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

Chagas disease, often overlooked, has made its presence felt in California and 29 other states in the U.S. It claims more lives each year in Latin America than malaria, and current estimates suggest that around 300,000 people in the U.S. could be living with it unknowingly.

The disease generally remains dormant for years, surfacing suddenly when a person suffers a heart attack, stroke, or even death. Caused by the parasite Trypanosoma cruzi, it’s transmitted through the kissing bug, which is present in various regions, including California. Some studies indicate that roughly one-third of kissing bugs in places like Griffith Park harbor the parasite.

This situation has prompted a group of epidemiologists, researchers, and doctors to urge the World Health Organization and the Centers for Disease Control and Prevention to officially recognize the disease as endemic in the U.S. They believe that this acknowledgment could lead to greater awareness, education, and perhaps even more funding for public health initiatives aimed at a disease often stigmatized as one primarily affecting impoverished migrants from tropical regions.

Norman Beatty, a medical epidemiologist at the University of Florida, noted, “This is a disease that has been neglected and has been impacting Latin Americans for many decades. But it’s also here in the United States.”

Interestingly, Salvadore Hernandez, a cardiologist from Kaiser Permanente, shared a case of a young patient from Hollywood Hills who contracted Chagas without any international travel. This highlights how kissing bugs can inhabit even affluent neighborhoods.

The parasite is also found in local wildlife, like wood rats, skunks, and some species of bats and raccoons. Sarah Hamer, an epidemiologist at Texas A&M, emphasized the diverse range of animals affected: “Kissing bugs are pretty equal opportunity when it comes to who they take a blood meal from,” which means the range of T. cruzi carriers is quite extensive.

California hosts the largest population of Chagas-affected individuals in the U.S., estimated between 70,000 and 100,000. The state’s demographics play a significant role; it has many residents from regions where the disease is already endemic. However, the presence of both the parasite and its vector means some cases might originate locally.

A small study by California’s Department of Public Health revealed that about 78% of the reported cases between 2013 and 2023 were contracted abroad, though local transmissions could not be ruled out.

Currently, Chagas is not classified as a reportable disease in California, so health authorities do not systematically track it like they do for flu or Lyme disease. However, it is mandatory in Los Angeles and San Diego counties, with L.A. being the first to implement such reporting.

From 2019 to 2023, only about 18 cases were confirmed in L.A. County, though officials suspect many more cases remain undiagnosed. Most known cases were attributable to international travel, yet some seem to be acquired locally.

Gabriel Hamer, an entomologist at Texas A&M, remarked that confirmed cases in the U.S. represent “just the tip of the iceberg,” as no comprehensive reporting system exists, and active surveillance is lacking.

Many individuals discover their Chagas infection only when trying to donate blood. Take Janeice Smith, a retired teacher in Florida, who found out she had the disease in 2022 after being informed by her donation center. She suspects she contracted it back in 1966 during a family trip to Mexico when she returned home with troubling symptoms that went undiagnosed for decades.

Interestingly, Hamer also notes that the saliva of kissing bugs can provoke severe reactions unrelated to the parasite itself, while the chronic effects of the disease often lead to severe health issues that can mimic other cardiac and organ conditions. Consequently, patients often arrive at clinics suffering from symptoms like heart arrhythmia or seizures without prior screening for Chagas.

“The disease is definitely underdiagnosed,” Hernandez pointed out. “If we screened for it and caught it early, most patients could be cured. The problem is we don’t, and people end up dying or needing very costly treatments,” which could include organ transplants.

Antiparasitic treatments are available to halt disease progression.

Chagas is also found in dogs, exhibiting similar clinical symptoms such as heart complications. Dr. Ashley Saunders from Texas A&M noted that younger dogs often suffer significantly, sometimes succumbing to acute infections, while older dogs might show chronic heart issues.

Many infected dogs acquire the disease by ingesting kissing bugs, which present a far greater risk than simple exposure to the parasites through bites.