A 5-yaer-old boy from Boliva was seen by a pediatrician at a children's health commuity clinic in Miami,Florida as part of a pre-adoption physical examination. No medical history was avaiable at the time of the visit. The docter ordered stool and blood exam to be performed. No parasite were reported form blood films. Figure a(200x) shows what was seen on a wet mount. What is your diagnosis? Based on what criteria?