Thursday, May 27, 2010

In the midst of global warming

Doomsday reports of malaria epidemics, stirred by global warming, have reared ominously for decades. New studies show that contrary “to a widespread assumption, global warming is unlikely to expand the range of malaria because of malaria control, development and other factors that are at work to corral the disease.”

“Scientists and public policy makers have been concerned that warming temperatures would create conditions that would either push malaria into new areas or make it worse in existing ones.” But a team of scientists, “including two University of Florida researchers, … analyzed a historical contraction of the geographic range and general reduction in the intensity of malaria -- a contraction that occurred over a century during which the globe warmed. They determined that if the future trends are like past ones, the contraction is likely to continue under the most likely warming scenarios.”

"If we continue to fund malaria control, we can certainly be prepared to counteract the risk that warming could expand the global distribution of malaria," one researcher said.

Malaria “control efforts over the past century have shrunk the prevalence of the disease”. "The globe warmed over the past century, but the range of malaria contracted substantially," Researcher Tatem said. "Warming isn't the only factor that affects malaria."

Reduction in malaria prevalence is attributed to mosquito control efforts, better health care, urbanization, and economic development. “The banned pesticide DDT was instrumental in ridding the disease from 24 countries in Southern Europe, the former Soviet Union and elsewhere in the world between 1955 and 1969.” “Researchers debate how the U.S. defeated malaria, but the reduction of mosquito breeding grounds, improved housing and reduced emphasis on agriculture that comes with development -- and the reduced risk of bites that accompanies urbanization -- probably played a role,” according to Researcher Smith.

"Malaria remains a huge public health problem, and the international community has an unprecedented opportunity to relieve this burden with existing interventions," Simon Hay, author of the Nature paper, said. "Any failure in meeting this challenge will be very difficult to attribute to climate change."

Peter W. Gething, David L. Smith, Anand P. Patil, Andrew J. Tatem, Robert W. Snow, Simon I. Hay. Climate change and the global malaria recession. Nature, 2010; 465 (7296): 342 DOI: 10.1038/nature09098

University of Florida (2010, May 19). Malaria control to overcome disease’s spread as climate warms. ScienceDaily. Retrieved May 27, 2010, from­ /releases/2010/05/100519143413.htm

Wednesday, May 19, 2010

Threatening malaria

"Malaria parasites can detect when they are being threatened and change their behaviour to survive, new research has suggested." Changes in behavior may "explain how malaria" resists "drug treatment".

The study, conducted in Edinburgh, provides insight that "could lead to better control of the disease."

"Caused by a parasite called Plasmodium, malaria is spread through the bites of infected mosquitoes and kills around a million people in the world each year. Some of the parasites multiply in the bloodstream and others change into a specialised transmission form, which enables the disease to spread."

The study indicates that "when exposed to low doses of anti-malarial drugs, this delicate balance of replicating and transmitting is upset." Malaria parasites respond to the drugs by attempting to increase "their chances of survival through a safety-in-numbers strategy: they produce fewer transmission forms and concentrate more on replication."

Malaria illness produces symptoms in a cyclical pattern. This pattern corresponds with the reproduction of the parasite. "If drugs push parasites into producing more replicating stages, which cause the symptoms, then this may lead to more serious illness," says Dr. Sarah Reece, from the University of Edinburgh's school of biological sciences. "This study uncovers a new way that parasites are able to resist the effects of drugs. This is also likely to have important implications for human disease control strategies."


Reece, Sarah. Proceedings of the Royal Society. The Press Association. 19 May 2010.

Sunday, May 16, 2010

Containment cells

When a human hurts another, the solution is often to restrict the aberrant human to a containment cell. The same principle may be applied to malaria parasites to prevent them from killing their human host.

Seeking to "block invasion of healthy red blood cells by malaria", researchers at the Harvard School of Public Health have "succeeded in locking the parasites within infected blood cells, potentially containing the disease."

"The findings reveal an essential step in the biology of the most common and severe malaria parasite, Plasmodium falciparum, and offer a new drug target for fighting one of the world's most common and dangerous infections."

