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Chagas Disease
American trypanosomiasis; Kissing bug disease
Chagas disease, also called American trypanosomiasis, is a potentially life-threatening illness caused by a parasite that is spread by "kissing bugs", mainly in continental Latin America. It can cause serious heart and gastrointestinal problems, and there are approximately 10,000 deaths every year. Learn about the signs and symptoms of Chagas disease.
“Kissing Bug”
Image by CDC/ CDC Connects; Photo credit: James Gathany
Chagas Bug
Image by CDC
Chagas disease is named after the Brazilian physician Carlos Chagas, who discovered the disease in 1909. It is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by insect vectors and is found only in the Americas (mainly, in rural areas of Latin America where poverty is widespread). Chagas disease (T. cruzi infection) is also referred to as American trypanosomiasis.
Source: Centers for Disease Control and Prevention (CDC)
Trypanosoma cruzi LifeCycle
Image by DPD CDC/Wikimedia
Chagas disease, or American trypanosomiasis, is caused by the parasite Trypanosoma cruzi. Infection is most commonly spread through contact with the poop of an infected triatomine bug (or “kissing bug”), a blood-sucking insect that feeds on humans and animals.
Infection can also occur from:
Chagas disease is common in parts of Mexico, Central America, and South America where an estimated 8 million people are infected. The triatomine bug thrives in poor housing conditions (for example, mud walls, thatched roofs), and in countries where the bug is present, people living in rural areas are at greatest risk for getting infected. Efforts by the public health community to prevent transmission of T. cruzi have resulted in a decrease in the number of new T. cruzi infections and, in some areas, have completely stopped transmission of the parasite by triatomine bugs. Many countries where Chagas disease is common have also started screening donated blood for this disease. However, new cases of Chagas disease transmitted through infected organs, or by mother-to-child (congenital) transmission can still occur.
CDC estimates that more than 300,000 persons with Trypanosoma cruzi infection live in the United States. Most people with Chagas disease in the United States were infected in the parts of Latin America where Chagas disease is found. Although there are triatomine bugs in the United States, only a few cases of Chagas disease from contact with the bugs have been documented in this country.
Source: Centers for Disease Control and Prevention (CDC)
T. cruzi trypomastigotes in peripheral blood smear
Image by CDC/Wikimedia
The protozoan parasite, Trypanosoma cruzi, causes Chagas disease, a zoonotic disease that can be transmitted to humans by blood-sucking triatomine bugs.
An infected triatomine insect vector (or “kissing bug”) takes a blood meal and releases trypomastigotes in its feces near the site of the bite wound. Trypomastigotes enter the host through the wound or through intact mucosal membranes, such as the conjunctiva (1). Common triatomine vector species for trypanosomiasis belong to the genera Triatoma, Rhodnius, and Panstrongylus. Inside the host, the trypomastigotes invade cells near the site of inoculation, where they differentiate into intracellular amastigotes (2). The amastigotes multiply by binary fission (3) and differentiate into trypomastigotes, and then are released into the circulation as bloodstream trypomastigotes (4). Trypomastigotes infect cells from a variety of tissues and transform into intracellular amastigotes in new infection sites. Clinical manifestations can result from this infective cycle. The bloodstream trypomastigotes do not replicate (different from the African trypanosomes). Replication resumes only when the parasites enter another cell or are ingested by another vector. The “kissing bug” becomes infected by feeding on human or animal blood that contains circulating parasites (5). The ingested trypomastigotes transform into epimastigotes in the vector’s midgut (6). The parasites multiply and differentiate in the midgut (7) and differentiate into infective metacyclic trypomastigotes in the hindgut (8).
Trypanosoma cruzi can also be transmitted through blood transfusions, organ transplantation, transplacentally (from mother to unborn baby), and in laboratory accidents.
Life cycle image and information courtesy of DPDx.
Source: Centers for Disease Control and Prevention (CDC)
How your Breast adapt to feeding
Image by TheVisualMD
In the United States, an estimated 40,000 women of childbearing age are infected with Trypanosoma cruzi, the parasite that causes Chagas disease. The risk of transmission from mother-to-child is thought to be low, with an estimated 1-5% of infants born in the United States to mothers with Chagas disease infected with T. cruzi. This translates to between 63 to 315 infected infants born every year.
