Kissing bug disease spreads in the USA

US health authorities are alarmed: Chagas disease, which originated in South America, is increasingly spreading in the United States . It has already been detected in at least eight states.

Researchers at the Centers for Disease Control and Prevention (CDC) now want to officially classify the infectious disease as endemic .

This isn't just a medical formality, but a wake-up call: The disease is no longer considered merely an imported tropical disease, but a permanently present health threat in the country itself. The planned classification would have far-reaching consequences for surveillance, research, and treatment.

The "kiss" of the bug

The disease is transmitted by the parasite Trypanosoma cruzi, which is found in certain species of assassin bugs. The insect is nicknamed the "kissing bug" because it prefers to bite the face while sleeping—on thin-skinned areas such as the lips or eyelids.

It's not the bite itself that's dangerous, but the bug's feces, which contains the pathogen. The parasite enters the body by scratching the bite or rubbing the eyes. Less commonly, infection occurs through blood transfusions, organ transplants, or from mother to child during pregnancy.

WHO warns of neglected danger

The disease was named after the Brazilian physician Carlos Chagas, who discovered it in 1907. Chagas is no longer a distant tropical disease . Through migration, blood transfusions, and global trade routes, Chagas disease has also spread to Europe and North America. In Spain, for example, it is estimated that around 6,000 people are infected, and in the USA, several hundred thousand.

The World Health Organization (WHO) estimates that over seven million people worldwide are infected with the pathogen , and that around 10,000 die annually as a result of the infection. The disease is particularly prevalent in poor regions of Latin America, which is why the WHO classifies it as a "neglected disease." With the new data from the USA, this potentially deadly "disease of the poor" is now receiving increased international attention.

What symptoms occur?

The infection progresses in two phases: Many affected individuals do not notice anything during the first weeks or months after infection. Some develop nonspecific symptoms such as fever, fatigue, or swelling at the bite site, typically eyelid edema, a painless, unilateral swelling of the eyelid, often accompanied by conjunctivitis. As the infection progresses, these symptoms usually disappear, but the parasite remains in the body.

After a latent phase, sometimes lasting years, the chronic form can break out, resulting in serious consequences: myocarditis, permanent heart failure, and cardiac arrhythmias have been documented, as has pathological dilation of the esophagus and colon. Up to 30 percent of infected individuals develop such complications.

The WHO warns that without treatment the disease can be fatal, especially for infants, children or immunocompromised individuals.

How is Chagas treated?

In the acute phase, the parasite can be detected microscopically in the blood. In later stages, antibody tests are the most important diagnostic tool.

There is currently no vaccine. Treatment relies on two antiparasitic drugs, nifurtimox and benznidazole, which are particularly effective during the acute phase.

However, both drugs can cause severe side effects and are not yet officially approved for the treatment of Chagas disease, for example, in the European Union . In the United States, the drugs can generally only be administered under inpatient supervision. In chronic cases, the therapy only alleviates the consequences; to date, the disease can hardly be prevented.

Domestic and wild animals can also become infected

Not only humans are sought-after victims: dogs, cats , rats, armadillos and opossums are considered important hosts.

There are now increasing reports of infections in dogs, especially in Texas and California - an indication that the pathogen's circulation has already become established in the southern United States.

How can you protect yourself from Chagas?

To prevent infection, experts recommend consistent insect protection: In affected regions, nets treated with insecticides, sealing house walls, and targeted pest control are helpful.

For pets, veterinarians recommend products that also protect against fleas and ticks. Blood donations are now routinely tested for the pathogen in many countries to prevent transmission through transfusions.