Chagas disease is one of the most insidious diseases you've likely never heard of, yet it is alarmingly present in California and 29 other states across the United States. Each year, this disease claims more lives in Latin America than malaria, and current estimates suggest that approximately 300,000 people in the U.S. are living with Chagas without even realizing it. This is largely because the illness can remain dormant for years, often revealing itself only when it leads to severe health issues like heart attacks, strokes, or even death.
Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted through a bloodsucking insect known as the kissing bug. In the United States, there are about a dozen species of kissing bugs, with four identified in California as potential carriers of this dangerous parasite. Research conducted in locations such as Griffith Park in Los Angeles indicates that roughly one-third of all kissing bugs in the area harbor the Chagas parasite.
In light of these findings, a coalition of epidemiologists, researchers, and medical professionals is urging the World Health Organization and the Centers for Disease Control and Prevention to officially classify Chagas disease as endemic in the United States. This designation would help raise public awareness, foster education on the disease, and potentially lead to increased public health funding to combat a condition that has long been stigmatized as solely affecting poor, rural migrants from tropical regions.
Norman Beatty, a medical epidemiologist at the University of Florida, emphasizes, “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.”
Surprisingly, Chagas disease has been diagnosed in affluent areas, as evidenced by a case involving a child from the Hollywood Hills who contracted the disease without ever leaving the country. This highlights the presence of kissing bugs in suburban environments, where they can infect local wildlife such as wood rats, skunks, and even black bears.
In California, it is estimated that between 70,000 and 100,000 people are infected with Chagas disease. While a significant portion of these cases stems from individuals originating from countries where the disease is endemic, local transmission cannot be completely ruled out. A small study by the state's Department of Public Health revealed that 31 out of 40 reported human cases between 2013 and 2023—approximately 78%—were acquired abroad, suggesting that some cases may be home-grown.
Chagas disease is not currently classified as a reportable disease in California, meaning that healthcare providers are not mandated to report or investigate cases as they do for other diseases like influenza or Lyme disease. However, in Los Angeles and San Diego counties, Chagas is reportable. Between 2019 and 2023, L.A. County confirmed about 18 cases of Chagas disease, but health officials believe that many more cases go undiagnosed.
According to Gabriel Hamer, an entomologist at Texas A&M University, confirmed cases in the U.S. represent just the tip of the iceberg. The lack of a standardized reporting system and active surveillance makes it difficult to determine the true prevalence of Chagas disease. Most individuals discover their infection only when attempting to donate blood, as was the case for Janeice Smith, a retired teacher from Florida, who learned about her condition long after her initial infection.
The symptoms of Chagas disease can often mirror those of other cardiac conditions, leading many to visit doctors with undiagnosed heart arrhythmias, swollen esophagus, seizures, and strokes. “The disease is definitely underdiagnosed,” says Dr. Salvadore Hernandez, a cardiologist with Kaiser Permanente. “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 requiring extremely expensive care, including organ transplants and surgery.”
Chagas disease is also a concern for pets, particularly dogs, which can exhibit symptoms similar to those seen in humans, such as heart failure and arrhythmias. According to Ashley Saunders, a veterinary cardiologist at Texas A&M, dogs often contract the disease by ingesting kissing bugs, which can deliver a higher dose of the parasite than mere contact.
In summary, Chagas disease poses a significant public health challenge in California and beyond. Increased awareness, education, and improved screening practices are essential for managing this neglected disease and preventing its potentially severe consequences.
