- Dorsal view of Triatoma infestans, a vector for American trypanosomiasis - Reprinted with permission from Centers for Disease Control and the World Health Organization
Chagas disease (American trypanosomiasis) has two phases— acute and chronic. Antiparasitic therapy will result in microbiologic cure when the patient takes it during the acute phase of the disease. If the patient does not receive medication during the acute phase, symptoms will resolve; however, the infection will continue for several decades and very likely for the lifetime (Centers for Disease Control, 2010).
Acute and Chronic Phases
The acute phase of American trypanosomiasis takes place during the initial weeks or months of the infection. There may be fever, fatigue, body aches, headache, rash, loss of appetite, diarrhea, and vomiting. Liver or spleen enlargement may occur as well as swelling of the lymph glands. At the location where the parasite entered the body for the initial infection, the patient may experience swelling; this lesion is a chagoma.
If the patient rubs his or her eye after the bite of the triatomine bug, swelling of the eyelids may occur on that same side. This clinical observation is Romaña’s sign, and it may also occur when the insect bite is near the eye.
In the chronic phase of American trypanosomiasis, the infection tends to be silent. However, the patient may develop serious medical complications over the next several decades. These may include cardiac disease in which there is gradual destruction of the heart muscle over many years. This may lead to congestive heart failure or sudden cardiac death.
The cardiovascular complications will likely necessitate a referral to a cardiologist as these patients may need a cardiac pacemaker or other therapies for rhythm disturbances of the heart. They may also develop gastrointestinal problems, and a gastroenterology consultation may be in order as well.
Antiparasitic Therapy
Consultation with a specialist in infectious diseases may be advisable too as the antiparasitic drugs benznidazole and nifurtimox are not standard agents in the United States. In fact, the physician must obtain them from the Centers for Disease Control in that country. The use of these drugs is a medical contraindication in patients who have liver or kidney disease, and since their safety for infants is not certain, women should withhold breastfeeding while they take this medication.
Pregnant women, therefore, should not take these antiparasitic agents, and individuals with neurologic or psychiatric disorders should not receive them.
Nevertheless, it is clear that early diagnosis of American trypanosomiasis will yield the best clinical outcome. In fact, the initiation of treatment within the acute phase of the disease will lead to a complete cure without any adverse sequelae or complications from the condition.
Sources
- Centers for Disease Control. (2010). Parasites—American trypanosomiasis (also known as Chagas disease). Retrieved January 27, 2012.
- World Health Organization. (2010). Chagas disease (American trypanosomiasis). Retrieved January 27, 2012.
Disclaimer: The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact their physician for advice.
Michael Koger - Dr. Koger obtained his medical education at Meharry Medical College and specialized in Internal Medicine.
