Chagas disease: is it curable? Symptoms, cycle, transmission

A small beetle, known as the Barber, is the source of a major health problem: Chagas disease. In Brazil alone, more than 150 thousand new cases are diagnosed each year.

Knowing how this disease is spreading is important to combat its prevalence in our society.

Learn more about Chagas disease in the text below!

What is Chagas disease?

Chagas disease is caused by a parasite called Trypanosoma cruzi , which is transmitted from animals to people by insect vectors, which are found on the American continent – more specifically in rural areas of Latin America.

It is estimated that at least 8 million people in Latin America have Chagas disease, most of whom are unaware that they are infected. If not treated properly, the disease can be life threatening.

The impact of this disease, however, is not limited only to rural areas in Latin America, where transmission through vectors predominates.

In urban areas, where there is less presence of disease vectors, transmission can occur vertically or in blood transfusions.

You can find Chagas disease in the International Classification of Diseases (ICD-10) through the codes: B57, B57.1, B57.2 and B57.3.

Causes

Chagas disease is caused by a protozoan called Trypanosoma cruzi , a type of parasite common in Latin America.

This parasite can be found in insect feces gender triatoma , especially a beetle named Barber , also known as hickey , procotó or weevil .

Barbers usually feed on blood and are contaminated by Trypanosoma when they suck blood from other infected mammal animals, including humans.

Once in the digestive tract of this insect, Trypanossoma is eliminated in the feces, which can come in contact with other human beings, contaminating them.

What are the vectors?

Most Chagas disease vector insects live in the wild and do not have as much contact with humans.

There are a total of 141 species of known triatomines, 63 of which were identified in Brazil and can be found in several forest strata of all biomes.

Also according to the international organization Médecins Sans Frontières, there are more than 300 species of insects capable of transmitting Chagas disease.

In Brazil, there are 4 species of Triatoma responsible for the transmission of Chagas disease to humans. Are they:

  • T. brasiliensis;
  • Panstrogylus megistus;
  • T. pseudomaculata;
  • T dirty.

How does transmission occur?

The transmission of Chagas’ disease can happen in several ways. According to data from the Ministry of Health, between 2016 and 2017, 69% of Chagas disease cases registered in Brazil happened through oral transmission, 9% through vector transmission and in 21% the way in which the contagion happened was not identified. Understand:

Vector transmission

When biting a person, the insect can deposit feces contaminated with the protozoan on the skin, in a place close to the bite, while the barber sucks the person’s blood.

As the wound causes itching, the person takes the hand to the location of the bite and can facilitate the entry of Trypanossoma into the body.

From mother to son

Mother-to-child transmission is also called vertical transmission . These cases happen when the mother passes on Trypanossoma to the baby during pregnancy or at the time of delivery.

In regions where Chagas disease vector insects have a controlled population, that is, where there is no risk of vector transmission, vertical transmission is the most common form of infection.

Blood transfusion

Blood transfusion procedures or organ transplants can be ways of transmitting the disease. If the blood or organ donor is infected, it may end up transmitting the patient who received the donation as well.

Oral transmission

Oral transmission occurs when a person consumes food contaminated with the beetle’s feces or the beetle itself.

The food most associated with Chagas disease is açaí , which is very popular in northern Brazil.

However, there are other foods that can end up causing oral transmission to happen. In 2005, the state of Santa Catarina, in the southern region of the country, experienced an outbreak of the disease caused by ingestion of contaminated sugarcane juice.

Sexual transmission

People who are in the acute phase of the disease and who have had sexual intercourse in which blood exposure has occurred may also end up transmitting Chagas’ disease in this way.

How is the disease cycle?

The life cycle of Trypanosoma Cruzi begins at the moment when the barber, when feeding on the blood of an animal or a human being, eliminates its infected feces and urine near the location of the bite.

When the person scratches the location of the bite, he ends up pushing Trypanossoma into the body.

There, the parasite first infects the cells, where they multiply, and leaves for the bloodstream, infecting the person.

