Earliest malaria parasite form can lay dormant and recover, research shows

A recent study showed that the earliest form of malaria parasites can lay dormant in red blood cells and recover after treatment with the antimalarial drug artesunate.

Researchers from the University of South Florida College of Public Health used a rodent model to determine that the early-stage dormancy phenomenon could contribute to the failure of artesunate, used alone or in combination with other drugs, according to

“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,” Dr. Dennis Kyle, a professor at USF, said, reports. “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 malaria parasites were treated with artesunate, dormant parasites were generally found in their blood within 24 hours. Researchers also found a positive association between malaria resurgence in the mice and the number of dormant parasites present.

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

Dr. Alex LaCrue was the lead author of the study, which was published in the online journal PLoS ONE and funded by the National Institutes of Health’s National Institute of Allergy and Infectious Diseases.