Chagas disease is a life-threatening disease caused by the protozoan parasite; Trypanosoma cruzi (T. cruzi), also known as American trypanosomiasis.
Infected with Trypansosoma cruzi, the parasite that causes American Sleeping Sickness is believed to be between 6 million to 7 million people worldwide. Chagas disease is found primarily in endemic areas of 21 continental Latin American countries, where it is mostly transmitted to humans through contact with faeces or urine of triatomine bugs, known as’ kissing bugs,’ depending on the geographical area, among many other popular names.
The cost of medical care for patients with chronic cardiac, digestive, neurological or mixed disease forms has been calculated to be > 80 percent higher than the cost of spraying residual insecticide for vector control and infection prevention.
Chagas disease was named after the 1909 discovery of the disease by Carlos Ribeiro Justiniano Chagas, a Brazilian physician, and scientist.
History Of Chagas Disease
Chagas disease is named after Dr. Carlos Chagas, who in 1909, while working for the Oswaldo Cruz Institute in Brazil, first identified the parasite Trypanosoma cruzi in infected humans. Chagas discovered that the parasites were transmitted to humans by breaking into the skin after being deposited in insect feces on the body. Chagas was the first scientist to discover all aspects of a new infectious disease: pathogen (T. cruzi), main insect vector (Triatominae, Triatoma genus, or kissing bugs), hosts (humans, mammals), medical manifestations, and epidemiology. To honor his boss and scientific mentor, Oswaldo Cruz, the parasite genus was called cruzi.
Chagas disease is also known as American trypanosomiasis, as it occurs mainly in the Americas where triatomine insects (kissing bugs) are usually found. This bugs and the species they infect spread from states along the U.S. border with Mexico through Central America to countries in South America (e.g. Argentina, Bolivia), where the disease is endemic. Nearly all cases diagnosed in the United States are refugees from other American countries.
Throughout Central and South America, the vector-borne disease is quite widespread, with an estimated 7.7-15 million people worldwide infected. Children experience more signs of the acute phase than adults. Thankfully, vector control systems are effective as prevalence rates in Brazil and other countries that have adopted such programs are decreasing. Nonetheless, some scientists expect that Chagas disease will become more common in the U.S. due to warming climate patterns.
This is expected because the vectors that carry the parasites, especially in the southern and middle states, are found more often in non-endemic areas such as the U.S. In 28 states in the U.S., the bugs that transmit the parasite was detected and are likely to spread to others.
Key Facts You Must Know
- It is estimated that about 6 million to 7 million people worldwide were infected with Trypansosoma cruzi, the parasite that causes Chagas disease, mostly in Latin America.
- Transmission of vectors occurs in the Americas. The insect vector is a triatomine bug carrying the disease-causing Trypanosoma cruzi.
- Chagas disease was once largely restricted to the Americas region – primarily Latin America – but has spread to other continents in recent decades.
- Diagnosis with trypanosoma cruzi is curable when care starts shortly after diagnosis.
- Antiparasitic therapy can also stop or mitigate the progression of disease in the chronic stage.
- Up to 30% of chronically infected people develop heart defects and up to 10% experience metabolic, neurological or combined changes that may require specific care.
- Vector regulation is Latin America’s most effective method of preventing Chagas disease.
- Blood testing is necessary for transfusion and organ transplantation to prevent infection.
- It is important to monitor newborns of infected parents, together with their siblings, without prior antiparasite care.
What Are The Symptoms Of Chagas Disease?
Anyone infected with the parasite of Trypanosoma cruzi is considered to have the disease of Chagas even if symptoms never occur. The parasite does not cause any damage in seven out of ten cases, so the fact that someone is “infected” doesn’t always mean that they will experience symptomatic disease.
The most common problems among those who develop symptoms of Chagas disease are:
Generally, these early symptoms go away. If you don’t treat the disease, however, it will stay in your body. This can later cause serious intestinal and heart problems including:
- An irregular heartbeat that can cause sudden death
- An enlarged heart that doesn’t pump blood well
- Problems with digestion and bowel movements
- An increased chance of having a stroke
Many children and adults with Chagas disease do not know when infected and live their entire lives with the infection without symptoms.
How Can Chagas Disease Be Transmitted?
Chagas disease can be transmitted in five different ways: through a vector (through the feces of an insect), through vertical or congenital transmission (from mother to child during pregnancy), by blood transfusion or transplantation of organs, by ingestion of contaminated food or drinks, or through laboratory accidents.
How Can Chagas Disease Be Diagnosed?
The diagnosis of Chagas disease depends on whether the infection is acute, chronic, or congenital.
Acute Chagas Disease
During the acute phase of the disease, the optimal time to treat Chagas disease is when the greatest risk of eradicating the infection with antitrypanosomal drugs is the Trypanosoma cruzi (T. cruzi).
Sadly, all too often this chance is lost. This is because the symptoms of acute Chagas disease are usually mild and not overly troubling, and people with acute Chagas do not generally seek medical assistance.
As for the physicians, it is critical that they also remain wary of the existence of Chagas disease and then conduct the required diagnostic tests. In actual practice, it generally only happens during known regional outbreaks when testing is implemented across the nation.
Making the Diagnosis
The amount of T. cruzi parasistes during the Chagas disease acute stage, are normally very high in the bloodstream. This allows Chagas diagnosis to be made by microscopic examination of specially prepared blood samples. However, the number of T. Cruzi falls rapidly in the bloodstream after the first 90 days, even if there is no treatment.
After that point, microscopic blood testing is no longer a reliable means to diagnose Chagas disease. During the recurrent process of Chagas, the microscope examination is almost never useful.
