http://pacmisc.net/ Aggregated malaria articles from multiple sources en-uk Tue, 7 Feb 2012 05:00:39 GMT Tue, 7 Feb 2012 05:00:39 Hand Blasted 1.0 Not edited very much web@pacmisc.net http://pacmisc.net/?4022 BATTLE CONTINUES: Malaria kills nearly 50 per cent more than previously thought, claims a new investigation.
Read More ]]> Mon, 6 Feb 2012 00:00:00 GMT http://pacmisc.net/?4022 Media http://pacmisc.net/?4023 A new analysis demonstrates that confronting several diseases at once is a viable way to make the most of thinly stretched donor dollars and national health care budgets, and help save more lives.
Read More ]]> Sun, 5 Feb 2012 23:26:26 GMT http://pacmisc.net/?4023 Media http://pacmisc.net/?4025 by James J. Moon, Heikyung Suh, Mark E. Polhemus, Christian F. Ockenhouse, Anjali Yadava, Darrell J. Irvine The parasite Plasmodium vivax is the most frequent cause of malaria outside of sub-Saharan Africa, but efforts to develop viable vaccines against P. vivax so far have been inadequate. We recently developed pathogen-mimicking polymeric vaccine nanoparticles composed of the FDA-approved biodegradable polymer poly(lactide-co-glycolide) acid (PLGA) enveloped by a lipid membrane. In this study, we sought to determine whether this vaccine delivery platform could be applied to enhance the immune response against P. vivax sporozoites. ]]> Sun, 5 Feb 2012 14:00:00 GMT http://pacmisc.net/?4025 Science http://pacmisc.net/?4021 Recent renewed emphasis on the eradication of malaria has highlighted the need for more tools with which to achieve this ambitious goal. One high priority area is the need to determine the gametocytocidal activity of both currently used anti-malarial drugs and those in the development pipeline. However, testing the activity of compounds against Plasmodium falciparum gametocytes is technically challenging both in vivo and in vitro.Here the use of a simple robust assay to screen a panel of currently used and experimental anti-malarial drugs against mature P. falciparum gametocytes is described.Eight of 44 compounds tested reduced gametocyte viability by at least 50% and three showed IC50 values in nM range.
Read More ]]> Sun, 5 Feb 2012 14:00:00 GMT http://pacmisc.net/?4021 Science http://pacmisc.net/?4020 In a prospective infant cohort, 21 infants developed Plasmodium vivax malaria during their first year. Twelve of their mothers also had vivax malaria in the corresponding pregnancies or postpartum period. The genotypes of the maternal and infant infections were all different. Eight of the 12 mothers and 9 of the 21 infants had recurrent infections. Relapse parasite genotypes were different to the initial infection in 13 of 20 (65%) mothers compared with 5 of 24 (21%) infants (P = .02). The first P. vivax relapses of life are usually genetically homologous, whereas relapse in adults may result from activation of heterologous latent hypnozoites acquired from previous inoculations.
Read More ]]> Sun, 5 Feb 2012 14:00:00 GMT http://pacmisc.net/?4020 Science http://pacmisc.net/?4019 For many decades, the cornerstone of malaria managementin Africa was to treat all febrile children with chloroquine.With high-level resistance to chloroquine and improved meansof malaria diagnosis, recommendations for the management ofmalaria in Africa have changed in two important ways in thelast few years.
Read More ]]> Sun, 5 Feb 2012 14:00:00 GMT http://pacmisc.net/?4019 Science http://pacmisc.net/?4018 We identified 480 persons with positive thick smears for asexual Plasmodium falciparum parasites, of whom 454 had positive rapid diagnostic tests (RDTs) for the histidine-rich protein 2 (HRP2) product of the hrp2 gene and 26 had negative tests. Polymerase chain reaction (PCR) amplification for the histidine-rich repeat region of that gene was negative in one-half (10/22) of false-negative specimens available, consistent with spontaneous deletion. False-negative RDTs were found only in persons with asymptomatic infections, and multiplicities of infection (MOIs) were lower in persons with false-negative RDTs (both P < 0.001). These results show that parasites that fail to produce HRP2 can cause patent bloodstream infections and false-negative RDT results. The importance of these observations is likely to increase as malaria control improves, because lower MOIs are associated with false-negative RDTs and false-negative RDTs are more frequent in persons with asymptomatic infections. These findings suggest that the use of HRP2-based RDTs should be reconsidered.
Read More ]]> Sun, 5 Feb 2012 14:00:00 GMT http://pacmisc.net/?4018 Science http://pacmisc.net/?4017 Home management of malaria is recommended for prompt, effective antimalarial treatment in children less than five years of age. Compliance, safety, and effectiveness of the new fixed-dose artesunate-amodiaquine regimen used to treat suspected malaria were assessed in febrile children enrolled in a 24-month cohort study in two settings in Madagascar. Children with fever were asked to visit community health workers. Presumptive antimalarial treatment was given and further visits were scheduled for follow-up. The primary endpoint was the risk of clinical/parasitologic treatment failure. Secondary outcomes included fever/parasite clearance, change in hemoglobin levels, and frequency of adverse events. The global clinical cure rate was 98.4% by day 28 and 97.9% by day 42. Reported compliance was 83.4%. No severe adverse effects were observed. This study provides comprehensive data concerning the clinical cure rate obtained with artesunate-amodiaquine and evidence supporting the scaling up of home management of malaria.
