Articles on adoption, foster care, & pediatrics

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Testing for Chagas Disease?

A number of parents with children adopted from Guatemala have contacted us asking about a page on the CDC website that says that testing for Chagas disease "may be appropriate" for children adopted from many parts of Mexico, Central, and South America.

What is Chagas Disease?

Chagas disease (American trypanosomiasis, more good info here) is an infection caused by Trypanosoma cruziprotozoa that is most common in rural, impoverished regions of Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, Uruguay, and Venezuela. The following information is adapted from the AAP Red Book, a resource for pediatric infectious diseases.

T. cruzi parasites are transmitted through the feces of a kissing bug (how romantic) that tends to defecate while biting, and said poop gets rubbed into the bite or mucous membranes of the bitten. Acute infection is often asymptomatic, although children are more likely to show signs than adults. Acute infection may consist of a nodule, or chagoma, at the site of inoculation, or a swollen eyelid. Fever, enlarged lymph nodes, or malaise may develop; more serious acute symptoms are rare. Most cases of acute Chagas disease resolve in 1-3 months, followed by an indeterminate period of chronic, asymptomatic infection.

The worrisome part about Chagas disease is that in 20-30% of cases, serious heart or gastrointestinal complications develop many years (or decades) after the original infection. The heart problems can include enlarged heart, arrythmias, and congestive heart failure, and are possibly fatal. The GI problems may include dilated esophagus or colon. It is an important cause of death in South America, where it is estimated that 8-10 million people are infected. In the US, blood bank screening in areas of the US where donors were expected to have undiagnosed Chagas disease found 61 positive donors out of 150,000 samples.

Chagas can also be transmitted in utero, occasionally producing symptoms like low birthweight, enlarged liver or spleen, or brain inflammation with seizures or tremors. However, most congenitally infected infants are asymptomatic. If diagnosed, antitrypanosomal treatment available from the CDC is effective, and recommended for all cases of acute, congenital, reactivated and chronic Chagas disease in children under 18 years of age.

Chagas in International Adoptees?

So what should we do about children adopted from countries where trypanosomiasis is prevalent, who were potentially exposed either during pregnancy or from insect bites? I spoke with an expert at the CDC, who says that they added Chagas disease to the list of conditions that should be considered for adoptees when a few teenagers adopted from South/Central American countries screened positive for T. cruzi infection when donating blood. We do not have any firm numbers on the prevalence of chronic Chagas disease in internationally adopted children.

The International Adoption Center at Cincinnati Children's is conducting a study which may shed some light on the prevalence of Chagas in Guatemalan adoptees, but we still may not get definitive numbers, as the study uses a convenience sample rather than screening all adoptees as they come through (pretty hard to do for Guatemala, since they're here already). If you can get to Cincinnati, you may be eligible for their study.

If parents/providers are interested in screening a child adopted from one of the countries above, the CDC is willing to run the tests. There are regional differences in Chagas risk within each country, but it's often a bit fuzzy which region the birth mother and child came from, so the CDC is willing to test any child from those countries.

Testing for Chagas

There is no perfect test for Chagas chronic infection. Currently, antibody screening is what is recommended for adoptees over 1yo, since other Chagas testing (microscopy, PCR, etc.) is meant for active or recent infection. The CDC performs two antibody tests, combining an ELISA antibody screen with good sensitivity, and an IFA test with good specificity (well, leishmaniasis cross-reacts, but picking that up could be a good thing). Commercial labs currently tend to offer just one test. The Ortho ELISA currently used by blood banks is excellent, but while approved by the FDA, it has not yet been released commercially.

Your provider and lab will need to contact their State Health Dept about getting the samples to the CDC, but the CDC testing part is free. It should only take a few mL's of blood. Drawing, sending, & reporting the tests likely won't be free, though, and insurance companies may try to evade paying for that. If so, point them to the CDC website or the AAP Red Book's section on Medical Evaluation of International Adoptees:

Chagas disease is endemic throughout much of Mexico, Central America, and South America. Risk of Chagas disease varies by region within countries with endemic infection. Although the risk of Chagas disease is low in internationally adopted children from countries with endemic infection, treatment of infected children is highly effective. Countries with endemic Chagas disease include Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, Uruguay, and Venezuela. Transmission within countries with endemic infection is focal, but if a child comes from a country with endemic Chagas disease, testing for Trypanosoma cruzi should be considered. Serologic testing should be performed only in children 12 months of age or older because of the potential presence of maternal antibody.

For questions regarding diagnostic considerations, your providers can contact the Division of Parasitic Diseases Public (770-488-7775; email For questions about laboratory testing for parasitic diseases at CDC, they can email the lab directly at; however, all testing requests should be routed via the state health department. This website gives more detail on how to access DPDx services.

Should you test?

I honestly don't know. The experts don't have a firm recommendation. We don't know how common Chagas is in our adoptee population. There haven't been a lot of cases, but then we haven't really been testing, other than at blood banks. If diagnosed, it's treatable, and worth treating. On the other hand, it's a blood draw, may involve some cost, and there's the possibility of a false-positive result.

If it were my child, I might not rush them off to the lab for a test, but if we had another reason for a blood draw, I'd probably add this test. Otherwise, I think that since the risk of Chagas infection is felt to be low, and because there is typically a "grace period" of years before long-term complications happen, I would be comfortable waiting a few years for more data. After all, the results of the Cincinnati study may nudge this waffley recommendation one way or the other. But that's my opinion; as with all info and advice from the internets, please discuss this issue with your health provider.

As for parents who traveled to higher-risk countries, I've not read any recommendations that casual travelers with no symptoms of Chagas be screened, especially folks who didn't "go native" for extended periods of time.

Thanks to Susan Montgomery, DVM, MPH and Paul Lee, MD for their expertise!