (PMA)/ionomycin, phytohaemagglutinin (PHA)], a malaria-unrelated test antigen [purified protein derivative of Mycobacterium tuberculin[purified protein derivative (PPD)] and Plasmodium falciparum schizont extracts. Mitogens induced strong proliferation and secretion of high concentrations of both IL-13 and sCD30 in CBMC from both groups. Conversely, significantly lower amounts of IFN- , were induced in the parasitized group in response to low doses of PHA. Protein antigens induced very low amounts of all tested cytokines, in particular IFN- ,. However, a significantly higher release of sCD30 was observed in response to schizont extracts in the parasitized group. Addition of LPS to activate APC to low doses of PHA or schizont extracts increased the IFN- , production in both groups but levels remained lower in CBMC from the parasitized group. This result correlates with the lower production of IL-12 found following lipopolysaccharide (LPS) stimulation in this group. Taken together, these data show that placental infection with P. falciparum affects Th1 differentiation and sCD30 priming of neonatal lymphocytes and that the probable mode of action is via APC. [source] Performance of the Now Malaria rapid diagnostic test with returned travellers: a 2-year retrospective study in a French teaching hospitalCLINICAL MICROBIOLOGY AND INFECTION, Issue 11 2005F. Durand Abstract Malaria caused by Plasmodium falciparum remains the major life-threatening parasitic infection in the world. The number of cases in non-endemic countries continues to increase, and it is important that misdiagnosis of malaria should not occur, especially in non-immune travellers, because of the high risk of a fatal outcome. In a retrospective study of 399 sera, the Now Malaria rapid test was compared with the quantitative buffy coat (QBC) test and microbiological examination of thin blood films. Compared with the QBC test and thin blood films, the Now Malaria test had sensitivity and specificity values of 96.4% and 97%, respectively, for the detection of pure P. falciparum infection. A negative predictive value of 99.4% allows this test to be included in diagnostic strategies for patients presenting with clinical suspicion of malaria. Two false-negative results were associated with low levels of parasitaemia in the specimens. Thus, use of the Now Malaria test alone to detect P. falciparum infection in non-endemic countries could lead to misdiagnosis of malaria. This rapid diagnostic test should therefore be performed in association with another prompt traditional method such as examination of thin blood films. [source] | ||||||||||||||||||||||