Friday, November 27, 2009

Pirate parasites

Parasitic Plasmodium invaders swarm the bloodstream, set up a base camp in the liver, and commandeer healthy red blood cells. These parasites "enter the body from the saliva of a mosquito" and send plague upon their victim (American). Malaria, the deadly and devastating disease that kills nearly a million people every year, is caused by the Plasmodium parasites as they pillage the human body for their own reproduction and survival.

"Inside the blood cells" of the malaria patient, "the parasites replicate and also begin to expose adhesive proteins on the cell surface that change the physical nature of the cells in the bloodstream" (American). Medical experiments "show that infected red blood cells are stiffer and stickier than normal ones." In "later stages of the disease" the cells can be "up to 10 times stiffer" than healthy red blood cells. These infected cells may also anchor onto "endothelial cells lining the vasculature, affecting the normal blood flow. This explains some of the common symptoms of malaria, such as anemia and joint pain" (American).

The parasites avoid a whirlpool of blood cell death in the spleen by anchoring in the safe harbors of the blood vessels. "Sticking to the walls of blood vessels is a survival mechanism for the parasite. In order to develop completely, it needs several days inside a red blood cell. Even though parasitized cells are nearly invisible for the immune system, they may be destroyed in the spleen while circulating freely in the bloodstream" (American).

Brown University professor George Karniadakis and student Dmitry Fedosov study "how malaria infections affect the physical properties of red blood cells, and alter normal blood flow circulation. In particular, they examine an increase in blood flow resistance, and dynamics of infected cells in the bloodstream." The properties that they measure are "used in modeling the flow of red blood cells in people infected with malaria" (American).

Fedosov says, "Our model predicts the dynamics of malaria-infected RBCs in the bloodstream, which anticipates the possible course of the disease." Each infected human contains a slightly different map and provides a unique environment that the parasites must navigate. The researchers recently discovered "that temperature fluctuations of infected red blood cell membranes measured in experiments are not directly correlated with the reported cell properties, hence, suggesting significant influence of metabolic processes" (American).

Hypothesizing on the metabolic processes that affect the patients' body temperatures, the researchers "measured an increase in resistance to blood flow in the capillaries and small arterioles during the course of malaria and found that parasitized red blood cells have a "flipping" motion at the vessel wall that appears to be due to stiffness of the infected cells. The developed models will aid to make realistic predictions of the possible course of the disease, and enhance current malaria treatments" (American).

Play the parasite game ( site), and see if you can navigate your way to the liver.

American Institute of Physics. "Measuring and Modeling Blood Flow in Malaria." ScienceDaily 22 November 2009. 27 November 2009 .

Tuesday, November 24, 2009

Call to action

"In this week's PLoS Medicine, the journal's editors call for concerted international action to address the crisis of malaria drug shortages across Africa." Compared to activism for many other causes, anti-malaria offensives are still developing to find novel ways to fight the disease. Editors reveal the signs of "an evolving 'malaria activism' (akin to AIDS activism)" (Public). "Probably no other disease in human history has been associated with social and political activism to the extent that the HIV epidemic has" (AIDS Activism). "Such activism played a huge role in reducing the costs of antiretroviral drugs in developing countries" (PLoS). Five years ago, a strong voice "argued that similar activism was needed to raise awareness of shortfalls in global efforts to control malaria" (Yarney). "We believe there are now signs of an evolving "malaria activism," which has resulted in two major successes" (PLoS). These outspoken agents assert that two waves of malaria activism have already occurred, and that we stand on the break of a third wave which will help deliver life-saving drugs to those who need them.