Identification and testing of infants at risk of infection is critical to prevent Chagas disease in the United States.
Most babies born with congenital Chagas disease have mild or no signs of illness. However, infection will persist for life and these infants are at risk for developing clinical manifestations of chronic Chagas disease later in life, unless treated.
Infants born with signs of Chagas disease may present with the following:
Severe disease—such as meningoencephalitis, pneumonitis, or anasarca—and even death can occur in infected infants but is rare.
Women at risk for Chagas disease should be screened for infection before or during pregnancy. Women who have lived in Mexico, Central America, and South America are at greatest risk for Chagas disease.
Although the triatomine insects that transmit Trypanosoma cruzi are present in the southern half of the United States, few cases have been documented as a result of exposure to these insects in the United States and the risk is likely low. Routine testing of pregnant women is not indicated unless there is concern for exposure to triatomines.
For women with Chagas disease, treatment with benznidazole or nifurtimox is typically delayed until after pregnancy and breastfeeding because of concerns about drug safety. Benznidazole is approved by FDA for use in children 2–12 years of age and is commercially available at http://www.benznidazoletablets.com/en/. Nifurtimox is not currently FDA approved and is available under an investigational protocol from CDC.
An infant should be evaluated for congenital Chagas disease if:
Infant diagnosis relies on detection of the parasite after birth by microscopic examination of blood smears and/or PCR testing for Trypanosoma cruzi DNA in blood. Because the infected mother’s antibody to T. cruzi can persist in her infant for up to 9–12 months, serologic testing is not useful for detecting congenital infection in newborn infants. Over time, the mother’s antibody will disappear and children who are uninfected should be antibody negative by 9–12 months of age.
Treatment is recommended for all cases of congenital Chagas disease. The cure rate is >90% when treatment is given in the first year of infection. Nifurtimox and benznidazole are both effective for treatment of congenital Chagas disease.
Siblings of an infant with congenital Chagas disease should be evaluated for Chagas disease.
Source: Centers for Disease Control and Prevention (CDC)
Chagas disease
Image by Extracted from the article: "Louis-Alexandre Romaña has granted permission for the reuse of the photographs that he owns and that he has provided (Figs 1 and 3) and for his letter. Written permission is included as Supporting information.Dr. Faustino TORRICO has granted permission for the reuse of the photograph that he owns and that he has provided (Fig 2)."The article has three authors, Beucler N, Torrico F and Hibbert DBeucler N, Torrico F, Hibbert D (2020) A tribute to Cecilio Romaña: Romaña’s sign in Chagas disease. PLoS Negl Trop Dis 14(11): e0008836. https://doi.org/10.1371/journal.pntd.0008836/Wikimedia
Chagas disease has an acute and a chronic phase. If untreated, infection is lifelong.
Acute Chagas disease occurs immediately after infection, and can last up to a few weeks or months. During the acute phase, parasites may be found in the circulating blood. This phase of infection is usually mild or asymptomatic. There may be fever or swelling around the site of inoculation (where the parasite entered into the skin or mucous membrane). Rarely, acute infection may result in severe inflammation of the heart muscle or the brain and lining around the brain.
Following the acute phase, most infected people enter into a prolonged asymptomatic form of disease (called “chronic indeterminate”) during which few or no parasites are found in the blood. During this time, most people are unaware of their infection. Many people may remain asymptomatic for life and never develop Chagas-related symptoms. However, an estimated 20–30% of infected people will develop severe and sometimes life-threatening medical problems over the course of their lives.
Complications of chronic Chagas disease may include
In people who have suppressed immune systems (for example, due to AIDS or chemotherapy), Chagas disease can reactivate with parasites found in the circulating blood. Reactivation can potentially cause severe disease.
Source: Centers for Disease Control and Prevention (CDC)
Trypanosoma cruzi in a blood smear
Image by Dr Graham Beards/Wikimedia
During the acute phase of infection, parasites may be seen circulating in the blood. The diagnosis of Chagas disease can be made by observation of the parasite in a blood smear by microscopic examination. A thick and thin blood smear are made and stained for visualization of parasites.
