Researchers at the University of California, San Francisco (UCSF), Sandler Center for Basic Research in Parasitic Disease, may have produced the first new treatment for Chagas’ disease in 35 years. This parasitic disease, particularly prevalent among the poor, has infected about 13 million people worldwide and claims 50,000 lives each year.
Named for the Brazilian physician Carlos Chagas—who published the first description of the ailment in 1909—Chagas’ disease is caused by the parasite Trypanosoma cruzi, which infects the triatomine bug, an insect sometimes called the “kissing bug” for its habit of biting near a person’s mouth. Found throughout Central and South America, the bugs emerge at night and bite sleeping people on the face. A bitten person may rub parasite-laden feces into the bite, the eyes, or the mouth, thereby becoming infected.
Most people do not know they are infected, and most people suffer no ill effects from chronic T. cruzi infection. But about one-third of those infected develop serious cardiac or intestinal complications, often decades after the initial infection.
New treatments for the disease are urgently needed. Currently, there are only two medications available to treat Chagas’ disease: benznidazole and nifurtimox, both of which have significant drawbacks. Treatment periods can be long, lasting up to 120 days, and can cause serious, possibly fatal, side effects.
For the past 10 years, NIAID has supported research to find new treatments. Researchers at UCSF’s Sandler Center tested more than 2,000 compounds through in vitro and in vivo studies and found that a protease inhibitor called K777 killed T. cruzi and produced no significant side effects.
K777 inhibits a vital protease enzyme called cruzain in T. cruzi, thereby killing the parasite. Although there are many strains of T. cruzi, UCSF researchers have verified that K777 is effective against several strains, including those that have developed resistance to the currently available drugs.
The K777 compound must now be tested in preclinical trials. Because T. cruzi parasites can linger in the body for up to 7 years, this stage may prove difficult.. Despite such difficulties, though, researchers are hopeful they may finally have found a safe and effective treatment for Chagas’ disease.
Last Updated July 29, 2010