"Working with the malaria parasite...the research team identified a single fast-acting protein …that enables it … to escape from a human red blood cell in preparation for quick invasion of many more healthy blood cells." If the protein is eliminated, then the escape plan is foiled.

Malaria parasites reproduce in red blood cells, producing up to 32 offspring every two days. Then, the parasites "burst out to infect more red blood cells."

"This is the stage where things have to happen very fast for the parasite," said senior author Manoj Duraisingh, HSPH assistant professor of immunology and infectious diseases and senior author of the paper in the May 14 Science. "The parasite doesn't like to spend much time outside the cell. It grows and matures, and immediately following rupture, enters a new cell. It was a surprise that this protein kinase, which we thought would be involved in red blood cell invasion, turns out to be essential for the parasite getting out of the cell."

"When the parasite gets out of the red blood cell, it has a matter of seconds or minutes to get into new red blood cells, or it will be cleared or killed by the human immune system."

Fortunately, this particular protein "is found in the parasite and in plants, but not in humans, which means a drug targeted to that protein may be less toxic for people."

Read more: Harvard School of Public Health (2010, May 14). New twist on potential malaria drug target acts by trapping parasites in cells. ScienceDaily. Retrieved May 16, 2010, from¬ /releases/2010/05/100514171912.htm

J. D. Dvorin, D. C. Martyn, S. D. Patel, J. S. Grimley, C. R. Collins, C. S. Hopp, A. T. Bright, S. Westenberger, E. Winzeler, M. J. Blackman, D. A. Baker, T. J. Wandless, M. T. Duraisingh. A Plant-Like Kinase in Plasmodium falciparum Regulates Parasite Egress from Erythrocytes. Science, 2010; 328 (5980): 910 DOI: 10.1126/science.1188191

Wednesday, May 12, 2010

Childhood deaths

"Preventable infectious diseases cause two-thirds of child deaths, according to a new study published by The Lancet." Based on information provided by the World Health Organization (WHO) and UNICEF's Child Health Epidemiology Reference Group (CHERG), the study examined causes of childhood death in 193 countries. "While the number of deaths has declined globally over the last decade, the analysis reveals how millions of children under five die every year from preventable causes."

It is estimated that 8.8 million children die annually. Over 5.5 million children die from pneumonia, diarrhea, malaria, and other infectious diseases. These diseases are preventable and treatable, but many victims are unable to reach or afford prophylactics or proper medical care.

"These findings have important implications for national programs," said UNICEF Chief of Health, Dr. Mickey Chopra. "The persistence of diarrhea, pneumonia and malaria, all of which are easily preventable and curable but which nonetheless remain the leading single causes of death worldwide, should spur us to do more to control these diseases."

Read more: Johns Hopkins University Bloomberg School of Public Health (2010, May 12). Infectious diseases caused two-thirds of the nearly 9 million child deaths globally in 2008. ScienceDaily. Retrieved May 12, 2010, from¬ /releases/2010/05/100511201732.htm

Robert E Black, Simon Cousens, Hope L Johnson, Joy E Lawn, Igor Rudan, Diego G Bassani, Prabhat Jha, Harry Campbell, Christa Fischer Walker, Richard Cibulskis, Thomas Eisele, Li Liu, Colin Mathers, for the Child Health Epidemiology Reference Group of the World Health Organization and UNICEF. Global, regional, and national causes of child mortality in 2008: a systematic analysis. The Lancet, 2010; DOI: 10.1016/S0140-6736(10)60549-1

Monday, May 10, 2010

Safer anti-malarials

In the arms race against malaria, humans wield the biggest weapons, but their cost is great. In recent years, malaria has mutated and adapted to resist the drugs used to combat it. Caused by a parasite and transmitted by mosquitoes, malaria is an infectious disease that kills nearly one million people each year. Humans struggle to prevent malaria transmission and to treat those infected with the deadly disease.

Unfortunately, some of the malaria treatments are potentially deadly as well. "Amodiaquine was introduced as an antimalarial drug, but. . . withdrawn from the market when it became clear that the drug caused serious adverse effects in the form of liver damage and impaired immune system." The drug is still used in the most severe cases of drug-resistant malaria. It saves lives, but endangers them as well.