Diagnosis of chronic Chagas disease is made after consideration of the patient’s clinical findings, as well as by the likelihood of being infected, such as having lived in a country where Chagas disease is common. Diagnosis is generally made by testing for parasite specific antibodies.
Source: Centers for Disease Control and Prevention (CDC)
Blood Smear
Also called: Peripheral Blood Smear, PBS, Blood Film, Manual Differential, Differential Slide, Blood Cell Morphology, Blood Smear Analysis
A blood smear examines the size, shape, and number of blood cells in a sample of your blood. A blood smear can also detect parasites in your blood. A blood smear may be used to help diagnose and monitor many conditions.
White Blood Count (WBC)
Also called: WBC, WBC Blood Test, White Blood Count, White Blood Cell Count, Leukocyte Count, Leukopenia Test, Leukocytosis Test
A white blood count measures the number of white cells in your blood. White blood cells are part of the immune system. A count that is too high or too low can indicate an infection, immune system disorder, or another health problem.
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Blood Differential Test
Also called: White Blood Cell Differential, WBC Differential, Leukocyte Differential Count, Differential Blood Count
A blood differential test measures the different types of white blood cells in a sample of your blood: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. The test helps diagnose infections, inflammation, immune diseases, cancer and other disorders.
Neutrophil Count
Also called: Neutrophils (Complete Blood Count), Neutrophils, Neutropenia Test, Neutrophilia Test
This test measures the amount of neutrophils in a sample of your blood. Neutrophils are the most common type of white blood cell. They are your body's main defense against infection when bacteria, viruses, or other germs enter your body. An abnormal level of neutrophils circulating in the blood could indicate a number of health issues.
Lymphocyte Count
Also called: Lymphocytes (Complete Blood Count), Lymphocytes, Lymphs, Lymphocytosis Test, Lymphocytopenia Test
This test measures the amount of lymphocytes in a sample of your blood. A lymphocyte is a type of white blood cell that is part of the immune system. It defends the body against infection, disease, and altered (mutated) cells. An abnormal level of lymphocytes circulating in the blood could indicate a number of health issues.
Monocyte Count
Also called: Monocytes (Complete Blood Count), Monocytes, Monocytosis Test, Monocytopenia Test
This test measures the amount of monocytes in a sample of your blood. Monocytes are a type of white blood cell. They help fight off infections and play a role in your body's immune response. An abnormal level of monocytes in the blood could indicate a number of issues, including infection, autoimmune disorder, or certain type of cancer.
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Eosinophil Count
Also called: Eosinophils (Complete Blood Count), Eosinophils, Eosins, Eos, Eosinopenia Test, Eosinophilia Test
This test measures the amount of eosinophils in a sample of your blood. Eosinophils are a type of white blood cell. They help fight off infections and play a role in your body's immune response. An abnormal level of eosinophils in the blood could indicate a number of issues, including infection, allergic reaction, and asthma.
Basophil Count
Also called: Basophils (Complete Blood Count), Basophils, Basos, Basopenia Test, Basoophilia Test
This test measures the amount of basophils in a sample of your blood. Basophils, a type of white blood cell, release enzymes during allergic reactions and asthma attacks. An abnormal level of basophils circulating in the blood could indicate a number of health issues.
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Red Blood Cell (RBC) Count
Also called: Erythrocyte Count, RBC Count, Red Blood Count, Red Blood Cell Count, Red Count
A red blood cell (RBC) count is a blood test that measures the number of red blood cells in your blood. Red blood cells carry oxygen from your lungs to the rest of your body. An abnormal RBC count can be a sign of a serious health problem.
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RDW (Red Cell Distribution Width) Test
Also called: Red Cell Distribution Width, RDW, RDW Blood Test, Erythrocyte Distribution Width, RBC Distribution Width
A red cell distribution width (RDW) test measures the size and volume of your red blood cells. RDW is usually part of a complete blood count (CBC) test. Measuring RDW can help diagnose anemia and other blood disorders.
