Chagas' disease is a tropical parasitic sickness that currently affects more than 16 million people, with a staggering 100 million at risk, largely in the tropical areas of South and Central America. And yet the main drug used to treat the disease is highly toxic and causes serious side effects.
Now, new research just published by scientists at the University of Georgia has identified for the first time a sensitive method for testing and assessing the efficacy of treatments for Chagas' disease. The study could lead to new treatments for long-term sufferers of a disease that can be fatal.
“It is the first time we've been able to identify a set of measurements to determine whether or not a drug for Chagas actually works,” said Rick Tarleton, distinguished research professor of cellular biology and a faculty member at UGA's Center for Tropical and Emerging Global Diseases.
The research was published today in the online edition of the journal Nature Medicine. Co-authors, also from the University of Georgia, are postdoctoral associate Juan Bustamante and master's degree student Lisa Bixby.
The research presents the first and only evidence that the current drug therapies for Chagas' disease can actually completely cure the infection. Still, current treatments have potentially severe side effects and are thought to be effective in less than 50 percent of those treated. More important, the model the team developed can be used for the development of better drugs against Trypanosoma cruzi, the parasite that causes the disease.
“We also found that the immunological markers of cure in this system, which we developed in mice, provide a means to monitor drug treatment efficacy in humans, something that has been the biggest impediment to developing new drugs,” said Tarleton.
There's a fourth finding more important to the big picture of immunology, however. This study shows that chronic infections do not by default exhaust the immune system.
“Current dogma on chronic infections is that constant stimulation of the immune system eventually wears it out, which is one of the problems in treating such disorders as HIV/AIDS,” said Tarleton. “This study shows that one can have an infection for more than a year, but, when cured, the immune system develops a stable, protective memory.”