<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.1 20151215//EN" "https://jats.nlm.nih.gov/publishing/1.1/JATS-journalpublishing1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink" specific-use="sps-1.9" dtd-version="1.1" xml:lang="pt" article-type="research-article">
  <front>
    <journal-meta>
      <journal-id journal-id-type="publisher-id">abc</journal-id>
      <journal-title-group>
        <journal-title>Arquivos Brasileiros de Cardiologia</journal-title>
        <abbrev-journal-title abbrev-type="publisher">Arq. Bras. Cardiol.</abbrev-journal-title>
      </journal-title-group>
      <issn pub-type="ppub">0066-782X</issn>
      <issn pub-type="epub">1678-4170</issn>
      <publisher>
        <publisher-name>Sociedade Brasileira de Cardiologia - SBC</publisher-name>
        <publisher-loc>S&#227;o Paulo, SP, Brazil</publisher-loc>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v3">RQjKZyfpjgDc6C4NpMwrJrm</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v2">S0066-782X2013002900009</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v1">S0066-782X(13)10100300009</article-id>
      <article-id pub-id-type="doi">10.5935/abc.20130144</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Artigos Originais</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>As manifesta&#231;&#245;es de ECG do maior surto da doen&#231;a de Chagas devido a infec&#231;&#227;o oral na Am&#233;rica Latina</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Marques</surname>
            <given-names>Juan</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Mendoza</surname>
            <given-names>Iv&#225;n</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Noya</surname>
            <given-names>Belkisyol&#233;</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Acquatella</surname>
            <given-names>Harry</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Palacios</surname>
            <given-names>Igor</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Marques-Mejias</surname>
            <given-names>Mar&#237;a</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
      </contrib-group>
      <aff id="aff01">
        <addr-line>
          <named-content content-type="state"/>
        </addr-line>
        <institution content-type="orgname">Universidad Central de Venezuela</institution>
        <country country="VE">Venezuela</country>
      </aff>
      <pub-date date-type="collection" publication-format="electronic">
        <month>09</month>
        <year>2013</year>
      </pub-date>
      <volume>101</volume>
      <issue>3</issue>
      <fpage>249</fpage>
      <lpage>254</lpage>
      <history>
        <date date-type="received">
          <day>27</day>
          <month>11</month>
          <year>2012</year>
        </date>
        <date date-type="accepted">
          <day>15</day>
          <month>04</month>
          <year>2013</year>
        </date>
        <date date-type="rev-recd">
          <day>17</day>
          <month>02</month>
          <year>2013</year>
        </date>
      </history>
      <permissions>
        <license license-type="open-access" xlink:href="http://creativecommons.org/licenses/by-nc/4.0/" xml:lang="en">
          <license-p>This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</license-p>
        </license>
      </permissions>
      <abstract>
        <p>FUNDAMENTO: A doen&#231;a de Chagas afeta mais de 15 milh&#245;es de pessoas em todo o mundo. Embora a transmiss&#227;o vetorial tenha diminu&#237;do, a transmiss&#227;o oral tornou-se relevante. Recentemente, nosso grupo publicou as caracter&#237;sticas cl&#237;nicas e epidemiol&#243;gicas do maior surto relatado at&#233; hoje da doen&#231;a de Chagas transmitida oralmente. OBJETIVO: Descrever altera&#231;&#245;es eletrocardiogr&#225;ficas que ocorrem na popula&#231;&#227;o de estudo durante o surto causado pela ingest&#227;o de suco de goiaba contaminado. M&#201;TODOS: Avaliamos 103 casos positivos, dos quais 76 (74%) tinham &lt;18 anos de idade (m&#233;dia das idades: 9,1 &#177; 3,1 anos) e 27 (26%) tinham &gt;18 anos (m&#233;dia das idades: 46 &#177; 11,8 anos). Todos os pacientes foram submetidos a avalia&#231;&#245;es cl&#237;nicas e ECG. Caso os pacientes apresentassem palpita&#231;&#245;es ou altera&#231;&#245;es evidentes do ritmo na linha basal, o monitoramento de ECG ambulatorial seria realizado. RESULTADOS: Um total de 68 casos(66%;53 crian&#231;as e15 adultos) apresentaram anormalidades no ECG. Al&#233;m disso, 69,7% (53/76) daqueles com idade &lt; 18anos e 56% (15/27) daqueles com idade &gt;18 anos apresentaram alguma altera&#231;&#227;o no ECG(p = ns). Anormalidades de ST-T foram observadas em 37,86% casos (39/103) e arritmias foram evidente sem 28,16% casos(29/103). Altera&#231;&#245;es de ST ocorreram em 72% daqueles com idade &lt; 18 anos em compara&#231;&#227;o aos de &gt; 18 anos (p &lt; 0,0001). CONCLUS&#195;O: Este estudo relata o maior n&#250;mero de casos no mesmo surto de doen&#231;a de Chagas causada por contamina&#231;&#227;o oral, com ECGs relatados. As altera&#231;&#245;es no ECG que sugerem miocardite aguda e arritmias foram as anormalidades encontradas com maior frequ&#234;ncia.</p>
      </abstract>
      <kwd-group xml:lang="pt" kwd-group-type="author-generated">
        <kwd>Doen&#231;a de Chagas</kwd>
        <kwd>Eletrocardiografia</kwd>
        <kwd>Cardiomiopatia Chag&#225;sica</kwd>
        <kwd>Arritmias Card&#237;acas</kwd>
        <kwd>Sucos</kwd>
        <kwd>Contamina&#231;&#227;o</kwd>
      </kwd-group>
      <pub-date publication-format="electronic" date-type="pub">
        <day>26</day>
        <month>07</month>
        <year>2013</year>
      </pub-date>
    </article-meta>
  </front>
  <body>
    <p>
      <bold>As manifesta&#231;&#245;es de ECG do maior surto da doen&#231;a de Chagas devido a infec&#231;&#227;o oral na Am&#233;rica Latina</bold>
    </p>
    <p>
      <bold>Juan Marques; Iv&#225;n Mendoza; Belkisyol&#233; Noya; Harry Acquatella; Igor Palacios; Mar&#237;a Marques-Mejias</bold>
    </p>
    <p>Universidad Central de Venezuela, Venezuela</p>
    <p>
      <xref ref-type="corresp" rid="end">Correspond&#234;ncia</xref>
    </p>
    <p>
      <bold>RESUMO</bold>
    </p>
    <p><bold>FUNDAMENTO:</bold> A doen&#231;a de Chagas afeta mais de 15 milh&#245;es de pessoas em todo o mundo. Embora a transmiss&#227;o vetorial tenha diminu&#237;do, a transmiss&#227;o oral tornou-se relevante. Recentemente, nosso grupo publicou as caracter&#237;sticas cl&#237;nicas e epidemiol&#243;gicas do maior surto relatado at&#233; hoje da doen&#231;a de Chagas transmitida oralmente. </p>
    <p><bold>OBJETIVO:</bold> Descrever altera&#231;&#245;es eletrocardiogr&#225;ficas que ocorrem na popula&#231;&#227;o de estudo durante o surto causado pela ingest&#227;o de suco de goiaba contaminado. </p>
    <p><bold>M&#201;TODOS:</bold> Avaliamos 103 casos positivos, dos quais 76 (74%) tinham <underline>&lt;</underline>18 anos de idade (m&#233;dia das idades: 9,1 &#177; 3,1 anos) e 27 (26%) tinham &gt;18 anos (m&#233;dia das idades: 46 &#177; 11,8 anos). Todos os pacientes foram submetidos a avalia&#231;&#245;es cl&#237;nicas e ECG. Caso os pacientes apresentassem palpita&#231;&#245;es ou altera&#231;&#245;es evidentes do ritmo na linha basal, o monitoramento de ECG ambulatorial seria realizado. </p>
    <p><bold>RESULTADOS:</bold> Um total de 68 casos(66%;53 crian&#231;as e15 adultos) apresentaram anormalidades no ECG. Al&#233;m disso, 69,7% (53/76) daqueles com idade <underline>&lt;</underline> 18anos e 56% (15/27) daqueles com idade &gt;18 anos apresentaram alguma altera&#231;&#227;o no ECG(p = ns). Anormalidades de ST-T foram observadas em 37,86% casos (39/103) e arritmias foram evidente sem 28,16% casos(29/103). Altera&#231;&#245;es de ST ocorreram em 72% daqueles com idade <underline>&lt;</underline> 18 anos em compara&#231;&#227;o aos de &gt; 18 anos (p &lt; 0,0001). </p>
    <p><bold>CONCLUS&#195;O:</bold> Este estudo relata o maior n&#250;mero de casos no mesmo surto de doen&#231;a de Chagas causada por contamina&#231;&#227;o oral, com ECGs relatados. As altera&#231;&#245;es no ECG que sugerem miocardite aguda e arritmias foram as anormalidades encontradas com maior frequ&#234;ncia.</p>
    <p><bold>Palavras-chave:</bold> Doen&#231;a de Chagas / complica&#231;&#245;es, Eletrocardiografia, Cardiomiopatia Chag&#225;sica, Arritmias Card&#237;acas, Sucos, Contamina&#231;&#227;o.</p>
    <p>
      <bold>Introdu&#231;&#227;o</bold>
    </p>
