Are hypnozoites the only source of relapse-like, recurrent Plasmodium vivax malaria? They might not be. See explanation here. Until such time as the matter has been cleared up via research, perhaps it would be appropriate to avoid expressing theoretical mathematical analyses (that incorporate hypnozoites) too restrictively. Merely a suggestion.
When analysing results obtained in genetic epidemiological studies, how can homologous recurrences of Plasmodium vivax malaria be explained? Link to a blog on the subject
The presumed hypnozoite reservoir is perceived to be a threat to the goal of eradicating human malaria. However, the same now applies to putative non-hypnozoite tissue stages as well, notably quiescent merozoites. Persistence of extra-vascular tissue merozoites in vivax malaria has on genetic grounds been suspected since 2011. So far, they have been parasitologically demonstrated in rodent malarial infections. There is no particular reason why they should not also occur in primate malaria of various kinds.
Speculative extrapolation from biological and genetic findings resulting from malarial research carried out in recent years, places in doubt aspects of the validity of the current concept of hypnozoite-mediated malarial relapse, entrenched though the hypothesis (usually stated by authors as a fact) is. A piece(s) of the puzzle might be missing.
A little waterbird (or was it a frog?) whispered in my ear. Aquatic organisms don’t want humans to destroy their habitats when trying to eliminate malaria. Draining of swamps, for example, would have negative consequences not only for mosquitoes but also for various other (innocent) creatures that live there. Where does this leave malariologists, so to speak? Just asking.
New Method under ultrasound for rapid extraction and efficient purification of the antimalarial drug "Artemisinin" from medicinal plants.
Free download from Elsevier available till July 30th : http://authors.elsevier.com/a/1TBDt4p3AWHr29
Early recurrences (which are often homologous) in treated Plasmodium vivax infections are usually considered to be hypnozoite-mediated relapses. Can such recurrences sometimes or frequently be, instead, recrudescences caused by reactivation of blood stages that became temporarily quiescent following drug exposure? The experimental background to this question is given here.
Therapeutic failure of primaquine in cases of Plasmodium vivax malaria is often noted by clinicians. A newly recognized, possible cause of such treatment failure is the reactivation of viable dormant parasites that might be present in one or more extra-hepatic and extra-vascular sites. Administration of primaquine will not necessarily result in these stages being killed. Here is the link to where this drug-associated matter is discussed.
BASF scientist, Matthias Witschel, is seeking new ways to combat malaria. A 19th century dyestuff is playing an important role.
Every April 25th, people across the globe take part in a wide range of activities to raise awareness about Malaria.
For half the world, every day is malaria day, a day to keep up the fight against this deadly disease. With our Automated Malaria Diagnostic App, xRapid contributes to this fight alongside health workers in the field.
On this World Malaria Day, why not give us one click to help us #EndMalaria.
Vote for us on Virgin’s Startup Challenge.: http://xrapid.com/vote
On April 19th, xRapid won the Audience Choice Award at the Pistoia Alliance Mini Startup Challenge.
“We are pleased that the members of the Pistoia Alliance were able to see the potential of the xRapid Automated Diagnostic App. This event has been a great platform to showcase our innovative technology in front of the pharmaceutical industry.” – Jean Viry-Babel, xRapid CEO
This is a comment concerning the hidden parasite reservoir, and it is partly drug-related.
In 2015 a Nobel Price was attributed to Youyou Tu, almost 50 years after a report describing artemisinin’s structure, pharmacology, and efficacy had been published in 1979 by the “Qinghaosu Anti-Malarial Coordinating Research Group,” where she was a member of. Mr Huang Shuze, Deputy Minister of Health, stated in his 1981 summary report “Project 523 mobilized multiple departments ; thirty scientific research units and medical schools in 1975”.
COMMENT: For many years, it has traditionally been considered that Plasmodium malariae does not have a hypnozoite stage in its life cycle. Evidence for this has been thought to perhaps include the longevity of hepatocytes and what happens after inoculation of parasitized erythrocytes into the primate host (see hepatocyte and P. malariae sections, respectively). More recently, there have been suggestions that hypnozoites might, in fact, be present in the liver in P.
See Allenby's cavalry charge .
This extreme example is useful for those who wish to see the difference between durable malaria elimination and a temporary practical intervention in what was referred to as one of the most malarious countries in the world.
Hi,
I want to share my research observations (on artemisinin resistance in Plasmodium falciparum) with malaria Professionals in this scientific community and welcome your candid comments.