Endeavoring to create safer drugs, scientists at the University of Gothenburg, Sweden, studied the byproducts of drugs, looking for toxins. "A pharmaceutical in the body is, in the optimal case, broken down into harmless products (metabolites) that leave the body, for example via the urine. Some pharmaceuticals, however, can be converted into toxic products, which may result in serious adverse effects." Proposed by Tove Johansson Mali'n, the scientists uncovered a process that can "simulate the metabolism of pharmaceuticals in the body". In this way they can identify and characterize several potentially toxic products that arise as the metabolites of drugs". With the aid of this methond, Mali'n "has now managed to identify. . . previously unknown metabolites that may have caused, or contributed to, the adverse effects of amodiaquine."

"We hope that the method can simplify the work of identifying potentially toxic metabolites at an early stage, and thus facilitate the development of safe drugs," says Tove Johansson Mali'n.

Tove Johansson Mali'n, Lars Weidolf, Neal Castagnoli, Ulrik Jurva. P450-catalyzed vs. electrochemical oxidation of haloperidol studied by ultra-performance liquid chromatography/electrospray ionization mass spectrometry. Rapid Communications in Mass Spectrometry, 2010; 24 (9): 1231 DOI: 10.1002/rcm.4505
University of Gothenburg (2010, May 9). New method for developing safer drugs. ScienceDaily. Retrieved May 10, 2010, from¬ /releases/2010/05/100509202645.htm

Friday, May 7, 2010


How does a vampire avoid that which kills him? He plays dead.

Plasmodium falciparum, a deadly disease known as malaria, proves just as apt to play dead as a fictive vampire facing the sunlight. Humans had a secret weapon against malaria. "Artemisinin (ART), a substance extracted from a Chinese plant," was "the first-line drug for malaria," since other compounds lost their efficacy from overuse and parasite mutation. Artermisinin-based Combination Therapies (ACT) were "the most effective treatment for malaria, achieving a 95% cure rate."

Then, malaria played dead.

In July 2009, artemisinin-resistant malaria was identified in South East Asia. Scientists, desperate to determine how malaria avoided their once brutal weapon, ran laboratory studies.

Françoise Benoit-Vical and his team at Laboratoire de Chimie de Coordination (CNRS) "sought to isolate ART-resistant strains in an experimental manner. This feat was achieved at the end of 2009 when the scientists managed to obtain a strain of Plasmodium falciparum that was resistant to this compound and some of its derivatives, and the first to be adapted to in vitro culture." In the process, the "researchers also identified and characterized a new mode of parasite resistance. To evade the action of ART, Plasmodium falciparum arrested its development and entered a so-called state of quiescence [temporary inactivity]. It thus functioned at a slow metabolic rate until the drug was eliminated", at which time, it would reawaken and wreak havoc again.

"Malaria still continues to kill nearly a million people each year throughout the world. There is no vaccine against this infectious disease", which is caused by a blood parasite and transmitted by mosquitoes."

This study demonstrated "a novel resistance mechanism" and provides "important tool that will allow a clearer understanding of the mechanisms of resistance to antimalarial drugs". Scientists plan further studies in order to "identify the genes responsible for the acquisition of ART resistance."

Sources: "How the parasite responsible…" 5 May 2010.
Witkowski B, Leličvre J, López Barragán MJ, Laurent V, Su XZ, Berry A, Benoit-Vical F. "Increased tolerance to artemisinin in Plasmodium falciparum is mediated by a quiescence mechanism." Antimicrobial Agents and Chemotherapy. Mai 2010.

Thursday, May 6, 2010

Pooling resources

South Africa aims to "speed development of drugs for neglected tropical diseases by freely sharing patented information owned by drug companies and academic institutions." The country "will use a new 'patent pool' to work on new drugs for tuberculosis and malaria, making it the first government to take advantage of the industry-led idea."

After GlaxoSmithKline set up a pool to share patents, in the effort to create an effective malaria vaccine, South Africa saw the possibility to use vast research from various channels to create medications that will change the world.

"The pool contains more than 2,300 patents that are available for use by industry, non-profit groups and academic researchers to develop new medicines for malaria, cholera and more than a dozen other diseases."

