Pitt Researcher Focuses on Quest for New Malaria Drugs

By: Cyndy McGrath

For most of us, mosquitoes are simply a summertime annoyance – tiny pests that we squish or swat away without a second thought. Not so in many developing countries, where one bite can mean months of misery, or death, a serious concern noted by today’s recognition of World Malaria Day.

Inside her laboratory in the University of Pittsburgh Graduate School of Public Health , Alice Tarun, Ph.D.,    studies the genes of the Plasmodium vivax bacteria, one of the two parasites that cause the most common forms of human malaria. They are microscopic targets, but Dr. Tarun hopes they will someday lead to a major breakthrough in malaria treatment, one of the biggest global health threats.
“The public health impact of malaria is second only to tuberculosis,” says Dr. Tarun, an assistant professor in the Department of Microbiology and Infectious Diseases. “If you look at the statistics, it’s just crazy.”
According to the World Health Organization, malaria is endemic to 90 countries, causing an estimated 660,000 deaths a year, mostly in sub-Saharan African countries. Ninety percent of the victims are children under the age of 5, or pregnant women.
Malaria spreads when a person gets bitten by an infected mosquito.  That mosquito deposits parasites into the bloodstream, which travel to the liver and amplify. The parasites invade and feed off of red blood cells, ultimately bursting out of the cells, at which time an infected person begins to feel the symptoms of the disease: cycles of fatigue, chills and fever.
The parasite has a complicated life cycle, and infectious disease researchers often study one phase of development or infection in the quest for new drug targets.
Dr. Tarun’s research focuses on the liver and sexual stages of the Plasmodium parasite.
“When the parasite is dividing in the blood, some parasites will form the gametes, or the sexual stage.  They can’t complete their development until a mosquito picks them up by biting an infected human,” says Dr. Tarun. “This is really an area where there is not a lot of research.”
According to Dr. Tarun, many of the available malaria drugs don’t kill parasites during their sexual stage.  A patient can be sick with malaria and receive treatment, yet they are still able to transmit the parasite because gametocytes are still circulating within their system.
“We are trying to see if there are genes and proteins that are essential for gametocyte development,” said Dr. Tarun.  “Then we mutate those genes to determine their importance.”
Dr. Tarun says this approach could ultimately lead to the development of drugs that could target and kill the gametocyte, which she describes as “remarkably resilient.”
“If we can stop the parasite in the liver, then we can prevent the disease and prevent transmission,” says Dr. Tarun. “Attacking malaria on multiple fronts is really the best strategy.”