 The presence of T. cruzi is diagnostic of Chagas disease . It can be detected by microscopic examination of fresh <unk> blood , or its <unk> coat , for <unk> parasites ; or by preparation of thin and thick blood <unk> stained with <unk> , for direct <unk> of parasites . <unk> , T. cruzi can be confused with Trypanosoma <unk> , which is not known to be pathogenic in humans . <unk> of T. cruzi can occur by <unk> into mice , by culture in specialized media ( for example , <unk> , <unk> ) ; and by <unk> , where uninfected <unk> bugs are fed on the patient 's blood , and their gut contents examined for parasites . 
