Some of the symptoms are relatively generic—fever, headache, fatigue—but that’s actually one of the risks for patients infected with Chagas disease, which can cause stroke and heart failure if it’s not caught and treated in time. If you have patients with those common complaints, look further to see if they have a rash or swelling without an explanation; if so, consider sending out a blood smear for analysis or referring them for testing immediately. Chagas is introduced into the body by a parasite, Trypanosoma cruzi, but it’s not the bite that’s dangerous—it’s the resultant feces. Once it’s fed on its host, it tends to defecate; infection occurs if the feces winds up in the bite wound, or is transferred to the patient’s eye through rubbing. An estimated 300,000 Americans in 27 states—all in the lower half of the country, for some reasons—already have it. The acute phase can last for weeks or months, during which antiparasitic medication has a success rate of 60%─90%. The chronic stage is marked by entry into the heart and digestive muscles, at which point Chagas disease is incurable. Medication may be successful in slowing down its progression in patients 50 years of age and under, however. As such, early diagnosis is essential for the best chance of a positive outcome.