Read More ]]> Sun, 5 Feb 2012 14:00:00 GMT http://pacmisc.net/?4017 Science http://pacmisc.net/?4016 The performance of two histidine-rich protein type-2based malaria rapid diagnostic tests (mRDTs) was examined in a rural area with a high prevalence of malaria and human immunodeficiency virus type-1 (HIV-1) infection in 113 and 445 febrile patients 15 years of age with and without HIV-1 infection, respectively. Patients were tested for HIV-1 infection by using a standard assay and for Plasmodium falciparum by using two mRDTs and microscopy. When microscopy was used as the gold standard, both mRDTs performed similarly in patients with and without HIV-1 infection: Bioline SD Malaria Antigen P.f, sensitivity 94.4% (95% confidence interval [CI]: 81.399.3%) versus 97.1% (95% CI:92.899.2%) and specificity 50.6% (95% CI: 39.062.2%) versus 47.2% (95% CI: 41.453.1%); and ICT diagnostics Malaria Pf, sensitivity 94.4% (95% CI: 81.399.3%) versus 97.1% (95% CI: 92.899.2%) and specificity 50.6% (95% CI:39.062.2%) versus 50.3% (95% CI: 44.456.1%). Infection with HIV-1 does not appear to affect the performance of these histidine-rich protein type-2 (HRP-2)-based mRDTs.
Read More ]]> Sun, 5 Feb 2012 14:00:00 GMT http://pacmisc.net/?4016 Science http://pacmisc.net/?4015 Establishing antibody correlates of protection against malaria in human field studies and clinical trials requires, amongst others, an accurate estimation of antibody levels. For polymorphic antigens such as apical membrane antigen 1 (AMA1), this may be confounded by the occurrence of a large number of allelic variants in nature. To test this hypothesis, plasma antibody levels in an age-stratified cohort of naturally exposed children from a malaria-endemic area in Southern Ghana were determined by indirect ELISA. Titres against four single PfAMA1 alleles were compared with those against three different allele mixtures presumed to have a wider repertoire of epitope specificities. Associations of antibody levels with the incidence of clinical malaria as well as with previous exposure to parasites were also examined. Antibody titres against PfAMA1 alleles generally increased with age/exposure while antibody specificity for PfAMA1 variants decreased, implying that younger children ([less than or equal to] 5 years) elicit a more strain-specific antibody response compared to older children. Antibody titre measurements against the FVO and 3D7 AMA1 alleles gave the best titre estimates as these varied least in pair-wise comparisons with titres against all PfAMA1 allele mixtures. There was no association between antibody levels against any capture antigen and either clinical malaria incidence or parasite density. The current data shows that levels of naturally acquired antigen-specific antibodies, especially in infants and young children, are dependent on the antigenic allele used for measurement. This may be relevant to the interpretation of antibody titre data from measurements against single PfAMA1 alleles, especially in studies involving infants and young children who have experienced fewer infections.
Read More ]]> Sun, 5 Feb 2012 14:00:00 GMT http://pacmisc.net/?4015 Science http://pacmisc.net/?4014 Despite a myriad of advances in the understanding and development of vaccine formulations, safe and effective vaccines have yet to be discovered for many pathogens. An excellent example of such is the malarial parasite Plasmodium vivax. Not only does this parasite transition between both extracellular and intracellular states during infection, but it can remain dormant in the liver and have greater transmission potential with lower titers than its more notorious counterpart, Plasmodium falciparum (1). As a consequence, it is important for a candidate vaccine to elicit both cellular (Th1) and humoral (Th2) immune responses that are potent and long-lived. Although vaccine antigens have been identified for the malarial sporozoites (2), the resulting immune responses elicited are short-lived and limited in scope, which is not uncommon for subunit vaccines that do not contain all of the components of a live-attenuated vaccine (3). For this reason, the malarial subunit vaccine is a hallmark example of a formulation that will require an appropriate adjuvant capable of boosting the most relevant immune responses to be effective. In PNAS, Moon et al. (4) describe a unique, lipid-based nanoparticle adjuvant (called an interbilayer-crosslinked multilamellar vesicle, or ICMV) that could not only be a promising candidate for prophylaxis against P. vivax but may even provide clues to how protective immunity to malaria is acquired. Nanoparticle adjuvants seem to be well suited for making this particularly challenging vaccine formulation effective. Indeed, nano- and microparticles are particularly flexible adjuvants that can serve as a point source for antigen retention and release in a sustained or even triggered fashion (57). Furthermore, as shown in the study by Moon et al. (4), synthetic particles can also be engineered to exhibit repetitive orientation of antigen on the surface.
