First Supplemental Chagas Disease Test Approved

Kate Johnson


November 21, 2011

November 21, 2011 — The US Food and Drug Administration (FDA) has approved the first test licensed as a supplemental test for the detection of antibodies to Trypanosoma cruzi, the parasite that causes Chagas disease.

The ESA Chagas assay (Abbot Laboratories) is the first test for use as an additional, more specific test on human serum and plasma specimens that are positive for antibodies to T cruzi, noted the FDA in a press release.

T cruzi, which causes Chagas disease, is carried by blood-sucking triatomine insects (commonly known as kissing bugs) and can also be spread through blood transfusions and organ transplants, as well as from mother to unborn child.

According to earlier FDA guidance for industry on serological tests to reduce the risk for transfusion-related transmission, "[t]he presence of antibodies to T. cruzi is strong evidence that a donor is infected with this parasite."

The industry guidance document suggests that a supplemental test for antibodies to T cruzi can be used for confirmation of true-positive screening test results.

There are currently 2 tests licensed to screen blood or organ donors for antibodies to the parasite: the Prism Test (Abbott Laboratories) and the Ortho T cruzi ELISA Test System (Ortho-Clinical Diagnostics, Inc).

The new test, an in vitro enzyme strip assay, is the first test licensed as a supplemental test.

"This test will help health care professionals to provide counseling to donors with positive screening test results," said Karen Midthun, MD, director of the FDA's Center for Biologics Evaluation and Research, in a news release.

The FDA estimates that at least 300,000 people living in the United States are infected with T cruzi, and are, therefore, at risk of developing Chagas disease, which is potentially fatal.

Since national screening of blood and organ donors began in early 2007, more than 5000 positive donors have been identified, said the release.

According to a recently published paper, 7 transfusion-associated and 6 organ donor–derived T cruzi infections have been documented in the United States and Canada (Clin Microbiol Rev. 2011;24:655-681).

There is currently no vaccine against Chagas disease, which is considered a Neglected Infection of Poverty, according to the US Centers for Disease Control and Prevention, as it is found mostly in people with limited resources and limited access to medical care.


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