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Thread: In the fight against malaria

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    Saving children from malaria...

    Researchers Find Gene That Fights Severe Malaria in Children
    May 19, 2011 - Scientists have discovered a genetic variant in children that significantly reduces their risk of developing a life-threatening form of malaria.
    Children with the unusual, or variant, gene have a 30 percent lower risk of developing cerebral malaria than those without the gene. Cerebral malaria is the most serious form of the parasitic illness that causes very high fever and coma, and leads rapidly to death in the 20 to 50 percent of people whose brains become infected. The mosquito-borne illness affects almost 300 million people every year. But most of the one million deaths occur in children under the age of five.

    Researchers at Germany’s Bernhard Nocht Institute for Tropical Medicine and Kumasi University in Ghana identified the protective gene in a study involving more than 6,000 children. Called FAS, the gene is responsible for a molecule involved in the programmed cell death of some white blood cells, which are immune system cells that attack and destroy microbes that invade the body. Researchers think that children who develop a life-threatening form of malaria have a hyper-immune response to the parasite. But youngsters with the FAS variant have increased expression of the molecule, called CD95, which appears to promote a greater number of immune system cell suicides - thus a less intense and ultimately survivable immune reaction to malaria.

    At least that’s the theory, according to Kathrin Schuldt, a biologist and co-author of the study. Schuldt says children who are vulnerable to cerebral malaria are constantly bitten by mosquitoes that carry the parasite. “So the immune response is constantly on a very high level trying to eliminate the pathogen from the body. And so what we found with this naturally occurring variant, these children probably have a regulation in their immune response which down-regulates the immune response to a certain level and therefore is kind of protective,” Schuldt said.

    Humans never develop full immunity against malaria, but they can gain a partial immunity to the parasite, which is why the disease is less severe in adults. But children can become quite sick because they have had less exposure to the disease. Schuldt says her goal now is to figure out the underlying mechanism for the protective effect of the genetic variant. Then, Schuldt says, it may be possible to develop drugs to protect children from this fatal form of malaria. An article on the protective malaria gene is published in the on-line journal PLoS Genetics.


  2. Cool

    Malaria vaccine advances to clinical trials...

    Malaria Vaccine in Clinical Trials in Africa
    June 20, 2011 - More than 2 million people die of malaria each year - a child every 45 seconds - with 90 percent of the cases in sub-Saharan Africa. That's why so much importance is placed on developing an effective vaccine.
    Organic farmers in Africa complain that insecticides used to control mosquitos that carry the malaria parasitecontaminate their crops and hurt sales. And this Ugandan nurse says the insecticide of choice is no longer effective. "It was realized that the mosquito had already developed resistance against the DDT," said Sam Dick Kale. So in malaria-prone regions, bed nets treated with insecticides, and drug treatment, also are used. That has helped to cut the number of cases nearly in half, but some 800,000 Africans still die from malaria each year, most of them children under five.

    Dr. Christian Loucq explains the challenges facing vaccine researchers. He is director of the PATH Malaria Vaccine Initiative that's conducting human trials in sub-Saharan Africa. “It is difficult to develop a malaria vaccine because we are dealing with a complex organism a parasite which has many, many components and that parasite organism can change, it’s very versatile," said Dr. Loucq. "It’s quite difficult to develop immunity against that parasite.” Dr. Loucq is hopeful the World Health Organization will approve the new vaccine by 2015. “It will reduce the number of times a child is going to have malaria, clinical malaria, and it means reducing the number of opportunities for that child to die from malaria," he said.

    The Malaria Vaccine Initiative also is trying to develop a second generation vaccine to prevent mosquitos from carrying the malaria parasite. "Once the mosquito will come to take the blood meal - the mosquito will take the antibodies that are going to stop the cycle in the mosquito," said Loucq. "Therefore the mosquito will not be in a position to transmit malaria to another child, and that would be a fantastic way to stop the transmission of malaria." Dr. Loucq says the new vaccine, called RTS,S, will be a major step toward getting rid of malaria. But for that to happen, he says, greater investment in research will be essential.


  3. Cool

    Sulfa powder is good for keepin' chiggers off ya when ya go fishin'...