When that person or animal is bitten again by the barber, the insect is infected, the Trypanossoma goes to its intestine, where it reproduces, until it is eliminated in the feces again, restarting the cycle.

Risk factors

There are several risk factors that can increase the chances of being infected with Chagas disease. Among them, we can mention:

  • Living in rural areas of Latin America;
  • Live in regions with the presence of triatomas.

It is possible to be infected with Chagas disease while traveling. If the place where you are going to stay does not have a good structure, cleaning and sanitation care, the risks of contracting the disease are increased.

Triatoma insects are usually found in places built with mud or straw, so look for places with good structures, as they, even when in risk areas, help to reduce the number of cases of the disease.

Acute phase symptoms

The acute phase begins as early as the first 3 months after infection and most cases have no symptoms, which makes early diagnosis and treatment difficult. When they do occur, they can last for about 2 to 4 months and include:

Rashes on the skin

One of the symptoms of Chagas disease is the appearance of red rashes on the skin that can itch a lot, causing discomfort and even pain.

Inflammatory nodules

Nodules are abnormal growths on the skin or any type of tissue in the body. In the case of chagas disease, they happen because the disease causes an inflammatory response in the body that ends up generating these growths.

Fever

One of the most characteristic symptoms of Trypanosoma infection is the increase in body temperature, causing high fever (above 37.8 ºC).

Headache

Because of fever and inflammation caused by the disease, symptoms such as headache may also appear.

Increased lymph nodes

Lymph nodes are structures spread throughout the human body and are responsible for filtering part of the blood, removing viruses and bacteria that can present disease.

It is normal that, in cases of infection, the nodes become swollen and increase in size, often becoming visible. In the case of Trypanossoma infection , it is no different.

Nausea, vomiting and diarrhea

The gastrointestinal system is also affected by Trypanosoma infection , which can lead to symptoms such as nausea, vomiting and diarrhea .

Difficulty breathing

Among the organs and systems affected by Trypanossoma are the lungs and the functioning of the bronchi. This can result in difficulty in breathing and shortness of breath.

Symptoms of the chronic phase

The symptoms of the acute phase tend to disappear on their own within 1 to 4 months. Thereafter, the disease enters the chronic phase, which can be divided into two categories:

Undetermined chronic phase

The indeterminate chronic phase can last for years or even decades. There is a total absence of symptoms and, despite this, the parasites are still present in the tissues of the organs.

At this stage, it is even possible to identify the parasite with more accurate tests, but it is hardly diagnosed, precisely because the patient does not have symptoms and, therefore, does not go to the doctor.

Symptomatic chronic phase

In about 30% to 40% of infected patients, the disease progresses to the chronic and symptomatic stage, which is considered the final stage of the disease.

Physical symptoms and signs, in this phase, happen due to three syndromes, which can coexist in the patient at the same time: heart failure, thromboembolism and anginal manifestations.

Heart failure syndrome

Cardiac arrhythmia syndrome causes symptoms such as fatigue , shortness of breath on exertion, pulmonary congestion, shortness of breath at night, weak pulse and a decrease in the body’s overall urine production.

Thromboembolism

Thromboembolism occurs when a blood clot, usually originating in veins in the legs, dislocates and obstructs the passage of blood in the pulmonary arteries.

This problem is common in patients with Chagas disease, as Trypanossoma can cause dysfunctions in blood clotting processes.

Anginal manifestations

The angina technical name of a type of chest pain caused by reduced blood flow to the heart. It causes a feeling of tightness, pressure, weight or pain in the chest, being sudden or chronic.

How is the diagnosis made?

During the acute phase of the infection, it is possible to detect the Trypanosoma cruzi parasites circulating in the blood. The diagnosis can then be made by observing the parasite on a microscopic examination.

The doctors capable of diagnosing this condition are the general practitioner and the infectious disease specialist .

In addition to blood tests, there are other tests that can help in the diagnosis of Chagas disease. Are they:

Electrocardiogram

The electrocardiogram is a procedure that monitors the electrical activity of the heart. Changes in the results can help the medical team determine what stage the disease is in.

chest X-ray

The chest x -ray is an examination that uses electromagnetic radiation to generate images of the internal structures of the body. Through this exam, it is possible to see changes in the heart and raise the suspicion of Chagas disease.

