Chagas disease is believed to be a very real threat in the U.S., but it mostly goes unnoticed.

The disease is caused by a parasite and can lead to severe heart disease and death, Burness Communications reported. The disease is typically spread through the feces of the blood-sucking triatomine bugs, nicknamed "kissing bugs" because they feed on people's faces at night.

The disease affects between seven and eight million people worldwide and is curable if caught in the early stages. While the disease is primarily found in Mexico, Central America and South America, cases in Texas have been on the rise. Among these cases a high percentage are believed to have been contracted within the borders of the U.S.

"We were astonished to not only find such a high rate of individuals testing positive for Chagas in their blood, but also high rates of heart disease that appear to be Chagas-related," said Baylor epidemiologist Melissa Nolan Garcia, one of the researchers who presented findings from a series of studies. "We've been working with physicians around the state to increase awareness and diagnosis of this important emerging infectious disease."

Kissing bugs are found across half of the U.S., and one in every 6,500 Texas blood donors tested positive for exposure to the parasite. These numbers are 50 times higher than the Center for Disease Control and Prevention's estimated infection rate of one in every 300,000 nationally.

"We think of Chagas disease as a silent killer," Garcia said. "People don't normally feel sick, so they don't seek medical care, but it ultimately ends up causing heart disease in about 30 percent of those who are infected."

People who test positive for Chagas disease usually go untreated. Out of the 2,000 people who tested positive through the American Association of Blood Banks' system only 422 doses of medication were administered by the CDC between 2007 and 2013.

"This highlights an enormous treatment gap," said Jennifer Manne-Goehler, a clinical fellow at Harvard Medical School and Beth Israel Deaconess Medical Center, collected data from the CDC and the American Association of Blood Banks . "In some of the areas of the country we know there are a lot of positive blood donors, yet people still don't get care. We don't know what happens to them because there is no follow up."

Some symptoms include fever, fatigue, body aches, and cardiac and intestinal complications.

The findings were presented at the American Society of Tropical Medicine and Hygiene (ASTMH) Annual Meeting.