    <p>A doen&#231;a de Chagas &#233; causada pelo <italic>Trypanosoma cruzi</italic> e transmitido por diversos tipos de triatom&#237;neos<sup>1</sup>. &#201; end&#234;mica na Am&#233;rica Latina, embora os fluxos de migra&#231;&#227;o tenham resultado na prolifera&#231;&#227;o da doen&#231;a na Europa e nos Estados Unidos<sup>2,3</sup>. Estima-se que h&#225; aproximadamente 15 milh&#245;es de casos diagnosticados e aproximadamente 109 milh&#245;es de pessoas com risco de contrair esta doen&#231;a<sup>1</sup>. Embora estes n&#250;meros tenham apresentado uma redu&#231;&#227;o de 1990 a 2006<sup>1</sup>, recentemente, a descri&#231;&#227;o de surtos end&#234;micos de doen&#231;a transmitida oralmente abriu uma nova &#225;rea de estudo e an&#225;lise<sup>4-8</sup>. Por ser um meio desconhecido, a contamina&#231;&#227;o via oral tornou-se um dos casos mais ativos na Venezuela, no Brasil, e na Col&#244;mbia<sup>4-8</sup>.</p>
    <p>Nosso grupo publicou anteriormente as caracter&#237;sticas cl&#237;nicas e epidemiol&#243;gicas do maior surto relatado at&#233; hoje da doen&#231;a de Chagas transmitida oralmente<sup>8</sup>. Neste estudo analisamos as manifesta&#231;&#245;es do ECG deste surto, considerado &#250;nico por ocorrer em um ambiente fechado (em uma escola) em uma capital da Am&#233;rica Latina.</p>
    <p>
      <bold>M&#233;todos</bold>
    </p>
    <p>A epidemiologia do surto &#233; apresentada na <xref ref-type="fig" rid="aop_5293fig01">Figura 1</xref><sup>9</sup>. Do total de casos positivos (n = 103), 76 tinham <underline>&lt;</underline> 18 anos (m&#233;dia das idades: 9,1 &#177; 3,1 anos) enquanto 27 tinham &gt; 18 anos (m&#233;dia das idades: 46 &#177; 11,8 anos). Todos os pacientes com diagn&#243;stico positivo ou indefinido foram submetidos ao ECG. Antes do ECG, os pacientes foram entrevistados e fisicamente examinados por um cardiologista. Os crit&#233;rios para as altera&#231;&#245;es do ECG foram baseados nas recomenda&#231;&#245;es de AHA/ACCF/HRS para a padroniza&#231;&#227;o e interpreta&#231;&#227;o de ECGs<sup>9</sup>. As altera&#231;&#245;es no segmento ST foram definidas por uma eleva&#231;&#227;o de <underline>&gt;</underline> 1 mm em uma ou mais deriva&#231;&#245;es nas quais n&#227;o est&#225; presente normalmente. As altera&#231;&#245;es na onda T foram definidas por uma onda T negativa em uma ou mais deriva&#231;&#245;es nas quais n&#227;o est&#225; presente normalmente. Somente os pacientes confirmados (n = 103) foram analisados neste estudo. Caso o paciente tenha relatado palpita&#231;&#245;es, ou se houvesse alguma evid&#234;ncia de dist&#250;rbio do ritmo no ECG da linha basal (arritmias), um monitoramento de ECG ambulatorial (Holter) seria realizado. O ecocardiograma foi realizado em pacientes com anormalidades no ECG. Os resultados foram analisados diferenciando pacientes com mais ou menos de 18 anos utilizando estat&#237;sticas descritivas. A signific&#226;ncia estat&#237;stica foi analisada ao comparar as propor&#231;&#245;es.</p>
    <p content-type="asset">
      <fig id="aop_5293fig01">
        <graphic xlink:href="1678-4170-abc-101-03-0249-30144-gf01.jpg"/></fig>
    </p>
    <p>
      <bold>Resultados</bold>
    </p>
    <p>Um total de 68 casos (66%; 53 crian&#231;as e 15 adultos) apresentaram altera&#231;&#245;es no ECG, enquanto 42 (33.9%; 23 crian&#231;as e 12 adultos) apresentaram ECG normal. Algumas altera&#231;&#245;es relevantes no ECG foram identificadas em 69,7% dos pacientes (53/76) com idade &lt; 18 anos e 55,5% (15/27) com idade &gt; 18 anos (p = ns). As manifesta&#231;&#245;es no ECG est&#227;o descritas na <xref ref-type="table" rid="aop_5293tab01">Tabela 1</xref>. Devido a alguns pacientes terem mais de uma altera&#231;&#227;o no ECG, o n&#250;mero total de altera&#231;&#245;es identificadas &#233; maior que o n&#250;mero de pacientes.</p>
    <p content-type="asset">
      <table-wrap id="aop_5293tab01">
        <graphic xlink:href="1678-4170-abc-101-03-0249-30144-gt01.jpg"/></table-wrap>
    </p>
    <p>O achado mais comum foi uma altera&#231;&#227;o do segmento T e da onda T que estava presente em 37,86% dos casos (39/103). O prolongamento de QT analisado pelo m&#233;todo de Bazett estava presente em 2,91% dos casos (3/103).</p>
    <p>O bloqueio do ramo direito estava presente em 1,94% dos casos (2/103), enquanto a inibi&#231;&#227;o do ramo esquerdo da subdivis&#227;o anterior estava presente em 2,91% dos casos (3/103). Observando os grupos de idade, claramente aqueles com <underline>&lt;</underline> 18 anos apresentaram incid&#234;ncia maior de anormalidades no ST em compara&#231;&#227;o aos com &gt; 18 anos (72% vs. 19%) (p &lt; 0,0001). N&#227;o houve diferen&#231;as significativas em outras altera&#231;&#245;es no ECG entre os dois grupos.</p>
    <p>Os ecocardiogramas foram realizados em 84% dos casos com altera&#231;&#245;es no ECG (57/68). Os ecocardiogramas de 68% dos casos estavam normais, enquanto 32% apresentaram efus&#227;o peric&#225;rdica leve a moderada.</p>
    <p>As arritmias eram evidentes em 32% dos casos (33/103). Os diferentes tipos de arritmias observadas est&#227;o exibidos na <xref ref-type="table" rid="aop_5293tab02">Tabela 2</xref>. As arritmias supraventriculares ocorreram em 22,3% dos casos (23/103), ventriculares em 5,8% dos casos (6/103), e bloqueio atrioventricular em 2,91% dos casos (3/103).</p>
    <p content-type="asset">
      <table-wrap id="aop_5293tab02">
        <graphic xlink:href="1678-4170-abc-101-03-0249-30144-gt02.jpg"/></table-wrap>
    </p>
    <p>A taquicardia sinusal inapropriada foi a arritmia mais comum em 9,71% dos casos (10/103), seguido pela arritmia atrial ect&#243;pica, que estava presente em 8,74% dos casos (9/103). Devido ao n&#250;mero reduzido de casos, a an&#225;lise estat&#237;stica em rela&#231;&#227;o &#224;s arritmias foi realizada ao comparar as propor&#231;&#245;es entre os grupos de idade.</p>
    <p>
      <bold>Discuss&#227;o</bold>
    </p>
    <p>A presen&#231;a de tripomastigotas sangu&#237;neos em animais inoculados oralmente, que posteriormente desenvolveram a doen&#231;a de Chagas<sup>10 </sup>foi demonstrada em 1921; no entanto, foi somente em 1991 que 26 casos da doen&#231;a causada pela ingest&#227;o de suco de cana no Estado da Para&#237;ba no Brasil foram relatados<sup>11</sup>. Embora a descri&#231;&#227;o das altera&#231;&#245;es no ECG associadas &#224; doen&#231;a de Chagas vetorial ter sido abrangente e detalhada<sup>12-16</sup>, o mesmo n&#227;o pode ser afirmado para casos resultantes de transmiss&#227;o oral<sup>17-19</sup>.</p>
    <p>O fato de que estes casos investigados ocorreram em uma cidade em um ambiente fechado (escola) nos permitiu analisar popula&#231;&#245;es contaminadas e n&#227;o contaminadas e administrar a interven&#231;&#227;o m&#233;dica r&#225;pida em toda a popula&#231;&#227;o. Dessa forma, a investiga&#231;&#227;o &#233; &#250;nica e pode ser um ponto de refer&#234;ncia. Al&#233;m disso, &#233; importante destacar que a nossa investiga&#231;&#227;o &#233; a &#250;nica que pode comparar as manifesta&#231;&#245;es no ECG em crian&#231;as e adultos, devido ao n&#250;mero de pacientes estudados. Comparamos os nossos resultados &#224;queles relatados por outros estudos de doen&#231;as vetoriais e doen&#231;as transmitidas oralmente.</p>
    <p>A <xref ref-type="table" rid="aop_5293tab03">Tabela 3</xref> mostra uma compara&#231;&#227;o de nossos resultados aos relatados em diferentes estudos de infec&#231;&#227;o oral<sup>4,11,17,18</sup>. &#201; importante observar que alguns relat&#243;rios representam uma recorda&#231;&#227;o dos casos e n&#227;o um surto da doen&#231;a em si. Al&#233;m disso, o tempo entre o in&#237;cio dos sintomas e a realiza&#231;&#227;o do ECG &#233; vari&#225;vel. Conforme demonstrado, o ECG anormal foi observado em 50%-100% dos casos (66% em nosso estudo). A altera&#231;&#227;o mais frequente no ECG foi a altera&#231;&#227;o da onda T e do segmento T, com varia&#231;&#245;es entre 16,6% e 100% (37,86% em nosso estudo). A presen&#231;a do bloqueio do ramo direito, caracter&#237;stica da doen&#231;a cr&#244;nica, foi constatada somente em 5%-25% dos casos (1,94% em nosso estudo). A presen&#231;a da fibrila&#231;&#227;o atrial varia entre 0% e 8% (2,9% em nosso estudo).</p>
    <p content-type="asset">
      <table-wrap id="aop_5293tab03">
        <graphic xlink:href="1678-4170-abc-101-03-0249-30144-gt03.jpg"/></table-wrap>
    </p>
    <p>Na <xref ref-type="table" rid="aop_5293tab04">Tabela 4</xref> comparamos nossos achados referentes a altera&#231;&#245;es no ECG na doen&#231;a de Chagas aguda transmitida atrav&#233;s de vetor aos achados relatados por Parada e cols.<sup>21</sup> na Venezuela e Shikanai-Yasuda e cols.<sup>11</sup> no Brasil. Em nosso estudo, observamos uma incid&#234;ncia maior de altera&#231;&#245;es de ST-T (37,86%) em compara&#231;&#227;o &#224; incid&#234;ncia relatada por Parada e cols.<sup>20</sup> (4,4%) e Shikanai-Yasuda e cols.<sup>11</sup> (6,9%). O bloqueio do ramo direito ocorreu em 1,94% de nossos casos, contra 5,1% no estudo de Parada e cols.<sup>20</sup> e 1,1% no estudo de Shikanai-Yasuda e cols.<sup>11</sup>.</p>
