EVALUATION OF ADULT CHRONIC CHAGAS HEART DISEASE DIAGNOSIS 1 BY MOLECULAR AND SEROLOGICAL METHODS 2 3 CHRONIC CHAGAS HEART DISEASE DIAGNOSTIC EVALUATION

37 Chagas disease caused by Trypanosoma cruzi is endemic in Latin America .T cruzi 38 presents heterogeneous populations and comprises two main genetic lineages, named T. 39 cruzi I and T. cruzi II. The diagnosis in the chronic phase is based on conventional 40 serological tests including IIF and ELISA, and in the acute phase based on parasitological 41 methods, including hemoculture. The objective of this study is to evaluate the diagnostic 42 procedures of Chagas disease in adult patients in the chronic phase using a PCR assay and 43 conventional serological tests including TESA-blot as the gold standard. Samples were 44 obtained from 240 clinical chronic Chagasic patients. The sensitivities using TESA-blot 45 were 70% for PCR using the kinetoplast region and 75% using nuclear repetitive region, 46 99% by IIF and 95% by ELISA. According to the serological tests results, we recommend 47 that researchers assess the reliability and sensitivity of the commercial kit Chagatest 48 ELISA recombinant, version 3.0 (Chagatest Rec v3.0; Wiener Lab®, Rosario, Argentina) , 49 due to the lack of sensitivity . Based on our analysis, we concluded that PCR cannot be 50 validated as a conventional diagnostic technique for Chagas disease. These data have been 51 corroborated by the low concordance values with serology tests. It is recommended that 52 PCR be used only as an alternative diagnostic support. Using the nuclear repetitive region 53 of T. cruzi, PCR could also be applicable for monitoring patients receiving etiologic 54 treatment. 55 56 Introduction 57 58 Chagas disease is a complex zoonosis caused by the parasite Trypanosoma cruzi. This 59 parasite can be genetically classified into two major lineages namely T. cruzi I that is 60 related to the South American northern countries while T. cruzi II is related to the South 61 American southern countries of America (46). Chagas disease is a chronic systemic disease 62 endemic to both South and Central America. T. cruzi is transmitted through the infected 63 dejections of triatomine bugs, by blood transfusion, congenital infection, laboratory 64 accidents, or by oral infection (44). Chagas disease constitutes a serious public health 65 problem in terms of both social and economic impact. The disease currently affects 15 66 million people and about 28 million are at risk of acquiring the infection. In America, 67 on N ovem er 5, 2017 by gest ht://jcm .sm .rg/ D ow nladed fom nearly 41,200 new cases occur each year along with an average of 12,500 deaths per year 68