San Diego's First Homegrown Chagas Case Raises Alarm About Kissing Bug Risk

A Parasite That Hides in Plain Sight

San Diego County health officials have confirmed the region's first locally acquired case of Chagas disease — identified during routine blood donation screening in a donor who had no symptoms. The announcement, made on Monday, July 7, sent a clear signal: a disease long dismissed as a distant Latin American problem has quietly established a foothold in Southern California.

Chagas is a parasitic infection primarily spread by triatomine bugs, colloquially known as "kissing bugs" because they tend to bite humans on the face near the mouth or eyes while they sleep. Infection only occurs when the bug's feces get into the bite wound, eyes, or mouth by scratching or rubbing. It's a slow, stealthy disease — and that's exactly what makes it so dangerous.

What Makes This Case Different

San Diego County made Chagas disease locally reportable in 2024 to better track its presence and raise awareness among local medical professionals. Since implementing the rule, the county has received 22 reports. Of those, four were confirmed — and this fourth confirmed case marks the first to be locally acquired. In other words, the infected person didn't travel to a country where Chagas is endemic. They got it here, at home.

Chagas is much more common in rural areas of Latin America, where the kissing bug hides in homes made of mud and straw. But the bug species found in San Diego County typically lives in rodent nests, making camping and outdoor exposure potential risk factors. This ecological difference shifts the risk profile for local residents toward outdoor activities like camping and hiking, officials said. Weekend hikers and campers, take note.

The Silent Long-Term Threat

Chagas disease, caused by the parasite Trypanosoma cruzi, is notoriously difficult to detect without targeted screening. Early stages of the infection are often asymptomatic or present with mild, flu-like symptoms — fever, headache, cough, abdominal pain, and swelling at the site of the insect bite. Because these symptoms mirror common viruses, many infections go unnoticed.

The real danger comes later, in the chronic phase, which can last years or even a lifetime. Most remain symptom-free — but some develop serious health problems. One to three decades after infection, up to a third suffer heart issues, while about 1 in 10 face digestive problems like an enlarged esophagus or colon. If untreated, the disease can also be passed to infants during pregnancy.

What Residents Should Do Now

"Identifying a locally acquired Chagas case reminds us that this disease is not limited to Latin America," said Dr. Sayone Thihalilopavan, county public health officer. "Our priority is making sure residents and healthcare providers have the information they need to stay protected." The American Heart Association estimates that around 300,000 people in the U.S. already have Chagas disease, and while most cases have been in the South, these bloodsuckers are steadily creeping north.

Treatment of Chagas disease involves a multi-faceted approach, including antiparasitic medications and targeted therapy if it has affected a person's organs. Health officials recommend that travelers to Chagas-endemic areas wear protective clothing and insect repellent, use insecticide-treated bed nets, sleep indoors, and avoid eating unpeeled or uncooked fruits and vegetables. People who have lived in Latin American countries should also consider being screened, especially pregnant women. There is currently no vaccine or medicine that can prevent Chagas disease — which makes awareness and early detection all the more critical. As San Diego's outdoor culture continues to draw residents into the foothills and wilderness where kissing bugs thrive, this first locally acquired case is unlikely to be the last.