http://pacmisc.net/ Aggregated malaria articles from multiple sources en-uk Mon, 21 May 2012 05:00:35 GMT Mon, 21 May 2012 05:00:35 Hand Blasted 1.0 Not edited very much web@pacmisc.net http://pacmisc.net/?4375 Malaria remains a significant health problem in Bangladesh affecting 13 of 64 districts. Therisk of malaria is variable across the endemic areas and throughout the year. A betterunderstanding of the spatial and temporal patterns in malaria risk and the determinantsdriving the variation are crucial for the appropriate targeting of interventions under theNational Malaria Control and Prevention Programme.Numbers of Plasmodium falciparum and Plasmodium vivax malaria cases reported by monthin 2007, across the 70 endemic thanas (sub-districts) in Bangladesh, were assembled fromhealth centre surveillance reports.
Read More ]]> Sun, 20 May 2012 14:00:00 GMT http://pacmisc.net/?4375 Science http://pacmisc.net/?4374 German chemist Peter Seeberger, head of a team of 70 researchers at the Max Planck Institute of Colloids and Interfaces in Potsdam, has found a way to produce artemisinin, the world's most important antimalaria medication, much more cheaply and easily than current methods allow. In January, Seeberger published a paper outlining how a technique called flow chemistry might make a key step in the drug's production chain more efficient. If the promise comes true, it could be a boon for the global fight against malaria, because the current price, between $0.80 and $1.20 per treatment course, is still a major factor hampering access to artemisinin drugs. Some scientists are impressed. But Seeberger's method has yet to prove its mettle.
Read More ]]> Sun, 20 May 2012 14:00:00 GMT http://pacmisc.net/?4374 Science http://pacmisc.net/?4373 Global efforts to control malaria are more complex than those for other infectious diseases, in part because of vector transmission, the complex clinical presentation of Plasmodium infections, >1 Plasmodium species causing infection, geographic distribution of vectors and infection, and drug resistance. The World Health Organization approach to global malaria control focuses on 2 components: vector control and diagnosis and treatment of clinical malaria. Although microscopy performed on peripheral blood smears remains the most widely used diagnostic test and the standard against which other tests are measured, rapid expansion of diagnostic testing worldwide will require use of other diagnostic approaches. This review will focus on the malaria rapid diagnostic test (MRDT) for detecting malaria parasitemia, both in terms of performance characteristics of MRDTs and how they are used under field conditions. The emphasis will be on the performance and use of MRDTs in regions of endemicity, particularly sub-Saharan Africa, where most malaria-related deaths occur.
Read More ]]> Sun, 20 May 2012 14:00:00 GMT http://pacmisc.net/?4373 Science http://pacmisc.net/?4372 Malaria remains a significant health problem in Bangladesh affecting 13 of 64 districts. Therisk of malaria is variable across the endemic areas and throughout the year. A betterunderstanding of the spatial and temporal patterns in malaria risk and the determinantsdriving the variation are crucial for the appropriate targeting of interventions under theNational Malaria Control and Prevention Programme.
Read More ]]> Sun, 20 May 2012 14:00:00 GMT http://pacmisc.net/?4372 Science http://pacmisc.net/?4371 Progress in eradicating malaria is jeopardised if programmes to combat the disease are cut, a study has concluded.The study, published in the Malaria Journal (2012;11:122, doi:10.1186/1475-2875-11-122), looked at 75 documented cases of malaria resurgence worldwide since the 1930s. It found that in 90% of the cases resurgence was linked, in part, to weakening of malaria control programmes.The researchersfrom the Clinton Health Access Initiative; the Johns Hopkins Malaria Research Institute; the independent Center for Disease Dynamics, Economics and Policy, which is based in Washington, DC, and New Delhi; and the Global Health Group at the University of California, San Franciscoreviewed the literature to find all documented instances of malaria resurgence.Their study looked at historical events, but its findings are relevant now after the cancellation last November of the latest funding round of the Global Fund to fight AIDS, Tuberculosis and Malaria, the biggest source of funding for malaria control worldwide (BMJ 2011;343:d7755, doi:10.1136/bmj.d7755).
