Chagas: An Unfamiliar and Emerging Disease

Ms. Stevens is a 32-year-old humanitarian aid worker. She recently returned to the United States after spending a month volunteering in rural Guatemala, where she was assisting with community housing construction. She reports having had multiple insect bites during her stay and occasional insects in her sleeping quarters. Six months after returning to the U.S., she developed intermittent low-grade fevers, malaise, and mild right eyelid swelling.

Chagas disease—also called American trypanosomiasis—is a potentially life‑threatening infection caused by the parasite Trypanosoma cruzi. The parasite is transmitted primarily through contact with an infected “kissing bug.” Transmission occurs when an infected bug feeds at night and defecates near the bite.

The bitten individual scratches or rubs the bite site and enables the parasites to enter the skin, or the eyes if rubbed. Other transmission routes include congenital (mother‑to‑fetus), blood transfusion, organ transplantation, laboratory accidents, and foodborne outbreaks from contaminated juices or foods. Illness has an acute phase that is often mild or asymptomatic and a chronic phase that can manifest decades later with a variety of cardiac and gastrointestinal symptoms.

Global and U.S. epidemiology

Although many of us have never heard of Chagas disease, globally more than 7 to 8 million people are estimated to be infected, with most living in the 21 endemic countries of continental Latin America. Migration has expanded the infection’s reach, with cases now detected in at least 44 countries, including the United States and many European nations. The Centers for Disease Control and Prevention (CDC) estimates that as many as 300,000 people are living with Chagas disease in the United States, many undiagnosed. Chagas is what is known as a ‘neglected’ tropical disease.’ These are a group of infectious diseases that primarily affect impoverished populations in tropical and subtropical regions of the world. They are often neglected due to a lack of attention, research, and funding, despite their significant impact on public health.

Current cases and notifiability in the United States

Most infections in the United States are believed to be imported among immigrants from endemic countries; however, locally acquired cases continue to be identified annually in some states. Eight U.S. states and some local jurisdictions list Chagas disease as reportable, but the absence of nationwide mandatory reporting complicates precise incidence estimates. Congenital transmission is a recognized route in the United States; the CDC estimates that about 40,000 women of childbearing age in the U.S. have Chagas disease, and targeted maternal–infant testing is advised.

Clinical recognition for nurses

Acute disease may present with fever, malaise, lymphadenopathy, hepatosplenomegaly, and sometimes Romaña’s sign (unilateral eyelid edema). Chronic infection is often silent until cardiac (conduction defects, arrhythmias, cardiomyopathy with apical aneurysm, heart failure, thromboembolism) or digestive (megaesophagus/megacolon) disease appears. For infants of at‑risk mothers, arrange maternal–infant testing and prompt treatment of congenital cases for high cure rates.

Diagnosis and treatment

Diagnosis usually requires serologic testing for chronic infection and PCR testing is useful in acute, congenital, or reactivated cases. Two antiparasitic drugs (benznidazole and nifurtimox [Lampit]) are available for treatment in the United States, but are less effective when given after the acute phase of the disease. Each drug has specific indications for use in children, and each may be contraindicated for individuals above certain ages and/or with certain preexisting conditions and sensitivities, since adverse effects are common.

Prevention and travel advice for nurses and families

There is no vaccine. Prevention focuses on avoiding contact with the insect and reducing non‑vector transmission through activities such as food safety. When traveling in endemic regions, choose well‑constructed lodging with intact screens/air‑conditioning; use bed nets treated with long‑lasting insecticide; apply EPA‑registered repellents (e.g., DEET); wear long sleeves/pants; and keep doors/windows closed at night. Avoid unpasteurized juices and foods that may be contaminated; wash/peel fruits and maintain food hygiene. Do not sleep in homes with thatched/adobe walls or cracks without protective measures; keep bags off floors/walls and check bedding for insects. In the U.S., advise at‑risk pregnant patients about screening, and encourage follow‑up if notified after blood donation of a reactive T. cruzi screen.

What nurses should know and teach

• Recognize risk, particularly during international travel.
• Practice prevention through use of insect repellent and protective clothing.
• Be aware of food safety practices.
• Consider Chagas disease as a risk factor among patients born outside the U.S. or those traveling to areas where Chagas disease has been identified.
• If a patient with Chagas disease is hospitalized, standard precautions are appropriate. It is not transmitted through routine or casual contact and is not transmissible like colds and flu.
• Chagas can be transmitted from mother to fetus, through blood transfusion and organ transplantation. Transmission by laboratory accident has also been reported.
• Be prepared to provide basic education regarding Chagas disease to patients who have questions or in whom testing may have been performed. Groups planning international travel for vacation, missions, humanitarian work, adoption, or study abroad should be education on prevention if they are traveling to areas where Chagas disease has been identified or risk is present.
• As recognition of the importance of Chagas disease is emerging, there are a variety of resources available through the CDC and the World Health Organization (WHO).

Ruth Carrico, PhD, FNP-C, CIC, FSHEA, FNAP, FAAN, adjunct professor, Division of Infectious Diseases, University of Louisville School of Medicine, Louisville, KY. Her last post for this blog was “Ticks and Tick-Borne Diseases: A Comprehensive Nursing-Focused Overview.”