Details of First Locally-Acquired Case of Chagas Disease in Missouri

In May 2019, the US Centers for Disease Control and Prevention (CDC) published details on the first detection of Triatoma sanguisuga—the insect vector for Chagas disease causing parasites—in Delaware.

While locally-acquired Chagas disease is rare in the United States, its precise impact is hard to quantify because few states have active surveillance measures in place. However, the CDC has recommended that more states with frequent travelers to/from countries where Chagas disease is endemic (such as Bolivia) introduce surveillance measures.

The CDC’s Morbidity and Mortality Weekly Report includes an article from Missouri health officials detailing an incident in their state in which a blood donation sample screened positive for antibodies to Chagas-causing Trypanosoma cruzi parasites. The case marks what is likely the first documented locally-acquired case of Chagas disease in Missouri.

The Missouri Department of Health and Senior Services was first notified of a potential case of Chagas disease in a Missouri woman on December 13, 2017. The 53-year-old patient had visited her local blood donation center in October 2017. An Abbott Prism Chagas screening test indicated the blood sample positive for antibodies to T cruzi. A further confirmatory multistep enzyme strip immunoassay test also returned a positive result.

The patient was not aware of any relevant insect bites. She had briefly crossed the Mexican border 28 years prior, but did not recall any medical incidents during the trip.

After further testing, an electrocardiogram was obtained due to the potential for T cruzi infection to cause cardiomyopathy. The electrocardiogram showed arrhythmias, including primary atrioventricular block. She also underwent an echocardiography which showed mild concentric left ventricular hypertrophy.

Both findings were consistent with chronic T cruzi infection. The individual completed a 60-day course of benznidazole to treat Chagas disease.

The patient had lived in Missouri for the entirety of her life. She did not report seeing triatomine bugs at any property she had lived at, though her husband recalled seeing some insects consistent with digital images of the bugs without being able to recall when or where.

“In Missouri, Triatoma sanguisuga vectors have been identified during 2012—2016 and as recently as July 2019,” the authors wrote.

T cruzi transmission involving triatomine and wild animal reservoirs has been documented in the southern United States for approximately 150 years. There are roughly 300,000 people likely living with Chagas disease in the United States, but only 28 locally-acquired infections have been confirmed and documented between 1955 and 2015.

“The likely autochthonous case described in this report underscores importance of health care provider awareness of possible Chagas disease even in the states considered low risk for this infection and need for the careful consideration of the patient’s history to identify possible risks for T cruzi infection,” authors concluded.