"This patent pool is an enormous boost for us to have a significant impact in South Africa," according to Mamphela Ramphele, chairwoman of the South African Technology Innovation Agency. "Her agency will coordinate and nurture drug development among local companies".

The patent pool is a tremendous wealth of information, providing not only "free use of patents, but also know-how and expertise".

"Frankly, expertise and know-how are often some of the more valuable aspects of drug development, and also things that companies don't usually share," says Melinda Moree, chief executive of BIO Ventures for Global Health. "This pool has both of these things (patents and expertise), which I think makes it fairly unusual."

"Moree said other large drug companies are interested in signing up to the pool, but would not name them. The pool contains patents for compounds that have a potential to be developed into drugs."

The pool opens "up the innovation process around drug development for neglected disease." Millions of people suffer every day. "Drug development has lacked. Tens of millions of people are too poor to pay for the drugs". "This is really a step on the part of industry to try a new model around one of the things that has sparked contentious debate around intellectual property," Moree said.'

In the past, some pharmaceutical companies received criticism for "fiercely backing patents that blocked cheaper competitors, even in the poorest countries, where brand-name medicines were unaffordable." GlaxoSmithKline and some other companies responded by "selling AIDS drugs in certain areas without a profit and offering licenses to generic makers." Companies and countries are now joining together with the common goal of disease eradication at all costs.

Steenhuysen, Julie. "S. Africa taps patent pool for neglected diseases." Reuters. 5 May 2010.

Tuesday, May 4, 2010

Malaria in Ethiopia

In 2005, US President George W. Bush instituted the President's Malaria Initiative (PMI) to "fight malaria in the region most affected by the disease. The President committed. . . $1.2 billion in malaria funding to this Initiative with the goal of reducing malaria-related deaths by 50 percent in 15 focus countries", including Ethiopia.

Five years later the PMI is still going strong. On the 26th of April 2010, "[t]housands of Long-Lasting Insecticidal Nets, or mosquito bed-nettings, were handed out by a U.S. Army Civil Affairs team to the people" in malaria-endemic regions of Ethiopia.

"We are distributing 35,000 nets to a population of approximately 93,000 people," said Lieutenant Daniel Deckard, commander of the Civil Affairs team, Combined Joint Task Force-Horn of Africa. "That's approximately two nets per household," he said.

The distributed nets are treated with insecticides to repel and kill mosquitoes in addition to serving as a physical barrier between humans and flying insects. Insecticide treated nets are estimated to be twice as effective as standard nets and may reduce malaria transmission by up to seventy percent (when used correctly). Participants in the PMI not only distribute nets, they are also "properly installing the nets in optimal locations within homes and are giving directions and other vital information to homeowners about proper use to minimize possible hazards and maximize protection" against malaria.

Malaria "is one of the leading causes of the deaths of pregnant women and children under five years of age in Africa. . .Malaria is a blood-borne infection caused by parasites and transmitted to people by the bite of female Anopheles mosquitoes, which are active from dusk to dawn, according to the PMI website. Malaria usually begins as a flu-like illness with fever and chills. Mild to moderate anemia is also common because the malaria parasite infects and destroys red blood cells."

Untreated, malaria may cause severe anemia, organ failure, coma, and death.

Based on the annual reports (reporting began in 2006), malaria relief efforts are producing results. For example:
* Zambia has seen a 10% decrease in malaria cases
* In Rwanda, child mortality rate has dropped from 168 deaths/1,000 to 119 deaths/1,000
* Infant mortality rate in Tanzania has also dropped

The initiative expects to see similar or better improvements in Ethiopia.


Barnett, Robert. "Fighting Malaria in Ethiopia". The Ethiopian Review. 4 May 2010.

PMI: Saving Lives in Africa.

Hope for Haiti

Spraying DDT in 1958 as part of The United States' National Malaria Eradication Program

The source article for this post should be considered an editorial, and it expresses the opinions of Henry I Miller.

Is there a hope for Haiti?

"On top of the almost unimaginable devastation caused by January's earthquake in Haiti, the nation is bracing for the ravages of the rainy season." Torrential downpours already flood homes and turn "tent cities into muddy misery. Ominously, the number of cases of malaria, which is spread by the bite of mosquitoes and which was endemic in Haiti even before the earthquake, is increasing."