Red Blood Cell (RBC) Morphology Test
Also called: RBC-M, Red Cell Morphology, Red Blood Cell Morphology, RBC Morphology, Erythrocyte Morphology
A red blood cell (RBC) morphology is a test done to evaluate the size, shape, structure, and color of your red blood cells (erythrocytes). This test is useful to help detect and help diagnose a wide variety of blood disorders.
Platelet Count
Also called: Platelets, PLT Count, Platelet Adequacy, Thrombocyte Count, Thrombocytopenia Test, Thrombocytosis Test, Platelet count
A platelet count test measures the number of platelets in your blood. Platelets, also known as thrombocytes, are small blood cells that are essential for blood clotting. Platelets may be counted to monitor or diagnose diseases, or to look for the cause of too much bleeding or clotting.
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NECT treatment
Image by Neil Brandvold-DNDi/Wikimedia
Treatment for Chagas disease is recommended for people diagnosed early in the course of infection (acute phase), babies with congenital infection, and for those with suppressed immune systems. Many patients with chronic infection may also benefit from treatment.
Patients should consult with their primary health-care provider. Some patients may be referred to a specialist, such as a cardiologist, gastroenterologist, or infectious disease specialist.
Source: Centers for Disease Control and Prevention (CDC)
Bungalow at Bird of Paradise
Image by Mx. Granger/Wikimedia
In areas of Mexico, Central America, and South America, where the Trypanosoma cruzi parasite is present in triatomine bugs, improved housing and spraying insecticide inside housing to eliminate the bugs has significantly decreased the spread of Chagas disease. Screening of blood donations for Chagas is another important public health tool to help prevent spreading the disease through blood transfusions. Early detection and treatment of new cases, including mother-to-baby (congenital) cases, will also help reduce the burden of disease.
In the United States and in other regions where Chagas disease is now found but is not widespread, control strategies are focused on preventing transmission from blood transfusion, organ transplantation, and mother-to-baby.
Source: Centers for Disease Control and Prevention (CDC)
DEET
Image by CDC
American trypanosomiasis, also known as Chagas disease, is caused by a parasite. This parasite lives in the feces (poop) of triatomine (kissing) bugs. The bug often poops when it bites. Most people get Chagas disease by unknowingly rubbing triatomine bug poop into the bug bite, for example, when they scratch the bite. People may also accidentally get triatomine bug poop in their eyes and mouth.
A few people experience swelling around the bite area. However, most people never have symptoms, but remain infected throughout their lives.
About 1 out of 3 people who get Chagas disease will develop more serious symptoms later in life, including heart conditions or gastrointestinal problems. These later symptoms can occur whether a person has early symptoms or not.
Chagas disease is spread by triatomine bugs in parts of Mexico, Central America, and South America, especially rural areas.
Most travelers to these areas don’t need to worry about Chagas disease. Travelers who sleep outdoors or stay in poorly constructed housing are more likely to get bitten by triatomine bugs.
There is no vaccine or medicine to prevent Chagas disease. Travelers can protect themselves by taking a few steps.
Avoid Bug Bites
If you traveled and feel sick, particularly if you have a fever, talk to a healthcare provider, and tell them about your travel. Avoid contact with other people while you are sick.
Source: Centers for Disease Control and Prevention (CDC)
Panstrongylus megistus on wood
Image by diogoluiz/Wikimedia
Chagas disease, or American trypanosomiasis, is an illness that can cause serious heart and stomach problems. It is caused by a parasite. Chagas disease is common in Latin America, especially in poor, rural areas. It can also be found in the United States, most often in people who were infected before they moved to the U.S.
Chagas disease is caused by the Trypanosoma cruzi parasite. It is usually spread by infected blood-sucking bugs called triatomine bugs. They are also known as "kissing bugs" because they often bite people's faces. When of these bugs bites you, it leaves behind infected waste. You can become infected if you rub the waste in your eyes or nose, the bite wound, or a cut.
Chagas disease can also spread through contaminated food, a blood transfusion, a donated organ, or from mother to baby during pregnancy.
