How dangerous is Chagas disease? Causes, symptoms, diagnosis and treatment

Sometimes insects can bring a person serious enough trouble. One of them is Chagas disease, or Chagas, caused by blood-sucking bugs. It was described more than 100 years ago by Brazilian doctor Carlos Ribeiro Chagas, than he perpetuated himself. The name of the disease sounds differently, depending on the pronunciation of the surname of its discoverer. Is Chagas disease dangerous and how serious is it? The answer to this question is positive. Yes, it is dangerous, although there are people who live with this ailment for many years without even suspecting that they are infected. But this is, rather, an exception than the rule. The more common result of the disease is sad: patients die within the first months after infection. How and where can you catch this infection and why do people have such a different reaction to it? Let's try to answer.

Chagas disease: geographical location

For the Russians, fortunately, while this ailment is exotic. But sometime and AIDS from us was far away, somewhere there, in overseas America. The same situation at the moment shows and Chagas disease. Where is it spread now? Among the people enrolled en masse on the South American continent and in some countries of the Caribbean, Brazil, Venezuela, Panama, Mexico, Peru, Argentina, Guatemala, Colombia, Ecuador, Costa Rica, Paraguay, Bolivia, Suriname, El Salvador, French Guiana , Belize, Nicaragua, Honduras. As for wild animals, which are also infected with Chagas disease (proteins, rats, opossums, cats, dogs and others, in total 150 species), infection is seen significantly to the north. This gives rise to fears that the disease will soon spread to the North American continent. Already there are cases of disease in Texas, Arizona, southern California and Maryland. Promotion of American trypanosomiasis on the planet is facilitated by migration of the population that has been going on beyond the control of the last 15-20 years. Inhabitants of the Latin American countries travel on light in searches of the best life, tourists - in search of adventures. Another reason for spreading the infection is that the poor from the above-mentioned regions not only grab for any work, but for money donate blood and even sell their organs (kidneys, eyes, etc.). When tested at some blood transfusion stations in the United States, it was found that the donor material with Chagas disease is greater than with hepatitis and AIDS. And at the autopsy of those who died of heart attacks or acute heart failure of people from the Latin American region, it turned out that every second person suffers from the same disease, only suffers chronic illness. So in the near future the borders of the Chagas disease area are likely to disappear.

Pathogens of the disease

The little-known Chagas disease is infection with microscopic unicellular living parasites - Trypanosoma cruzi. So they named Carlos Chagas in honor of the institute Osvaldo Cruz. These creatures are colorless (in the photo they are shown in the patient's blood, colored with a marker), with an elongated body resembling a spindle. At one end, there is a flagellum that helps trypanosomes move through the body of the victim (mostly by blood). Reaching the organ they need, they penetrate the membranes into the cells and form a formless egg-like form (amastigot). In cells, trypanosomes actively multiply, again forming spindle-like "babies" with flagella, which penetrate the blood of the victim for further settling through the body. A very bad feature of these microscopic assassins is that they are able to influence the immunity of the victim, forcing him to give up the fight. Trypanosomes lead exclusively parasitic way of life, making thus a way: the person (animal) - a bug - the person (animal). These circles of the life cycle are changing their forms: from the egg to the adult. They actively multiply and in the stomachs of bedbugs, which are used to move into the bodies of healthy people.

Ways of infection

Chagas disease, the carrier of which is a special kind of blood-sucking triathom bug, is picked up mainly at night, while sleeping in the premises where these insects live. Someone jokingly called them "kissing", because they prefer to bite mostly on the lips. The name was fixed. True, not everywhere. In Chile and Argentina they are called uncomplicated - vinchuca, which means an insect, and in Brazil - a bug-barber. In total, among a large army of triathom bugs numbering 130 species, in only one of the Americas were found more than 10 species that carry the microorganism such as the causative agent of Chagas disease. In addition to insects, you can get infected from a sick person with close contact if his blood gets into the body of a healthy contactor through the wounds on the skin. What is not a new AIDS? Therefore, often the infection occurs in hospitals with blood transfusions or organ transplants. Infants are still infected in the womb, if they are carriers of the disease. The most peaceful way to catch an infection is through the food on which the feces of the bug fell. This can happen if people who are infected with Chagas disease have not cooked cleanliness. Therefore, when traveling in countries that are not suitable for triathom bugs, it is advisable to choose a place for overnight accommodation more civilized (the hotel is better), to buy the fruit and vegetables carefully, and to abstain from domestic food that the local merchants offerfully offer.