Laboratory blood testing can also be very effective in the diagnosis of acute Chagas disease in addition to the microscopic examination. This is achieved with a sample of a polymerase chain reaction (PCR) which detects T’s DNA. Blood sample cruzi. A positive PCR test, like the test for the microscope, shows that T. There are cruzi cells in the bloodstream.
The symptoms of acute Chagas disease— such as fatigue, cough, sore throat, swelling, and muscle pain — can easily be confused with those of other diseases, such as signs of infectious mononucleosis, or acute HIV infection. So when a person is being screened for either of these conditions in an area prone to Chagas disease, it is usually a good idea to test for T. Infection with cruzi, too.
In chronic disease of Chagas, the T. Cruzi organisms are usually no longer present in the bloodstream, and therefore microscopic blood sample testing is almost always negative, as is the PCR test.
Chronic Chagas disease diagnosis is usually based on the body’s production of antibodies to ward off the infection. A number of tests to look for antibodies to T. cruzi have been established, including an immunosorbent enzyme-linked assay (ELISA) and an immunofluorescent antibody assay (IFA).
Neither of these antibody tests is sufficiently accurate to be used on their own, so at least two separate antibody tests are usually performed to diagnose chronic Chagas disease — and if the findings vary from each other, a third test is performed to act as a tie breaker.
At the same time, research should also be carried out to examine any of the other potential causes for the forms of cardiovascular and gastrointestinal problems associated with chronic Chagas disease. Sadly, the list of conditions that can do this is quite long, so physicians must use a great deal of medical judgment to determine when and in what order to do the test.
Up to 10% of babies born to T. cruzi-infected mothers, Acute Chagas disease, known as congenital Chagas disease, will develop. To avoid chronic complications, it is important to treat a baby with congenital Chagas disease with antitrypanosomal therapy.
In any infant whose mother is from a region where the disease is common, the risk of congenital Chagas disease should be recognized. Prenatal screening is often performed in pregnant women living in such places, and babies can then be tested for the disease from the mothers who test positive.
Baby screening for congenital Chagas disease is usually performed at birth with cord blood PCR analysis, or on a blood sample collected during the first few days after birth. If the mother is considered to be positive for the Chagas disease and the infant’s initial testing is negative, the child should be repeatedly tested for one or two months.
How Can Chagas Disease Be Prevented?
According to WHO, no vaccine is available to prevent the disease of Chagas. However, depending on the geographical area(s) affected, the following prevention and control tools are useful:
- Insecticide spraying of homes and surrounding areas.
- Home improvement to avoid vector infestation (such as plastering walls and construction of concrete floors and corrugated iron roofs).
- Good hygiene practices in food preparation, transportation, processing, and consumption.
- Private preventive measures such as bednets.
- Blood donor screening.
- Organ, tissue, cell donor and recipient testing.
In addition, primary congenital transmission control strategies include screening infected pregnant women and early detection of possible infections in neonates (secondary prevention) and their siblings to provide early diagnosis and treatment.
A newborn infected can be detected at birth by detecting parasites directly in the baby’s umbilical cord or venous blood or by detecting antibodies to T. cruzi when the child is 8 months old.
Recently, a surveillance system for Chagas disease has been introduced in areas where malaria is also transmitted. Technicians for malaria microscopy were trained to identify T. Cruzi parasites in malaria films and in individual cases diagnose acute Chagas disease. We can also track and monitor potential foodborne outbreaks and active transmission areas for the disease.
How Can Chagas Disease Be Treated?
Chagas disease can be treated today. Therapy is highly effective when offered during the acute phase of the disease and when delivered during the chronic period is less effective. That’s why it’s so important to diagnose early. Treatment provides a complete cure for children below 1 year of age. Treatment also yields good results in young people. Chagas therapy is associated with less adverse effects in both children and youth than in adults.
A cure is not guaranteed in adults, but treatment can prevent the progression of the disease and prevent or delay heart complications.
Although breastfeeding, women can not receive treatment for Chagas disease. Individuals taking the drug must prevent pregnancy before completion of the course of treatment.
Patients can not drink alcohol during medication because it can interfere with the medications and increase the likelihood of adverse effects. There are two medications commonly used for the treatment of Chagas disease: benznidazole and nifurtimox. Both of these medications can cause side effects, so under medical supervision, care should always be given. Depending on which drug is used, the medication is taken orally for two to three months.
The annual check-up is just as critical as treatment, including an electrocardiogram. When new symptoms occur, it is equally important to seek medical attention.
Adverse Effects Of Treatment
The most common side effects associated with the treatment of American trypanosomiasis are as follows:
- Skin reactions
- Abdominal pain
- Sleep disturbances
Therapy may cause more severe side effects, such as fever and nausea, which may lead to cessation of treatment in rare cases. When you have any side effects, even if they are not serious, consult your doctor immediately.
Individuals who have already experienced complications due to Chagas disease must seek medical care in a clinic or hospital where the doctor may prescribe individualized treatment for their symptoms.
There are many different types of specific treatments ranging from simple steps such as a high fiber diet and taking laxatives and heart pills to others as complex as a heart transplant in a few rare cases.
It is also important to treat this disease in patients in whom the improvements are still in the early stages. When cardiac abnormalities are at an advanced stage, all that is recommended is the specific treatment for these complications.
What Is The Difference Between American Chagas Disease And African Trypanosomiasis?
American trypanosomiasis (Chagas disease) is differentiated from African trypanosomiasis (sleeping sickness or African sleeping sickness) by the part of the world in which it occurs, its causes and its various symptoms and treatments (see Table 1).