Read More ]]> Sun, 20 May 2012 14:00:00 GMT http://pacmisc.net/?4371 Media http://pacmisc.net/?4370 Concerned by the emerging threat that resistance to insecticides poses to programmes to control malaria vectors, the World Health Organization this week launched a new global plan for insecticide resistance management.WHO says, Vector control is a central, critical component of all malaria control strategies. Control relies primarily on two interventions: long lasting insecticidal nets and indoor residual spraying. Use of both has increased significantly over the past decade as part of a drive towards universal coverage of all populations at risk, saving hundreds of thousands of lives.
Read More ]]> Sun, 20 May 2012 14:00:00 GMT http://pacmisc.net/?4370 Media http://pacmisc.net/?4369 In areas mesoendemic for malaria transmission, symptomatic individuals play a significantrole as reservoirs for malaria infection. Understanding the pathogenesis of symptomaticmalaria is important in devising tools for augmenting malaria control. In this study, the effectof TLR9 polymorphisms on susceptibility to symptomatic malaria was investigated amongGhanaian children.Four hundred and twenty nine (429) healthy Ghanaian children, aged three to eleven years(3-11 years), were enrolled into a cohort study and actively followed up for symptomaticmalaria for one year.
Read More ]]> Wed, 16 May 2012 14:00:00 GMT http://pacmisc.net/?4369 Science http://pacmisc.net/?4368 Parenteral artesunate has been shown to be a superior treatment option compared toparenteral quinine in adults and children with severe malaria. Little evidence, however, isavailable on long-term safety. Recently, cases of late-onset haemolysis after parenteraltreatment with artesunate have been reported in European travellers with importedPlasmodium falciparum malaria. Therefore, an extended follow-up of adult patients treatedfor severe imported malaria was started in August 2011 at the University Medical CenterHamburg-Eppendorf.Until January 2012, three patients with hyperparasitaemia (range: 14-21%) were included foranalysis. In all three patients, delayed haemolysis was detected in the second week after thefirst dose of intravenous artesunate.
Read More ]]> Wed, 16 May 2012 14:00:00 GMT http://pacmisc.net/?4368 Science http://pacmisc.net/?4366 Biologists have succeeded in engineering algae to produce potential candidates for a vaccine that would prevent transmission of the parasite that causes malaria.
Read More ]]> Wed, 16 May 2012 07:44:44 GMT http://pacmisc.net/?4366 Media http://pacmisc.net/?4363 The war to bring malaria to heel has made slow but steady progress during the past decade, with the overall mortality rate dropping by more than 25% since 2000. A key factor in this progress has been improved control of mosquitoes, which transmit the Plasmodium parasite a potent killer that claimed an estimated 655,000 lives in 2010 alone. But health officials fear that the spread of insecticide-resistant mosquitoes could bring about a resurgence of the disease. To help combat this threat, on 15 May the World Health Organization (WHO), based in Geneva, Switzerland, issued a strategic plan to curb the spread of resistance.
Read More ]]> Tue, 15 May 2012 20:00:26 GMT http://pacmisc.net/?4363 Science http://pacmisc.net/?4367 by James A. Gregory, Fengwu Li, Lauren M. Tomosada, Chesa J. Cox, Aaron B. Topol, Joseph M. Vinetz, Stephen Mayfield Subunit vaccines are significantly more expensive to produce than traditional vaccines because they are based primarily on recombinant proteins that must be purified from the expression system. Despite the increased cost, subunit vaccines are being developed because they are safe, effective, and can elicit antibodies that confer protection against diseases that are not currently vaccine-preventable. ]]> Tue, 15 May 2012 14:00:00 GMT http://pacmisc.net/?4367 Science http://pacmisc.net/?4362 Long-lasting treatment kits, designed to transform untreated nets into long-lasting insecticidal nets (LLINs), may facilitate high coverage with LLINs where non-treated nets are in place. In this study, the efficacy of ICON(R) Maxx (Syngenta) was evaluated under laboratory conditions and in an experimental hut trial in central Cote d'Ivoire, where Anopheles gambiae s.s. are resistant to pyrethroid insecticides. In contrast to previous laboratory investigation, ICON(R) Maxx-treated nets showed only moderate KD and mortality rates.