    <p content-type="asset">
      <table-wrap id="aop_5293tab04">
        <graphic xlink:href="1678-4170-abc-101-03-0249-30144-gt04.jpg"/></table-wrap>
    </p>
    <p>Anselmi e cols.<sup>21</sup> utilizaram um modelo experimental de inocula&#231;&#227;o intraperitoneal e sinais observados de miocardite aguda em 54% dos casos (17/31), ressaltando a import&#226;ncia da via de transmiss&#227;o e carga parasit&#225;ria em manifesta&#231;&#245;es cl&#237;nicas e ECGs.</p>
    <p>Como podemos ver, h&#225; diferen&#231;as ao comparar a transmiss&#227;o oral e vetorial, bem como entre estudos de transmiss&#227;o oral. As poss&#237;veis explica&#231;&#245;es para estas diferen&#231;as podem ser:</p>
    <p>1. - Diferen&#231;as na patogenicidade de cepas de <italic>T</italic>. cruzi. Camandaroba e cols.<sup>22 </sup>mostraram diferen&#231;as na patogenicidade entre diferentes cepas administradas a camundongos oralmente e intraperitonealmente. Ao comparar cepas do Peru e da Col&#244;mbia, descobriram que as cepas peruanas apresentavam alta infectividade e patogenicidade quando administradas intraperitonealmente, mas baixa infectividade e patogenicidade quando administradas oralmente; em contraste, as cepas colombianas (biodeme tipo III) apresentaram alto n&#237;vel de patogenicidade ap&#243;s administra&#231;&#227;o via oral.</p>
    <p>2. - Diferen&#231;as em patogenicidade oral. Covarrubias e cols.<sup>23</sup> usaram uma cepa de <italic>T. cruzi</italic> associada a um surto de doen&#231;a transmitida oralmente em Santa Catarina para analisar a express&#227;o de mol&#233;culas de superf&#237;cie e infectividade quando administradas oralmente a camundongos. Foi descoberto que tripomastigotas metac&#237;clicos, que <italic>in vitro</italic> possuem alta concentra&#231;&#227;o de gp90, uma mol&#233;cula de superf&#237;cie que age como um regulador negativo da invas&#227;o de c&#233;lulas hospedeiras, t&#234;m seus n&#237;veis bastante reduzidos quando administrados oralmente, pois s&#227;o destru&#237;dos pelo &#225;cido g&#225;strico. [Observa&#231;&#227;o 2] Em contraste, gp89, uma mol&#233;cula de superf&#237;cie que promove a invas&#227;o celular, &#233; resistente ao fluido g&#225;strico. Dessa forma, as mol&#233;culas de superf&#237;cie que promovem a invas&#227;o celular persistem, por&#233;m, os inibidores s&#227;o destru&#237;dos pelo fluido g&#225;strico, o que faz com que a mesma cepa se torne muito mais agressiva se administrada oralmente que se estudada <italic>in vivo</italic> ou administrada por via parenteral.</p>
    <p>3. - Diferen&#231;as no hospedeiro - intera&#231;&#227;o parasita. Embora um aumento na infectividade tenha sido demonstrado quando o parasita &#233; administrado oralmente, por causa da destrui&#231;&#227;o de gp90<sup>23,24</sup> pelo suco g&#225;strico, n&#227;o houve estudos que avaliem como as varia&#231;&#245;es no pH do est&#244;mago relacionadas &#224; idade podem estar associadas a uma infectividade maior ou menor de acordo com a capacidade de destruir gp90.</p>
    <p>4. - Um grupo de estudo mais controlado. Nosso estudo &#233; a maior investiga&#231;&#227;o de casos que ocorreram em um ambiente "fechado", neste caso, uma escola. Dessa forma, foi poss&#237;vel estudar todas as pessoas expostas, o que n&#227;o ocorre em outras investiga&#231;&#245;es.</p>
    <p>5. - Um est&#225;gio anterior da doen&#231;a. Em nosso estudo, o tempo entre a ingest&#227;o do suco de goiaba contaminado (28 de outubro de 2007), o in&#237;cio dos sintomas, (primeiro paciente: 9 de novembro de 2007), diagn&#243;stico do caso &#237;ndice (6 de dezembro de 2007), um registro de ECG da popula&#231;&#227;o (11-14 de dezembro de 2007) foi extremamente preciso. Esta precis&#227;o dos registros n&#227;o &#233; comum em outros estudos, e poderia resultar em diferen&#231;as ao analisar outros momentos do perfil cl&#237;nico.</p>
    <p>&#201; importante ressaltar que as altera&#231;&#245;es no ECG n&#227;o estavam relacionadas &#224; presen&#231;a de efus&#227;o peric&#225;rdica. Uma descri&#231;&#227;o completa de altera&#231;&#245;es no ecocardiograma ser&#225; discutida em um documento separado. A an&#225;lise da evolu&#231;&#227;o de ECG nestes pacientes, que poderia ser melhor definida em fases diferentes da doen&#231;a ap&#243;s a infec&#231;&#227;o oral, &#233; a pr&#243;xima etapa.</p>
    <p>
      <bold>Conclus&#227;o</bold>
    </p>
    <p>Este &#233; o maior estudo de casos cl&#237;nicos de um &#250;nico surto da doen&#231;a de Chagas transmitida oralmente, com ECGs registrados. Descobrimos altera&#231;&#245;es no ECG que sugerem miocardite aguda e arritmias como as anormalidades encontradas com maior frequ&#234;ncia.</p>
    <p>
      <bold>Agradecimentos</bold>
    </p>
    <p>Agradecemos todos os pacientes que concordaram em participar deste estudo.</p>
    <p>
      <bold>Contribui&#231;&#227;o dos autores</bold>
    </p>
    <p>Concep&#231;&#227;o e desenho da pesquisa e An&#225;lise e interpreta&#231;&#227;o dos dados: Marques J, Mendoza I, Noya B; Obten&#231;&#227;o de dados: Marques J, Mendoza I, Noya B, Acquatella H; An&#225;lise estat&#237;stica: Marques J; Reda&#231;&#227;o do manuscrito: Marques J, Mendoza I, Marques-Mejias M; Revis&#227;o cr&#237;tica do manuscrito quanto ao conte&#250;do intelectual: Pal&#225;cios I.</p>
    <p>
      <bold>Potencial Conflito de Interesses</bold>
    </p>
    <p>Declaro n&#227;o haver conflito de interesses pertinentes.</p>
    <p>
      <bold>Fontes de Financiamento</bold>
    </p>
    <p>O presente estudo n&#227;o teve fontes de financiamento externas.</p>
    <p>
      <bold>Vincula&#231;&#227;o Acad&#234;mica</bold>
    </p>
    <p>N&#227;o h&#225; vincula&#231;&#227;o deste estudo a programas de p&#243;s-gradua&#231;&#227;o.</p>
    <p>
      <fn id="end" fn-type="corresp">
        <label>
          <bold>Correspond&#234;ncia:</bold>
        </label>
        <p> Maria Marques-Mejias </p>
        <p> Calle San Francisco, Qta. G&#225;lata, Prados del este </p>
        <p> C&#243;digo Postal 1080, Caracas, Miranda </p>
        <p> E-mail: </p>
        <p><email xlink:href="mandreina.marques@gmail.com">mandreina.marques@gmail.com</email>, </p>
        <p>
          <email xlink:href="juan.alberto.marques@gmail.com">juan.alberto.marques@gmail.com</email>
        </p>
      </fn>
    </p>
    <p>Artigo recebido em 27/11/12; revisado em 17/02/13; aceito em 15/04/13.</p>
    <p>
      <bold>Abrevia&#231;&#245;es:</bold>
    </p>
    <p>
      <italic>T. cruzi - Trypanosoma cruzi</italic>
    </p>
    <p>ECG - Eletrocardiograma</p>
    <p>NS - N&#227;o significativo</p>
    <p>AAC - Associa&#231;&#227;o Americana de Cardiologia</p>
    <p>CAC - Col&#233;gio Americano de Cardiologia</p>
    <p>SIAC - Sociedade Internacional de Arritmias Card&#237;acas</p>
    <p>ST - Segmento ST</p>
    <p>T - Onda T</p>
    <p>BR Direito - Bloqueio do ramo direito</p>
    <p>BR Esquerdo - Bloqueio do ramo esquerdo</p>
  </body>
  <back>
    <ref-list>
      <ref id="B1">
        <mixed-citation>1. Rassi A Jr, Rassi A, Marin-Neto JA. Chagas disease. Lancet. 2010;375(9723):1388-402.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Chagas disease</article-title>
          <source>Lancet</source>
          <date>
            <year>2010</year>
          </date>
          <fpage>1388</fpage>
          <lpage>402</lpage>
          <issue>9723</issue>
          <volume>375</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Rassi Jr</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Rassi</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Marin-Neto</surname>
              <given-names>JA</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B2">
        <mixed-citation>2. Schmunis GA Epidemiology of Chagas disease in non-endemic countries: the role of international migration. Mem Inst Oswaldo Cruz. 2007;102 Suppl 1:75-85. Erratum in Mem Inst Oswaldo Cruz. 2007;102(8):2.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Epidemiology of Chagas disease in non-endemic countries: the role of international migration</article-title>
          <source>Mem Inst Oswaldo Cruz</source>
          <date>
            <year>2007</year>
          </date>
          <fpage>75</fpage>
          <lpage>85</lpage>
          <volume>102</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Schmunis</surname>
              <given-names>GA</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B3">
