The influx of insects carrying parasites from Mexico into Texas is on the rise, raising concerns about increased exposure to disease.

Known as ‘kissing bugs,’ these triatomine insects are being found in greater numbers near El Paso, and they are often hosts to Trypanosoma cruzi, the parasite responsible for causing Chagas disease.

Chagas disease, also referred to as American trypanosomiasis, is a chronic condition that can pose significant health risks. Approximately 230,000 Americans are affected, many of whom may be unaware due to the disease’s often silent symptoms and limited public knowledge and testing.

These nocturnal insects transmit the parasite through their bites. Infection occurs when the bug’s parasite-laden feces enter the body through the bite wound, eyes, or mucous membranes, often by accidental rubbing.

Chagas disease is prevalent across 21 countries in Latin America, from Argentina to Mexico, which is home to over 30 species of triatomine bugs. In contrast, the United States has just 10 species, creating a particular vulnerability in border states like Texas, New Mexico, and Arizona.

Globalization and migration have contributed to the spread of Chagas disease beyond its traditional boundaries, with cases increasingly reported in the US, Canada, Europe, Japan, and Australia, predominantly among migrants from endemic areas.

Researchers from the University of El Paso found that nearly 85 percent of kissing bugs they collected in the El Paso and Las Cruces, New Mexico areas were infected with the parasite, a sharp increase from a similar study completed seven years earlier that showed a 63 percent infection rate.

The bugs were found close to homes, hidden under patio furniture, firewood and in yards, not just in wild areas. This movement into residential spaces raises the risk of the disease spreading to people and pets along the border region.

Kissing bugs collected near the US-Mexico border in El Paso are testing positive for the Chagas parasite at a rising rate (stock)

Researchers collected kissing bugs over 10 months, from April 2024 to March 2025, from wild and residential areas around El Paso using special light traps placed about three feet off the ground in the desert landscape.

They dissected the captured bugs’ digestive tracts and extracted DNA. Using a highly sensitive molecular test, they checked this DNA for the specific parasite that causes Chagas disease.

Researchers found the bugs in the Franklin Mountains State park in natural shelters such as rock piles and dry creek beds. 

They also found them in urban backyards in El Paso under piles of wood, garden furniture and debris, as well as a garage in rural Las Cruces.

Testing 26 bugs revealed that 84.6 percent were infected with the Chagas parasite, higher than the 63.3 percent found in a previous study in 2017.

The results, published in the journal Epidemiology & Infection, prove that the dangerous bugs have settled in areas inhabited by people, which researchers said ‘underscores the increasing public health significance’ of Chagas disease.

Chagas is often asymptomatic for weeks or even months after initial infection, or with relatively mild, nonspecific symptoms such as fever, fatigue, body aches, headaches and rashes. A telltale sign is swelling of the area near the bite or where the infected feces were rubbed in.

This phase is usually mild but can be severe in young children or people with weakened immune systems.

This map shows that kissing bugs, the insects that spread Chagas disease, live throughout the southern US, Mexico, Central America and South America. In the southern US alone, eleven different species have been identified 

About 30 to 40 percent of infected people progress to a debilitating, decades-long, silent phase of disease characterized by irreversible changes to the heart, digestive system and the nervous system.

Two antiparasitic drugs are available: Benznidazole and Nifurtimox. They are highly effective in the acute phase, in cases of newborns with the virus and in reactivations, often due to a weakened immune system.

Chagas is a silent killer. The long latency period means many are unaware they are infected until severe organ damage appears. There is also a lack of awareness among patients and healthcare providers, especially in non-endemic countries like the US.

An estimated six to seven million people are infected worldwide, causing approximately 10,000 deaths annually. Death figures for the US are unknown.

While significant progress has been made in insect control in Latin America, it remains a major public health challenge with a growing global footprint.

The southwestern US, specifically Texas, New Mexico and Arizona is on the front line of what researchers referred to as a growing public health concern. While the US is home to roughly 10 species of kissing bugs, neighboring Mexico has more than 30.

This close proximity creates a unique risk. Constant travel across the border and similar desert environments allow both the insects and the parasite they carry to easily cross international borders.

In fact, infected bugs have been found throughout the southern US, from Florida to California.