Kissing bugs can be found throughout the Americas, but they are more common in certain areas. The people who are most at risk for Chagas disease
In the beginning, there may be no symptoms. Some people do get mild symptoms, such as
These early symptoms usually go away. However, if you don't treat the infection, it stays in your body. Later, it can cause serious intestinal and heart problems such as
A physical exam and blood tests can diagnose it. You may also need tests to see whether the disease has affected your intestines and heart.
Medicines can kill the parasite, especially early on. You can also treat related problems. For example, a pacemaker helps with some heart complications.
There are no vaccines or medicines to prevent Chagas disease. If you travel to areas where it occurs, you are at higher risk if you sleep outdoors or are staying in poor housing conditions. It is important to use insecticides to prevent bites and practice food safety.
Source: Centers for Disease Control and Prevention / MedlinePlus
Chagas disease
Image by CDC
Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by insect vectors that are found only in the Americas (mainly, in rural areas of Latin America where poverty is widespread). Chagas disease (T. cruzi infection) is also referred to as American trypanosomiasis.
It is estimated that as many as 8 million people in Mexico, Central America, and South America have Chagas disease, most of whom do not know they are infected. If untreated, infection is lifelong and can be life threatening.
The impact of Chagas disease is not limited to only rural areas of Latin America in which vectorborne transmission (diseases transmitted by insects) occurs. Large-scale population movements from rural to urban areas of Latin America and to other regions of the world have increased the geographic distribution and changed the epidemiology of Chagas disease. In the United States and in other regions where Chagas disease is now found but is not endemic, control strategies should focus on preventing transmission from blood transfusion, organ transplantation, and mother-to-baby (congenital transmission).
People can become infected in several ways. In areas where Chagas disease is common, the main way is through vectorborne transmission. The insect vectors are called triatomine bugs. These blood-sucking bugs get infected with T. cruzi by biting an infected animal or person. Once infected, the bugs pass the 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 bite 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
It is generally considered safe to breastfeed even if the mother has Chagas disease. However, if the mother has cracked nipples or blood in the breast milk, she should pump and discard the milk until the nipples heal and the bleeding resolves.
Chagas disease is not transmitted from person-to-person like a cold or the flu or through casual contact with infected people or animals.
Possibly. They should be tested if they:
People who have Chagas disease can be found anywhere in the world. However, transmission of the disease by kissing bugs (vectorborne transmission), only occurs in the Americas. Most people with Chagas disease became infected in rural areas of Mexico, Central America, and South America. In some regions of Latin America, efforts to eliminate kissing bugs, called vector control programs, have succeeded in stopping this type of disease spread. Vectorborne transmission does not occur in the Caribbean (for example, in Puerto Rico or Cuba). Rare vectorborne cases of Chagas disease have been noted in the southern United States.
Much of the clinical information about Chagas disease comes from experience with people who became infected as children through contact with triatomines. The severity and course of an individual infection can vary based on a number of factors, including the age at which a person became infected, the way in which a person acquired the infection, or the particular strain of the T. cruzi parasite.
There are two phases of Chagas disease: the acute phase and the chronic phase. Both phases can be symptom free or life threatening.
Acute phase: During this phase, which lasts for the first few weeks or months infection, a person may have no symptoms or mild ones, such as fever, fatigue, body aches, headache, rash, loss of appetite, diarrhea, and vomiting. Because these symptoms are similar to those of other illnesses, most people do not know their illness is from infection with the T. cruzi parasite.
However, a doctor may be able to pick up other signs of infection, including mild enlargement of the liver or spleen, swollen glands, or swelling at the site of the bite (called a chagoma), where the parasite entered the body. Some people with acute phase infection may have swelling of the eyelids on the side of the face near the bite wound or where the bug poop was accidentally rubbed into the eye, called Romaña’s sign. Even if a person develops symptoms during the acute phase, they usually feel well within a few weeks or months but if the person is not treated with antiparasitic medication, the infection remains in the body. Rarely, young children (less than 5%) die from severe inflammation and infection of the heart muscle (myocarditis) or brain (meningoencephalitis). The acute phase also can be severe in people with weakened immune systems, such as patients taking chemotherapy or those with advanced HIV infection.