How does the infection occur?

Many people think that Chagas disease is caught when a bug bites through the skin and starts to drink blood. In fact, this is not so. You can be bitten ten times and stay healthy. And all because the infection occurs when the victim makes trypanosome kruzi, located in the feces of the bug, in your skin or mucous. These insects belong to the people who eat where they eat and shit. A person in a dream involuntarily scratches (and animals lick) a bitten place. So parasites fall into the body of their new master. By itself, a healthy bug is not dangerous. But by biting infected people, it almost completely gets infected with trypanosomes, and with the next bites the Chagas disease is transmitted to new victims. The causative agent lives and multiplies in the stomach of the insect. Infectious bug remains his whole life (approximately 2 years). Ripe parasites are localized in the intestines of the victim and are excreted outward with feces. Once in the human body, trypanosomes first multiply in the blood, and then settle in the muscles (mainly in the heart and in the epithelium of the digestive tract). The poor people in Latin America live in crowded, large families, in dilapidated houses, where there are many nooks for bugs. Quite often Chagas disease infected all family members and even entire neighborhoods. Information for consideration: laboratory animals were infected with trypanosomes even when there was no damage to their skin.

Acute form of the disease

It is noted that the moment of biting by the bug of the skin is painless and imperceptible. Subsequently, a small redness appears in that place (and sometimes there is nothing), some people have swelling and itching. The latent (incubation) period, as long as the parasite in the victim's blood is diligently multiplying, can take from a couple of days to 10 days, depending on the strength of the patient's body and its propensity for allergy. Then comes the so-called acute form. It is during this period that Chagas disease is extremely dangerous by lethality. Symptoms are as follows:

• A sharp rise in temperature to critical levels;
• fever;
• Severe headaches;
• Problems with breathing;
• Malfunctioning of the heart;
• Significant abdominal pain, chest, all muscles;
• Defeat of the adrenal glands;
• An increase in the thyroid gland, spleen, lymph nodes.

When introducing parasites into nerve fibers, Chagas disease is particularly difficult. Symptoms in this case are:

• Paralysis;
• Speech impairment;
• Athetosis;
• Infringement of intelligence.

External manifestations:

• Swelling of the lips;
• Swelling of the eyes;
• Purchase of a bronze hue by the skin.

The acute form can last two months, during which many (especially children) die. In survivors of the crisis, the main symptoms disappear, and the disease passes into the next stage. The infectious person becomes infected 10-11 days after the bite.

Chronic form

At this stage, Chagas disease can for a long time not manifest at all, which is observed in about 80% of patients. Trypanosomes in the blood no longer dominate, but settle in the tissues and cells of the patient and gradually destroy them. The "chronicles" are periodically observed exacerbations, followed by a complete remission. Chagas identified the following types of chronic course of the disease:

• Pseudomicroxidematous;
• Myxedematous;
• Nervous;
• Heart.

Pseudomixidematous type is noted in children aged 15 years and under. It is characterized by a slight increase in thyroid gland and lymph nodes. During periods of exacerbations, children develop fever, fever, tachycardia. Parasites infiltrate into the subcutaneous tissue, which especially disfigures the face. For characteristic swelling and redness, Chagas disease can be visually recognized. Photos presented in a wide range of specialized medical resources, cause, to put it mildly, unpleasant sensations.

Myxedematous type differs from the previous one in much larger disruptions in the thyroid gland.