Read More ]]> Mon, 14 May 2012 14:00:00 GMT http://pacmisc.net/?4362 Science http://pacmisc.net/?4361 Flow cytometry and cell sorting are powerful tools enabling the selection of particular cell types within heterogeneous cell mixtures. These techniques, combined with whole genome amplification that non-specifically amplify small amounts of starting DNA, offer exciting new opportunities for the study of malaria genetics. Among them, two are tested in this paper: (1) single cell genotyping and (2) parasite DNA purification for subsequent whole genome sequencing using shotgun technologies.The method described allows isolation of Plasmodium falciparum trophozoites, genotyping and whole genome sequencing from the blood of infected patients.
Read More ]]> Sun, 13 May 2012 14:00:00 GMT http://pacmisc.net/?4361 Science http://pacmisc.net/?4360 International public health workers are challenged by a burden of arthropod-borne disease thatremains elevated despite best efforts in control programmes. With this challenge comes theopportunity to develop novel vector control paradigms to guide product development andprogramme implementation. The role of vector behaviour modification in disease control wasfirst highlighted several decades ago but has received limited attention within the public healthcommunity. This paper presents current evidence highlighting the value of sub-lethal agents,specifically spatial repellents, and their use in global health, and identifies the primary challengestowards establishing a clearly defined and recommended role for spatial repellent products indisease control.
Read More ]]> Sun, 13 May 2012 14:00:00 GMT http://pacmisc.net/?4360 Science http://pacmisc.net/?4359 Malaria is one of the leading public health problems in most of sub-Saharan Africa,particularly in Ethiopia. Almost all demographic groups are at risk of malaria because ofseasonal and unstable transmission of the disease. Therefore, there is a need to developmalaria early-warning systems to enhance public health decision making for control andprevention of malaria epidemics. Data from orbiting earth-observing sensors can monitorenvironmental risk factors that trigger malaria epidemics. Remotely sensed environmentalindicators were used to examine the influences of climatic and environmental variability ontemporal patterns of malaria cases in the Amhara region of Ethiopia.
Read More ]]> Sun, 13 May 2012 14:00:00 GMT http://pacmisc.net/?4359 Science http://pacmisc.net/?4358 Despite intensive research, malaria remains a major health concern for non-immune residentsand travelers in malaria-endemic regions. Efficient adjunctive therapies against lifethreateningcomplications such as severe malarial anaemia, encephalopathy, placental malariaor respiratory problems are still lacking. Therefore, new insights into the pathogenesis ofsevere malaria are imperative. Haemozoin (Hz) or malaria pigment is produced during intraerythrocyticparasite replication, released in the circulation after schizont rupture andaccumulates inside multiple organs. Many in vitro and ex vivoimmunomodulating effects aredescribed for Hz but in vivo data are limited.
Read More ]]> Sun, 13 May 2012 14:00:00 GMT http://pacmisc.net/?4358 Science http://pacmisc.net/?4357 Maternally transferred immunity can have a fundamental effect on the ability of offspring to deal with infection. However, levels of antibodies in adults can vary both quantitatively and qualitatively between individuals and during the course of infection. How infection dynamics and their modification by drug treatment might affect the protection transferred to offspring remains poorly understood. Using the rodent malaria parasite Plasmodium chabaudi, we demonstrate that curing dams part way through infection prior to pregnancy can alter their immune response, with major consequences for offspring health and survival. In untreated maternal infections, maternally transferred protection suppressed parasitaemia and reduced pup mortality by 75 per cent compared with pups from nave dams. However, when dams were treated with anti-malarial drugs, pups received fewer maternal antibodies, parasitaemia was only marginally suppressed, and mortality risk was 25 per cent higher than for pups from dams with full infections. We observed the same qualitative patterns across three different host strains and two parasite genotypes. This study reveals the role that within-host infection dynamics play in the fitness consequences of maternally transferred immunity. Furthermore, it highlights a potential trade-off between the health of mothers and offspring suggesting that anti-parasite treatment may significantly affect the outcome of infection in newborns.