Read More ]]> Sun, 5 Feb 2012 14:00:00 GMT http://pacmisc.net/?4014 Science http://pacmisc.net/?4011 Researchers are questioning results from a high-profile paper suggesting that malaria may kill twice as many people worldwide as previously estimated.The statistical analysis, published yesterday in The Lancet by researchers at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington in Seattle, nearly doubles the World Health Organization (WHO) estimate of global malaria deaths in 2010, revising the figure upwards from 655,000 to 1.24 million.But Bob Snow, of the Malaria Public Health & Epidemiology Group at the Centre for Geographic Medicine in Nairobi, Kenya, who was one of the papers peer reviewers, says that there are considerable weaknesses in the researchers methodology.
Read More ]]> Sat, 4 Feb 2012 05:00:20 GMT http://pacmisc.net/?4011 Science http://pacmisc.net/?4012 During the past decade, renewed global and national efforts to combat malaria have led to ambitious goals. We aimed to provide an accurate assessment of the levels and time trends in malaria mortality to aid assessment of progress towards these goals and the focusing of future efforts. Our findings show that the malaria mortality burden is larger than previously estimated, especially in adults. There has been a rapid decrease in malaria mortality in Africa because of the scaling up of control activities supported by international donors. Donor support, however, needs to be increased if malaria elimination and eradication and broader health and development goals are to be met. ]]> Fri, 3 Feb 2012 14:00:00 GMT http://pacmisc.net/?4012 Science http://pacmisc.net/?4008 Refugee children have scant access to medical care and are particularly vulnerable to disease. Fresh research results show that just a few hours of schooling a week may have a pronounced positive impact on their health not only in childhood but later in life when they achieve adulthood.
Read More ]]> Fri, 3 Feb 2012 04:15:15 GMT http://pacmisc.net/?4008 Media http://pacmisc.net/?4013 by Catherine G. Sutcliffe, Tamaki Kobayashi, Harry Hamapumbu, Timothy Shields, Sungano Mharakurwa, Philip E. Thuma, Thomas A. Louis, Gregory Glass, William J. MossBackground In regions of declining malaria transmission, new strategies for control are needed to reduce transmission and achieve elimination. Artemisinin-combination therapy (ACT) is active against immature gametocytes and can reduce the risk of transmission. We sought to determine whether household screening and treatment of infected individuals provides protection against infection for household members. Methodology/Principal Findings The study was conducted in two areas in Southern Province, Zambia in 2007 and 2008/2009. ]]> Thu, 2 Feb 2012 14:00:00 GMT http://pacmisc.net/?4013 Science http://pacmisc.net/?4010 by Joseph Kim, M. L. Richard Yip, Xiaoming Shen, Hubert Li, Li-Yu Charlie Hsin, Samuel Labarge, Eileen L. Heinrich, Wendy Lee, Jianming Lu, Nagarajan Vaidehi Despite recent advances in targeted therapies, patients with pancreatic adenocarcinoma continue to have poor survival highlighting the urgency to identify novel therapeutic targets. Our previous investigations have implicated chemokine receptor CXCR4 and its selective ligand CXCL12 in the pathogenesis and progression of pancreatic intraepithelial neoplasia and invasive pancreatic cancer; hence, CXCR4 is a promising target for suppression of pancreatic cancer growth. ]]> Thu, 2 Feb 2012 14:00:00 GMT http://pacmisc.net/?4010 Science http://pacmisc.net/?4006 New research says that malaria kills twice as many people a year as previously thought. The study published in the journal The Lancet shows that malaria kills 1,2 million people worldwide each year.
Read More ]]> Thu, 2 Feb 2012 14:00:00 GMT http://pacmisc.net/?4006 Media http://pacmisc.net/?4005 Cytoadherence of infected red blood cells to brain endothelium is causally implicated in malarial coma, one of the severe manifestations of falciparum malaria. Cytoadherence is mediated by specific binding of variant parasite antigens, expressed on the surface of infected erythrocytes, to endothelial receptors including, ICAM-1, VCAM and CD36. In fatal cases of severe falciparum malaria with coma, blood vessels in the brain are characteristically congested with infected erythrocytes. Brain sections from a fatal case of knowlesi malaria, but without coma, were similarly congested with infected erythrocytes. The objective of this study was to determine the binding phenotype of Plasmodium knowlesi infected human erythrocytes to recombinant human ICAM-1, VCAM and CD36.
Read More ]]> Thu, 2 Feb 2012 14:00:00 GMT http://pacmisc.net/?4005 Science http://pacmisc.net/?4002 Models suggest that malaria kills eight times as many adults in Africa as the World Health Organization estimates
Read More ]]> Thu, 2 Feb 2012 14:00:00 GMT http://pacmisc.net/?4002 Media http://pacmisc.net/?4009 Malaria is killing more people worldwide than previously thought -- 1.2 million -- but the number of deaths has fallen rapidly as efforts to combat the disease have ramped up, according to new research. Researchers say that deaths from malaria have been missed by previous studies because of the assumption that the disease mainly kills children under age five.
Read More ]]> Thu, 2 Feb 2012 10:17:17 GMT http://pacmisc.net/?4009 Media