According to the medical journal, the "first wave of malaria activism highlighted the gap between the huge burden of malaria and the tiny amount of international development assistance dedicated to its control. Such advocacy helped motivate donors to increase their malaria commitments." The second wave of activism "focused on making sure that the extra funding was used to purchase" combination therapy drugs (like artemisinin combination therapies) that are more effective in Africa than single drug therapies (like cholorquine).
"These are big victories," the editors declare. "But one benchmark of successful ACT [Artemisinin Combination Therapy] scale-up is whether the drugs are available at the point of care. One of us has just returned from a health reporting fellowship in East Africa, where he found that ACT 'stock-outs' (shortages) were common." This crisis is due in part to "inadequate funding" to purchase the necessary combination therapies, "delays in procuring the drug, and weak health information systems that can't properly track national drug needs and flows".
The editors of the medical journal call for action. It is time for a third wave of activism. This new wave will raise awareness of the shortages of necessary drugs in regions of the world where they are desperately needed.

AIDS Activism.

PLoS. "Time for a Third Wave of Malaria Activism."

Public Library of Science. "It's Time for a 'Third Wave' of Malaria Activism to Tackle Drug Shortages." ScienceDaily 23 November 2009. 24 November 2009 .

Yarney, G. "Roll Back Malaria."

Wednesday, November 18, 2009

Male infertility

How does male sterility combat malaria? When mosquitoes are sterile, they devastate the entire mosquito population. Called the Sterile Insect Technique (SIT), "the release of sexually sterile male insects to wipe out a pest population" is suggested as a "solution to the problem of malaria in Africa" (BioMed).

Malaria "control in sub-Saharan Africa, where 90 percent of the 300 to 500 million malaria cases and one to three million deaths occur from malaria each year, still depends on only two technologies for vector intervention: indoor residual spraying and insecticide-treated bed nets" (Klassen). Overtime mosquitoes become resistant to pesticides and insect populations bounce back from elimination efforts. According to researcher, Mark Benedict, "In the context of elimination, SIT could play a unique role. As part of an area-wide integrated pest management programme, the SIT may be able to minimize problems due to insecticide resistance to antimalarial drugs" (BioMed).

This technique "involves the generation of 'sterile' male mosquitoes, which are incapable of producing offspring despite being sexually active. Because female mosquitoes only mate once during their lifetimes, a single mating with a sterile male can ensure that she will never breed" This leads to an increasing reduction in the population over time, in contrast to insecticides, which kill a certain fraction of the insect population" (BioMed).

Considerable "research and development on the suppression of mosquitoes with the sterile insect technique (SIT) was conducted from the mid-1950s to the mid-1970s"; however, "nearly all of the scientists who pioneered this approach have retired and several of the greatest have died." The resurgence of this idea is due in part to "new technologies" that are "available to support area-wide integrated pest management (AW-IPM) programmes" (Klassen).

If implemented in Africa, the sterile insect technique when combined with other measures could effectively eliminate the malaria-carrying mosquito population in Africa.

For an overview of the history of malaria and the SIT project, please read the study's introduction in the malaria journal:

BioMed Central. "Are Sterile Mosquitoes the Answer to Malaria Elimination?." ScienceDaily 17 November 2009. 18 November 2009 .
Klassen, Wauldemar. "Introduction: development of the sterile insect technique for African malaria vectors". Homestead, Florida. 16 November 2009.

Tuesday, November 17, 2009

New Moon -- The Twilight Saga

Hold on to your teeth, Ana Revenant is writing a blog article about New Moon. You should ask yourself: why? Then, you should realize that malaria must be involved.

Congratulations, you've cracked the code. I will do almost anything to raise awareness of the threat of malaria...even if that means promoting glittering vampires.

Malaria No More, a non-profit organization that provides malaria awareness education and relief, "is offering Twilight fans the chance to win two tickets to the early and exclusive New York City Press Screening of 'The Twilight Saga: New Moon' Wednesday, November 18th at Lincoln Center".

Excerpts from Malaria No More about their contest: [CONTEST CLOSED]

On Facebook, the contest is to recruit the most friends to join the Malaria No More Twilight Causes Page. The "Top Recruiter" will be notified via a private Facebook message. Malaria No More Causes Page:

On Twitter, the contest is to create a catchy tweet that relates a malarial mosquito to a vampire, and includes the hashtag #MNMBLOOD. The person that tweets the most interesting relationship in 140 characters and with the hashtag will be notified with a direct message. Twitter:

More information can be found on the Malaria No More blog page:

Enjoy the contest, and be warned: I may be lurking outside the movie theater waiting to dine on the well-marinated dinner entrees that walk into my arms. Ciao!

