Health authorities across the United States are increasingly concerned as cases of Chagas disease, which originates from South America, are being reported in at least eight states. Researchers from the Centers for Disease Control and Prevention (CDC) are set to classify this infectious disease as endemic. This classification would signify that Chagas disease is no longer just an imported tropical ailment but a persistent health risk within the U.S. This proposed change is significant, as it will impact the monitoring, research, and treatment strategies associated with the disease.
Chagas disease is caused by the Trypanosoma cruzi parasite, which is transmitted through the bite of certain predatory bugs, commonly known as kissing bugs. These insects tend to bite humans on the face, particularly on thinner-skinned areas, like the lips or eyelids. The danger lies not in the bite itself but in the feces of the bug, which contain the parasite. When individuals scratch the wound or rub their eyes, the Trypanosoma cruzi enters the body. Less frequently, infections can occur through blood transfusions, organ transplants, or from a mother to her child during pregnancy.
Chagas disease was named after the Brazilian physician Carlos Chagas, who first identified it in 1907. However, it is no longer confined to the tropics. Migration, blood transfusions, and global trade have facilitated its spread to Europe and North America. Current estimates suggest that there are approximately 6,000 infected individuals in Spain and several hundred thousand in the U.S. The World Health Organization (WHO) estimates that over seven million people worldwide are infected, resulting in about 10,000 deaths annually. The disease is particularly prevalent in impoverished regions of Latin America, prompting the WHO to classify it as a neglected disease. Recent data from the U.S. has prompted renewed international attention towards this potentially lethal disease.
Chagas disease manifests in two phases. Many individuals infected in the initial weeks or months may not exhibit any symptoms. However, some may experience vague symptoms such as fever, fatigue, or swelling near the bite site, often presenting as eyelid edema—a painless, one-sided swelling of the eyelid frequently accompanied by conjunctivitis. Although these symptoms often subside, the parasite can remain dormant in the body. After a prolonged period, which may last years, the chronic phase can emerge, leading to severe complications such as myocarditis, permanent heart failure, cardiac arrhythmias, and pathological enlargement of the esophagus and colon. Approximately 30% of those infected may develop such complications, with the WHO warning that without treatment, Chagas disease can be life-threatening, particularly for infants, children, and immunocompromised individuals.
During the acute phase of Chagas disease, the Trypanosoma cruzi parasite can be identified microscopically in the blood. In later stages, antibody tests become the primary diagnostic tool. Currently, there is no vaccine available for Chagas disease. Treatment typically involves two antiparasitic medications, Nifurtimox and Benznidazole, which are most effective during the acute phase. However, both drugs can produce severe side effects and may not be officially approved for use in the European Union. In the U.S., these medications are generally administered during inpatient treatment only. In chronic cases, treatment focuses on alleviating symptoms, as prevention of the disease remains a challenge.
Chagas disease does not only affect humans; it can also infect pets and wild animals. Species such as dogs, cats, rats, armadillos, and opossums are known hosts of the parasite. Recent reports from Texas and California indicate that infected dogs are becoming more common, suggesting that the pathogen is already well-established in southern regions of the U.S.
To prevent Chagas disease, experts recommend implementing strict measures against insect bites. In regions where the disease is prevalent, using insecticide-treated nets, sealing home walls, and specific pest control measures can be effective. For pets, veterinarians suggest medications used against fleas and ticks. Additionally, blood donations in many countries are now routinely screened for the Trypanosoma cruzi pathogen to minimize the risk of infection through blood transfusions.
As Chagas disease continues to be a significant public health concern, awareness and preventive measures are crucial in mitigating its impact in the United States and beyond.