Chronic phase: During this phase, which can last for decades or even for the entirety of someone’s lifetime, most people have no symptoms. Approximately 20–30 percent of infected people develop
You should discuss your concerns with your health-care provider, who will examine you and ask you questions (for example, about your health and where you have lived). Chagas disease is diagnosed by blood tests. If you are found to have Chagas disease, you should have a heart tracing test (electrocardiogram), even if you feel fine. You might be referred to a specialist for more tests and for treatment.
Two approaches to therapy, that can be life-saving include:
Antiparasitic treatment is most effective early in the course of infection but is not limited to cases in the acute phase. In the United States, there are two types of treatments available. Benznidazole is approved by FDA for use in children 2–12 years of age and is commercially available at http://www.benznidazoletablets.com/en/. Nifurtimox is not currently FDA approved and is available under an investigational protocol from CDC. Your health-care provider can talk with CDC staff about whether and how you should be treated. Most people do not need to be hospitalized during treatment.
Symptomatic treatment may help people who have cardiac or gastrointestinal problems from Chagas disease. For example, pacemakers and medications for irregular heartbeats may be life saving for some patients with chronic cardiac disease.
No drugs or vaccines for preventing infection are currently available. Travelers who sleep indoors, in well-constructed facilities (for example, air-conditioned or screened hotel rooms), are at low risk for exposure to infected triatomine bugs that usually live in poor-quality dwellings and are most active at night. Preventive measures include spraying infested dwellings with long-lasting insecticides, using bed nets treated with long-lasting insecticides, wearing protective clothing, and applying insect repellent to exposed skin. Travelers should observe food and beverage precautions and avoid consuming salads, uncooked vegetables, unpeeled fruits, and unpasteurized fruit juices.
This information is not meant to be used for self-diagnosis or as a substitute for consultation with a health care provider. If you have any questions about the parasites described above or think that you may have a parasitic infection, consult a health care provider.
Source: Centers for Disease Control and Prevention (CDC)
Blood Smear
Image by CDC/Steven Glenn
The transmission of Trypanosoma cruzi through blood transfusion is a recognized risk. Screening tests have been approved by the U.S. Food and Drug Administration. Screening for Trypanosoma cruzi infection makes the blood supply even safer for everyone.
The blood screening test allows blood banks to destroy potentially infectious blood before it is given to anyone.
The blood that tests positive will be removed from the blood supply.
Yes. In the United States, donors are tested once and if the result of their test is negative for T. cruzi infection, they will not be tested when they donate again at that blood bank.
Probably. However, no test is perfect and occasionally a test can give a “false-positive” result. You should discuss your results with your health-care provider.
A “false-positive” result is when test results look like a person has a disease, but further testing indicates the person does not have the disease after all.
Yes. The blood bank will contact you if you test positive for Trypanosoma cruzi infection and will provide general information about the disease.
No. You cannot contract Chagas disease from donating blood. The needles are only used once and are discarded. Sterile procedures and equipment are routine at blood banks.
Yes. The disease can be spread by receiving blood that came from a person with Chagas disease.
Maybe. You should contact the blood bank about possible retesting to see if you can donate blood again. In 2017, the U.S. Food and Drug Administration issued new rules about how donors who tested false positive can be evaluated to see if they are eligible to donate blood again. If you were diagnosed by your doctor, you cannot donate blood.
No. If you have ever been diagnosed with Chagas disease, you cannot donate blood.
Probably not. The risk is very low. You should, however, be aware of the potential risk for Chagas disease infection and the need to monitor your health. If you have symptoms of Chagas disease or other concerns you should contact your health-care provider.
Source: Centers for Disease Control and Prevention (CDC)
Trypanosoma cruzi life cycle
Image by Kárita C. F. Lidani, Lorena Bavia, Altair R. Ambrosio and Iara J. de Messias-Reason/Wikimedia
Triatomine bugs are a type of reduviid bug that can carry Trypanosoma cruzi, the parasite that causes Chagas disease.