I am a Ph.D student working on surveillance for artemisinin-resistant Plasmodium falciparum in dried blood spots sampled from Nigeria. I sequenced the K13 propeller domain at Macrogen using the PCR primers published in Nature Ariey 2014 titled 'A molecular marker of artemisinin resistant Plasmodium falciparum malaria'.
Our CTO and Co-founder David Mendels answers our most commonly asked question.
The paper « Efficacy of a Novel Sublingual Spray Formulation of Artemether in African Children with Plasmodium falciparum Malaria » (Daryl Bendel et al.,Antimicrob. Agents Chemother. November 2015 vol. 59 no. 11 6930-6938) which was posted recently on www,malariaworld.org raises this important question. The clinical trials were run by an Australian pharmaceutical company in Burkina Faso, Rwanda and Ghana
In view of the tragedy, the barbarity and shocking loss of life in Syria, I felt this may be a timely reminder about how malaria elimination was, and could still be, a huge inspiration to all mankind and an aid towards a calmer and more peaceful world.
Countries known to have ebola are avoided by tourists because people die of it, and recently this disease has been given much media attention.
Charlwood JD, Wilkes TJ. Studies on the age composition of Anopheles darlingi Root from Brazil. Bulletin of Entomological Research, 1979 67, 337-342.
Working on Anopheles darling with the great Tony Wilkes – perhaps best person that I know, and, apart from Gillies, certainly the best field entomologist that I have known. An enormous influence on yours truly, not just in terms of entomology and how to approach field work but how to approach life.
Would anyone please explain why the example below of a successful method of malaria elimination is not being followed elsewhere?
When IBM dominated the computer world in the 1970s, an expression arose ‘No-one was ever fired for buying IBM’, even though competitors’ machines may have been more suitable for the task. Has a similar attitude now arisen towards bednets by those considering malaria elimination? Is the default position with regard to malaria elimination ‘No-one ever gets fired for buying mosquito bednets’? By 1970, Malaria was eliminated in North America and Europe. Were bednets extensively used there?
The quest for the anti-malaria ‘silver-bullet’/’magic-bullet’ drug or vaccine. Has this confused, distracted, mesmerised or misled the practical (cf theoretical lab-based) anti-malaria scientists?
Google’s definition of ‘Silver Bullet’ includes “ A simple remedy or a quick solution for a difficult problem”. Simple. Quick. And its definition of ‘Magic Bullet’ includes “A drug or treatment that cures a disease quickly and easily without producing bad effects”. Quickly. Easily.
Tomnod has teamed up with the University of California San Francisco's Malaria Elimination Initiative to develop a population map of Swaziland to assist in planning and implementing malaria elimination activities.
Tomnod uses DigitalGlobe satellite imagery to engage online volunteers to scan small portions of a large area. The volunteers scan the imagery and mark locations of interest to that particular survey. In this case the survey is looking for villages across Swaziland. When buildings are spotted by a volunteer in a polygon, that polygon is marked.
On 7th August 2012, Bart Knols brought to our attention a lecture by Margaret Heffernan entitled ‘Dare to Disagree’, and which can be seen at http://www.malariaworld.org/blog/margaret-heffernan-must-see-all-mw-subscribers . Margaret Heffernan spoke amongst other things about a scientist, Alice Stewart, who, in the 1950s, investigated and demonstrated the incidence of childhood cancer and its connection with the practice of X-raying pregnant women.
In the past 15 years malaria mortality and morbidity rates have been halved. This owes not least to insecticide based interventions and in particular the Long Lasting Insecticidal Net (LLIN). In recent years, increased findings of insecticide resistance have caused serious concerns whether these advances are threatened, although how much and how to respond remain topics for discussion.
This article will focus on the improved likelihood of a successful outcome where malaria elimination is conducted by scientists who live in the affected area. The blog by Alvaro Pemartin of 22nd January 2015 entitled "Column: Public health concerns (too) far away from home. Who cares?" is both instructive and fascinating. He showed statistics that revealed the global burden of swine flu, avian flu and ebola is far lower than the losses caused by malaria. He demonstrated that the media seems to overlook this point.
As a comment to Bart's Blog, I would like to add our thoughts as requested by the Secretariat. The document was sent in before the deadline, so I hope it was read, and raises some thoughts. As is seen from the picture below, the national malaria elimination campaign, begun in 1922 in Palestine, clearly worked.
For different aspects of this campaign generally, see Aspects of the malaria elimination .
But in particular, for what was so unique that made this malaria elimination so durable, see Durability .
