Frequently asked questions about the disease

What is the Chagas disease?.
It is a disease transmitted by an insect (Kissing bedbug or vinchuca) and it is produce by a parasite.(trypanosoma cruzi) affecting adults and kids as well as hot blooded animals. It seriously damages the heart and other organs like the nervous and digestive system .

What produces it?.
The causal agent is the Trypanosoma cruzi which is a hemoflagellate parasite that reproduce itself inside the tissues cells and circulates free in the blood. It has great mobility and its length is similar to 3 red corpuscles. In the initial stages of the infection parasites appear diminishing since the third or fourth month of the infection as the immunological defenses grow in the organism.

Who can get infected?.

The human being wild animals and domestic mammals (dogs, cats, etc) exposed to the bites of infected vinchucas, are sensible to this parasitosis. The birds ca also suffer the bites of these insects but they do not get infected.

Can domestic animals transmit the disease?

Not directly infected animals act like reserving of parasites, when the vinchucas bite them they get infected and in posterior bites the infection can be transmitted to an animals or healthy person, completing, in this way, the cycle. Birds can not be reserving of parasites.

How the disease evolves?.

There are 3 clinical stages: acute, indeterminate and chronic. These stages have different clinical evolutional, anatomical and pathological characters.

What are those stages?

The acute disease immediately appears right after the transmission of the disease. The indeterminate stage may last all lifetime and the chronic stage might happen in a percentage that goes from 20% and 30% of the patients causing injuries.

What kind of injuries?

Cardiac injuries and in the central and peripheral nervous system. It also affects the digestive.

Is Chagas disease mortal?

The mortality of acute Chagas varies from 1% to 5% with major incidence in young kids. This disease may became mortal in those patients that develop serious cardiac injuries which takes to death in syncopal form or progressive cardiac failure.

Fortunately, this percentage is not very high ini nfected people. On the other hand, there are efficient clinical treatments that diminish the mortality in high percentage.

Frequently Asked Questions about the infection.

How is it transmitted?

The ways are vectorial (by the Kissing bedbug or vinchuca), blood transfusion, transplacental (during pregnancy or delivery) and by transplants.

How the vectorial infection is produced?

It is produced by the kissing bedbug or vinchuca. It is an insect that only eats human blood of blood from warm-blooded animals. The vinchuca can infect only if it has already eaten blood from an infected human or animal. The insect immediately defecates right after each meal. If the insect is infected, the feces will contain trypanosomes and if these feces are deposited on the skin, the parasites may enter through scratches or mucus, reaching inside the organism and spreading in the blood and later reaching and staying in the tissues.

Where the point of entry of the infection?

It can be located in any part of the body, but since the vinchuca eats at night, when the individuals is sleeping, the most accessible place is the face. The very thin skin of the eyelids, scratches and the existence of mocus make the entrance of the parasites easier.

How long is the incubation period?.

Since the entrance of the parasites a week passes in which the first generations of parasites are produced in the infected person and in 19-30 days the first clinical symptoms appear.

How frequent are the symptoms that allow the diagnosis of patient with the initial infection ?

Most of the individuals don't realize that they get infected because there are not clear or evident symptoms of the disease. Only 5% of the infected ones (usually children under 5 years old), present some evident signs of the infection ( the most frequent is the chagoma) that characterize the acute disease.

What is the chagoma?

It is a swelling that surrounds the eye ( also called romana sign). It is know in most of the cases because of the swelling in the eyelids. It is painless and the eyelids look very red: also swollen ganglions and some other swollen areas. It appears in 5% of the acute infected patients.

What is the inoculation chagoma?

It is another typical sign of the acute infection, becoming in the point of entry to other parts of the body in which the skin is swollen and reddish. It may became ulcerous and pain may appear in the ganglions that are near to that zone. The healing process of the inoculation chagoma comes spontaneously between 30 and 60 days, but the parasite remains in the blood.

What other clinical aspects can be seen in this period?

The patient might present fever, generalized edema (swelling), increase in the size of the liver spleen and swollen ganglions. The most serious are cardiac and neurological manifestations.

Are these any other clinical aspects that can confuse patients with Chagas disease?

Yes, general symptoms that are applicable to any other infectious disease such as fever, sore muscles anorexia (lost of appetite), vomits, irritability and diarrhea.

Which is the time in the year with major incidence of acute cases?

The incidence of these cases increases during the warm months of the year, when there are many vinchucas and its number increases.

Who can present the severest form of the acute chagasic infection?

According to researches, young children specially in the fist year of life are the ones that present the severest forms.

Can the infection be accidentally transmitted?

Yes, it may happen to people who work manipulating infecting materials in laboratories. To prevent these accidents the laboratories have to have well trained professionals as well as good biosecurity standards.

Can it be transmitted from person to person?.

Only if a healthy person receives infected blood.

Can the ingestion of contaminated (poultry, etc) infect the human being?

It is a accidental mechanism that can happen when the food has contact with the feces of an infected vinchuca. It is not very frequent, hence, not very important epidemiologically.

Source of Information

• La Infección
  Federacion Argentina de Cardiologia
  Foro de Educación Continua en Cardiologia
  http://www.fac.org.ar/fec/chagas/fatala/infec.htm

• La Enfermedad de Chagas
  Federacion Argentina de Cardiologia
  Foro de Educación Continua en Cardiologia
  http://www.fac.org.ar/fec/chagas/fatala/enferm.htm

More Information

• The Chagas Disease
• Historical Review
      • Dr. Carlos Justiniano Riveiro Chagas (1879-1934)
      • Dr. Salvador Mazza (1886 -1946)
      • Dr. Mario Fatala Chabén (1936-1962)
      • Dr. Oswaldo Cruz (1872-1917)
• Medical Information
      • Epidemiology
      • Mortality
      • Race, sex and age.
      • Modes of Transmission
      • Pathophysiology
      • Clinical Information
      • Diagnosis
      • Other Medical Information
• Prevention and Control
• Frequently Asked Questions