Stories tagged malaria
Next year, researchers plan to start small-scale human trials of a malaria vaccine that's proven 75-80% successful in mice.
Tags : So I'm surfing the web and I come across an item about DDT use in Africa. If it's true, then this is the kind of thing that really frosts my shorts. But, as the blogger notes, the item has only appeared in a couple of fringe outlets. Not that I consider the MSM the font of credibility. But I've already been taken to task for the Space Camp Barbie post, so it would be nice to have verification.
Anyway, according to this report, a Dutch textile firm is refusing to buy cotton from parts of Uganda which use the chemical DDT to combat malaria. Malaria kills up to 100,000 Ugandans every year. DDT effectively controls the mosquitoes that spread the disease.
But DDT has a downside -- it gets into the environment and poisons fish, birds and other wildlife. For this reason, it has been banned in the US and other Western countries for more than 30 years.
Countries that use DDT today don't spray food crops. They use small, safe amounts and generally confine its use to indoors, protecting people from malaria-ridden mosquitoes.
But this apparently is not good enough for the Dutch. According to the report, the company is refusing to buy cotton from areas that use DDT, claiming the crop is no longer "organic." As a result, farmers from those areas cannot sell their cotton at full price, and are losing money.
Basically, European eco-purists are giving African farmers a choice: avoid DDT and die of malaria, or use DDT and die of starvation. The Euro-elites, of course, face neither of these fates.
Like I said, this is based on just one report. It would be nice to get independent confirmation.
Red blood cells infected with Plasmodium falciparum: This thin film Giemsa stained micrograph reveals ring-forms, and gametocytes of Plasmodium falciparum.
Courtesy cdc
- Malaria is both preventable and curable.
- A child dies of malaria every 30 seconds.
- More than one million people die of malaria every year, mostly infants, young children and pregnant women and most of them in Africa.
A recent article in the NY Times discussed if it is possible to eliminate malaria. They need more money, better health systems and a vaccine. Some experts feel the big push to eradicate malaria is counterproductive or even dangerous. Dr. Arata Kochi, the W.H.O. malaria chief stated in the article that, “… enough money, current tools like nets, medicines and DDT could drive down malaria cases 90 percent. But eliminating the last 10 percent is a tremendous task and very expensive.” He doesn’t want people to have false hope.
A new vaccine
In spite of the debate, research is progressing to reach the goal of eliminating malaria. The Seattle Biomedical Research Institute (SBRI) is home to one of the largest malaria research programs in the United States. SBRI's Malaria Program is focused on vaccine discovery for malaria during pregnancy, severe malaria in children and liver-stage malaria. SBRI scientists are working on a vaccine that uses genetic engineering to render malaria parasites harmless. According to an article in the Seattle Times SBRI is looking for volunteers to be bitten by malaria-infected mosquitoes to aid in the quest for new vaccines and drugs. Scientists will analyze blood from the human volunteers to learn more about the body's immune response to the disease.
What do we do?
Economists believe that malaria is responsible for a ‘growth penalty’ of up to 1.3% per year in some African countries. When compounded over the years, this penalty leads to substantial differences in GDP between countries with and without malaria and severely restrains the economic growth of the entire region. Malaria costs Africa $12 billion every year in lost productivity alone.
What do you think? Where should we be putting our resources?
- Developing a vaccine (the Bill and Melinda Gates foundation alone has spent $258 million
- More money to distribute long-lasting insecticidal nets (each net costs $5-7)
- Mosquito control with indoor residual spraying like DDT (costs nearly $4 per person)
- Getting effective drug treatments to the infected (effective therapy costs $2.40 for a round of treatment)
Another type of Disease Detective
in Life Science, Scientific World View, Chemical Reactions, and Scientific Inquiry
Since 1998 there has been a serious public health problem in South East Asia of counterfeit antimalarial drugs containing no or minimal amounts of the active antimalarial ingredient, this has led to deaths from untreated malaria, reduced confidence in this vital drug, created large economic losses for the legitimate manufacturers, and led to concerns that this antimalarial drug might cause resistance. As the situation continues to deteriorate, a group of police, criminal analysts, chemists, palynologists (people who study pores, pollen and certain algae), and health workers collaborated to determine the source of these counterfeits.
What did they find?
Red blood cells infected with Plasmodium falciparum: This thin film Giemsa stained micrograph reveals ring-forms, and gametocytes of Plasmodium falciparum.
Courtesy cdcThey analyzed a total of 391 samples of genuine and counterfeit artesunate (the anti-malarial drug) collected in Vietnam (75), Cambodia (48), Lao PDR (115), Myanmar (Burma) (137) and the Thai/Myanmar border (16). They found sixteen different fake types of the drug. High-performance liquid chromatography and/or mass spectrometry confirmed that all specimens thought to be counterfeit (195/391, 49.9%) contained no or small quantities of artesunate (up to 12 mg per tablet as opposed to ∼ 50 mg per genuine tablet). Chemical analysis demonstrated a wide diversity of wrong active ingredients, including banned pharmaceuticals, such as metamizole, and safrole, a carcinogen, and raw material for manufacture of methylenedioxymethamphetamine (‘ecstasy'). Evidence from chemical, mineralogical, biological, and packaging analysis suggested that at least some of the counterfeits were manufactured in southeast People's Republic of China. This evidence prompted the Chinese Government to act quickly against the criminal traders with arrests and seizures. Go to PLoS Medicine for the full scientific article and a very well written editor’s summary.