In addition, through this exam it is possible to check the health of the lungs and the presence of embolisms. That way, the medical team will be able to tell you at what stage the disease is.

Echocardiogram

The echocardiogram is a test that uses sound waves to capture images of the heart, allowing the doctor to evaluate the functioning of this organ.

If the medical team already knows about Chagas’ diagnosis, through this exam they will be able to know if she is already in the chronic phase.

If Chagas’ diagnosis is not known, the test may raise suspicion and lead to other tests specific to the disease.

X-ray of the abdomen

The abdomen x-ray also uses electromagnetic radiation to generate internal images of the body. Through this exam, the doctor can check changes in the liver and spleen, which indicates to the medical team that the disease has evolved to the chronic phase.

Upper endoscopy

Upper endoscopy is a procedure in which the patient swallows a tube, called an endoscope, that produces images of the inner part of the esophagus for the camera. Through it it is possible to check the health status of the esophagus and the presence of enlargements.

In cases where there are changes, doctors can more clearly diagnose what stage the disease is in and treat these specific symptoms.

Is there a cure?

Yes , Chagas’ disease can be cured . The earlier it is diagnosed, the greater the chances that the treatment will work. However, if it is diagnosed late, it can bring complications to the heart, intestine and esophagus.

What is the treatment?

The treatment of Chagas disease has the main objective of killing Trypanossoma cruzi , relieving and reducing symptoms.

In the acute phase, prescription drugs are the main form of treatment and are usually effective in eliminating the parasite.

In the chronic phase, however, treatment aims to improve other symptoms caused by the disease, such as problems in the heart and intestines. In addition, it seeks to eliminate the infection in asymptomatic patients.

In the case of patients with decreased heart function, treatment is the same as for heart failure due to other causes. In such cases, there may be a need for transplantation.

Medicines

Among the drugs that can be used to treat Chagas disease are:

Benznidazol ou Benznidazole

The benznidazole or benznidazole is the main drug used in Brazil for the treatment of Chagas disease. It is provided free of charge by the Ministry of Health at the State Health Secretariats.

This medication should be used in the acute phase of the disease and, because it is very toxic, it should be administered for a maximum of 3 to 4 months, being especially effective in the treatment of the acute phase.

Nifurtimox

Treatment with nifurtimox lasts an average of 60 days and the sooner treatment is started, the greater the chance of a cure. Unfortunately, the drug is not yet available in Brazil.

Attention!

NEVER self-medicate or stop using a medication without first consulting a doctor. Only he will be able to tell which medication, dosage and duration of treatment is the most suitable for his specific case. The information contained in this website is only intended to inform, not in any way intended to replace the guidance of a specialist or serve as a recommendation for any type of treatment. Always follow the instructions on the package insert and, if symptoms persist, seek medical or pharmaceutical advice.

Prognosis

When identified in the acute phase, the prognosis for Chagas disease is usually good. In such cases, with the proper medical care, it is possible to reach a cure without major problems.

The problem occurs when the disease becomes chronic. It can bring major complications to heart health, for example. Approximately 6 thousand people die annually in Brazil due to the complications of the chronic phase.

However, the lack of knowledge about the disease and the difficulty in diagnosing and notifying Chagas’ disease can increase this number due to unregistered cases.

Complications

There are some complications that can be caused by Chagas disease. They usually appear in the chronic phase, bringing digestive or cardiac complications. Understand:

Cardiac insufficiency

Heart failure is when the heart is weakened or stiffened. In such cases, he is so weak or stiff that he cannot pump blood properly in order to meet all the needs of the body.

Enlargement of the esophagus

Enlargement of the esophagus, also called megaesophagus, is a common complication of the disease and can cause difficulty in swallowing and digesting food.

Colon enlargement

Colon enlargement occurs when that part of the intestine is dilated, causing abdominal pain, distension and severe constipation .