Monday, November 16, 2009

Malaria in Vanuatu

"Vanuatu, an archipelago of over 80 islands in the South Pacific, ranks behind only the Solomon Islands for having the highest rate of malaria infections. Malaria in Vanuatu has been getting steadily worse since the 1980s, which is why UCSF scientists are among the medical professionals working hard to control malaria in this region" (UCSF).

Malaria parasites are found in all regions of Vanuatu, and "[t]ransmission occurs from December to May. Either mefloquine (Lariam), atovaquone/proquanil (Malarone), or doxycycline may be given. Mefloquine is taken once weekly in a dosage of 250 mg, starting one-to-two weeks before arrival and continuing through the trip and for four weeks after departure." Malarone is a "combination pill taken once daily with food," the side-effects of which are "typically mild". Doxycycline "is effective," against malaria in Vanuatu "but may cause an exaggerated sunburn reaction, which limits its usefulness in the tropics" (MD Health). It is important to know that "Chloroquine is NOT an effective antimalarial drug in Vanuatu and should not be taken to prevent malaria in this region" (CDC). Malaria resistance to Chloroquine is becoming increasingly throughout the world as the parasite adapts.

"UCSF researchers, with funding from the Bill and Melinda Gates Foundation", "are conducting a large-scale household-level survey of malaria treatment and prevention practices in Vanuatu. Over 900 households on four islands (out of a total of more than 80, although only a few are populated) have participated in the study. Researchers also collected blood samples from all members of the households selected for the survey, which will permit them to link survey responses on prevention and treatment practices to biological markers" (UCSF).

For more information on the study, please visit UCSF web page.

CDC. Malaria in Vanuatu.

MD Travel Health. 'Vanautu'.

UCSF. Malaria Prevention.

Tuesday, November 3, 2009

Vaccine trials

Raise your hand if you took note of the press release regarding the malaria vaccine to jump at the chance to announce it before me. I see you there, sitting alone, sheepishly raising your hand. Actually, I'm quite proud of you. You're paying attention, spreading the word, and enlightening the world. Raise your hand higher, be proud! Oh wait. You in the public library: Put your hand down. People can see you.

So why is Ana so late to the party? No one told me the media gods were releasing the news today. I'm not psychic, you know. Also, I was preoccupied with public transit issues. Don't ask...

Of the emails and messages I received from avid followers, these are my favorites:
Can this really be true? Yaa!
Vampire fans -- this could be a breakthough.
Look [link] Why haven't you written yet? Did you get staked?

Calm yourselves, people. I'm not hindered by the strike of a little stake. The picketing version may be a different story, however.

Now that I'm back online, let me abbreviate the news:

"A pivotal efficacy trial of RTS,S, the world's most clinically advanced malaria vaccine candidate, is now underway in seven African countries: Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique and Tanzania" (PATH). This vaccine is the first to be designed specifically for malaria in Africa. Trials are being conducted in seven countries and different regions "across Sub-Saharan Africa" in order "to evaluate the vaccine candidate's efficacy in a variety of settings, with diverse patterns of malaria transmission. For example, some trial sites are located in areas where there is a year-round threat of malaria, while others experience only seasonal transmission". "The vaccine profile is intended primarily for infants, as they and children under the age of five are the most vulnerable to malaria" (PATH).

Previous research "studies showed that RTS,S reduced clinical episodes of malaria by 53 percent over an eight-month follow-up period" (PATH). Phase III trials are being conducted in what is now "the largest trial ever conducted in Africa of a vaccine specifically designed for use with African children."

PATH Malaria Vaccine Initiative (2009, November 3). World's Largest Malaria Vaccine Trial Now Underway In Seven African Countries. ScienceDaily. Retrieved November 3, 2009, from¬ /releases/2009/11/091103102248.htm