What Do these Findings Mean?
From the PLoS editor’s summary…
The results were crucial in helping the authorities establish the origin of the fake artesunate. For example, the authors identified two regional clusters where the counterfeit tablets appeared to be coming from, thus flagging a potential manufacturing site or distribution network. The presence of wrong active pharmaceutical ingredients (such as the older antimalarial drugs) suggested the counterfeiters had access to a variety of active pharmaceutical ingredients. The presence of safrole, a precursor to the illicit drug ecstasy, suggested the counterfeits may be coming from factories that manufacture ecstasy. And the identification of minerals indigenous to certain regions also helped identify the counterfeits' origin. The researchers concluded that at least some of the counterfeit artesunate was coming from southern China. The Secretary General of INTERPOL presented the findings to the Chinese government, which then carried out a criminal investigation and arrested individuals alleged to have produced and distributed the counterfeit artesunate.
The collaboration between police, public health workers and scientists on combating fake artesunate is unique, and provides a model for others to follow. However, the authors note that substantial capacity in forensic analysis and the infrastructure to support collaborations between these different disciplines are needed.
Plasmodium falciparum, the parasite that causes malaria.: Photo courtesy NIH
Malaria is one of the most deadly diseases in the world. Spread by mosquitoes, each year it kills more than 1 million people, and makes 300 million seriously ill, mostly children, mostly in Africa.
For years researchers have tried to find a vaccine that will prevent people from contracting the disease. The problem is, the parasite enters the bloodstream at a particular phase in its life cycle. Collecting the parasite at that stage is tricky, because it lives in the salivary glands of the mosquito.
But now a research lab in suburban Maryland has figured out a way to collect the parasites. They breed their own highly infectious mosquitoes, which they keep locked behind five doors so none escape. Once the parasite has reached the proper stage, workers kill the mosquitoes and extract the parasite.
After they collect the parasite, they disable it and render it harmless. It can then be injected into a person. The body recognizes the parasite as a foreign body and produces antibodies to fight it. These antibodies stay in the bloodstream, protecting the person from any real parasites they may later pick up.
Early test indicate the vaccine could be up to 90% effective, and protect against malaria for 10 months or more. Human trials are to begin next year.
You can learn more about malaria in The Science Museum’s on-line exhibit.
Happy Birthday, Rachel Carson
in Chemical Reactions, Interdependence of Life, Historic Perspectives, and Flow of Matter and Energy
Rachel Carson, inspiration for the modern environmental movement: Photo from US Fish & Wildlife Service
Today is the 100th anniversary of the birth of Rachel Carson, whom many credit as the inspiration for the modern environmental movement. Her 1962 book Silent Spring warned the world of the dangers of environmental degradation, especially due to the overuse of chemical pesticides. The book stirred millions of people worldwide to take action. In the United States, we saw the passage of the Clean Air Act, the Endangered Species Act, and the establishment of the Environmental Protection Agency – all the result of the movement Carson inspired.
Today, our air and water are cleaner thanks to these actions, and dangerous chemicals are more closely regulated. But some people are re-evaluating Carson’s legacy, especially with regards to the pesticide DDT. Carson explained how insects absorbed the poisonous chemical. Birds which ate enough insects often died themselves, or would have trouble hatching eggs. Carson promoted restricting the use of DDT.
However, some of her followers went further, pushing for a total ban of DDT in many countries. Unfortunately, DDT is extremely effective at killing mosquitoes that spread malaria – a disease that kills some one million people each year. Responsible, limited use of DDT could save millions of lives.
(Science Buzz has discussed malaria here and here,and the possible effects of preventative measures such as mosquito nets, drugs, and genetic engineering.)
Carson’s legacy reminds us not only of the importance of protecting our environment, but also that one person can have a tremendous impact. It also reminds us that even the best ideas can have unintended consequences, and any major changes need to be undertaken in a balanced, rational and flexible manner.
Photo from US Fish & Wildlife Service
Please contact us if you have questions about the rights on this image.
Pretty cool, although it's not ready for testing in humans yet.
Mosquito: Malaria is spread by mosquitoes infected by a parasite. But a new drug might help eliminate the disease. (Photo USDA)
More on malaria from Science Buzz:
Malaria: you can help
Preventable disease, BIG problem
Vote in the malaria poll
Building a better mosquito
Malaria isn’t even on the radar screen of most people in the US, but it is a huge global problem! Did you know that a child dies from malaria in Africa every 30 seconds? That is seven jumbo jets of children everyday. A powerful video has been produced by the Against Malaria organization.
Malaria is spread through mosquitoes that bite at night and can’t be spread person to person without a mosquito vector. This means using bed nets is an effective way to prevent the spread of malaria. Using bed nets is something that can be used right now while scientists continue to work on other methods (like vaccines, GM mosquitoes, better treatment options…)
A team of us at the Science Museum of Minnesota is developing an exhibition about infectious diseases called Disease Detectives which will open in the Human Body Gallery in January 2008. We feel stopping the spread of malaria is very important and have started our own page to encourage others to help too by donating funds for the purchase of bed nets. Each bed net costs only $5 and 100% of the money goes to purchase bed nets. For more information go to www.AgainstMalaria.com/DiseaseDetectives.
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