News / Health

New Malaria Drugs Stop Parasite Early

Animal tests promising, but human trials still ahead

US scientists are experimenting with a compound of anti-malaria drugs that kill the parasite in its dormant liver stage.
US scientists are experimenting with a compound of anti-malaria drugs that kill the parasite in its dormant liver stage.

Multimedia

Audio
Art Chimes

U.S. medical researchers report a possible breakthrough that might prevent infection by one of the two most widespread varieties of malaria.

A new class of anti-malaria compounds kills the parasites in the developmental stages in the liver, before they get into the bloodstream.

The compounds proved highly successful in animal tests, according to a study published in Science, but their effectiveness in humans is still unproven.

Plasmodium vivax is the dominant strain of the malaria parasite outside Africa. Unlike the more deadly Plasmodium falciparum, vivax can infect a person but stay dormant in the liver for months or even years, before emerging to cause disease.

Scientists at the Scripps Research Institute in California and other institutions evaluated chemical compounds that were known to kill the malaria parasite in the blood. They were looking for ones that also might kill the parasite in its dormant liver stage.

In this study, the researchers mixed each one of the compounds with malaria parasites taken from live mosquitoes. Each combination was put with liver cells into individual compartments, called wells, on a microscope slide. Author Elizabeth Winzeler explains that to screen thousands of chemicals as potential malaria drugs required some sophisticated technology.

"We used an automated microscope to go and take about 100 images of each of the wells, and then we used computer scripts to analyze the images and identify those wells that had compounds that appeared to affect the development of the parasites."

To test potential drugs developed from the chemicals that looked promising, Winzeler and her colleagues infected laboratory mice with the malaria parasite. Left alone, the mice died within 10 days.  But "if you give the mice the same treatment, and you give them a small oral dose of the compounds that we made, the mice are cured or they never develop malaria in the first place."

These new substances, called IZPs, are effective in mice, Winzeler says, "but there's always a big step between going from something that works in a mouse model and actually going into something that's safe and efficacious in humans."

Researchers at Scripps, backed by the pharmaceutical company Novartis, are now considering that next step, safety testing in humans.

If successful, this work could lead to a malaria drug that attacks the dormant stage of the parasite, which occurs only in the Plasmodium vivax form of the disease. Scientists theorize that this period of dormancy was an evolutionary strategy to keep infection active through the cold winter months.

"For example, vivax malaria was found in places like Finland and England, up until about 100 years ago. And clearly, there weren't mosquitoes out biting people in December."

Vivax now occurs mainly in Asia and Latin America.

You May Like

Video Indiana Controversy Points to Divergent Notions of Religious Freedom

Gay-marriage opponents are looking for ways to maintain their beliefs in face of changing culture, one writer says More

UNICEF Denies North Korean Measles Outbreak

Agency dismisses Russian media report after government, WHO assurances More

Turkey Seen Taking Harder Stance Against Militant Kurds

Stance comes as President Recep Tayyip Erdogan is being seen as moving closer to generals More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Indiana Controversy Highlights Divergent Meanings of Religious Freedomi
X
Jerome Socolovsky
April 01, 2015 1:41 AM
Indiana’s state government has triggered a nationwide controversy by approving a law that critics say is aimed at allowing discrimination against gays and lesbians. The controversy stems from divergent notions of religious freedom in America. VOA's Jerome Socolovsky reports.
Video

Video Indiana Controversy Highlights Divergent Meanings of Religious Freedom

Indiana’s state government has triggered a nationwide controversy by approving a law that critics say is aimed at allowing discrimination against gays and lesbians. The controversy stems from divergent notions of religious freedom in America. VOA's Jerome Socolovsky reports.
Video

Video Nigerians Welcome Buhari's Return to Power

Crowds of jubilant Nigerians nationwide have celebrated the return to power of former military ruler Muhammadu Buhari. The retired army general won this year's presidential election with more than 2 million votes more than incumbent President Goodluck Jonathan. Buhari's supporters hope he can strengthen the country's economy and security once he takes office in late May. Zlatica Hoke has this story.
Video

