Chagas Disease
Chagas is also caused by a trypanosome with an insect vector (carrier). Chagas is common in South and Central America.
Nearly 8-11 million people in central and South America are infected with Chagas, many of whom do not know they are infected. If left untreated, Chagas can be a lifelong and life threatening illness. People can become infected in various ways. Chagas is typically transmitted by a biting bug. These blood-sucking bugs get infected by biting an infected animal or person. Once infected, the bugs pass T. cruzi parasites in their feces. The bugs are found in houses made from materials such as mud, adobe, straw, and palm thatch. During the day, the bugs hide in crevices in the walls and roofs. During the night, when the inhabitants are sleeping, the bugs emerge. Because they tend to feed on people’s faces, triatomine bugs are also known as “kissing bugs. ” After they bite and ingest blood, they defecate (poop) on the person. The person can become infected if T. cruzi parasites in the bug feces enter the body through mucous membranes or breaks in the skin. The unsuspecting, sleeping person may accidentally scratch or rub the feces into the bite wound, eyes, or mouth. People also can become infected through eating uncooked food that is contaminated with feces from infected bugs.
There are two phases of Chagas disease: the acute phase and the chronic phase. Both phases can be symptom free or life threatening.
The acute phase lasts for the first few weeks or months of infection. It usually occurs unnoticed because it is symptom free or exhibits only mild symptoms and signs that are not unique to Chagas disease. The symptoms noted by the patient can include fever, fatigue, body aches, headache, rash, loss of appetite, diarrhea, and vomiting. The signs on physical examination can include mild enlargement of the liver or spleen, swollen glands, and local swelling (a chagoma) where the parasite entered the body. The most recognized marker of acute Chagas disease is called Romaña's sign, which includes swelling of the eyelids on the side of the face near the bite wound or where the bug feces were deposited or accidentally rubbed into the eye. Even if symptoms develop during the acute phase, they usually fade away on their own, within a few weeks or months. Although the symptoms resolve, the infection, if untreated, persists. Rarely, young children (<5%) die from severe inflammation/infection of the heart muscle (myocarditis) or brain (meningoencephalitis). The acute phase also can be severe in people with weakened immune systems.
During the chronic phase, the infection may remain silent for decades or even for life. However, some people develop cardiac complications, which can include an enlarged heart (cardiomyopathy), heart failure, altered heart rate or rhythm, and cardiac arrest (sudden death); and/or intestinal complications, which can include an enlarged esophagus (megaesophagus) or colon (megacolon) and can lead to difficulties with eating or with passing stool.
In the pictures below, you can see the Kissing bug on the left. The middle image shows one of the telltale symptoms of the acute phase. The last photo shows what a scientist or doctor might see in a blood smear (blood on a glass slide looked at under a microscope). Notice how similar it looks to the Sleeping Sickness trypanosome. (they are related!)
Nearly 8-11 million people in central and South America are infected with Chagas, many of whom do not know they are infected. If left untreated, Chagas can be a lifelong and life threatening illness. People can become infected in various ways. Chagas is typically transmitted by a biting bug. These blood-sucking bugs get infected by biting an infected animal or person. Once infected, the bugs pass T. cruzi parasites in their feces. The bugs are found in houses made from materials such as mud, adobe, straw, and palm thatch. During the day, the bugs hide in crevices in the walls and roofs. During the night, when the inhabitants are sleeping, the bugs emerge. Because they tend to feed on people’s faces, triatomine bugs are also known as “kissing bugs. ” After they bite and ingest blood, they defecate (poop) on the person. The person can become infected if T. cruzi parasites in the bug feces enter the body through mucous membranes or breaks in the skin. The unsuspecting, sleeping person may accidentally scratch or rub the feces into the bite wound, eyes, or mouth. People also can become infected through eating uncooked food that is contaminated with feces from infected bugs.
There are two phases of Chagas disease: the acute phase and the chronic phase. Both phases can be symptom free or life threatening.
The acute phase lasts for the first few weeks or months of infection. It usually occurs unnoticed because it is symptom free or exhibits only mild symptoms and signs that are not unique to Chagas disease. The symptoms noted by the patient can include fever, fatigue, body aches, headache, rash, loss of appetite, diarrhea, and vomiting. The signs on physical examination can include mild enlargement of the liver or spleen, swollen glands, and local swelling (a chagoma) where the parasite entered the body. The most recognized marker of acute Chagas disease is called Romaña's sign, which includes swelling of the eyelids on the side of the face near the bite wound or where the bug feces were deposited or accidentally rubbed into the eye. Even if symptoms develop during the acute phase, they usually fade away on their own, within a few weeks or months. Although the symptoms resolve, the infection, if untreated, persists. Rarely, young children (<5%) die from severe inflammation/infection of the heart muscle (myocarditis) or brain (meningoencephalitis). The acute phase also can be severe in people with weakened immune systems.
During the chronic phase, the infection may remain silent for decades or even for life. However, some people develop cardiac complications, which can include an enlarged heart (cardiomyopathy), heart failure, altered heart rate or rhythm, and cardiac arrest (sudden death); and/or intestinal complications, which can include an enlarged esophagus (megaesophagus) or colon (megacolon) and can lead to difficulties with eating or with passing stool.
In the pictures below, you can see the Kissing bug on the left. The middle image shows one of the telltale symptoms of the acute phase. The last photo shows what a scientist or doctor might see in a blood smear (blood on a glass slide looked at under a microscope). Notice how similar it looks to the Sleeping Sickness trypanosome. (they are related!)