Doctors advocate fresh efforts to combat Chagas disease, a silent killer

Reviewed by Danielle Ellis, B.Sc.Aug 22 2023

When Maira Gutiérrez was diagnosed with Chagas disease in 1997, neither she nor her primary care physician had even heard of the malady. She discovered her illness only by chance, after participating in a Red Cross blood drive organized by her employer, Universal Studios.

The Red Cross tests donated blood for a range of diseases, including Chagas, which is caused by a parasite and can develop silently for decades before causing symptoms. The test detected Chagas in her body, and an MRI years later, in 2013, confirmed it had reached her heart.

"They showed me the image with the trace of the parasite to my heart. It was really scary," Gutiérrez, originally from El Salvador, said in Spanish. Now 50, she remains healthy but undergoes a battery of tests annually to monitor for heart damage.

Trypanosoma cruzi, the parasite that causes Chagas, is transmitted through an insect called the triatomine bug, known as the kissing bug, because it usually bites close to the lips. The bugs defecate on the skin, and the feces, which can contain the parasite, can enter a person's body through the nose, mouth, or breaks in the skin.

Chagas disease affects people primarily in rural Latin America, where the insect thrives in thatched roofs and mud walls. It is not transmitted from person to person, except for a mother passing it to a newborn, or through blood transfusions or organ transplants.

But it's increasingly present in the United States, where it often goes unrecognized: The Centers for Disease Control and Prevention estimates more than 300,000 people living in the U.S. have Chagas, though lack of awareness and testing means only 1% of cases have been identified.

Doctors, researchers, and patient advocates say the nation could be doing far more to combat Chagas, which causes serious heart disease in an estimated 30% of infected people and can also lead to crippling digestive problems such as enlargement of the esophagus and colon. They are pushing for increased access to testing and treatment and are optimistic about a new drug that's set for human trials next year. A bill in Congress to up funding for rare diseases, which supporters hope will be debated in the fall, could help too.

Still, in the U.S., there is "a tremendous lack of awareness about this disease," said Rachel Marcus, a cardiologist and the medical director of the Latin American Society of Chagas, who runs a Chagas testing clinic in northern Virginia. "We were taught that it is something we don't see in the United States."

A large proportion of those with Chagas are from Latin America, and many are living in the U.S. without legal permission. Marcus notes that many of those most at risk from Chagas use community health centers that could be testing sites but have limited resources and tend to focus on more common conditions such as high blood pressure and diabetes.

Chagas initially produces flu-like symptoms but can then go unnoticed for decades while it reproduces in the body. Drug treatments can sometimes eradicate the parasite, especially in its first stages, but the window for early detection is short: It does not stay in the bloodstream for long, instead migrating to tissues and organs, where it is harder to detect.

Often by the time a patient sees a doctor, that person has already developed serious complications, including heart rhythm abnormalities or a dilated heart that doesn't pump blood well. Patients may eventually need pacemakers or heart transplants.

“It is a disease resulting from systemic failures in the health care system,” said writer Daisy Hernández, author of “The Kissing Bug: A True Story of a Family, an Insect, and a Nation’s Neglect of a Deadly Disease.” In her book, Hernández tells the story of her aunt Dora, who was diagnosed with Chagas in the U.S. Before, in her country, Colombia, she had an exploratory surgery because of a swollen stomach and the doctors told her that she had “the intestines of 10 people” due to the amount of inflammation. No one suspected it could have been caused by the Chagas parasite.

Hernández said interviews with over 70 doctors and patients convinced her that the real barrier to Chagas care is inaction.

"While a person living in Virginia who is originally from Bolivia [where Chagas is endemic] knows that if diagnosed with Chagas, they should start saving up for a pacemaker," Hernández said in Spanish, "here, the government does nothing and doesn't even know what the disease is."

Between 6 and 7 million people worldwide live with the parasite. In the U.S., two long-standing drugs have had FDA approval: benznidazole and nifurtimox, which can beat back the parasite but don't always eradicate it. The medications can have serious side effects, and are most effective if given early: Babies born with Chagas have a 90% cure rate if treated within their first year of life.

To combat the disease, doctors familiar with Chagas recommend testing pregnant women from at-risk communities and urge earlier treatments. They also advocate screening all transplant organs. In 2018, a Connecticut man died after receiving a heart infected with the Chagas parasite, prompting a lawsuit and calls for mandatory organ screening. The organization that governs transplant policies in the U.S. recently voted to require such testing.

Few facilities in the country screen for Chagas. Advocates say that with greater awareness, many health care providers could conduct initial screenings and, if positive, send results to the CDC for confirmation.

However, building awareness has been an uphill battle. The Center of Excellence for Chagas Disease, the only center in the U.S. dedicated to Chagas diagnosis and treatment, recently suspended operations after its longtime director, Sheba Meymandi, retired.

A pioneer in the diagnosis and treatment of Chagas, Meymandi said she is still working as a volunteer at Olive View-UCLA Medical Center in Los Angeles, where the center was based, to ensure her patients receive care. "The political leadership has stopped supporting the center, and we no longer actively conduct tests," Meymandi said. Now, she refers Chagas patients to the cardiology clinic.

A spokesperson for the county's Department of Public Health wrote in a statement that the center is not technically closed, and that treatment of Chagas patients with heart conditions had been taken over by the cardiology department at the UCLA hospital. But at least for now it is not offering general screening for Chagas infection. California has the most Chagas cases of any state.

Another hope for beating Chagas lies in new drugs. Rick Tarleton, the head of the Tarleton Research Group in the University of Georgia's Department of Cellular Biology, said his group had collaborated with Anacor Pharmaceuticals to identify and optimize compounds that could kill the T. cruzi parasites. They had found one.

"It could completely eradicate the infection in mice and in nonhuman primates," Tarleton said.

The team tested the compound on 19 macaques at a research center in Texas that had acquired the parasite naturally. The infection was defeated, the monkeys had no significant side effects, and they are still clinically healthy after more than five years.

Tarleton's team also observed that some of the parasites can become dormant, making them resistant to drug treatment. As a result, Tarleton said, it's critical not only to develop more effective drugs, but to optimize timing of treatments.

Tarleton and his team hope to launch a clinical trial of the compound next year.

There is also some hope on the political front. Sen. Cory Booker (D-N.J.) reintroduced the Study, Treat, Observe, and Prevent (STOP) Neglected Diseases of Poverty Act in February to address the growing health problem posed by maladies like Chagas spreading in low-income communities. The list also includes dengue fever, leprosy, and chikungunya.

"Whenever we go into low-income communities and look for these illnesses, we usually find them," said Peter Hotez, who worked with Booker's office on the legislation and is the dean of the National School of Tropical Medicine at Baylor College of Medicine. "Tragically, too often our nation ignores or neglects these communities, and we fail to look."

Meanwhile, Maira Gutiérrez, the patient who was lucky to have a diagnosis and a consistent treatment, has some advice for them: “Donate blood; at the very least, you’ll know if you have the parasite, and it’ll cost you nothing.”

This article was produced by KFF Health News, which publishes California Healthline, an editorially independent service of the California Health Care Foundation.