Health experts in California are sounding the alarm over a silent but deadly threat: Chagas disease, spread by the parasite-carrying “kissing bug.” Researchers estimate that as many as 100,000 people in the state could already be infected, most without knowing it.

What is the kissing bug, and why is it dangerous?

The insect behind the outbreak is the Triatomine bug, commonly known as the “kissing bug” because it often bites sleeping humans near the mouth, lips, or eyes.

• The bite itself is not lethal. The danger comes from the parasite it carries, Trypanosoma cruzi, which enters the bloodstream.
• Silent infection: Early symptoms mimic mild illnesses (fever, fatigue, body aches) or may not appear at all.
• Long-term risks: The parasite can remain dormant for years before causing severe complications, including heart failure, cardiac arrest, and stroke.

Health officials describe Chagas as “a disease that hides in plain sight,” often going unnoticed until it causes irreversible damage.

How widespread is Chagas disease in California?

The kissing bug was once limited to Mexico, Central America, and South America. But it has steadily spread across the United States and is now found in at least 30 states, including California.

• California cases: Researchers estimate 70,000–100,000 residents may be living with the parasite.
• US cases: Nationwide, about 280,000 people are believed to carry Chagas.
• Global cases: Nearly 8 million people are infected worldwide, primarily in Latin America.

The disease is more common in California due to the state’s large immigrant population from regions where Chagas is endemic. According to the California Health Department, 31 of 40 cases reported between 2013 and 2023 were traced to infections acquired outside the United States.

Which animals also carry the parasite?

Chagas disease isn’t confined to humans. In the US, researchers have detected the parasite in several mammals, which act as reservoirs:

• Wood rats
• Skunks
• Mice

This increases the risk of the parasite spreading further, as the bugs feed on both animals and humans.

How many species of kissing bugs live in the US?

Entomologists have identified about 12 species of kissing bugs across the country, with four found in California alone. These species thrive in rural and suburban environments, often hiding in cracks, under porches, or inside rodent nests.

Why is Chagas disease so hard to fight?

One of the biggest challenges is the lack of awareness. Many infected people never realize they are carriers until the disease reaches an advanced stage.

• No vaccine: Currently, there is no vaccine to prevent infection.
• Limited treatment: Two drugs, benznidazole and nifurtimox, can treat Chagas, but they are most effective in the early stages.
• Long dormancy: The parasite can quietly damage the body for decades, making detection difficult.

Researchers are urging the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) to classify Chagas as endemic in the US, which could accelerate funding for research, screening, and prevention programs.

How can people protect themselves?

Since there is no vaccine, prevention focuses on avoiding contact with the insect. Health officials recommend:

• Sealing cracks and gaps around homes.
• Installing screens on windows and doors.
• Avoiding sleeping in areas where bugs are common, especially outdoors.
• Keeping yards clean of woodpiles and debris where bugs and rodents may hide.

Public health experts emphasize that awareness is key. Identifying and treating Chagas disease early could save thousands of lives.

TL;DR

Nearly 100,000 Californians may be living with Chagas disease, a potentially fatal illness spread by the parasite-carrying “kissing bug.” The disease often shows no early symptoms but can lead to heart failure and stroke decades later. With no vaccine available, prevention and early detection are the only defenses.