        <mixed-citation>3. Guerri-Guttenberg RA, Grana DR, Ambrosio G, Milei J. Chagas cardiomyopathy: Europe is not spared. Eur Heart J. 2008;29(21):2587-91.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Chagas cardiomyopathy: Europe is not spared</article-title>
          <source>Eur Heart J</source>
          <date>
            <year>2008</year>
          </date>
          <fpage>2587</fpage>
          <lpage>91</lpage>
          <issue>21</issue>
          <volume>29</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Guerri-Guttenberg</surname>
              <given-names>RA</given-names>
            </name>
            <name>
              <surname>Grana</surname>
              <given-names>DR</given-names>
            </name>
            <name>
              <surname>Ambrosio</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Milei</surname>
              <given-names>J</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B4">
        <mixed-citation>4. Pinto AY, Ferreira AG, Valente Vda C, Harada GS, Valente SA. Urban outbreak of acute Chagas disease in Amazon region of Brazil: four years follow-up after treatment with benzidazole. Rev Panam Salud Publica. 2009;25(1):77-83.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Urban outbreak of acute Chagas disease in Amazon region of Brazil: four years follow-up after treatment with benzidazole</article-title>
          <source>Rev Panam Salud Publica</source>
          <date>
            <year>2009</year>
          </date>
          <fpage>77</fpage>
          <lpage>83</lpage>
          <issue>1</issue>
          <volume>25</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Pinto</surname>
              <given-names>AY</given-names>
            </name>
            <name>
              <surname>Ferreira</surname>
              <given-names>AG</given-names>
            </name>
            <name>
              <surname>Valente Vda</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Harada</surname>
              <given-names>GS</given-names>
            </name>
            <name>
              <surname>Valente</surname>
              <given-names>SA</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B5">
        <mixed-citation>5. Dias JP, Bastos C, Araujo E, Mascarenhas AV, Martins Netto E, Grassi F, et al. Acute Chagas disease outbreak associated with oral transmission. Rev Soc Bras Med Trop. 2008;41(3):296-300.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Acute Chagas disease outbreak associated with oral transmission</article-title>
          <source>Rev Soc Bras Med Trop</source>
          <date>
            <year>2008</year>
          </date>
          <fpage>296</fpage>
          <lpage>300</lpage>
          <issue>3</issue>
          <volume>41</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Dias</surname>
              <given-names>JP</given-names>
            </name>
            <name>
              <surname>Bastos</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Araujo</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Mascarenhas</surname>
              <given-names>AV</given-names>
            </name>
            <name>
              <surname>Martins Netto</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Grassi</surname>
              <given-names>F</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B6">
        <mixed-citation>6. Valente SA, da Costa Valente V, das Neves Pinto AY, de Jesus Barbosa C&#233;sar M, dos Santos MP, Miranda CO, et al. Analysis of an acute Chagas disease outbreak in the Brazilian Amazon: human cases, triatomines, reservoirs mammals, and parasites. Trans R Soc Trop Med Hyg. 2009;103(3):291-7.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Analysis of an acute Chagas disease outbreak in the Brazilian Amazon: human cases, triatomines, reservoirs mammals, and parasites</article-title>
          <source>Trans R Soc Trop Med Hyg</source>
          <date>
            <year>2009</year>
          </date>
          <fpage>291</fpage>
          <lpage>7</lpage>
          <issue>3</issue>
          <volume>103</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Valente</surname>
              <given-names>SA</given-names>
            </name>
            <name>
              <surname>da Costa Valente</surname>
              <given-names>V</given-names>
            </name>
            <name>
              <surname>das Neves Pinto</surname>
              <given-names>AY</given-names>
            </name>
            <name>
              <surname>de Jesus Barbosa C&#233;sar</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>dos Santos</surname>
              <given-names>MP</given-names>
            </name>
            <name>
              <surname>Miranda</surname>
              <given-names>CO</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B7">
        <mixed-citation>7. Nicholls RS. Enfermedad de Chagas como enfermedad transmitida por alimentos: la experi&#234;ncia en Colombia. In: Informe de la Consulta T&#233;cnica enepidemiolog&#237;a, prevenci&#243;n y manejo de latransmisi&#243;n de laenfermedad de Chagas como enfermedad transmitida por alimentos (ETA). Rio de Janeiro: Organizaci&#243;nPanamericana de laSalud/Organizaci&#243;n Mundial de la Salud; 2006.</mixed-citation>
        <element-citation publication-type="book">
          <source>Informe de la Consulta T&#233;cnica enepidemiolog&#237;a, prevenci&#243;n y manejo de latransmisi&#243;n de laenfermedad de Chagas como enfermedad transmitida por alimentos (ETA)</source>
          <date>
            <year>2006</year>
          </date>
          <person-group person-group-type="author">
            <name>
              <surname>Nicholls</surname>
              <given-names>RS</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B8">
        <mixed-citation>8. Alarc&#243;n de Noya B, D&#237;az-Bello Z, Colmenares C, Ruiz-Guevara R, Mauriello L, Zavala-Jaspe R, et al. Large urban outbreak of orally acquired acute Chagas disease at a school in Caracas, Venezuela. J Infect Dis. 2010;201(9):1308-15.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Large urban outbreak of orally acquired acute Chagas disease at a school in Caracas, Venezuela</article-title>
          <source>J Infect Dis</source>
          <date>
            <year>2010</year>
          </date>
          <fpage>1308</fpage>
          <lpage>15</lpage>
          <issue>9</issue>
          <volume>201</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Alarc&#243;n de Noya</surname>
              <given-names>B</given-names>
            </name>
            <name>
              <surname>D&#237;az-Bello</surname>
              <given-names>Z</given-names>
            </name>
            <name>
              <surname>Colmenares</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Ruiz-Guevara</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Mauriello</surname>
              <given-names>L</given-names>
            </name>
            <name>
              <surname>Zavala-Jaspe</surname>
              <given-names>R</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B9">
        <mixed-citation>9. Surawicz B, Childers R, Deal BJ, Gettes LS, Bailey JJ, Gorgels A, Hancock EW, et al; American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; American College of Cardiology Foundation; Heart Rhythm Society. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part III: intraventricular conduction disturbances: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society. Endorsed by the International Society for Computerized Electrocardiology. J Am Coll Cardiol. 2009;53(11):976-81.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part III: intraventricular conduction disturbances: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society. Endorsed by the International Society for Computerized Electrocardiology</article-title>
          <source>J Am Coll Cardiol</source>
          <date>
            <year>2009</year>
          </date>
          <fpage>976</fpage>
          <lpage>81</lpage>
          <issue>11</issue>
          <volume>53</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Surawicz</surname>
              <given-names>B</given-names>
            </name>
            <name>
              <surname>Childers</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Deal</surname>
              <given-names>BJ</given-names>
            </name>
            <name>
              <surname>Gettes</surname>
              <given-names>LS</given-names>
            </name>
            <name>
              <surname>Bailey</surname>
              <given-names>JJ</given-names>
            </name>
            <name>
              <surname>Gorgels</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Hancock</surname>
              <given-names>EW</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B10">
        <mixed-citation>10. Nattan-Larrier. Infections a Trypanosomes et voies de penetration des virus. Bull Soc Path Exot. 1921;14:537-42.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Infections a Trypanosomes et voies de penetration des virus</article-title>
          <source>Bull Soc Path Exot</source>
          <date>
            <year>1921</year>
          </date>
          <fpage>537</fpage>
          <lpage>42</lpage>
          <volume>14</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Nattan-Larrier</surname>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B11">
        <mixed-citation>11. Shikanai-Yasuda MA, Marcondes CB, Guedes LA, Siqueira GS, Barone AA, Dias JC, et al. Possible oral transmission of acute Chagas disease in Brazil. Rev Inst Med Trop S&#227;o Paulo. 1991;33(5):351-7.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Possible oral transmission of acute Chagas disease in Brazil</article-title>
          <source>Rev Inst Med Trop S&#227;o Paulo</source>
          <date>
            <year>1991</year>
          </date>
          <fpage>351</fpage>
          <lpage>7</lpage>
          <issue>5</issue>
          <volume>33</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Shikanai-Yasuda</surname>
              <given-names>MA</given-names>
            </name>
            <name>
              <surname>Marcondes</surname>
              <given-names>CB</given-names>
            </name>
            <name>
              <surname>Guedes</surname>
              <given-names>LA</given-names>
            </name>
            <name>
              <surname>Siqueira</surname>
              <given-names>GS</given-names>
            </name>
            <name>
              <surname>Barone</surname>
              <given-names>AA</given-names>
            </name>
            <name>
              <surname>Dias</surname>
              <given-names>JC</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B12">
        <mixed-citation>12. Espinoza RA, Pericchi LR, Carrasco HA, Escalante A, Martinez O, Gonzalez R. Prognostic indicators of chronic chagasic cardiopathy. Int J Cardiol. 1991;30(2):195-202.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Prognostic indicators of chronic chagasic cardiopathy</article-title>
          <source>Int J Cardiol</source>
          <date>
            <year>1991</year>
          </date>
          <fpage>195</fpage>
          <lpage>202</lpage>
          <issue>2</issue>
          <volume>30</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Espinoza</surname>
              <given-names>RA</given-names>
            </name>
            <name>
              <surname>Pericchi</surname>
              <given-names>LR</given-names>
            </name>
            <name>
              <surname>Carrasco</surname>
              <given-names>HA</given-names>
            </name>
            <name>
              <surname>Escalante</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Martinez</surname>
              <given-names>O</given-names>
            </name>
            <name>
              <surname>Gonzalez</surname>
              <given-names>R</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B13">
        <mixed-citation>13. Moleiro F Mendoza I. Miocardiopat&#237;a cr&#243;nica Chag&#225;sica, un estudio epidemiol&#243;gico utilizando m&#233;todos electrofisol&#243;gicos de exploraci&#243;n cl&#237;nica. Acta Cient Venez. 1980;31(6):66-72.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Miocardiopat&#237;a cr&#243;nica Chag&#225;sica, un estudio epidemiol&#243;gico utilizando m&#233;todos electrofisol&#243;gicos de exploraci&#243;n cl&#237;nica</article-title>
          <source>Acta Cient Venez</source>
          <date>
            <year>1980</year>
          </date>
          <fpage>66</fpage>
          <lpage>72</lpage>
          <issue>6</issue>
          <volume>31</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Moleiro</surname>
              <given-names>F</given-names>
            </name>
            <name>
              <surname>Mendoza</surname>
              <given-names>I</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B14">
        <mixed-citation>14. Puigbo JJ, Rhode JR, Barrios HG, Suarez JA, Yepez CG. Clinical and epidemiological study of chronic heart involvement in Chagas disease. Bull World Health Organ. 1996;34(5):655-69.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Clinical and epidemiological study of chronic heart involvement in Chagas disease</article-title>
          <source>Bull World Health Organ</source>
          <date>
            <year>1996</year>
          </date>
          <fpage>655</fpage>
          <lpage>69</lpage>
          <issue>5</issue>
          <volume>34</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Puigbo</surname>
              <given-names>JJ</given-names>
            </name>
            <name>
              <surname>Rhode</surname>
              <given-names>JR</given-names>
            </name>
            <name>
              <surname>Barrios</surname>
              <given-names>HG</given-names>
            </name>
            <name>
              <surname>Suarez</surname>
              <given-names>JA</given-names>
            </name>
            <name>
              <surname>Yepez</surname>
              <given-names>CG</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B15">
        <mixed-citation>15. Acquatella H, Catalioti F, Gomez-Mancebo JR, Davalos V, Villalobos L. Long term control of Chagas disease in Venezuela: effects on serologic findings, electrocardiographic abnormalities and clinical outcome. Circulation. 1987;76(3):556-62.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Long term control of Chagas disease in Venezuela: effects on serologic findings, electrocardiographic abnormalities and clinical outcome</article-title>
          <source>Circulation</source>
          <date>
            <year>1987</year>
          </date>
          <fpage>556</fpage>
          <lpage>62</lpage>
          <issue>3</issue>
          <volume>76</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Acquatella</surname>
              <given-names>H</given-names>
            </name>
            <name>
              <surname>Catalioti</surname>
              <given-names>F</given-names>
            </name>
            <name>
              <surname>Gomez-Mancebo</surname>
              <given-names>JR</given-names>
            </name>
            <name>
              <surname>Davalos</surname>
              <given-names>V</given-names>
            </name>
            <name>
              <surname>Villalobos</surname>
              <given-names>L</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B16">
        <mixed-citation>16. Dias E, Laranja FS, Miranda A, Nobrega G. Chagas&#180;disease: a clinical, epidemiologic and pathologic study. Circulation. 1956;14(6):1035-60.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Chagas&#180;disease: a clinical, epidemiologic and pathologic study</article-title>
          <source>Circulation</source>
          <date>
            <year>1956</year>
          </date>
          <fpage>1035</fpage>
          <lpage>60</lpage>
          <issue>6</issue>
          <volume>14</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Dias</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Laranja</surname>
              <given-names>FS</given-names>
            </name>
            <name>
              <surname>Miranda</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Nobrega</surname>
              <given-names>G</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B17">
        <mixed-citation>17. Pinto AY, Valente SA, Valente Vda C, Ferreira Junior AG, Coura JR. [Acute phase of Chagas disease in the Brazilian Amazon region: study of 233 cases from Par&#225;, Amap&#225; and Maranh&#227;o observed between 1988 and 2005]. Rev Soc Bras Med Trop. 2008;41(6):602-14.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Acute phase of Chagas disease in the Brazilian Amazon region: study of 233 cases from Par&#225;.Amap&#225; and Maranh&#227;o observed between 1988 and 2005</article-title>
          <source>Rev Soc Bras Med Trop</source>
          <date>
            <year>2008</year>
          </date>
          <fpage>602</fpage>
          <lpage>14</lpage>
          <issue>6</issue>
          <volume>41</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Pinto</surname>
              <given-names>AY</given-names>
            </name>
            <name>
              <surname>Valente</surname>
              <given-names>SA</given-names>
            </name>
            <name>
              <surname>Valente Vda</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Ferreira Junior</surname>
              <given-names>AG</given-names>
            </name>
            <name>
              <surname>Coura</surname>
              <given-names>JR</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B18">
        <mixed-citation>18. Bastos CJ, Aras R, Mota G, Reis F, Dias JP, de Jesus RS, et al. Clinical outcomes of thirteen patients with acute Chagas disease acquired through oral transmission from two urban outbreaks in northeastern Brazil. PLoS Negl Trop Dis. 2010;4(6):e711.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Clinical outcomes of thirteen patients with acute Chagas disease acquired through oral transmission from two urban outbreaks in northeastern Brazil</article-title>
          <source>PLoS Negl Trop Dis</source>
          <date>
            <year>2010</year>
          </date>
          <fpage>e711</fpage>
          <issue>6</issue>
          <volume>4</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Bastos</surname>
              <given-names>CJ</given-names>
            </name>
            <name>
              <surname>Aras</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Mota</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Reis</surname>
              <given-names>F</given-names>
            </name>
            <name>
              <surname>Dias</surname>
              <given-names>JP</given-names>
            </name>
            <name>
              <surname>de Jesus</surname>
              <given-names>RS</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B19">
        <mixed-citation>19. Barbosa-Ferreira JM, Guerra JA, Santana Filho FS, Magalh&#227;es BM, Coelho LI, Barbosa MG. [Cardiac involvement in Acute Chagas' Disease cases in the Amazon region]. Arq Bras Cardiol. 2010;94(6):147-9.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Cardiac involvement in Acute Chagas' Disease cases in the Amazon region</article-title>
          <source>Arq Bras Cardiol</source>
          <date>
            <year>2010</year>
          </date>
          <fpage>147</fpage>
          <lpage>9</lpage>
          <issue>6</issue>
          <volume>94</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Barbosa-Ferreira</surname>
              <given-names>JM</given-names>
            </name>
            <name>
              <surname>Guerra</surname>
              <given-names>JA</given-names>
            </name>
            <name>
              <surname>Santana Filho</surname>
              <given-names>FS</given-names>
            </name>
            <name>
              <surname>Magalh&#227;es</surname>
              <given-names>BM</given-names>
            </name>
            <name>
              <surname>Coelho</surname>
              <given-names>LI</given-names>
            </name>
            <name>
              <surname>Barbosa</surname>
              <given-names>MG</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B20">
        <mixed-citation>20. Parada H, Carrasco H, A&#241;ez N, Fuenmayor C, Inglessis I. Cardiac involvement is a constant finding in acute Chagas disease: a clinical, parasitological and histopathological study. Int J Cardiol. 1997;60(1):49-54.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Cardiac involvement is a constant finding in acute Chagas disease: a clinical, parasitological and histopathological study</article-title>
          <source>Int J Cardiol</source>
          <date>
            <year>1997</year>
          </date>
          <fpage>49</fpage>
          <lpage>54</lpage>
          <issue>1</issue>
          <volume>60</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Parada</surname>
              <given-names>H</given-names>
            </name>
            <name>
              <surname>Carrasco</surname>
              <given-names>H</given-names>
            </name>
            <name>
              <surname>A&#241;ez</surname>
              <given-names>N</given-names>
            </name>
            <name>
              <surname>Fuenmayor</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Inglessis</surname>
              <given-names>I</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B21">
        <mixed-citation>21. Anselmi A, Pifano F, Suarez A, Dominguez A, Diaz Vazquez A, Anselmi G. Experimental Schizotrypanum cruzy myocarditis: correlation between histopathologic and electrocardiographic findings in experimental Chagas' heart disease. Am Heart J. 1965;70(5):638-56.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Experimental Schizotrypanum cruzy myocarditis: correlation between histopathologic and electrocardiographic findings in experimental Chagas' heart disease</article-title>
          <source>Am Heart J</source>
          <date>
            <year>1965</year>
          </date>
          <fpage>638</fpage>
          <lpage>56</lpage>
          <issue>5</issue>
          <volume>70</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Anselmi</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Pifano</surname>
              <given-names>F</given-names>
            </name>
            <name>
              <surname>Suarez</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Dominguez</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Diaz Vazquez</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Anselmi</surname>
              <given-names>G</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B22">
        <mixed-citation>22. Camandaroba EL, Pinheiro Lima CM, Andrade SG. Oral transmission of Chagas disease: importance of Trypanosoma cruzi biodeme in the intragastric experimental infection. Rev Inst Med Trop S Paulo. 2002;44(2);97-103.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Oral transmission of Chagas disease: importance of Trypanosoma cruzi biodeme in the intragastric experimental infection</article-title>
          <source>Rev Inst Med Trop S Paulo</source>
          <date>
            <year>2002</year>
          </date>
          <fpage>97</fpage>
          <lpage>103</lpage>
          <issue>2</issue>
          <volume>44</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Camandaroba</surname>
              <given-names>EL</given-names>
            </name>
            <name>
              <surname>Pinheiro Lima</surname>
              <given-names>CM</given-names>
            </name>
            <name>
              <surname>Andrade</surname>
              <given-names>SG</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B23">
        <mixed-citation>23. Covarrubias C, Cortez M, Ferreira D, Yoshida N. Interaction with host factors exacerbates Trypanosoma cruzi cell invasion capacity upon oral infection. Int J Parasitol. 2007;37(14):1609-16.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Interaction with host factors exacerbates Trypanosoma cruzi cell invasion capacity upon oral infection</article-title>
          <source>Int J Parasitol</source>
          <date>
            <year>2007</year>
          </date>
          <fpage>1609</fpage>
          <lpage>16</lpage>
          <issue>14</issue>
          <volume>37</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Covarrubias</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Cortez</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Ferreira</surname>
              <given-names>D</given-names>
            </name>
            <name>
              <surname>Yoshida</surname>
              <given-names>N</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B24">
        <mixed-citation>24. Yoshida N. Trypanosoma cruzi infection by oral route: how the interplay between parasite and host components modulates infectivity. Parasitol Int. 2008;57(2):105-9.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Trypanosoma cruzi infection by oral route: how the interplay between parasite and host components modulates infectivity</article-title>
          <source>Parasitol Int</source>
          <date>
            <year>2008</year>
          </date>
          <fpage>105</fpage>
          <lpage>9</lpage>
          <issue>2</issue>
          <volume>57</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Yoshida</surname>
              <given-names>N</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
    </ref-list>
  </back>
  <sub-article article-type="translation" id="TRen" xml:lang="en">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Original Articles</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title xml:lang="en">ECG manifestations of the biggest outbreak of Chagas disease due to oral Infection in Latin-America</article-title>
      </title-group>
      <abstract xml:lang="en">
        <p>BACKGROUND: Chagas disease affects more than 15 million people worldwide. Although vector-borne transmission has decreased, oral transmission has become important. Recently, our group published the clinical and epidemiological characteristics of the largest outbreak of orally transmitted Chagas disease reported till date. OBJECTIVE: To describe electrocardiographic changes occurring in the study population during the outbreak caused by ingestion of contaminated guava juice. METHODS: We evaluated 103 positive cases, of which 76 (74%) were aged &lt;18 years (average age: 9.1 &#177; 3.1 years) and 27 (26%) were aged &gt; 18 years (average age: 46 &#177; 11.8 years). All patients underwent clinical evaluations and ECG. If the patients had palpitations or evident alterations of rhythm at baseline, ambulatory ECG monitoring was performed. RESULTS: A total of 68 cases (66%; 53 children and 15 adults) had ECG abnormalities. Further, 69.7% (53/76) of those aged &lt; 18 years and 56% (15/27) of those aged &gt;18 years showed some ECG alteration (p = ns). ST-T abnormalities were observed in 37.86% cases (39/103) and arrhythmias were evident in 28.16% cases (29/103). ST alterations occurred in 72% of those aged &lt;18 years compared with 19% of those aged &gt;18 years (p &lt; 0.0001). CONCLUSIONS: This study reports the largest number of cases in the same outbreak of acute Chagas disease caused by oral contamination, with recorded ECGs. ECG changes suggestive of acute myocarditis and arrhythmias were the most frequent abnormalities found.</p>
      </abstract>
      <kwd-group xml:lang="en">
        <kwd>Chagas Disease</kwd>
        <kwd>Electrocardiography</kwd>
        <kwd>Chagas Cardiomyopathy</kwd>
        <kwd>Arrhthmias, Cardiac</kwd>
        <kwd>Juices</kwd>
        <kwd>Contamination</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <p>
        <fn id="enda-body2">
          <label>
            <bold>ECG manifestations of the biggest outbreak of Chagas disease due to oral Infection in Latin-America</bold>
          </label>
          <p>
            <bold>Juan Marques; Iv&#225;n Mendoza; Belkisyol&#233; Noya; Harry Acquatella; Igor Palacios; Mar&#237;a Marques-Mejias</bold>
          </p>
        </fn>
      </p>
      <p>Universidad Central de Venezuela, Venezuela</p>
      <p>Mailing Address</p>
      <p>
        <bold>ABSTRACT</bold>
      </p>
      <p><bold>BACKGROUND:</bold> Chagas disease affects more than 15 million people worldwide. Although vector-borne transmission has decreased, oral transmission has become important. Recently, our group published the clinical and epidemiological characteristics of the largest outbreak of orally transmitted Chagas disease reported till date.</p>
      <p><bold>OBJECTIVE:</bold> To describe electrocardiographic changes occurring in the study population during the outbreak caused by ingestion of contaminated guava juice.</p>
      <p><bold>METHODS:</bold> We evaluated 103 positive cases, of which 76 (74%) were aged <underline>&lt;</underline>18 years (average age: 9.1 &#177; 3.1 years) and 27 (26%) were aged &gt; 18 years (average age: 46 &#177; 11.8 years). All patients underwent clinical evaluations and ECG. If the patients had palpitations or evident alterations of rhythm at baseline, ambulatory ECG monitoring was performed.</p>
      <p><bold>RESULTS:</bold> A total of 68 cases (66%; 53 children and 15 adults) had ECG abnormalities. Further, 69.7% (53/76) of those aged <underline>&lt;</underline> 18 years and 56% (15/27) of those aged &gt;18 years showed some ECG alteration (p = ns). ST-T abnormalities were observed in 37.86% cases (39/103) and arrhythmias were evident in 28.16% cases (29/103). ST alterations occurred in 72% of those aged <underline>&lt;</underline>18 years compared with 19% of those aged &gt;18 years (p &lt; 0.0001).</p>
      <p><bold>CONCLUSIONS:</bold> This study reports the largest number of cases in the same outbreak of acute Chagas disease caused by oral contamination, with recorded ECGs. ECG changes suggestive of acute myocarditis and arrhythmias were the most frequent abnormalities found.</p>
      <p><bold>Keywords:</bold> Chagas Disease / complications; Electrocardiography; Chagas Cardiomyopathy; Arrhthmias, Cardiac; Juices; Contamination.</p>
      <p>
        <bold>Introdu&#231;&#227;o</bold>
      </p>
      <p>Chagas disease is caused by <italic>Trypanosoma cruzi</italic> and transmitted by several types of triatomines<sup>1</sup>. It is endemic in Latin America, although migration flows have resulted in the spread of the disease in Europe and the United States as well<sup>2,3</sup>. It has been estimated that there are approximately 15 million diagnosed cases and approximately 109 million people at risk of contracting this illness<sup>1</sup>. Although these numbers have shown a decrease from 1990 to 2006<sup>1</sup>, in recent years, the description of endemic outbreaks of orally transmitted disease have opened a new area of study and analysis<sup>4-8</sup>. From being an unknown route of contamination, the oral route has become one of the most active in cases reported in Venezuela, Brazil, and Colombia<sup>4-8</sup>.</p>
      <p>Our group previously published epidemiological and clinical characteristics of the largest outbreak of orally transmitted Chagas disease reported till date<sup>9</sup>. Here we analyze ECG manifestations of this outbreak, considered unique for occurring in a closed environment (in a school) in a Latin American capital.</p>
      <p>
        <bold>Methods</bold>
      </p>
      <p>The epidemiology of the outbreak is shown in <xref ref-type="fig" rid="en_aop_5293fig01-body2">Figure 1</xref><sup>9</sup>. Of the total positive cases (n = 103), 76 were aged <underline>&lt;</underline> 18 years (average age: 9.1 &#177; 3.1 years), whereas 27 were aged &gt;18 years (average age: 46 &#177; 11.8 years). All positive or undefined patients underwent ECG. Before ECG, the patients were interviewed and physically examined by a cardiologist. The criteria for ECG alterations were based on the AHA / ACCF / HRS recommendations for the standardization and interpretation of ECGs<sup>9</sup>. ST segment alterations were defined by an elevation <underline>&gt;</underline>1 mm in one or more derivations in which it is not present normally. T wave alterations were defined as a negative T wave in one or more derivations in which it is not present normally. Only confirmed patients (n = 103) were analyzed in this study. If the patient reported palpitations, or if there was any evidence of rhythm disturbance in the baseline ECG (arrhythmias), an ambulatory ECG monitoring (Holter) was performed. Echocardiogram was performed in patients with ECG abnormalities. The results were analyzed differentiating patients younger or older than 18 years using descriptive statistics. Statistical significance was analyzed by comparing proportions.</p>
      <p content-type="asset">
        <fig id="en_aop_5293fig01-body2">
          <graphic xlink:href="1678-4170-abc-101-03-0249-30144-gf01-en.jpg"/></fig>
      </p>
      <p>
        <bold>Results</bold>
      </p>
      <p>A total of 68 cases (66%; 53 children and 15 adults) had ECG alterations, whereas 42 (33.9%; 23 children and 12 adults) had normal ECGs. Some major ECG changes were identified in 69.7% patients (53/76) aged &lt;18 years and 55.5% (15/27) of those aged &gt;18 years (p = ns). ECG manifestations are described in <xref ref-type="table" rid="en_aop_5293tab01-body2">Table 1</xref>. Because some patients had more than one ECG alteration, the total number of alterations identified is greater than the number of patients.</p>
      <p content-type="asset">
        <table-wrap id="en_aop_5293tab01-body2">
          <graphic xlink:href="1678-4170-abc-101-03-0249-30144-gt01-en.jpg"/></table-wrap>
      </p>
      <p>The most common finding was alteration of the ST segment and T wave that was present in 37.86% cases (39/103). QT prolongation analyzed by the method of Bazett was present in 2.91% cases (3/103).</p>
      <p>Blockade of the right branch was present in 1.94% cases (2/103), whereas inhibition of the left branch of the anterior subdivision was present in 2.91% cases (3/103). Looking at age groups, it was clear that those aged <underline>&lt;</underline> 18 years had a higher incidence of ST abnormalities compared with those aged &gt;18 years (72% vs. 19%) (p &lt; 0.00001). There were no significant differences in other ECG alterations between both groups.</p>
      <p>Echocardiograms were performed in 84% cases with ECG alterations (57/68). The echocardiograms of 68% cases were normal, whereas 32% showed mild to moderate pericardial effusion.</p>
