Discovery could help control life-threatening disease
International research team announces break from 30
years of dogma for ancient disease agent.
(ATHENS, Ohio) A discovery by a team of researchers
from Ecuador, the United Kingdom and the Ohio University College of
Osteopathic Medicine (OU-COM) could prove key to creating control
programs for a parasite that causes a life-threatening disease in
The findings were published in the article, “Sex,
Subdivision, and Domestic Disperal of Trypanosoma cruzi
Lineage I in Southern Ecuador,” in the most recent version of the
on-line journal PLoS Neglected Tropical Diseases (http://www.plosntds.org/doi/pntd.0000915).
The team, which
includes Mario J. Grijalva, Ph.D., associate professor of
microbiology and director of the OU-HCOM Tropical Disease Institute,
found novel evidence that the population of protozoan parasites in
Southern Ecuador reproduce sexually, in stark contrast to
populations across the continent and contradicting a belief held for
thirty years that sex is largely absent from this organism.
Of sex in this
protozoan, Grijalva said “This was the first time this had been
found in the field, and it is a very important basic scientific
The parasite, called
Trypanosoma cruzi, is transmitted by bloodsucking insects
known as triatomines, and it commonly infects wild and domestic
mammals in South and Central American, including humans. Human
infection with T. cruzi, known as Chagas disease, is a major
public health concern in Latin America, affecting more than 13
million people, including more than 200,000 Ecuadorians.
complex dynamics of parasite spread between wild and domestic
environments is essential to design effective control measures to
prevent the spread of Chagas disease,” the authors wrote.
The researchers also
discovered that the parasites in southern Ecuador are of a
genetically different population than those in others parts of
Central and South America, Grijalva said. “They have entirely
different characteristics,” he said.
indicate that the parasite circulates in two largely independent
cycles: one corresponding to the sylvatic environment and one
related to the domestic/peridomestic environment,” Grijalva said.
“Furthermore, our data indicate that human activity might promote
parasite dispersal among communities.”
other authors of the paper included Sofia Ocana-Mayorga and Jaime A.
Costales of the Center for Infectious Disease Research at the
Pontificia Universidad Catolica del Ecuador in Quito, Ecuador, and
Martin S. Llewellyn and Michael Miles of the London School of
Hygiene and Tropical Medicine in London, United Kingdom. This
research was supported by the National Institutes of Health and the
Chagas Epidemiological Network.
Each year, Grijalva
leads a team of more than 40 researchers, scientists and medical
students, including several from OU-HCOM, to study tropical diseases
in Ecuador. The World Health Organization has cited this program as
an example of how to develop a new strategy for a global fight
against this disease.