    Drug Used to Treat Head Lice is Effective Against Malaria
    July 06, 2011 - Researchers have found that an inexpensive and widely-available drug used to treat river blindness in Africa and head lice in American school children is also effective in reducing malaria transmission, especially during seasonal epidemics of this worldwide scourge.
    “Can you kill a mosquito when it’s biting you [with] something that’s in your blood," asked Brian Foy. Malaria researcher Brian Foy of Colorado State University found out that yes, you can. He is working on a malaria control program and says there are many benefits to killing mosquitos as they bite their hosts. Foy says that this not only is a clever way of getting a toxin directly to the malaria-causing parasite living in mosquitos, but it also saves the environment from harmful insecticides. In a field study done on malaria transmission in Senegalese villages, Foy and his colleagues found that a drug already widely used for treating the two most common parasitic diseases in Africa - river blindness and elephantiasis - also has insecticidal properties. “We are repurposing a really cheap and important drug for worm control potentially to control malaria," he said.

    The study shows that after single doses of the drug Ivermectin were administered to residents of several Senegalese villages, there was a 79 percent reduction in mosquitoes found to be carrying the malaria parasite. In villages where the drug was not given, the malarial mosquitoes increased by 246 percent. Researchers found that the drug circulating in people’s blood killed the mosquitoes. Ivermectin is given once every year in many countries in sub-Saharan Africa to fight common infections. But researchers say that if the drug is given more often, it can provide other benefits. “If you give it more often, [as] we are proposing for malaria transmission control, it will start to have an effect against the soil-transmitted illness that people have in their guts - things like whip worm, round worm and maybe even hookworms, which cause a lot of hidden illnesses in people," said Foy.

    Peter Hotez, president of the American Society for Tropical Medicine and Hygiene, calls Foy's study groundbreaking. He says it proves what many public health researchers have long suspected - that drugs used to combat neglected tropical diseases have important collateral health benefits. “It opens up a new pathway for discovering an additional class of drugs specifically for this purpose - maybe a drug that can circulate in the body longer and then be better targeted for malaria specifically," said Hotez. Malaria kills almost 800,000 people around the world each year. Experts say Ivermectin would be a welcome addition to the anti-malaria arsenal of bed nets, pesticides, drugs and, perhaps one day soon, a vaccine. Public health experts say all these weapons will be needed in the years ahead to eradicate malaria permanently.


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    Malaria study raises doubt about effectiveness of program...

    Study raises doubts about effectiveness of malaria program
    Fri, Aug 19, 2011 : Insecticide-treated bednets, whose use is being widely promoted in Africa to combat malaria, may paradoxically be linked to local resurgence of the disease, according to concerns raised by a study yesterday.
    Based on observations in a village in Senegal, the study points to evidence that mosquitoes develop resistance to the insect-killing chemical that coats the nets. In addition, people may lose their immunity to the malaria parasite when the mosquito population is in decline and then become exposed when the insect pest recovers, it suggests. Doctors led by Jean-Francois Trape of the Institute for Development Research in Dakar sought to assess the impact of bednets that were introduced in the central village of Dielmo in August 2008. A year and a half before the operation, the team checked more than 500 villagers for sickness from malaria and studied local populations of mosquitoes. They pursued this work over the next four years, in an exceptionally detailed probe.

    From August 2008 to August last year, incidence of malaria fell dramatically, to less than 8 percent of the pre-scaleup level, the investigators found, but between September and December last year, the numbers rose sharply again, to where incidence was 84 percent of previous levels. Among adults and children aged 10 or more, the rate was even higher than before. The researchers found that the proportion of Anopheles gambiae mosquitoes with a genetic variant conferring resistance to pyrethroid — the insecticide used in the netting — had risen from 8 percent in 2007 to 48 percent late last year. “These findings are of great concern,” Trape’s team reported in the British journal The Lancet Infectious Diseases.

    “They support the idea that insecticide resistance might not permit a substantial decrease in malaria morbidity in many parts of Africa where A. gambiae is a vector and acquired clinical immunity is a key epidemiological factor.” The suspicion — but not supported by clinical evidence in the study — is that older villagers gradually lost immunity to the malaria parasite as the threat receded and therefore became exposed when the mosquito population rebounded. Malaria claimed 781,000 lives in 2009, according to the WHO, which is spearheading the campaign to distribute insecticide-treated nets and spray reproduction sites. About 90 percent of malaria deaths each year occur in Africa and 92 percent of those are children aged under five.

    In a commentary, Joseph Keating and Thomas Eisele, specialists at Tulane University in New Orleans, cautioned against leaping to conclusions. They praised the study for its thoroughness, but said its duration was too short and focused only on one village in rural Senegal. By itself, this is not enough to confirm that the bednet program is flawed or that the same problems apply across Africa, the pair said.


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    Granny says God made mosquitoes to bug us...

