Chagas disease

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at April 29, 2016
StartDiseasesChagas disease

Chagas disease, which is also known as kissing bug disease, was first diagnosed in Brazil in the year 1909. It is caused by a parasite called Trypanosoma cruzi, which is transmitted to humans via the feces of the triatomine bugs. This disease is not transmitted from person to person.


Definition & Facts

Chagas disease is endemic in Latin America, especially in the more rural areas, but there has been migration to the more urban areas of Latin America and also to parts of the United States. The Centers for Disease Control and Prevention (CDC) has said that it is now found in 28 states in the US. It often occurs in areas with poor housing conditions. There are estimates of 8 million people in Latin America unknowingly having the disease.

Chagas disease has two phases: acute and chronic. Symptoms associated with either phase can range in severity - from having no symptoms at all to having life-threatening symptoms. The acute phase occurs after one has become infected and lasts for the first few weeks up to a few months. The chronic phase is an ongoing infection lasting decades that can be asymptomatic or involve severe complications.

Symptoms & Complaints

The telltale symptom of Chagas disease is Romana's sign. This is a swelling of the eyelids near where the bite that transmitted the infection occurred. Bug feces that accidentally entered the eye often times from rubbing or scratching can also be a cause of this.

Other symptoms that also occur during the acute phase include rashes, fever, nausea, and vomiting, headaches, body aches, fatigue, swollen lymph nodes, diarrhea, and mild swelling of the spleen and/or liver. Any symptoms present usually go away or diminish over a few weeks.

Even though there may be a lack of symptoms, infection may still persist if it goes untreated. Children and those with weakened immune systems can have severe symptoms, and although rare, even fatal symptoms can sometimes occur in the acute phase, so it is important to seek treatment.

The chronic phase can last for an entire lifetime and symptoms can range from nonexistent to severe. The symptoms tend to affect the cardiovascular system and gastrointestinal tract. Cardiac symptoms can include heart failure, heart palpitations, enlarged heart, irregular heartbeat, cardiac arrest which can lead to death, and stroke. Intestinal symptoms during the chronic phase can include pain in the abdomen, constipation, difficulty swallowing, enlarged colon, and enlarged esophagus.


There are a few different ways that people come down with Chagas disease, but the most common is through transmission from triatomine bugs. What happens is these bugs bite an infected animal or human and become infected. The parasite Trypanosoma Cruzi is then present in their feces. They then bite a person, usually at night and on their face, leaving feces behind. If that feces enters the body through breaks in the skin or through the eye often due to scratching or rubbing then the person can become infected.

There are also a few other ways people become infected with Chagas disease. They could get infected from a blood transfusion or transplanted organ from a person who has the disease. A pregnant woman could pass it on to her child. Infection can occur from inhaling the parasites. People also come down with Chagas disease if they eat raw food that has been contaminated with feces on it. The parasites will enter the bloodstream and then travel to different organs.

Diagnosis & Tests

If Chagas disease is suspected, the doctor will perform a physical examination. They will ask questions to get background information such as locations the patient may have been in. There are a few types of blood tests that test for Chagas so the patient will likely be given one. The blood tests usually focus on seeing if the body has developed the antibodies against the parasites. Occasionally the blood may be examined under a microscope to see if there is the presence of the parasites in the blood.

Many people are not aware that they even have the disease, so cases of Chagas disease in the US are frequently diagnosed when a person who unknowingly is infected donates blood. Most blood is now tested with the FDA approved test and any positively testing donors will be notified that they are infected with Chagas disease. If the disease has already progressed to the chronic phase, the patient will still be diagnosed via the blood test, but the diagnosis of chronic phase Chagas disease is often because of other physical ailments that occur from the progressed infection.

Treatment & Therapy

If a patient is found to have Chagas disease, he or she will probably be referred to a specialist to have a heart electrocardiogram to see if the heart has incurred complications from the disease. The patient will very likely be treated with antiparasitic drugs to reduce and kill the parasites, most likely nifurtimox or benznidazole.

These drugs are most effective early on in the disease but can still be given during later stages. If the patient is in the USA these drugs will come from the CDC in collaboration with the doctor. Treatment is then done to treat any of the symptoms that have arisen due to Chagas disease. This can include collaboration with a gastroenterologist to treat any intestinal concerns, a cardiologist to treat any heart concerns, and specialists in infectious diseases.

Prevention & Prophylaxis

There has been no vaccine developed to prevent Chagas disease. If one is traveling to areas that are known to have Chagas disease, one should sleep indoors in places that are well made as this will lessen the likelihood of contracting the disease, since Chagas disease occurs more often among those who live in poorly constructed dwellings.

One is much more likely to contract Chagas disease at night, so quality sleeping arrangements are a must. One can take preventative action by spraying sleeping areas with insecticides and using treated bed nets while sleeping. Keeping repellent on diligently on exposed skin will also help prevent the occurrence of infection.