The nervous type is fraught with a delay in the development of children and infantilism.

Cardiac results in pericarditis, bradycardia and other heart problems.

With the localization of trypanosomes, cruzes in the walls of the organs of the gastrointestinal tract are accompanied by achalasia of the cardia, that is, disturbances in the peristalsis of the musculature of these organs. This leads to an obstruction of the esophagus and an increase in the parts of the stomach and intestines. Patients experience pain when swallowing food and passing through the esophagus, vomiting, belching, loss of body weight, despite a satisfactory appetite. These symptoms do not depend on the consistency of food and appear even from liquid foods.

Diagnostics

Chagas disease is established by external signs during a clinical examination of the patient and by further laboratory studies of blood under a microscope and serological tests. However, in the chronic form of the disease in the blood, trypanosomes remain small, and therefore it becomes more difficult to detect them.

When parasites can not be isolated in a blood sample, their presence is checked in the lymph nodes (biopsy).

Also apply xenodiagnostics. It consists in the fact that laboratory healthy bugs are planted on a sick person, and later (after 14 days) they study whether parasites have appeared in their intestines or not.

Another test is the sowing of blood and grafting it to experimental animals.

Blood transfusion stations use methods based on the reactions of fluorescent antibodies, as well as gamma-glutination inhibition reactions, which are more sensitive, although not so specific.

Good results are also shown by the Mashad-Guerreiro trial. It is based on the reaction of binding a compliment, that is, on the detection of antibodies to the parasite antigen. This analysis is extremely valuable in the chronic stage of the disease, when other methods are not particularly strong.

Treatment

Currently, there are already such drugs, with which you can completely defeat Chagas disease. Unfortunately, the treatment is effective only at the initial stage, until the trypanosomes penetrate the vital organs. This is Nifurtimox and Benznidazole. They can be purchased in the US and Latin America strictly according to the prescription. Assign these medications to patients with acute disease, to children, during relapse, if the chronic form of the disease is not neglected. At later stages it does not help at all. Therefore, all the actions of doctors are focused on the treatment of complications - heart disease, gastrointestinal tract, nervous system, thyroid and other organs.

Forecast

Many people, especially those who have an apparent recovery after an acute form, do not think how dangerous Chagas disease is. Meanwhile, about 50,000 people die of it every year from it. Infected at the moment, according to various estimates, from 15 to 20 million people, but these figures are not entirely reliable, since the poor, among whom Chagas / Chagas disease is particularly widespread, turn to doctors very rarely. The prognosis for this disease is favorable only in cases of early correct diagnosis and treatment. At the initial stage, if measures are taken in time, an absolute recovery is possible. Late ones can not be cured anymore. It is also impossible to restore the affected and destroyed parasites organs. Annually, in the presence of chronic disease, many patients die from acute heart failure, heart attacks, strokes and other health problems caused by trypanosomes cruzi.

Prevention

To avoid Chagas disease, prevention is extremely important, since there is no vaccine against trypanosome cruzi. For residents of dangerous regions, it is as follows:

• As closely as possible to inspect their homes for the detection of nests of bedbugs, whenever possible, sanitation with insecticides in homes;
• If there is an opportunity, to build over the beds canopies;
• Observe hygiene.

For tourists:

• Avoid visiting the jungle, especially in open summer clothes;
• Critically approach the choice of a place to stay overnight;
• Do not be tempted by the overseas delicacies for a snack, offered by street and market traders (if there is no certainty that the food was prepared keeping hygienic standards).

For sanitary and epidemiological services:

• To examine infants and older children whose mothers have Chagas disease;
• To carry out the reconstruction of dilapidated buildings;
• Regularly sanitize insecticides living quarters of citizens;
• Screening of donor blood, and carefully screening donors.

There is a proposal to examine all emigrants coming from the epidemic countries, which should prevent the spread of Chagas disease in other regions. However, given the high contamination with trypanosomes of Cruzi animals, the problem with the disease in the coming years is unlikely to be resolved.