    Spermless mosquitoes could help halt malaria spread
    Mon Aug 8, 2011 - Releasing genetically modified, spermless male mosquitoes into the wild could in future help to prevent malaria transmission and reduce the chances of large outbreaks of the killer disease, British scientists said on Monday.
    Researchers from Imperial College London sterilized male mosquitoes by genetically modifying them to neutralize a gene required for sperm production. In a study to see how these mosquitoes would fare when trying to get a mate, they found that female mosquitoes cannot tell if the males they mate with are fertile, or spermless and therefore unable to fertilize the females' eggs.

    The researchers said findings suggest that in future it might be possible to control the size of the malaria-carrying mosquito population by introducing a genetic change that makes males sterile. Female mosquitoes would then unknowingly mate with the modified males and fail to produce any offspring. Malaria is a mosquito-borne disease that affects up to 300 million people and kills nearly 800,000 every year. Its threat is greatest in Africa, where the World Health Organization says a child dies of malaria about every 45 seconds.

    Public health experts are working toward the eventual global eradication of malaria, but progress is slow and there is a constant need for better and cheaper ways to get there. "In the fight against malaria, many hope that the ability to genetically control the mosquito vector will one day be a key part of our armory," said Flaminia Catteruccia from Imperial's life sciences department, who led the study.

    But she added that for these currently theoretical control ideas to work in practice, scientists have to establish whether the insects would continue to mate as normal, unaware that their sexual mechanisms had been tampered with.


  6. Default

    Quote Originally Posted by waltky View Post
    Granny says God made mosquitoes to bug us....
    Grandpa says God made our blood to feed mosquitoes....
    "The Palestinian/Israeli issue (more accurately, the conflict between Jews and Muslims) could never be resolved permanently." -- reedak

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    Malaria death toll significantly decreases...

    Malaria deaths fall over 20% worldwide in last decade
    18 October 2011 - Malaria accounts for 20% of childhood deaths in Africa.
    There has been a fall of just over 20% in the number of deaths from malaria worldwide in the past decade, the World Health Organization says. A new report said that one-third of the 108 countries where malaria was endemic were on course to eradicate the disease within 10 years. Experts said if targets continued to be met, a further three million lives could be saved by 2015. Malaria is one of the deadliest global diseases, particularly in Africa.

    In 2009, 781,000 people died from malaria. The mosquito-borne disease is most prevalent in sub-Saharan Africa, where 85% of deaths occurred, most of them children under five. An earlier report here incorrectly referred to a 40% drop in deaths. It has been eradicated from three countries since 2007 - Morocco, Turkmenistan and Armenia. The Roll Back Malaria Partnership aims to eliminate malaria in another eight to 10 countries by the end of 2015, including the entire WHO European Region.

    Robert Newman, director of the WHO's Global Malaria Programme, said "remarkable progress" had been made. "Better diagnostic testing and surveillance has provided a clearer picture of where we are on the ground - and has shown that there are countries eliminating malaria in all endemic regions of the world," he told an international Malaria Forum conference in Seattle. "We know that we can save lives with today's tools."

    Global eradication

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    Malaria vaccine makes good showing in clinical trials...

    Malaria Vaccine Shows Acceptable Safety, Efficacy Results
    October 18, 2011 - An international health alliance working to develop a vaccine against malaria says one of its most advanced vaccines, called RTS,S, shows promising results. After two years of human clinical trials in Africa, the PATH Malaria Vaccine Initiative and its collaborators report the vaccine provides protection against malaria for children aged five to 17 months.
    Scientists working on the world’s first-ever malaria vaccine are calling the RTS,S trials a significant milestone. “For 40 years people have been trying to develop malaria vaccine and here we are,” said Dr. Christian Loucq, the director of Malaria Vaccine Initiative, which is an international non-profit group involved in assessing the safety and effectiveness of the new vaccine. Thousands of children in seven countries in Africa received the vaccine. Investigators found that in vaccinated children, the risk of severe and clinical malaria was reduced by half. “Phase Three is where you look into efficacy and safety for which we had consistent results and we are very happy and encouraged to move on,” said Dr. Daniel Ansong, a pediatrician and researcher at one of the clinical-trial sites in Ghana.

    Dr. Ansong believes the vaccine will be a valuable new weapon in the global war on malaria. Critics note that in the field trials, the new vaccine was only 47 percent effective against severe malaria, a level of protection they say should be higher. But pediatricians say that with malaria killing 800,000 children every year, even this level of efficacy could save thousands of lives. Dr. Joe Cohen is co-inventor of the RTS,S vaccine and a researcher at the drug companty GlaxoSmith-line. It has invested $300 million in malaria vaccine development. Cohen says developing a vaccine against malaria has been a major scientific challenge. “The problem, I think, is the parasite itself. Malaria parasite - parasites in general - very complex organisms, with complex DNA makeup with many thousands of genes, in contrast to bacteria or viruse,” he said.