Triatomine bugs (also called “kissing bugs”, cone-nosed bugs, and blood suckers) can live indoors, in cracks and holes of substandard housing, or in a variety of outdoor settings including the following:
They are typically found in the southern United States, Mexico, Central America, and South America (as far south as southern Argentina). The map below details triatomine occurrence by U.S. state.
Eleven different species of triatomine bugs have been found in the southern United States:
Triatomines are mostly active at night and feed on the blood of mammals (including humans), birds, and reptiles. Triatomine bugs live in a wide range of environmental settings, generally within close proximity to an animal the bug can feed on, called a blood host. In areas of Latin America where human Chagas disease is an important public health problem, the bugs nest in cracks and holes of substandard housing.
Because most indoor structures in the United States are built with plastered walls and sealed entryways to prevent insect invasion, triatomine bugs rarely infest indoor areas of houses. Discovery of the earlier stages of the bug (wingless, smaller nymphs) inside can be a sign of a triatomine infestation. When the bugs are found inside, they are likely to be in one of the following settings:
Synthetic pyrethroid bug sprays have been used successfully in Latin America to get rid of house infestations. Although similar chemicals are available in the United States, none have been specifically approved for use against triatomine bugs. A licensed pest control operator should be consulted before using any insecticides to kill triatomine bugs. Roach hotels or other “bait” formulations do not work against triatomine bugs. Long lasting insecticide treated bednets and curtains have been shown to kill these bugs.
Other precautions to prevent house infestation include the following:
If you find a bug you suspect is a triatomine, do not touch or squash it. Place a container on top of the bug, slide the bug inside, and fill it with rubbing alcohol or, if not available, freeze the bug in the container. Then, you may take it to your local extension service, health department, or a university laboratory for identification.
Surfaces that have come into contact with the bug should be cleaned with a solution made of 1 part bleach to 9 parts water (or 7 parts ethanol to 3 parts water).
There are many beetles and non-triatomine reduviid bugs that resemble the triatomine bug. Two examples of non-triatomine reduviid bugs that do not feed on human blood, but prey upon other insects are the wheel bug and the western corsair. Some plant-feeding bugs, such as the leaf-footed bug also resemble the triatomine. If you are unsure if the bug you’ve found is a triatomine, you may wish to consult with an expert, such as an entomologist, for clarification.
More on: Bugs Commonly Confused with Triatomine Bugs
Yes. However, the transmission of the Trypanosoma cruzi parasite from a bug to a human is not easy. The parasite that causes the disease is in the bug feces. The bug generally poops on or near a person while it is feeding on her blood, usually when the person is sleeping. Transmission of the parasite happens when poop is accidentally rubbed into the bite wound or into a mucous membrane (for example, the eye or mouth), and the parasite enters the body.
It is important to note that not all triatomine bugs are infected with the parasite that causes Chagas disease. The likelihood of getting T cruzi infection from a triatomine bug in the United States is low, even if the bug is infected.
Yes. The saliva of certain types of triatomines can cause an allergic reaction in some people. An allergic reaction can have severe redness, itching, swelling, welts, hives, or, rarely, anaphylactic shock (severe allergic reaction). People with a history of anaphylactic shock should consult a physician to obtain medication to use in case of a bite. It is important to note that not all triatomines are infected with the parasite even though their saliva may cause an allergic reaction.
An allergic reaction after a triatomine bite does not mean that you have been infected with the parasite T cruzi, the cause of Chagas disease. The swelling that may develop at the site of parasite inoculation (where the parasite entered the body through the skin or mucous membranes) is called a chagoma. When the parasite enters the body through the eye, the swelling around the eye is called Romaña’s sign. Chagomas, including Romaña’s sign, usually last longer than an allergic reaction and are less likely to be severely itchy.
If you suspect you have Chagas disease, consult your health-care provider. Or, to find a physician familiar with diagnosis and treatment of Chagas disease and other parasitic infections, ask your general practitioner or primary care physician for a referral. You may wish to consider visiting a physician who specializes in infectious diseases. To locate a clinician in your area, please visit the American Society of Tropical Medicine and Hygiene’s Clinical Consultants Directory.
Source: Centers for Disease Control and Prevention (CDC)
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