Malaria News Science |
A large proportion of asymptomatic Plasmodium infections with low and sub-microscopic parasite densities in the low transmission setting of Temotu Province, Solomon Islands: challenges for malaria diagnostics in an elimination setting 
Many countries are scaling up malaria interventions towards elimination. This transition changes demands on malaria diagnostics from diagnosing ill patients to detecting parasites in all carriers including asymptomatic infections and infections with low parasite densities. Detection methods suitable to local malaria epidemiology must be selected prior to transitioning a malaria control programme to elimination. A baseline malaria survey conducted in Temotu Province, Solomon Islands in late 2008, as the first step in a provincial malaria elimination programme, provided malaria epidemiology data and an opportunity to assess how well different diagnostic methods performed in this setting.
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Culicidae diversity, malaria transmission and insecticide resistance alleles in malaria vectors in Ouidah-Kpomasse-Tori district from Benin (West Africa): A pre-intervention study 
To implement an Insecticide Resistance Management (IRM) strategy through a randomized controlled trial (phase III), 28 villages were selected in southern Benin. No recent entomological data being available in these villages, entomological surveys were performed between October 2007 and May 2008, before vector control strategies implementation, to establish baseline data. This study updates information on mosquito diversity and malaria risk in rural villages from south Benin. It showed a high spatial heterogeneity in mosquito distribution and malaria transmission and underlines the need of further investigations of biological, ecological, and behavioral traits of malaria vectors species and forms. This study is a necessary prerequisite to cartography malaria risk and to improve vector control operations in southern Benin.
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Protective Efficacy of Intermittent Preventive Treatment of Malaria in Infants (IPTi) Using Sulfadoxine-Pyrimethamine and Parasite Resistance 
Intermittent Preventive Treatment of malaria in infants using sulfadoxine-pyrimethamine (SP-IPTi) is recommended by WHO for implementation in settings where resistance to SP is not high. Here we examine the relationship between the protective efficacy of SP-IPTi and measures of SP resistance.
Methods and Results
We analysed the relationship between protective efficacy reported in the 7 SP-IPTi trials and contemporaneous data from 6 in vivo efficacy studies using SP and 7 molecular studies reporting frequency of dhfr triple and dhps double mutations within 50km of the trial sites. We found a borderline significant association between frequency of the dhfr triple mutation and protective efficacy to 12 months of age of SP-IPTi.
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Rapid Detection of Lactate Dehydrogenase and Genotyping of Plasmodium falciparum in Saliva of Children with Acute Uncomplicated Malaria 
The diagnosis of malaria in biological fluids other than blood using non-invasive, rapid diagnostic techniques provides a valuable approach in case management and epidemiological studies of malaria. Rapid detection of Plasmodium falciparum lactate dehydrogenase (pLDH) in saliva samples from 130 of 144 children with microscopically confirmed P. falciparum infection was evaluated using Optimal-IT dipsticks. Genotyping of parasites was also performed in saliva and blood samples from a cohort of patients by polymerase chain reaction (PCR). The sensitivity of the dipstick in whole-blood, whole-saliva, or supernatant of spun saliva samples was 97.2%, 77.9%, and 48.4%, respectively. The sensitivity of the dipstick in whole-saliva samples was significantly higher than in supernatant of spun saliva samples (P < 0.0005). Mutant T76 allele was detectable in 60% and 57% of blood and saliva samples, respectively. This finding shows rapid detection of pLDH in patient saliva.
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A brief history of malaria chemotherapy 
Malaria is one of the worst sicknesses to affect humankind. For centuries there was no specific treatment, and it was not until the seventeenth century that Spanish colonisers brought back from Peru tree bark from which quinine was later extracted. In the twentieth century, synthetic alternatives to quinine were developed. Of these, chloroquine was the most successful, but by the 1970s widespread resistance had developed and the world was left without an effective treatment for malaria. During the same decade Chinese scientists extracted from sweet wormwood plant the drug artemisinin, which has proved to be very effective against chloroquine-resistant malarial parasites. The use of a combination therapy including artemisinin has made it possible to contemplate the eradication of malaria. Efforts to produce a stable and inexpensive supply of artemisinin are under way.
5/09/2010 3:00:00 AM from The Journal of the Royal College of Physicians of Edinburgh Read More Permalink
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Evaluation of Recurrent Parasitemia after Artemether-Lumefantrine Treatment for Uncomplicated Malaria in Children in Western Kenya
From April 2005 to April 2006, a phase 2 malaria vaccine trial in Kenya enrolled 400 children aged 12-47 months. Each received mixed supervised and unsupervised artemether-lumefantrine for uncomplicated malaria, using a standard six-dose regimen, by weight. Children were followed for detection of parasitemia and clinical malaria. A median of two negative malaria blood films occurred during every recurrent parasitemia (RP) episode, suggesting reinfection over late recrudescence. Median time to RP after starting artemether-lumefantrine was 37 days (36-38). Of 2,020 evaluable artemether-lumefantrine treatments, there were no RPs in 99% by day 14, 71% by day 28, and 41% by day 42. By World Health Organization standards, 71% of treatment courses had adequate responses. Although recrudescence in some cannot be ruled out, our cohort had a shorter median time to RP compared with other artemether-lumefantrine treatment studies. This underscores patient counseling on completing all treatment doses for optimal protection from RP.
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Is the Tide Turning for New Malaria Medicines? 
Every so often, the tide turns in a field of science. In malaria research, for a while an approach called "rational design" held sway, with great optimism that new drugs would emerge from understanding the biology of the malaria parasite at the molecular level. On page 1175 of this issue, however, Rottmann et al. (1) take our thinking back up to the level of the parasite.
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Antimalarial drug targets in Plasmodium falciparum predicted by stage-specific metabolic network analysis
Despite enormous efforts to combat malaria the disease still afflicts up to half a billion people each year of which more than one million die. Currently no approved vaccine is available and resistances to antimalarials are widely spread. Hence, new antimalarial drugs are urgently needed. The results suggest that the set of essential enzymes predicted by our flux balance approach represents a promising starting point for further drug development.
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