Read More ]]> Sun, 13 May 2012 14:00:00 GMT http://pacmisc.net/?4357 Science http://pacmisc.net/?4356 Pregnant women who travel to malarious areas and their clinicians need data on the safety of malaria chemoprophylaxis. The effect of exposure to mefloquine on pregnancy and offspring outcomes was evaluated using the F. HoffmannLa Roche global drug safety database for the time frame 31 January 1986 through 26 October 2010. We investigated pregnancy and fetal outcomes in maternal, paternal, and both-parent exposure cases with a focus on congenital malformations and fetal loss. The main outcome measures were birth defect prevalence and types of malformations. A total of 2506 cases of mefloquine exposure during pregnancy or in the pre- and periconception period were evaluated. Most cases were maternal prospective (outcome of the pregnancy unknown at the time of reporting; n = 2246 [89.6%]) followed by maternal retrospective cases (outcome of the pregnancy known at the time of reporting; n = 227 [9.0%]), with small numbers of paternal and both-parent exposure cases. Of the total 2246 mefloquine maternal prospective exposures (95.2%), 2139 occurred before conception and/or during the first trimester. Of 1383 maternal prospective cases with known outcome, 978 (70.7%) resulted in delivery, 405 (29.3%) resulted in abortion (112 spontaneous, 293 therapeutic), and 43 resulted in birth defects, corresponding to a birth defect prevalence of 4.39% (43 of 978). Prospective cases overall showed no specific pattern of birth malformations. The drug safety database analysis of mefloquine exposure in pregnancy showed that the birth defect prevalence and fetal loss in maternal, prospectively monitored cases were comparable to background rates.
Read More ]]> Sun, 13 May 2012 14:00:00 GMT http://pacmisc.net/?4356 Science http://pacmisc.net/?4355 Accurate diagnosis of malaria infection during pregnancy remains challenging because of low parasite densities and placental sequestration of Plasmodium falciparum. The performance of different methods to detect P. falciparum in pregnancy and the clinical relevance of undetected infections were evaluated. P. falciparum infections were assessed in 272 Mozambican women at delivery by microscopy, placental histology, quantitative polymerase chain reaction (qPCR) and detection of histidine-rich protein 2 (HRP2) in plasma by enzyme-linked immunosorbent assay (ELISA) and a rapid diagnostic test (RDT). Association between infection and delivery outcomes was determined. Among the 122 women qPCR-positive for P. falciparum in peripheral and/or placental blood samples, 87 (71.3%) did not receive a positive diagnosis by peripheral microscopy, 75 (61.5%) by HRP2 ELISA, and 74 (60.7%) by HRP2 RDT in plasma. Fifty-seven of the 98 qPCR-positive placental infections (58.2%) were not detected by histology. Women who were qPCR-positive but negative in their peripheral blood by microscopy or HRP2 RDT in plasma (n = 62) were at increased risk of anemia, compared with negative women (n = 141; odds ratio, 2.03; 95% confidence interval, 1.073.83; P = .029). Microscopy, placental histology and HRP2-based plasma diagnostic methods fail to identify the majority of the P. falciparum infections detected by qPCR in peripheral and placental blood. Undetected infections were associated with maternal anemia, highlighting the urgent need for more accurate malaria diagnostic tools for pregnant women to avoid the negative clinical impact that hidden infections can have during pregnancy.
Read More ]]> Sun, 13 May 2012 14:00:00 GMT http://pacmisc.net/?4355 Science http://pacmisc.net/?4354 Bolivia has the globe's highest infection rates of Chagas disease, a slow-developing illness caused by the Trypanosoma cruzi parasite that can lead to extreme lethargy and even organ failure. The vector, known as the vinchuca (Triatoma infestans), lives in the walls of mud or adobe huts and feeds on farm animals. Research shows that shoddy and sporadic fumigation has resulted in a pesticide-tolerant bug population. Spanish chemist Pilar Mateo believes that her insecticidal paintInesfly 5A IGRis the solution. Studies show it is effective for four to 20 times longer than traditional pesticide applications, and its microcapsule packaging of active agents reduces environmental and toxic risks. But adoption of Inesfly has been slow, partly because it lacks the approval of the World Health Organization's Pesticide Evaluation Scheme, the gateway to biocide use in the developing world. But Inesfly now seems poised for a debut.
Read More ]]> Sun, 13 May 2012 14:00:00 GMT http://pacmisc.net/?4354 Science Media