Chagas Disease

Approximately 8 million people worldwide are infected by the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease. After a latent period that can last years or decades, 10% to 30% of infected people develop serious complications, such as cardiomyopathy or gastrointestinal dysfunction. Contrary to popular belief, Chagas disease is not solely a vector-borne infection of Latin America. Clinicians in nonendemic regions must be aware of the potential for childhood T cruzi infections. Humans typically acquire the parasite through contact with the infected feces of blood-feeding triatomine insects. Vector-mediated transmission occurs in endemic regions that extend from the southern United States to the southern cone of South America. T cruzi can also be transmitted in food and beverages contaminated with triatomine feces, via infected organ transplants and blood transfusions, and vertically from mother to child. In the United States, human contact with triatomines isminimal, and blood donations are screened for Tcruzi. However, more than 300,000 US residents, mostly immigrants from Latin America, may harbor chronic T cruzi infections. Many of those infected are children and reproductive-age women. Vertical transmission is an underrecognized problem. Children born to infected mothers have an approximately 5% chance of acquiring the parasite. Although there has been only one reported case of congenital Tcruzi infection in the United States (in an infant born in 2010 to a Bolivian mother), several hundred undetected congenital T cruzi infections are estimated to occur in the United States each year. Diagnosis is difficult becausemost infected newborns are asymptomatic. A minority of infected infants demonstrate nonspecific signs and symptoms, including low Apgar scores, low birthweight, respiratory distress, hepatosplenomegaly, anasarca, pericardial and pleural effusions, and meningoencephalitis. The presentation can easily be confused with neonatal sepsis or TORCH infections (which include toxoplasmosis, rubella, cytomegalovirus, and herpes viruses). Clinicians may overlook T cruzi in the differential diagnosis, especially in nonendemic areas. To improve detection of congenital infections, the World Health Organization recommends antenatal T cruzi screening in all pregnant women who have ever lived or received a blood transfusion in an endemic region. Infected women are not treated prenatally to prevent vertical transmission because antitrypanosomal medications are contraindicated during pregnancy and breastfeeding. Instead, children born to T cruzi-infected mothers should be tested during infancy and treated if necessary. Unfortunately, prenatal screening recommendations are not widely followed, even in endemic countries. Many at-risk infants are born to mothers with unknown Tcruzi status. Pediatricians should consider testing these newborns forTcruzi, especially if they are symptomatic. Diagnostic testing should AUTHOR DISCLOSURE Dr Tustin has disclosed no financial relationships relevant to this article. Dr Bowman has disclosed that she receives grant support from NIH (NIAID) and BWF/ASTMH to research Chagas disease (Grants K23 AI113197-02, P30 AI50410, and others). This commentary does contain a discussion of an unapproved/investigative use of a commercial product/device.