Featured Research

from universities, journals, and other organizations

Dormant malaria parsites in red blood cells may contribute to treatment failure, study suggests

Date:
November 4, 2011
Source:
University of South Florida (USF Health)
Summary:
Researchers have shown for the first time in a rodent model that the earliest form of malaria parasites can lay dormant in red blood cells and "wake up," or recover, following treatment with the antimalarial drug artesunate.

Alexis LaCrue, PhD, lead author of the study, with principal investigator Dennis Kyle, PhD.
Credit: Image courtesy of University of South Florida (USF Health)

Researchers at the University of South Florida (USF) College of Public College Health have shown for the first time in a rodent model that the earliest form of malaria parasites can lay dormant in red blood cells and "wake up," or recover, following treatment with the antimalarial drug artesunate.

Related Articles


The study, which appears in the online journal PLoS ONE, suggests that this early-stage dormancy phenomenon contributes to the failure of artesunate alone, or even combined with other drugs, to eliminate the mosquito-borne disease. Alexis LaCrue, PhD, research associate in the USF Department of Global Health, is the lead author of the study, which was funded by the National Institute of Allergy and Infectious Diseases (NIAID).

The emergence of parasites resistant to artesunate therapy along the Thai-Cambodian border could seriously undermine the success of global malaria control efforts, the World Health Organization has reported.

"There is an urgent public health need to understand why this antimalarial drug resistance is happening and the basis for it, so we can help arrest its spread," said principal investigator Dennis Kyle, PhD, distinguished university health professor at the USF College of Public Health.

"Our study was able to induce the same dormant stage in vivo -- in a rodent malaria model -- that was previously seen only in the test tube," Kyle said. "The work suggests that dormancy is involved in the earliest stage of parasite development in the red blood cells. It may be a new mechanism for how the parasite avoids being wiped out by artemisinin drugs."

When mice infected with rodent malaria parasites were treated with artesunate, dormant parasites were present in their red blood cells 24 hours following treatment. The researchers also found a positive association between the number of dormant parasites present and when malaria infection re-emerged in the mice.

More studies are needed to help explain the mechanism behind the early-stage dormancy and its contribution to treatment failure.

"Now that we have a robust animal model for studying how the parasites become dormant and then recover," Kyle said, "we may be able to change our dosing regimens and investigate drug partners for artemisinin that are better at killing the dormant parasites."

Malaria parasites are transmitted by the bite of an infected mosquito. In humans, they enter red blood cells and start replicating after being released from the disease's first target, the liver. Once parasites escape into the bloodstream, disease symptoms emerge including chills, fever, headache, body aches, vomiting and exhaustion.

Malaria affects 10 percent of the world's population, killing nearly one million people a year in developing countries and crippling their economies. Most who die or become ill are poor pregnant women and children under age 5 in tropical and subtropical regions of Africa, Asia and South America.

In addition to LaCrue and Kyle, the study authors were Misty Scheel, Katherine Kennedy and Nikesh Kumar -- all members of the USF Global Infectious Disease Research team.


Story Source:

The above story is based on materials provided by University of South Florida (USF Health). Note: Materials may be edited for content and length.


Journal Reference:

  1. Alexis N. LaCrue, Misty Scheel, Katherine Kennedy, Nikesh Kumar, Dennis E. Kyle. Effects of Artesunate on Parasite Recrudescence and Dormancy in the Rodent Malaria Model Plasmodium vinckei. PLoS ONE, 2011; 6 (10): e26689 DOI: 10.1371/journal.pone.0026689

Cite This Page:

University of South Florida (USF Health). "Dormant malaria parsites in red blood cells may contribute to treatment failure, study suggests." ScienceDaily. ScienceDaily, 4 November 2011. <www.sciencedaily.com/releases/2011/10/111025102326.htm>.
University of South Florida (USF Health). (2011, November 4). Dormant malaria parsites in red blood cells may contribute to treatment failure, study suggests. ScienceDaily. Retrieved November 21, 2014 from www.sciencedaily.com/releases/2011/10/111025102326.htm
University of South Florida (USF Health). "Dormant malaria parsites in red blood cells may contribute to treatment failure, study suggests." ScienceDaily. www.sciencedaily.com/releases/2011/10/111025102326.htm (accessed November 21, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

WFP: Ebola Risks Heightened Among Women Throughout Africa

WFP: Ebola Risks Heightened Among Women Throughout Africa

AFP (Nov. 21, 2014) Having children has always been a frightening prospect in Sierra Leone, the world's most dangerous place to give birth, but Ebola has presented an alarming new threat for expectant mothers. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com
Milestone Birthdays Can Bring Existential Crisis, Study Says

Milestone Birthdays Can Bring Existential Crisis, Study Says

Newsy (Nov. 21, 2014) Researchers find that as people approach new decades in their lives they make bigger life decisions. Video provided by Newsy
Powered by NewsLook.com
Ebola: Life Without School in Guinea

Ebola: Life Without School in Guinea

AFP (Nov. 21, 2014) Following the closure of schools and universities in Guinea because of the Ebola virus, students look for temporary work or gather in makeshift classrooms to catch up on their syllabus. Duration: 02:14 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins