ABC | Volume 113, Nº2, August 2019

Anatomopathological Correlation Pinesi et al. 26-year-old man with congenital chagas disease and heart transplantation Arq Bras Cardiol. 2019; 113(2):286-293 Figure 5 – Post-transplantation electrocardiogram: low frontal plane voltage and end-conduction disorder. transmitted in different ways. Vector transmission through hematophagous insects is the most classic one, although it has declined in importance in recent years with measures to control the vector population. 2 Transfusion transmission, as well as vector transmission, have shown a drastic reduction in the last decades, and no cases have been reported in Brazil for years. 3 In contrast, there was an increase in reports of oral transmission. This form of contagion was little known but gained importance, with several descriptions of micro‑epidemic events in the country, especially related to the consumption of açai berry. The development of the acute phase of the disease is more common in the oral transmission. 4 In the context of controlling the main forms of contagion, vertical transmission has become relevant. The World Health Organization (WHO) estimates there are approximately 8 million individuals infected with Chagas disease worldwide, with an annual mortality of 10,000 people due to disease complications. 5 Most of these cases are found in Latin America, and Brazil is the country with the majority of infected individuals (approximately 4.6 million individuals). The decrease in transmission was accompanied by a reduction in mortality, estimated in 2007 to be 2.78 deaths/year for every 10,000 inhabitants. 6 Another change in the disease epidemiology in recent years has been the increase in cases in non-endemic regions, such as the USA and Europe, which has contributed to the increased attention given by the international scientific community to Chagas’ disease. 5 The pathophysiology of Chagas' disease is multifactorial, depending on several characteristics of both the host and the parasite. 7 It is known that the inflammatory response triggered by the parasite plays a crucial role in this pathophysiology. 8 This hypothesis is supported by low tissue parasitism and low parasitemia in the chronic phases of the disease. More recent studies have identified an autoimmune response triggered by the cross-reaction between parasite antigens and host proteins, such as troponin. 9 Diagnosis is attained by serological tests in the vast majority of cases, with the direct investigation of the parasitic agent being reserved for acute phases or reactivations, situations in which the parasitemia may be higher. 7 Congenital Chagas’ disease is a separate group. It occurs when there is vertical transmission, that is, during pregnancy. In Brazil, Martins-Melo et al. 10 demonstrated that the mean prevalence of infected pregnant women is 1.7%, with a mean percentage of congenital transmission of 1.7%. Extrapolating these data to the population based on the 2010 census, Brazil would have approximately 34,629 infected pregnant women, with an incidence of 587 children born with congenital Chagas per year. 10 Due to these numbers, the WHO recommended in 2018 increased attention to cases of congenital Chagas through maternal-fetal transmission, not only in Brazil, but in all countries with endemic disease. In a study carried out in Argentina in 2014, Fabbro et al. 11 demonstrated that children of pregnant women who received treatment with antitrypanosomal drugs during their lives have a much lower chance of developing congenital Chagas’ disease than children of women who have not been treated. 11 Thus, in addition to indications of etiological treatment included in the I Latin American Guideline for Chagas' disease in 2011, it is recommended that women of childbearing age also receive antitrypanosomal drugs. In Brazil, the available drug is benznidazole, which should be used at a dose of 5mg/kg/day divided into 2 or 3 doses a day for 60 days. 7 It is worth noting that benznidazole use is contraindicated during pregnancy, due to the risk of teratogenicity found in animal studies. 12 The clinical picture of congenital Chagas disease is extremely variable and non-specific, being similar to several other infections seen in the neonatal period, such as toxoplasmosis, rubella, HIV and syphilis. The main symptoms are preterm birth, intrauterine growth restriction, neuropsychomotor development deficit, low Apgar score, respiratory distress syndrome, jaundice, and hepatosplenomegaly. These symptoms may appear days or even weeks after birth. Mortality is approximately 5% and is usually related to more severe manifestations, such as meningitis and myocarditis. 13 The diagnosis, in addition to the clinical picture, is based on the direct screening for the parasite up to 6 months of age and on the serological tests after 9 months, due to the presence of circulating antibodies from the mother. All cases should be treated with antitrypanosomal drugs as soon as the diagnosis is confirmed. 14 The earlier treatment is implemented, the lower the incidence of side effects and the higher the cure rate, which is 100% when implemented in the first year of life. 12 289