Aid groups plan to distribute over three million bed nets in order to minimize the number of malaria cases. However, this "ultra-low-tech" solution stands as "only modestly effective intervention". "What is really needed is the chemical DDT, an old, cheap and safe tool to control the vector -- the Anopheles mosquito -- that spreads the disease."

"Malaria is a scourge of humanity, particularly for the inhabitants of poor tropical countries." Over forty percent of the world's population lives at-risk for contracting malaria. 350 to 500 million cases of malaria occur worldwide each year. It is "a crushing economic burden on malaria-endemic countries" and impedes economic growth.

Once contracted, malaria is treatable. "A drug called chloroquine is a useful preventive but many strains of the malaria parasite in Haiti have developed resistance to it." Artemisinin-combination medicines "are safe and exhibit potent, rapid antimalarial activity", but resistance to these drugs is also rising. It is clear "that in the absence of a vaccine", "elimination of the mosquitoes that spread the disease is the key to preventing epidemics."

"Unfortunately, flawed public policy limits the available options."

Humans, armed with the weapon of DDT, are capable of destroying the deadly mosquito population; however, "on the basis of data on toxicity to fish and migrating birds" the U.S. Environmental Protection Agency (EPA) banned "virtually all uses of the pesticide DDT" in 1972. Subsequently, DDT was banned for "agricultural use worldwide under the 2001 Stockholm Convention on Persistent Organic Pollutants, which stigmatized the chemical and effectively constituted a prohibition."

"Although DDT is a (modestly) toxic substance, there is a vast difference between applying large amounts of it in the environment -- as farmers did before it was banned -- and using it carefully and sparingly to fight mosquitoes and other disease-carrying insects."

DDT is an effective pesticide because it is long lasting, and it works by poisoning and repelling mosquitoes. Treatment of mosquito breeding grounds prevents malaria transmission by reducing the insect population. Spraying DDT in homes and on door frames repels adult mosquitoes and prevents malaria transmission within the home. Because of its dual effectiveness, it is logical to assume that DDT will help prevent malaria even if mosquitoes develop resistance to it…a resistance that is yet to manifest.

"Since the banning of DDT, insect-borne diseases such as malaria and dengue have been on the rise. In fact, the huge toll of diseases spread by mosquitoes caused some public health officials to rethink DDT's use…In 2006, after some 50 million preventable deaths, the U.N.'s World Health Organization reversed course and endorsed the use of DDT to kill and repel malaria-causing mosquitoes."

"Poor tropical countries like Haiti where malaria is endemic desperately need cheap, effective control of mosquitoes. Instead of continuing the politically correct stigmatization of DDT, United Nations agencies and NGOs such as the Red Cross should be rushing supplies of it to Haiti."

Henry I. Miller, a physician and molecular biologist, is a fellow at Stanford University's Hoover Institution. He was an official at the NIH and FDA.

Read more:


Miller, Henry I. "DDT can stymie malaria-carrying mosquitoes in Haiti." Miami Herald. 3 May 2010.

Sunday, May 2, 2010

Never too young or too small

Determined to help prevent needless deaths from malaria, middle school students in Westfield, Massachusetts set a lofty fundraising goal of $5,000. They raised money to purchase mosquito nets through the Nothing but Nets program, which sends mosquito nets to families in Africa. After learning that experts estimate that "one child dies every 30 seconds from malaria", this group of 93 students diligently campaigned to save lives.

Their fund-raising project succeeded in meeting and surpassing their goal. The seventh-grade students "raised more than $18,000 for the cause". For their efforts, the director of Nothing but Nets, Adrianna Logalbo, "presented the students with the first ever Notable Net Raisers Award". Mozzie the Mosquito, the project mascot, joined Logalbo in praising the fund-raising effort.

"Logalbo said that with the assistance of North Middle School the project has sent more than 3 million mosquito nets to families in Africa. She said the project was started four years ago and has raised over $30 million."

Donate to Nothing But Nets

LaBorde, Ted. "Westfield students raise money to fight malaria…" The Republican. 2 May 2010.