A neglected parasitic disease, Chagas disease is considered endemic in low-income populations in numerous Latin American countries. Due to migratory movements over the last decades, it has also become present in many European countries, the United States, Japan and Australia, for example.

Current estimates show that Chagas disease affects around 8 million people worldwide, and 1.9 to 4.6 million in Brazil. It is, therefore, a public health problem that represents a large socioeconomic impact on the countries of Latin America.

To break the cycle of neglect, it is essential to educate people about the risk factors for infection, to have up-to-date clinical management protocols, trained health professionals and supplies to offer diagnosis and treatment.

It was precisely to warn about the importance of awareness regarding the fight against the disease that was stipulated, as of 2020, April 14th as the World Day of Chagas Disease, a flag raised by the Brazilian Society of Car diology (SBC) , since it is a disease that affects the heart, which can lead the individual to death due to heart failure, arrhythmias and thrombotic complications.

Due to the importance of the subject, the entity is developing a new guideline on cardiomyopathy caused by Chagas disease, which is updated about 10 years from the previous guideline, published in 2011. “The document, prepared by specialists based on the best scientific evidence, aims to guide health professionals, managers and patients on the best practices to be followed in the management of cardiomyopathy and Chagas disease, hoping that this will be incorporated into basic public health care services in Brazil and in other countries endemic countries” , explains Anis Rassi Junior, one of the editors of the new guideline and scientific director of the Anis Rassi Hospital in Goiânia.

A major objective with the new guideline is to improve the list of conducts to be recommended based on a hierarchical set and meticulously examined by specialists in the so-called scientific evidence that support the recommendations themselves. In essence, scientific evidence is the rational basis for which a recommendation is strong, that is, it must be applied routinely, or weakly, conditionally, requiring an individualized decision for the various clinical scenarios and patients with cardiomyopathy.

“In this sense, given the scarcity of specific studies with individuals affected by Chagas disease, it is very important to demonstrate the level of evidence corresponding to each diagnostic and, above all, therapeutic recommendation, to ensure the best application bility and scope of the guideline”, exposes José Antonio Marin-Neto, also editor of the new guideline and head professor of cardiology at the University of São Paulo (USP) in Ribeirão Preto.

According to Rassi Junior, the document is quite comprehensive, with an extensive review of the literature and a proposal for a new classification for the classes of recommendations and levels of evidence, since most of the therapeutic recommendations for Chagas’ disease cardiomyopathy are extrapolated from results of randomized clinical studies carried out in other heart diseases.

“A greater emphasis will be given to the role of the etiological treatment in preventing the appearance or delaying the progression of heart lesions. Another question to be answered is: to what extent can we extrapolate the recommendations related to the treatment of heart failure and cardiac arrhythmias in other diseases to the heart disease of Chagas disease?

For Marin-Neto, fortunately we are experiencing a more auspicious phase than a few decades ago, because there is more interest, more motivation, more stimulus and more resources for research. “We even count on the contribution of investigations carried out by and with the support of so-called non-endemic countries”, he reveals.

In Spain, for example, where it is estimated that there are 70,000 chronically infected individuals, Chagas disease is recognized as a real public health problem. Due to migratory factors, the disease, which was previously only found in rural areas and in socioeconomically vulnerable populations, common in Latin American countries in general, is now detected in substantial numbers in several European countries, due to the Latin Americans who settled down in these regions. For the same reason, there are also cases in Japan, Australia and New Zealand. In the United States, the most conservative estimate accounts for at least 300,000 individuals with the disease.

“Chagas disease has, in fact, become literally cosmopolitan, and there are recent publications that show how it has become a global challenge, which is why it needs to be better addressed and receive more investments. We hope that the SBC’s new guideline will contribute, in a certain way, to this”, highlights Marin-Neto.

Structure

The new guideline has 15 chapters, starting with epidemiology, with updates on everything that happened over the last decades. In the United States, for example, although considered a non-endemic country, the estimates shown above constitute a great concern, so much so that, according to federal policy, blood or organ donors must show two negative tests for Chagas disease, so that the donation be allowed.

Another chapter deals with conduct, guiding doctors, managers and even patients on certain situations, such as the practice of physical exercises; risk during anesthesia for surgical procedures related to other diseases; Chagas disease in pregnant women, which requires special treatment; and the development of Covid-19 in the individual with Chagas disease, due to double inflammation of the heart (the arising from the viral pandemic added to caused by T. cruzi).

The guideline also is objective to help de-stigmatize the social condition of the patient, who cannot be limited by the disease, without access to job, nor to therapeutic and diagnosis resources. According to Marin-Neto, when the individual has the indeterminate form of the disease (the most prevalent in the chronically infected population), in which the heart attack has not yet manifested, he is not limited in anything, and may even exercise any type of function or job.

“We need to release it for physical exercises and any professions, because we have epidemiological evidence showing that while the heart attack is not clinically perceptible, the life expectancy is similar to that of an individual of the same age and sex who does not have the disease. They need to be protected psychologically and also from a social point of view”, he says, emphasizing that one of the last chapters, on the structuring of dedicated services, was developed to primarily serve these patients and leave them in less vulnerable conditions.

Gláucia Maria Moraes de Oliveira, a member of the Fiscal Council of the Brazilian Society of Cardiology (SBC), is also part of the group of three fundamental editors of the new guideline. “We would like to emphasize the importance of the guideline to help approach Chagas disease, which will be highlighted in a guideline session and also in a discussion on the treatment of the disease within the global scope of neglected diseases”, she stresses.

Challenges

One of the main challenges related to Chagas disease, not only in Brazil, but in any endemic country, is having accurate knowledge about the number of individuals infected with Trypanosoma cruzi. “It is even more important to find out where these people are so that they can be diagnosed and treated satisfactorily, still in an early stage, given that there is a gap of 10 to 30 years between the transmission of the infection and the appearance of the chronic disease. cardiac and/or digestive system”, explains Rassi Junior.

According to the World Health Organization, it is estimated that more than 70 to 80 million people are at risk of contracting the infection. And what is more serious, out of every ten people affected, seven are unaware of their condition and only 1% of the candidates for the etiological treatment actually receive the antiparasitic drug (benznidazole or nifurtimox), the only effective drugs currently available.

Being diagnosed early and having a good response to specific treatment is the only way to avoid the chronic sequelae of the disease. “Thus, it is necessary, in the first place, that both (diagnosis and treatment) are duly incorporated into primary health care and are easily accessible. Afterwards, it is necessary that the trypanocidal treatment, in all stages of the disease, become a reality, covering the largest possible number of infected individuals”, explains Rassi Junior.

Marin-Neto takes advantage of World Chagas Disease Day to revere the memory of Professor Anis Rassi, who died last year, aged 90, and contributed greatly to studies on the disease. “Over the last decades, we have lost other important figures, such as professors Aluizio Prata and Romeu Cançado and, more recently, professors Zilton Andrade and José Rodrigues Coura.”

The new guideline was published bilingually, in Portuguese and English.

Original text: https://www.portal.cardiol.br/post/sbc-lançará-nova-diretriz-sobre-a-cardiomiopatia-da-doença-de-chagas-durante-77º-cbc