Insects infected with parasites are spreading across the border intoTexasfrom Mexico in increasing numbers.
‘Kissing bugs,’ or triatomine insects,gathered at the southern borderclose to El Paso, Texas, are increasingly displaying infection from Trypanosoma cruzi, the parasite responsible for Chagas disease.
Chagas disease, alternatively referred to as American trypanosomiasis, is a severe long-term infection that affects approximately 230,000 individuals in the United States, many of whom are unaware they have it due to the absence of symptoms and the lack of public knowledge and screening.
Nocturnal kissing bugs that carry the parasite transmit it when they bite a person and leave their feces near the bite area. Infection occurs when the feces containing the parasite are unintentionally rubbed into the bite wound, eyes, or other mucous membranes.
It is found in 21 mainland Latin American countries, ranging from Argentina to Mexico, where there are over 30 triatomine species. The United States only has 10 species, leading to ‘vulnerability’ in border states such as Texas, New Mexico andArizona, experts say.
Owing to globalisation and movement of people, Chagas disease has beenmore frequently identified in the US, Canada, Europe, Japanand Australia, mainly among immigrants from areas where the parasite is common.
Scientists from the University of El Paso discovered that almost 85 percent of kissing bugs they gathered in El Paso and Las Cruces,New Mexicoregions were affected by the parasite, a significant rise compared to a previous study conducted seven years ago which reported a 63 percent infection rate.
The insects were discovered near residences, concealed beneath outdoor furniture, firewood, and in backyards, not solely in natural habitats. This encroachment into living areas increases the likelihood of the illness transmitting to humans and animals within the border area.
Scientists gathered kissing bugs over a period of 10 months, between April 2024 and March 2025, from both natural and urban environments near El Paso. They used specialized light traps positioned approximately three feet above the ground in the desert terrain.
They examined the digestive systems of the captured insects and isolated DNA. With an advanced molecular test, they analyzed this DNA for the particular parasite responsible for Chagas disease.
Scientists discovered the insects in the Franklin Mountains State Park within natural habitats like stone heaps and dry riverbeds.
They also discovered them in urban backyards in El Paso, beneath stacks of wood, garden furniture, and rubbish, as well as in a garage located in rural Las Cruces.
A test on 26 bugs showed that 84.6 percent were affected by the Chagas parasite, which is higher than the 63.3 percent reported in a 2017 study.
The findings, released in the journalEpidemiology & Infection, demonstrate that the harmful insects have established themselves in regions where humans reside, as researchers noted ’emphasizing the growing public health importance’ of Chagas disease.
Chagas may not show any symptoms for weeks or even months following the initial infection, or it might present with mild, general symptoms like fever, tiredness, muscle pains, headaches, and skin rashes. A distinctive indicator is swelling in the region around the bite or where the infected feces were rubbed into the skin.
This stage is typically mild but may become serious in young children or individuals with compromised immune systems.
Approximately 30 to 40 percent of those infected advance to a severe, long-term, hidden stage of the illness, marked by permanent damage to the heart, digestive system, and nervous system.
Two medications used to treat parasites are Benznidazole and Nifurtimox. These are very effective during the initial stage of the infection, in infants infected with the virus, and in cases where the condition recurs, typically because of a compromised immune system.
Chagas is a hidden threat. The extended period without symptoms often leads people to remain unaware of their infection until significant organ harm occurs. Additionally, there is limited knowledge among patients and medical professionals, particularly in countries where the disease is not common, such as the United States.
Around six to seven million individuals are affected globally, leading to roughly 10,000 fatalities each year. The death statistics in the United States remain unclear.
Although considerable advancements have been achieved in managing insects in Latin America, it continues to pose a significant public health issue with an expanding worldwide impact.
The southwestern region of the United States, particularly Texas, New Mexico, and Arizona, is at the forefront of a public health issue that scientists have identified as an increasing problem. Although the US is home to approximately 10 species of kissing bugs, Mexico has over 30.
This nearness poses a distinct danger. Frequent movement across the border and comparable desert conditions enable both the insects and the parasite they transmit to readily move between countries.
Indeed, contaminated insects have been discovered across the southern United States, ranging from Florida to California.
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