Parasite is a growing concern for healthcare professionals
One in 3,800 donors in the L.A. area tested positive for
Chagas, a deadly disease that is mainly found in Latin America.
By: Rong-Gong Lin II, Times Staff Writer
Posted: March 17, 2007
A little-known but potentially deadly parasite from Latin America
has become one of the latest threats to the blood and organ supplies
in the United States, especially in Los Angeles, where many donors
have traveled to affected countries, health officials say.
Last year, two heart transplant patients at different Los Angeles
hospitals contracted the parasitic disease, called Chagas, causing
health authorities to issue a national bulletin. Within months,
both patients subsequently died, although not directly from
Chagas, according to the U.S. Centers for Disease Control and
The parasite, which is generally passed to humans from a blood-sucking
insect that looks like a striped cockroach, can feed over years
on tissues of the heart and gastrointestinal tract. After decades,
tissues can be eroded so much that the organs fail.
Insect transmission of the parasite in the United States is
rare, but public health and blood bank officials have been concerned
about its increasing prevalence in the blood supply.
In 1996, using an experimental test, the American Red Cross
found that one in 9,850 blood donors in the L.A. area tested
positive for the parasite, Trypanosoma cruzi. Two years later,
it was one in every 5,400. By 2006, a more refined test detected
the parasite in one in 3,800 donors. About 10% to 30% of infected
people develop symptoms of chronic disease, experts say.
By contrast, HIV, which blood banks screen for, shows up in
one of every 30,000 donors, said Susan Stramer, executive scientific
officer for the Red Cross.
If caught early, strong anti-protozoal drugs such as nifurtimox
can bring the parasite to undetectable levels or, in some cases,
eliminate it entirely.
If the parasite is given the chance to multiply over years
or decades, however, those infected may have to be treated with
heart-regulating drugs or get a pacemaker or heart transplant.
The U.S. Food and Drug Administration approved a test suitable
for widespread screening in December. Blood banks have now begun
systematically checking their supplies for the Chagas parasite.
By late January, the American Red Cross and Phoenix-based Blood
Systems, which collect about 65% of the U.S. blood supply, had
started screening blood for T. cruzi. Other banks, including
the Blood Bank of San Bernardino and Riverside Counties, have
no immediate plans for screening but are monitoring test results
from banks that are using the test. In late February, the CDC
reported that the "FDA is expected to recommend implementation
of the test by all blood-collection establishments."
No organ donors in the United States are now being screened
for the parasite, although the organ procurement agency that
covers much of Southern California plans to begin testing some
donors in mid-April. At first, the screening will be focused
on people who have lived in or traveled to rural parts of Latin
America, said Thomas Mone, chief executive of the agency, OneLegacy.
In Latin America, about 10 million to 12 million people are
believed to be infected with the Chagas parasite. As many as
1 million of them are expected to die from the disease unless
there are advances in treatment, according to Dr. James Maguire,
a University of Maryland expert on the disease.
"Chagas is very, very prevalent in South and Central America,"
said Marek Nowicki, a USC blood-disease expert who studied the
effect of Chagas on the Southern California organ supply with
the National Institute of Transplantation.
"The number of [immigrant] Latinos in Southern California,
Texas and other parts of the United States are growing, but
especially in L.A., a large proportion of organ donors are Latino,"
Nowicki said. "They're basically bringing with them the
disease prevalence in the area they used to live."
The problem is not limited to immigrants. Tourists, too, can
be carriers. The heart transplant cases in Los Angeles last
year illustrate the problem.
One donor was a native of El Salvador living in Los Angeles,
and the other was born in the U.S. but had traveled to Guadalajara,
Mexico, where T. cruzi is endemic.
Richard Edward Russo, then 73, received the heart from the
Salvadoran native. The Burbank retiree appeared to be recovering
nicely last year when, several weeks after his transplant at
St. Vincent Medical Center in Los Angeles, he developed a fever
and a rash. He complained of being tired and couldn't eat or
About the same time, a 64-year-old man developed similar symptoms
after receiving a transplant at UCLA Medical Center. He had
received the heart from the American tourist.
At both hospitals, doctors submitted the patients to a battery
of tests, concluding separately that they had Chagas.
The CDC sent anti-parasitic medication out from Atlanta. The
drug reduced the parasite in the blood of both men to undetectable
levels. But Russo never got better, his wife, Carolyn, said.
He suffered from other hospital-acquired infections and had
pneumonia at least twice.
Article at: latimes.com