Video Report: State of Black America a 'Tale of Two Nations'

The National Urban League has described this year's "State of Black America" report as a "tale of two nations." The group's annual report, released earlier this month (March), found that under an equality index African Americans had only 72% parity compared to whites in areas such as education, economics, health, social justice and civic engagement. It’s a gap that educators and students at Brooklyn’s Medgar Evers College are looking to close. VOA's Daniela Schrier reports from the school.
Video

Video Film Tells Story of Musicians in Mali Threatened by Jihadists

At this year's annual South by Southwest film and music festival in Austin, Texas, some musicians from Mali were on hand to promote a film about how their lives were upturned by jihadists who destroyed ancient treasures in the city of Timbuktu and prohibited anyone from playing music under threat of death. As VOA’s Greg Flakus reports from Austin, some are afraid to return to their hometowns even though the jihadists are no longer in control there.
Video

Video Gamma Ray Observatory to Open Soon in Mexico

American and Mexican scientists have completed construction of the world's largest gamma ray observatory, situated high in central Mexico’s Sierra Negra Mountain. The observatory's huge array of water-based detectors will soon start discovering secrets about black holes and supernovas. VOA’s George Putic reports.
Video

Video Ebola Vaccine Trials Underway in West Africa

Ebola has claimed the lives of more than 10,000 people in West Africa. Since last summer, researchers have rushed to get anti-Ebola vaccines into clinical trials. While it's too early to say that any of the potential vaccines work, some scientists say they are seeing strong results from some of the studies. VOA's Carol Pearson reports.
Video

Video Philippines Wants Tourists Spending Money at New Casinos

Tourism is a multi-billion dollar industry in the Philippines. Close to five million foreign visitors traveled there last year, perhaps lured by the country’s tropical beaches. But Jason Strother reports from Manila that the country hopes to entice more travelers to stay indoors and spend money inside new casinos.
Video

Video Civilian Casualties Push Men to Join Rebels in Ukraine

The continued fighting in eastern Ukraine and the shelling of civilian neighborhoods seem to be pushing more men to join the separatist fighters. Many of the new recruits are residents of Ukraine made bitter by new grievances, as well as old. VOA's Patrick Wells reports.
Video

Video Islamic State Prisoners Talk of Curiosity, God, Regret

Islamic State fighter, a prisoner of Kurdish YPG forces, asked his family asking for forgiveness: "I destroyed myself and I destroyed them along with me." The Syrian youth was one of two detainees who spoke to VOA’s Kurdish Service about the path they chose; their names have been changed and identifying details obscured. VOA's Zana Omer reports.
Video

Video Germanwings Findings Raise Issue of Psychological Testing for Pilots

More is being discovered about the co-pilot in the crash of Germanwings Flight 9525 in the French Alps. Investigators say he was hiding a medical condition, raising questions about the mental qualifications of pilots. VOA's Carolyn Presutti reports.
Video

Video Liberia's Almost Last Ebola Patient Grateful but Still Grieving

Beatrice Yardolo was to make history as Liberia’s last Ebola patient. Liberians recently started counting down 42 days, the period that has to go by without a single new infection until the World Health Organization can declare a country Ebola-free. That countdown stopped on March 20 when there was another new case of Ebola, making Yardolo’s story a reminder that Ebola is far from over. Benno Muchler reports from Monrovia.
Video

Video Cambodian Land Grabs Threaten Traditional Communities

Indigenous communities in Cambodia's Ratanakiri province say the government’s economic land concession policy is taking away their land and traditional way of life, making many fear that their identity will soon be lost. Local authorities, though, have denied this is the case. VOA's Say Mony went to investigate and filed this report, narrated by Colin Lovett.

VOA Blogs

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More