Chagas, a disease that can lead to life-threatening heart and digestive disorders, is in the United States, according to the Centers for Disease Control and Prevention.
So far, seven cases have been diagnosed in Arizona and California.
Researchers at the University of Texas at Austin said the bugs that cause the disease, the Triatomid or "kissing bug," were already discovered in 11 southern and central Texas counties.
Entomologists said the bugs feed on human blood.
In most cases, the bugs targeted people who were sleeping, biting near the mouth, nose and eyes.
Doctors said Chagas can be hard to spot because it mirrors many different illnesses.
The initial symptoms could including fever and swelling around one eye and at the site of the bug bite.
The disease has been known go into remission and reemerge years later as a more serious illness, resulting in potentially deadly digestive and heart failure.