Sudden death

Sudden death is the main cause of mortality from Chagas’ disease, corresponding to 55% to 65% of deaths. It usually happens when the patient makes a lot of effort.

Since the patient’s heart is already compromised because of the disease, the effort can cause an arrhythmia or cardiac arrest, leading to the patient’s death.

How to prevent Chagas disease?

There are some things that can be done to prevent Chagas disease. Unfortunately, there is still no vaccine to guarantee prevention, however, there are other methods that can be useful depending on the affected region. Are they:

  • Use insecticide in homes and surrounding areas;
  • Improvements in the house to prevent infestation by insect vectors, such as using concrete floors and plastering walls;
  • Maintain hygiene when preparing, transporting and storing food.

It is also possible to prevent vertical transmission through examinations. If the pregnant woman detects a possible infection, it is easier to prevent the disease from being transmitted vertically, that is, from mother to child.

Risk areas

Another way to prevent Chagas disease is to avoid moving to areas at risk and, if it is necessary to go to the region, to take preventive measures such as using insect repellents.

All Brazilian states have some risk of vector transmission, however, insects do not usually appear in cities, concentrating more in rural areas.

Therefore, depending on the region, the tactics adopted by government agencies in controlling the disease are different.

With the exception of the Legal Amazon – a Brazilian region composed of the states of Acre, Amapá, Amazonas, Roraima, Rondônia, Pará and part of Tocantins, Maranhão and Mato Grosso – the policy adopted by the state is to prevent the formation of colonies of the insect vector.

In the states of the Legal Amazon, the tactic adopted by the government is to try to detect acute cases and outbreaks, seeking to treat patients in the acute phase, avoiding complications.

What to do when you find a barber at home?

The beetles we find in our homes are not always barbers. This is because there are several different species that are very anatomically similar to the transmitter of Chagas disease.

In addition, it is necessary to check whether the beetle, if it is a barber, is infected and can transmit the disease or not.

To resolve these doubts, carry out prevention and provide guidance, there are Zoonosis Control Centers or Units. This government agency is responsible for controlling infectious diseases in animals, such as dengue , rabies and Chagas disease itself.

When you suspect the incidence of a barber in your home, there are 3 options:

  1. Call the Call Center of your city and inform of the suspicion: the Center will contact the Zoonosis Control, who will go to your residence to collect the insect;
  2. Call the Zoonoses Control Center directly: this will make the organ go to your home to collect the suspect animal;
  3. Carefully collect the animal and take it to the nearest health facility: you must keep the suspect beetle in a pot with holes in the lid so that it does not die on the way.

Once collected, the Zoonosis Control will check whether the beetle is a barber or not and whether or not it can transmit the disease.

Once it is confirmed that the collected barber is infected and is at risk of transmitting the disease, the Zoonosis Control Center itself will go to your home to analyze the location and check the incidence of these animals.

That is, it will seek to know if it is an isolated incident or if there are more beetles in the region.

From this analysis, the agents will remove the insects and provide all necessary guidance so that it does not reappear.

It is very important that you follow these guidelines, as this will prevent this disease from spreading and end up infecting other people.

Common questions

Is there a vaccine for Chagas disease?

No. Unfortunately, there is still no vaccine that can prevent infection with Chagas disease.

How long does a person live with Chagas disease?

It depends . The disease can take up to 30 years to manifest and this will vary according to the patient’s general health.

What is the risk of consuming açaí?

About 80% of Chagas disease transmissions happen due to the ingestion of contaminated food, with açaí being one of the main foods to cause this infection.

Usually, the barber ends up depositing his feces on the stored fruit, as the sweet smell of the food is attractive to the insect.

As long as proper hygiene measures are taken, which involve washing and pasteurizing the fruit, there are no risks.

Pasteurization is an industrial process that exposes the product to temperatures above 80ºC for about a minute to eliminate any parasites found in the food.

You can make sure that the açaí you are buying has gone through all the proper hygiene processes by checking for the Ministry of Health or Agriculture Ministry seal.


Chagas disease is transmitted by very characteristic insects and combating these animals is key to decreasing the prevalence of the disease.

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