Chagas disease, which can cause long-term cardiac damage, is mainly
found in rural Central and South America, but some experts are concerned
that cases are beginning to rise in southern U.S. states.
Infections
have been reported in Arkansas, Arizona, Massachusetts, Tennessee and
Texas, according to the CDC.
The disease is caused by the Trypanosoma cruzi parasite and is spread
almost exclusively through bites from the triatomine insect, also called
the "kissing bug," since it usually bites around the eyes and mouth,
usually when they come out to feed at night. In rural Central and South
America, the bugs are often found in the walls of homes made from mud,
adobe or straw. The insect has also been found in other U.S. states but
that does not necessarily mean the bugs carry the parasite, experts
said.
Once in the body, the parasite can remain hidden for years, or even decades, eventually resulting in serious heart disease,
including stretching of the heart muscle called cardiomyopathy or
irregular heartbeat. Other early acute symptoms include fever, fatigue,
body aches, headache and rash.
While the disease can lead to serious complications, the vast majority
of those infected will likely not show any symptoms, according to the
CDC, which estimated that 300,000 people with Chagas disease live in the
United States. A spokeswoman for the CDC said the agency does not have
data on how many people are infected within the U.S. versus those
infected before they arrive.
Dr. William Schaffner, an infectious disease expert at Vanderbilt
University, said since the virus can remain in the body for decades,
it's extremely difficult to tell when a person was infected and that
most people in the U.S. with the disease were likely infected before
arriving in the country.
"Once the bug gets into you, it goes throughout the body and sets up
quiet housekeeping ... in particular in the heart," Schaffner said. "It
smolders there for many years, anywhere from 20 to 30 years."
The parasite resides in the insect's intestinal tract and can enter a
human bloodstream if a person scratches a bite and the parasite enters
through the scratches. The disease is not spread from person to person.
In previous decades, cardiologists almost never saw the infection,
Schaffner said, but anecdotally infectious disease doctors and
cardiologists are encountering the rare infection more and more.
Patients in the U.S. may have been infected years before they arrived
and as they age their immune system gets weaker, and they "may develop
these illnesses of cardiomyopaty or arrythmia," Schaffner said, noting
the patients "had parasite silently traveling with them."
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