Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Chagas disease is an infection caused by a
protozoan parasite (Trypanosoma cruzi) that can result in acute inflammatory
skin changes (chagomas) and may eventually cause infection and inflammation of
many other body tissues, especially those of the heart and intestinal tract.
Chagas disease was first described in 1909 in Brazil.
Chagas disease is caused
by a protozoan parasite named Trypanosoma cruzi that is transmitted to humans
from the feces of triatomine bugs (kissing bugs).
The parasites usually enter
the mammalian (human) host through the bug bite, or breaks in the skin or
conjunctiva, replicate in mammalian cells, and may eventually reach other organs
through the blood.
Chagas disease may proceed through three phases in an
individual: acute, intermediate or indeterminate, and chronic.
symptoms vary widely from no symptoms to severe in the chronic phase.
Patient history, physical exam, direct microscopic
visualization of the parasites, and detection of antibodies against the parasites
are methods used to diagnose Chagas disease.
Treatment with antiparasitic
drugs benznidazole (Rochagan, Ragonil) and nifurtimox (Lampit) kill or inhibit
T. cruzi parasites; drugs are available from the CDC.
Chronic-phase patients are usually treated using treatments directed at the specific symptoms or organ damage.
There is no
vaccine against Chagas disease parasites for humans, but many experts suggest
that elimination of primitive housing and increasing education about the disease may prevent most cases of Chagas disease.
There are reports that dogs, especially in the southern U.S. and in particular, Texas, may be infected with these parasites and some reports imply there is a danger for humans to become infected because the vectors now reside in the southern U.S. However, the percentage of dogs found to be infected with the parasites is relatively low (about 8.8%) and it is often associated with dogs that are feral, strays, or abandoned. In Mexico, the infection rate of dogs is higher (about 17%-21%). However, all dogs are at some risk to become infected if they are bitten by the vector.