    GlaxoSmith-Kline says it expects to invest an additional $50 to 100 million in the vaccine program. Researchers say they will start testing the vaccine on larger populations after the successful completion of ongoing Phase Three trials. The developers plan to submit the final results of the vaccine trials to the World Health Organization by 2014. Their hope is that the WHO will recommend that the malaria vaccine become a routine part of all future childhood immunization programs.


  9. Angry

    Global recession affects fight against diseases...

    Cash crisis hits disease battle
    24 November 2011 - Projects to protect people against diseases including malaria are under threat
    Efforts to tackle diseases which kill millions each year could be badly affected by a severe shortfall in donations to a worldwide funding body. The Global Fund to Fight Aids, TB and Malaria will make no new grants until 2014, and there is a threat to some existing projects. It asked international donors for $20bn, but received just $11.5bn. This misses even the fund's "minimum" $13bn target, which it says is needed to maintain programmes until 2014.

    HIV charities said they were "extremely alarmed" by the decision. This is the first time in its 10 year history that the fund has been forced to cancel its three-yearly funding round. It blames the problem on a combination of "substantial budget challenges" in some of the countries who would normally contribute, and low interest rates cutting returns on its investments.

    'Worst possible time'

    However, in recent years it has faced accusations of failing to make sure money reached those in need, commissioning a review in March after reports of "grave misuse of funds" in four recipient countries. This led to some donors, including Germany and Sweden, holding back their funding temporarily. The HIV/Aids Alliance, whose member organisations rely heavily on the fund for projects across the world, said that it was the worst possible time for money to be withdrawn. It said that planned projects to tackle high rates of HIV in areas of China and South Sudan might be affected by the funding cut.

    Alvaro Bermejo, its director, said: "These should be exciting times - the latest scientific developments are showing us that HIV treatment can have a powerful HIV prevention effect. "Never again must we reach a position where life-saving programmes are cancelled or delayed." Another medical charity, Médecins Sans Frontières, described the financial situation as "dire". He said that some countries with low HIV treatment coverage, such as Kenya, Lesotho and South Africa, had already been refused funding for larger scale programmes.

    Dr Tido von Schoen-Angerer, one of its executive directors, said: "Donors are really pulling the rug out from under people living with HIV/Aids at precisely the time when we need to move full steam ahead and get life-saving treatment to more people." He called for other governments to help make up some of the shortfall in donations. The fund, which is based in Geneva, said that only "essential" programmes in low or middle-income countries would receive more funding to keep them going until 2014. It says it intends to bring in new management to improve administration.


  10. Cool

    Approaching malaria vaccine from a different direction...

    New approach to malaria vaccine revealed by Oxford researchers
    20 December 2011 - Malaria is caused by parasites injected into the blood by infected mosquitoes
    A potential new malaria vaccine has shown promise in animal studies, according to research. An Oxford University team is to start safety trials in human volunteers after lab tests showed the vaccine works against all strains of the parasite. UK scientists recently found the route malaria uses to enter blood cells. They hope to target this pathway in a new approach to developing a vaccine against malaria, which kills hundreds of thousands of people a year. Several potential malaria vaccines are already being tested in clinical trials; although no vaccine has yet been licensed for use.

    Early clinical trials in Africa suggest a vaccine known as RTS,S appears to protect about half of people vaccinated from malaria. While these results are encouraging, some scientists believe a more effective vaccine is needed to fight the disease. One possibility is to exploit a recently-discovered potential weakness in the parasite's life cycle. A team at the Sanger Institute found in November that a single receptor on the surface of red blood cells and a substance known as "PfRh5" on the parasite are crucial to the success of malaria in invading blood cells. Early lab tests suggest a vaccine against the protein may prove effective, at least in animals.

    Dr Sandy Douglas is a Wellcome Trust Clinical Research Training Fellow from the University of Oxford and first author on the study, published in the journal, Nature Communications. He told the BBC: "We have found a way of making antibodies that kill all different strains of malaria parasites. This is still early phase research in animals. The next step is to do clinical trials in people." If safety tests of the vaccine prove successful, clinical trials in patients could begin within the next two to three years, says the Oxford team. Dr Gavin Wright, from the Wellcome Trust Sanger Institute, said recent findings on how the malaria parasite invades red blood cells were unexpected. Dr Wright, a co-author on both studies, added: "It revealed what we think is the parasite's Achilles heel in the way it invades our cells and provided a target for potential new vaccines."


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