      <p>Arrhythmias were evident in 32% cases (33/103). The different types of arrhythmias observed are shown in <xref ref-type="table" rid="en_aop_5293tab02-body2">Table 2</xref>. Supraventricular arrhythmias occurred in 22.3% cases (23/103), ventricular in 5.8% cases (6/103), and AV block in 2.91% cases (3/103).</p>
      <p content-type="asset">
        <table-wrap id="en_aop_5293tab02-body2">
          <graphic xlink:href="1678-4170-abc-101-03-0249-30144-gt02-en.jpg"/></table-wrap>
      </p>
      <p>Inappropriate sinus tachycardia was the most common arrhythmia occurring in 9.71% cases (10/193), followed by atrial ectopic arrhythmia that was present in 8.74% cases (9/103). Because of the reduced number of cases, statistical analysis in relation to arrhythmias was performed by comparison of proportions between age groups.</p>
      <p>
        <bold>Discussion</bold>
      </p>
      <p>The presence of blood trypomastigotes in orally inoculated animals who later developed Chagas disease<sup>10 </sup>was shown as early as 1921; however, it was not until 1991 that 26 acute cases of the disease caused by ingestion of infected cane juice in the state of Par&#237;ba in Brazil were described<sup>11</sup>. Although the description of ECG changes associated with vector-borne Chagas disease has been extensive and detailed<sup>12-16</sup>, the same cannot be said for cases caused by oral transmission<sup>17-19</sup>.</p>
      <p>The fact that the cases we investigated occurred in a city in a closed environment (school) allowed us to analyze both non-contaminated and contaminated populations and administer rapid medical intervention in the entire population. Thus, this investigation is unique and can be a point of reference. Moreover, it is important to highlight that ours is the only investigation that can compare ECG manifestations in children and adults, because of the number of patients studied. We have compared our results with those reported by other studies of vector-borne and orally transmitted disease.</p>
      <p><xref ref-type="table" rid="en_aop_5293tab03-body2">Table 3</xref> shows a comparison of our results with those reported in different studies of oral infection<sup>4,11,17,18</sup>. It is worth noting that some reports represent recollection of cases and not an outbreak of the disease itself. In addition, the time between the onset of symptoms and realization of ECG is variable. As shown, abnormal ECG was observed in 50%-100% cases (66% in our study). The most frequent ECG alteration was the change of the T wave and ST segment, ranging between 16.6% and 100% (37.86% in our study). The presence of right branch blockage, characteristic of chronic disease, was present only in 5%-25% cases (1.94% in our study). The presence of atrial fibrillation varies between 0% and 8% (2.9% in our study).</p>
      <p content-type="asset">
        <table-wrap id="en_aop_5293tab03-body2">
          <graphic xlink:href="1678-4170-abc-101-03-0249-30144-gt03-en.jpg"/></table-wrap>
      </p>
      <p>In <xref ref-type="table" rid="en_aop_5293tab04-body2">Table 4</xref> we compare our findings on ECG changes in acute Chagas disease transmitted via vector with those reported by Parada et al<sup>21</sup> in Venezuela and Shikanai-Yasuda et al<sup>11</sup> in Brazil. In our study, we observed a higher incidence of ST-T changes (37.86%) compared with that reported by Parada et al<sup>20 </sup>(4.4%) and Shikanai-Yasuda et al<sup>11 </sup>(6.9%). Right branch blockage occurred in 1.94% of our cases, compared with 5.1% in the study of Parada et al<sup>20</sup> and 1.1% in the study of Shikanai-Yasuda et al<sup>11</sup>.</p>
      <p content-type="asset">
        <table-wrap id="en_aop_5293tab04-body2">
          <graphic xlink:href="1678-4170-abc-101-03-0249-30144-gt04-en.jpg"/></table-wrap>
      </p>
      <p>Anselmi et al<sup>21</sup> used an experimental model of intraperitoneal inoculation and observed signs of acute myocarditis in 54% of cases (17/31), underscoring the importance of the transmission route and parasite load in clinical manifestations and ECGs.</p>
      <p>As we can see, there are differences when comparing vector-borne and oral routes of transmission, as well as among studies of oral transmission. Possible explanations for these differences may be as follows:</p>
      <p>1. - Differences in pathogenicity of strains of <italic>T</italic>. cruzi. Camandaroba et al<sup>22 </sup>showed differences in pathogenicity between different strains administered to mice orally as well as intraperitoneally. Comparing Peruvian and Colombian strains, they found that Peruvian strains had high infectivity and pathogenicity when administered intraperitoneally, but low infectivity and pathogenicity when administered orally; in contrast, Colombian strains (biodeme type III) had high pathogenicity following oral administration.</p>
      <p>2. - Differences in oral pathogenicity. Covarrubias et al<sup>23</sup> used a strain of <italic>T. cruzi</italic> related to an outbreak of orally transmitted disease in Santa Catarina, Brazil, to analyze the expression of surface molecules and infectivity when administered to mice orally. They found that metacyclic trypomastigotes, that in vitro have high concentrations of gp90, a surface molecule that acts as a negative regulator of the invasion of host cells, when administered orally have low levels of themselves, because they are destroyed by gastric acid. [Remark 2] In contrast, gp89, a surface molecule that promotes cellular invasion, is resistant to gastric fluid. Thus, surface molecules that promote cell invasion persist, whereas the inhibitors are destroyed by gastric fluid, which causes the same strain to become much more aggressive when administered orally than when studied <italic>in vivo</italic> or administered parenterally.</p>
      <p>3. - Differences in host-parasite interaction. Although an increase in infectivity has been demonstrated when the parasite is administered orally, because of the destruction of gp90<sup>23,24</sup> by gastric juice, there have been no studies that assess how aging-related variations in pH of the stomach could be associated with greater or lesser infectivity according to the capacity to destroy gp90.</p>
      <p>4. - A more controlled study group. Our study is the largest investigation of cases occurring in a "closed" environment, in this case a school. Thus, we could study all the people exposed, which does not occur in other investigations.</p>
      <p>5. - An earlier stage of the disease. In our study, the time between ingestion of the contaminated guava juice (October 28, 2007), the onset of symptoms, (first patient: November 9, 2007), diagnosis of the index case (December 6, 2007), and ECG recording of the population (December 11-14, 2007) was extremely accurate. This preciseness of records is not common in other studies, and could result in differences when analyzing other moments of the clinical profile.</p>
      <p>It is important to mention that ECG alterations were not related to the presence of pericardial effusion. A full description of echocardiographic alterations will be discussed in a different paper. Analysis of ECG evolution in these patients, which would more clearly define the different phases of the disease after oral infection, is the next step.</p>
      <p>
        <bold>Conclusion</bold>
      </p>
      <p>This is the largest study of clinical cases from a single outbreak of orally transmitted Chagas disease, with recorded ECGs. We found ECG changes suggestive of acute myocarditis and arrhythmias to be the most frequent abnormalities.</p>
      <p>
        <bold>Acknowledgments</bold>
      </p>
      <p>We are grateful to all patients who agreed to participate in this study.</p>
      <p>
        <bold>Author contributions</bold>
      </p>
      <p>Conception and design of the research and Analysis and interpretation of the data: Marques J, Mendoza I, Noya B; Acquisition of data: Marques J, Mendoza I, Noya B, Acquatella H; Statistical analysis: Marques J; Writing of the manuscript: Marques J, Mendoza I, Marques-Mejias M; Critical revision of the manuscript for intellectual content: Pal&#225;cios I.</p>
      <p>
        <bold>Potential Conflict of Interest</bold>
      </p>
      <p>No potential conflict of interest relevant to this article was reported.</p>
      <p>
        <bold>Sources of Funding</bold>
      </p>
      <p>There were no external funding sources for this study.</p>
      <p>
        <bold>Study Association</bold>
      </p>
      <p>This study is not associated with any post-graduation program.</p>
      <p>
        <bold>References</bold>
      </p>
    </body>
  </sub-article>
</article>
