In the shadows of public awareness lies Chagas disease, one of the most insidious illnesses affecting millions. Although it kills more people in Latin America than malaria each year, the disease has largely flown under the radar in the United States. Currently, an estimated 300,000 people in the U.S. may be living with Chagas disease without even realizing it, as the illness often remains dormant for years. This delayed onset can result in devastating health outcomes, including heart attacks, strokes, or even death.
Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted primarily through the bite of an insect known as the kissing bug. In the United States, there are approximately a dozen species of kissing bugs, with four identified in California that are known carriers of this dangerous parasite. Recent studies indicate that in specific locations, such as Griffith Park in Los Angeles, nearly one-third of these kissing bugs are infected with the Chagas parasite.
“This is a disease that has been neglected and has been impacting Latin Americans for many decades,” noted Dr. Norman Beatty, a medical epidemiologist at the University of Florida and a leading expert on Chagas. He emphasized, “But it’s also here in the United States.”
Chagas disease is not solely confined to specific demographics or regions. Recent cases have emerged across various communities, including upscale neighborhoods. Dr. Salvadore Hernandez, a cardiologist with Kaiser Permanente in Northern California, shared a striking case involving a child from Hollywood Hills who contracted the disease without ever having traveled outside the country. This indicates that local transmission is a genuine risk.
The parasite has also been found in local wildlife, including wood rats, skunks, and mice in Griffith Park, as well as bats, raccoons, and black bears in other areas of California. “Kissing bugs are pretty equal opportunity when it comes to who they take a blood meal from,” explained Dr. Sarah Hamer, an epidemiologist at Texas A&M University. This broad range of potential hosts means that the reservoir for T. cruzi is extensive, complicating efforts to control its spread.
California has the highest number of Chagas disease cases in the U.S., with estimates ranging from 70,000 to 100,000 infected individuals. This prevalence is attributed to the state’s significant population of residents from endemic countries, in addition to the presence of both the parasite and its vector. A small study by California’s Department of Public Health revealed that between 2013 and 2023, approximately 78% of reported cases were acquired abroad; however, local transmission could not be ruled out for the remaining cases.
Chagas disease is not classified as a reportable disease in California, meaning physicians and health systems aren't mandated to report cases, unlike other diseases such as influenza or Lyme disease. However, some counties, including Los Angeles and San Diego, do require reporting. From 2019 to 2023, about 18 cases were confirmed in Los Angeles County, though many cases likely remain undiagnosed and unreported.
Dr. Gabriel Hamer, an entomologist at Texas A&M, emphasized that the confirmed cases represent “just the tip of the iceberg.” The absence of a standardized reporting system and active surveillance complicates efforts to assess the true prevalence of Chagas disease in the U.S.
Many individuals only discover their Chagas infection when they attempt to donate blood. For instance, Janeice Smith, a retired teacher in Florida, found out she had the disease in 2022 after a notification from her local blood donation center. Smith believes she contracted the disease during a family vacation in Mexico in 1966, when she experienced severe symptoms that went undiagnosed for decades.
While some acute reactions, such as swollen limbs and eyes, can be caused by the kissing bugs’ saliva, the chronic effects of Chagas disease can be much more severe. Symptoms often mimic other forms of cardiac damage, leading to misdiagnosis and late treatment. Dr. Hernandez emphasized the urgent need for screening, stating, “If we screened for it and caught it early, most patients could be cured.”
Chagas disease is not confined to humans; it also affects our canine companions. Dr. Ashley Saunders, a veterinary cardiologist at Texas A&M, explained that young dogs can show severe symptoms, including heart failure and arrhythmias. These pets often contract the disease by ingesting kissing bugs, which deliver a significant dose of the parasite.
As awareness of Chagas disease grows, it is crucial to recognize its presence in both humans and animals. With early detection and treatment, the impacts of this hidden disease can be significantly mitigated, saving lives and improving health outcomes.
