Chagas disease

Chagas disease: description

Chagas disease (American trypanosomiasis) is an infectious disease caused by one-celled parasites (Trypanosoma cruzi). The pathogen is transmitted through the bites of raub bugs. Predatory bugs live mainly in dry wood crevices and thatched roofs, therefore endangered are above all people who live in such simple conditions. The Chagas disease occurs mainly in Central and South America, occasionally in the southern United States.

The time between the predator bite and the onset of the disease (incubation period) is between five and 20 days. However, the pathogen can also be transmitted by infected blood transfusions; then the incubation period is 30 to 40 days. Chagas’ disease occurs at various stages. In the end, there is often a chronic disease, the consequences of which can be fatal.

Worldwide, about seven to eight million people are infected with the causative agent of Chagas disease. The majority of them are inhabitants of the endemic areas. About 70 percent of all infected people do not have strong symptoms throughout their lives and therefore usually know nothing about their infection. You can pass on the pathogen at any time.

Chagas disease: symptoms

Not all infected people express Chagas’ disease with acute symptoms. First and foremost, children and adolescents under the age of 15 are affected by the disease. It is divided into two stages, one acute and one chronic. In between, there may be a long symptom-free phase (latency phase):

Acute phase of Chagas disease:

One third of all infected people have acute symptoms of Chagas disease. First, the spot where the pathogen has entered the body (the bite of the predatory bug) swells and can turn red. In many cases, the so-called Romaña syndrome occurs, that is, the entry point swells, the lymph nodes of the environment are thickened and there is conjunctivitis when the injection site is close to the eye.

Within a few days the following symptoms occur:

• fever
• shortness of breath
• stomach pain
• diarrhea
• lymphadenopathy
• Enlargement of the liver and spleen

Newborns and infants who are particularly affected by acute Chagas disease can also experience complications that can be fatal:

• Myocarditis (myocarditis)
• Brain inflammation (encephalitis)

The symptoms of acute Chagas disease persist for about four weeks. In many cases, the disease is cured and there are no further complaints.

Latent phase:

Over a period of up to 20 years, the pathogens of Chagas disease can remain in the body after an acute course, but show no symptoms. With a weakening of the immune system, such as a cold, complaints of the acute phase can occur again, which, however, are usually not attributed to those affected by Chagas disease.

Chronic phase of Chagas disease:

In about 30 percent of those infected, Chagas’ disease is chronic. Most of the time it comes to a heart muscle inflammation and chronic heart failure (heart failure), which can lead to sudden cardiac death.

In addition, the following symptoms may occur:

• Chest tightness and pain in the heart area (angina pectoris)
• Arrhythmia
• Partial or complete occlusion of an artery due to alluvial blood clots (arterial emboli)
• Palpitations, tachycardia
• Expansion of the heart (Megacor)
• shortness of breath
• pulmonary edema

In rare cases, symptoms of chronic Chagas’ disease can also be found in the digestive tract, usually in the form of enlargement of the intestine (megacolon) and enlargement of the esophagus (megaesophagus). In the early stages there is more diarrhea and severe pain, followed by chronic constipation, nausea, vomiting, chills and palpitations. Untreated, the megacolon can lead to a breakthrough of the intestine (perforation) and end in death. Infestation of the lungs and the nervous system is possible, but very rare.

Chagas Disease: Causes and Risk Factors

The causative agents of Chagas’ disease are small, single-celled parasites (trypanosomes) that are transmitted to humans by various types of predatory bugs. The raub bugs infect themselves with the pathogen by sucking on infected people or – far more often – on infected domestic and farm animals. In the case of blood sucking, but rather bugs, infectious faeces. If the feces come into contact with the conjunctiva of the eyes, mucous membranes or skin injuries, the pathogen can invade the body. In most cases, the victims still help him: As bugs of predator bites itch strongly, those affected often scratch themselves and rub the pathogens in the wound.

In rare cases, the pathogens of Chagas’ disease are transmitted by blood transfusions or organ transplants. An infection before or during the birth of an infected mother on her child or during breastfeeding is possible.

Chagas disease: examinations and diagnosis

The diagnosis of Chagas disease consists of three parts:

First, the Medical history (anamnesis) The description of the symptoms and the reference to southern or central American areas as countries of origin or country of origin provide initial indications of Chagas disease. The doctor can then give you further symptoms physical examination determine.

However, a clear diagnosis is only with the help of one blood test possible. An attempt is made to detect the pathogen microscopically in the blood. Since the pathogen is not directly detectable in all cases, it is also checked whether there are antibodies in the blood that are specifically directed against trypanosomes. The necessary investigations are carried out in special laboratories. It can also exclude other infectious diseases with similar symptoms such as typhoid or malaria.

If the Chagas disease is already in the chronic phase, effects in the brain can be detected by computed tomography (CT) or magnetic resonance imaging (MRI). If the heart muscle is affected, this can be detected with a heart ultrasound (echocardiography).

Chagas disease: treatment

For the treatment of Chagas disease, especially two drugs are used: benznidazole and nifurtimox. The remedies are so-called antiprotozoics, ie agents that specifically fight and kill single-celled parasites. Nifurtimox is given for about 120 days, and benznidazole for about half as long. Both medicines should not be taken by pregnant women and people with kidney or liver failure.

The two active ingredients only lead to success in the acute phase. In the latency phase, the effect of the therapy is controversial; In the chronic phase no benefit could be proven by antiprotozoa. Here are directly the symptoms that show in the heart or in the digestive tract, treated.

The earlier the treatment of Chagas disease begins after the infection, the better the chances of recovery. Rapid drug treatment can also reduce consequential damage to the heart or digestive tract.

Chagas Disease: Prevention

As a tourist, you can prevent Chagas disease: do not sleep in straw, mud or wooden huts, but sleep in an intact tent that protects you well against predatory bugs. In addition, insect repellents offer good protection against predatory bugs and thus against Chagas’ disease. They are offered as sprays or lotions in every pharmacy without prescription. If you are outdoors, a mosquito net and tight clothing protects. A vaccination against the Chagas disease there is not any.

Chagas disease: disease course and prognosis

The prognosis in Chagas’ disease depends primarily on whether complications occur and how severely the heart is affected (in the form of heart failure, for example).

If there are no changes in the heart of a patient, the prognosis is generally favorable. With rapid treatment in the acute phase, sufferers can then be completely cured.

On the other hand, if heart muscle or brain inflammation occurs in the acute phase of Chagas’ disease, this can be fatal, especially in infants. In a chronic course of the disease depends on the extent of heart failure and the success of their treatment. Most patients die from sudden cardiac death (as a result of heart failure). Other causes of a fatal outcome of Chagas’ disease are pulmonary infarction, peritonitis and intestinal perforation.