Chagas Disease: An Overlooked Threat in the U.S.

While studying wildlife diseases in Illinois, I stumbled upon something shocking: over half of the raccoons I examined were infected with Trypanosoma cruzi, the parasite responsible for Chagas disease.

You might not know much about this disease. Though it’s often classified as a neglected tropical disease, it’s no longer just a concern for tropical regions. It’s gradually making its way into the U.S., quietly affecting wildlife.

Chagas disease has a sneaky way of operating, remaining dormant in humans for years before manifesting serious health issues like heart failure, stroke, arrhythmias, or even sudden death. Once you start noticing symptoms, it’s usually too late to reverse the damage. The parasite is primarily spread by triatomine bugs, or “kissing bugs,” that feed on infected animals like raccoons and opossums. They defecate near their bite, and if that feces gets into broken skin or mucous membranes, humans can become infected. There are also rare cases where it spreads through organ transplants, blood transfusions, or congenital exposure.

Even though Chagas is a significant public health issue in Latin America, it’s largely ignored here. The Centers for Disease Control and Prevention (CDC) estimates that around 300,000 people in the U.S. are infected with Trypanosoma cruzi. Many of them are immigrants from regions where the disease is common, yet most have no idea they carry it.

There’s this outdated notion that Chagas only affects immigrants or travelers, but my research reveals that T. cruzi is circulating actively among U.S. wildlife. Studies have confirmed the presence of infected kissing bugs and mammalian hosts in Texas, California, Louisiana, and more recently, the Midwest.

While having T. cruzi in raccoons and triatomine bugs doesn’t automatically mean humans will be infected, the conditions certainly allow for it. Some research has already confirmed nearly 90 locally acquired cases between 2000 and 2020, mostly in Texas, but also in Arkansas, Missouri, Louisiana, and California. A recent study in Florida found that about 35% of triatomine bugs collected inside homes tested positive for T. cruzi, with 23% having fed on humans, indicating ongoing contact that could lead to unnoticed transmission. Another study in 2022 estimated around 10,000 cases acquired locally in the U.S.

Although reported cases remain relatively rare, concerns are growing that they could become more common.

A report from the University of Florida suggests that people living in proximity to wooded areas or those with features like dog shelters or stacked firewood may have a higher risk of encountering infected bugs. These environments provide perfect hiding spots and blood sources for them, increasing the likelihood of them entering homes. With climate change and land development changing ecosystems, awareness and monitoring of these risks is essential.

The unpreparedness is troubling. Most U.S. physicians don’t consider Chagas disease when diagnosing patients. Routine testing for it is nearly non-existent, and most infections are discovered incidentally, often during blood screening. By that time, it’s frequently too late.

Even among those aware of Chagas, there’s a belief that it’s still rare or only an import issue. My own fieldwork tells a different story. If raccoons in rural Illinois are carrying this parasite in high numbers, what does that mean for human exposure? Hunters, campers, agricultural workers—those living in rural and wooded areas are all at potential risk, especially with the spread of triatomine bugs due to environmental changes.

The CDC has provided some data and guidelines on T. cruzi, but many in the clinical community remain oblivious to its relevance in the U.S. This gap in knowledge is both dangerous and avoidable. Each year we wait to act, we miss chances for early detection, treatment, and public education.

To clarify, Chagas disease is treatable if caught early. Medications like benznidazole can help reduce the parasite load and prevent further complications, particularly for children and newly infected individuals. But we first need to acknowledge its presence here and implement appropriate testing.

It’s not about creating panic, but focusing on preparation. What we need is:

• Awareness campaigns to educate both clinicians and the public
• Expanded access to diagnostics in high-risk areas
• Targeted screenings for patients with unexplained cardiac issues in endemic regions
• Continued wildlife surveillance to keep track of the spread

Throughout my research, I’ve learned that the divide between neglected and recognized diseases is not biological—it’s about attention. Chagas has all the markers of a looming public health crisis: silent spread, climate-driven expansion, minimal awareness, and significant long-term health repercussions. What it lacks is urgency.

We’ve seen this pattern before—COVID-19, mpox, and now emerging tick-borne diseases, all stemming from the complex interplay between humans, wildlife, and environmental change. Trypanosoma cruzi fits into this narrative. It’s not a question of whether this will become a larger issue in the U.S., but rather when, and whether we’ll be prepared for it. It’s time we stop underestimating Chagas disease and start treating it like the real threat it represents.